                                       
                  U.S. ENVIRONMENTAL PROTECTION AGENCY (EPA) 
               SCIENTIFIC ADVISORY COMMITTEE ON CHEMICALS (SACC)
                                       
                                 OPEN MEETING
                                       
Draft TSCA Screening Level Approach for Assessing Ambient Air and Water Exposures to Fenceline Communities Version 1.0

                                 SACC WEBSITE:
                     https://www.epa.gov/tsca-peer-review
                                DOCKET NUMBER:
                         EPA - HQ - OPPT - 2021-0415 
                                       
                    Virtual Location via Zoom.gov platform
                                       
                               March 15-17, 2022


                                  ATTENDEES 
DESIGNATED FEDERAL OFFICIAL

DR. ALAA KAMEL, PHD
OFFICE OF PROGRAM SUPPORT
OFFICE OF CHEMICAL SAFETY AND POLLUTION PREVENTION
TSCA SACC CHAIR

DR. DANIEL SCHLENK, PHD
DEPARTMENT OF ENVIRONMENTAL SCIENCES
UNIVERSITY OF CALIFORNIA, RIVERSIDE
TSCA SACC MEMBERS

UDAYAN APTE, PHD
DEPARTMENT OF PHARMACOLOGY, TOXICOLOGY, AND THERAPEUTICS
UNIVERSITY OF KANSAS MEDICAL CENTER
MARISSA BAKER, PHD
DEPARTMENT OF ENVIRONMENTAL & OCCUPATIONAL HEALTH SCIENCES
UNIVERSITY OF WASHINGTON SCHOOL OF PUBLICH HEALTH
SHERI BLYSTONE, PHD
SNF HOLDING COMPANY
CHRISTINE CHAISSON, PHD
THE LIFELINE GROUP
GEORGE P. COBB, PHD
BAYLOR UNIVERSITY
DEPARTMENT OF ENVIORNMENTAL SCIENCE
HOLLY DAVIES, PHD
WASHINGTON STATE DEPARTMENT OF HEALTH
WILLIAM DOUCETTE, PHD 
(RETIRED) UTAH WATER RESEARCH LABORATORY
DEPT. OF CIVIL & ENVIRONMENTAL ENGINEERING
WENDY HEIGER-BERNAYS, PHD
DEPARTMENT OF ENVIRONMENTAL HEALTH
SCHOOL OF PUBLIC HEALTH
BOSTON UNIVERSITY
MARK JOHNSON, PHD
US ARMY PUBLIC HEALTH CENTER
JOHN KISSEL, PHD
(RETIRED) ENV. & OCCUPATIONAL HEALTH SCIENCES 
SCHOOL OF PUBLIC HEALTH
CARMEN MESSERLIAN, PHD
DEPARTMENT OF ENVIRONMENTAL HEALTH
DEPARTMENT OF EPIDEMIOLOGY
HARVARD T.H. CHAN SCHOOL OF PUBLIC HEALTH
JENNIFER PRZYBYLA, PHD
AGENCY FOR TOXIC SUBSTANCES AND DISEASE REGISTRY 
CENTERS FOR DISEASE CONTROL AND PREVENTION
DAVID REIF, PHD
NORTH CAROLINA STATE UNIVERSITY
CRAIG ROWLANDS, PHD
UNDERWRITERS LABORATORIES, LLC
SHEELA SATHYANARAYANA, MD
SEATTLE CHILDREN'S RESEARCH INSTITUTE
UNIVERSITY OF WASHINGTON
CHARLES V. VORHEES, PHD
COLLEGE OF MEDICINE AND DIVISION OF NEUROLOGY
CINCINNATI CHILDREN'S RESARCH FOUNDATION
UNIVERSITY OF CINCINNATI
TSCA SACC AD HOC PEER REVIEWERS

RYAN CALDER, SCD, PE
VIRGINIA POLYTECHNIC INSTITUTE AND STATE UNIVERSITY
JOHN FERRY
DEPARTMENT OF CHEMISTRY AND BIOCHEMISTRY
UNIVERSITY OF SOUTH CAROLINA

MATTHEW O. GRIBBLE, PHD, DABT
SCHOOL OF PUBLIC HEALTH 
UNIVERSITY OF ALABAMA AT BURMINGHAM
LUCAS HENNEMAN, MS, PHD
DEPT. OF CIVIL, ENVIRONMENTAL, & INFRASTRUCTURE ENGINEERING
GEORGE MASON UNIVERSITY
LI LI, PHD
SCHOOL OF PUBLIC HEALTH
UNIVERSITY OF NEVADA, RENO
RICK REISS, SCD
EXPONENT, INC
MONICA E. UNSELD, PHD, MPH
UNTIL JUSTICE DATA PARTNERS, INC.
PRESENTERS AND EPA STAFF

MARK HARTMAN
EPA/OCSPP/OPPT

MICHAL FREEDHOFF, PHD
EPA/OCSPP
KEVIN VUILLEUMIER, PHD
EPA/OCSPP/OPPT/ECRA
KEITH JACOB, PHD
EPA/OCSPP/OPPT/ECRA
FRANKLYN HALL, PHD
EPA/OCSPP/OPPT/ECRA
JASON TODD, PHD
EPA/OCSPP/OPPT/ECRA
REHAN CHOUDHARY, PHD
EPA/OCSPP/OPPT/ECRA
PUBLIC COMMENTERS

DAN BAKER
CONSULTANT
ENVIRONMENTAL REACTION ENGINEERING EXPERTS CONSULTING
UNI BLAKE
AMERICAN PETROLEUM INSTITUTE
EBONI COCHRAN
REACT
PAUL DELEO
AMERICAN CHEMISTRY COUNCIL
ELKE JENSEN
THE DOWN CHEMICAL COMPANY
RASHMI JOGLEKAR
EARTHJUSTICE
AMY KYLE 
UNIVERSITY OF BERKELEY, SCHOOL OF PUBLIC HEALTH (RETIRED)
SONYA LUNDER
SIERRA CLUB
LINDSAY MCCORMICK
ENVIRONMENTAL DEFENSE FUND
MAYA NYE
COMING CLEAN
KATHELINE PIERRE
FOUNDATION OF MEDICINE 501C3 PRIVATE FOUNDATION
MOLLY RAUCH
MOMS CLEAN AIR FORCE
SWATI RAYASAM
UCSF PROGRAM ON REPRODUCTIVE HEALTH AND THE ENVIRONMENT
KARI RHINEHART
IF IT WAS YOUR CHILD
JENNIFER SASS
NATURAL RESOURCES DEFENSE COUNCIL
KAREN SLANEY
MOMS CLEAN AIR FORCE


TABLE OF CONTENTS
  
OPENING OF MEETING	6
INTRODUCTION AND IDENTIFICATION OF PANEL MEMBERS	12
INTRODUCTION AND WELCOME	22
WELCOME AND INTRODUCTORY COMMENTS	25
OPPT TECHNICAL PRESENTATION  -  OVERVIEW OF DRAFT TSCA FENCELINE METHODOLOGY	37
SACC QUESTIONS ON OPPT TECHNICAL PRESENTATION	93
PUBLIC COMMENTS	147
CHARGE QUESTION 1	248
OPENING OF MEETING - DAY 2	307
PANEL MEMBERS: FOLLOW-UP ON PREVIOUS DAY	311
CHARGE QUESTION 2	318
CHARGE QUESTION 3	357
CHARGE QUESTION 4a	421
CHARGE QUESTION 4b	467
OPENING OF MEETING - DAY 3	524
PANEL MEMBERS: FOLLOW-UP ON PREVIOUS DAY PRESENTATIONS	528
CHARGE QUESTION 4C	535
CHARGE QUESTION 4D	585






OPENING OF MEETING 
                  
                  DR. ALAA KAMEL:  Well, good morning, everyone.  My name is Alaa Kamel, and I'll be serving as the Designated Federal Official to the U.S. EPA Science Advisory Committee on Chemicals.  For this meeting, and in my role, I will be opening this public meeting.  I want to thank Dr. Daniel Schlenk for agreeing to serve as chair of the Committee for this meeting.  I also want to thank both members of the Committee, ad hoc reviewers, and the public for attending this important meeting. 
                  We appreciate the time and efforts of the Committee members in preparing for this meeting, taking into account the busy schedules.  In addition, I also want to thank EPA's Office of Pollution Prevention and Toxics, OPPT, and my colleagues at the peer review and ethics branch in EPA for their hard work in preparing for this important review of EPA's draft TSCA Screening Level Approach for Assessing Ambient Air and Water Exposures to Fenceline Communities Version 1.0. 
                  As an added note, Dr. Todd Peterson, my colleague and Designated Federal Official, and Steve Knott, our executive secretary -- they are online this week, and they will serve as backups to my role as Designated Federal Official.  Now, the SACC is a Federal Advisory Committee that provides independent scientific peer review and advice to the EPA on chemical-related issues regarding impact of proposed regulatory actions on human health and the environment.  The SACC provides advice and recommendations to EPA; decision-making and implementation authority remains with the Agency.  The SACC for this meeting is comprised of 17 members who are expert in toxicology, environmental risk assessments, exposure assessments, and related sciences.
                  The expertise of these members is augmented by ad hoc reviewers who are temporary participants in SACC activities providing additional scientific expertise including models to estimate chemical fate and transport in ambient air and water pathways and public health protection for at-risk communities in order to assist in reviews conducted by the SACC Committee. 
                  As the DFO of this meeting, I serve as a liaison between the SACC and the Agency.  I am also responsible for ensuring provisions of the Federal Advisory Committee Act, FACA -- that they are all met.  Federal Advisory Committee Act of 1972 established a system that governs the creation, operation, and termination of executive branch advisory committees.  SACC meetings are subject to all FACA requirements.  These include open meetings, timely public notice of meetings, and document availability to the public.
                  All documents are available to the public in the docket at www.regulations.gov.  As the Designated Federal Official for this meeting, a critical responsibility is to work with appropriate agency officials to ensure that all appropriate ethics regulations are satisfied.  In that capacity, Committee members receive training and provisions of federal conflict of interest laws.  In addition, each participant has filed a standard government financial disclosure report.  Our deputy ethics official for the Office of Program Support in EPA and in consultation with the Office of General Counsel have reviewed these reports to ensure all ethic requirements are met. 
                  The SACC will review challenging scientific issues over the next three days.  We have a full agenda, so meeting times are approximate.  Thus, we may not keep to exact times as noted due to the discussions and public comments.  We strive to ensure adequate time for Agency presentations, public comments, and Committee deliberations.  For presenters, SACC members, and public commenters, please identify yourself and speak into the microphones provided or actually your computer microphone since this meeting is being webcasted, transcribed, and recorded.
                  I'd like to note that there is a live video webcast of this meeting via YouTube.  To access this website, or this webcast, please go to the meeting website at www.epa.gov/tsca-peer-review.  Copies of all EPA presentation materials, written public comments, and other documents related to this meeting are available in the public docket at regulations.gov.
                  Copies of presentation materials submitted this week by public commenters will be available in the public docket within the next week.  The docket number and website are noted on the meeting agenda.  For this meeting, there are so far over 180 registered attendees; 24 of them will be giving oral comments.  Registration is open until the last day of the meeting on March 17.  Members of the Committee and ad hoc reviewers are encouraged to fully consider all written and oral public comments submitted for this meeting.
                  At this time, the agenda is full.  However, as we move through the proceedings, if time allows, we may be able to accommodate additional brief oral comments of five minutes or less.  For members of the press, EPA media relations staff are available to answer your questions about this meeting.  Please address all questions to Cathy Milbourn, and her email is milbourn.cathy@epa.gov.  
                  At the conclusion of the meeting, the SACC will prepare a report as a response to questions posed by the Agency, background materials, presentations, and public comments.  This final report also serves as meeting minutes.  We anticipate the final report and meeting minutes to be completed in 60 days after the meeting.  
                  Again, I wish to thank the Committee and ad hoc peer reviewers for your participation.  I'm looking forward to both a challenging and interesting discussion over the next three days.  And now, I turn the meeting over to our chair, Dr. Daniel Schlenk.  Thank you.
                  DR. DANIEL SCHLENK:  Thanks, Alaa.  Good morning, everybody.  Thanks for joining us this morning for our Draft TSCA Screening Level Approach for Assessing Ambient Air and Water Exposures to Fenceline Communities Version 1.0.  I'd like to thank EPA and Alaa for putting this all together -- the EPA staff.  I'd like to thank the presenters that will be presenting here in a few minutes, as well as the public commenters which will be presenting after them, and for their participation.  And we look forward to a very useful meeting that would be able to provide some information for the Agency in this regard.  
                  
INTRODUCTION AND IDENTIFICATION OF PANEL MEMBERS
                  
                  DR. DANIEL SCHLENK:  At this point in time, I'd like to introduce the panel and the Committee.  Forgive me for keep using "panel." I keep using that word from the FIFRA panel that I chaired a few years ago, but it's a Committee.  So, at this point in time, we'd like to introduce members of the Committee.  So, I'm going to go through the list alphabetically and, if you would just state your name, your organization, and a brief statement of your expertise, and then we'll move forward with that.
                  So, at this point, Dr. -- well, maybe I should begin myself.  My name is Daniel Schlenk.  I am an environmental toxicologist.  I'm at the University of California, Riverside, and I'll be chairing this committee for the next three days.  Our next member would be Dr. Apte.
                  DR. UDAYAN APTE:  Hi, my name is Udayan Apte.  I'm a professor of toxicology at the University of Kansas Medical Center.  My expertise is in liver toxicology, environmental chemical effect on the liver.  I'm a board-certified toxicologist.  
                  DR. DANIEL SCHLENK:  Thank you.  Dr. Baker. 
                  DR. MARISSA BAKER:  I'm Marissa Baker.  I'm an assistant professor at the University of Washington in environmental and occupational health sciences.  I'm an industrial hygienist and exposure science person.  
                  DR. DANIEL SCHLENK:  Thanks.  Dr. Blystone.
                  DR. SHERI BLYSTONE:  Hello.  Sheri Blystone.  I'm a chemist by training.  I've worked in the chemical industry for a long time now.  I'm doing safety and compliance currently with SNF Holding Company.
                  DR. DANIEL SCHLENK:  Thank you.  Dr. Calder.
                  DR. RYAN CALDER:  Hi, I'm Ryan Calder.  I'm assistant professor of environmental health and policy at Virginia Tech.  I am a professional engineer, and my background is in water quality modeling and coupling models of environmental systems to models for human exposure assessment.  I'm interested in minimizing human exposures to chemical contaminants in the environment. 
                  DR. DANIEL SCHLENK:  Great.  Thanks.  Dr. Chaisson.
                  DR. CHRISTINE CHAISSON:  Hello.  I'm with the LifeLine Group and I'm a toxicologist, but most of my career has been with exposure assessment, risk assessment methods, and models, with particular emphasis on unique communities ranging from urban centers to tribal and rural lands.  Really pleased to be part of the Committee.
                  DR. DANIEL SCHLENK:  Yeah.  Thanks.  Dr. Cobb.
                  DR. GEORGE COBB:  Hi, I'm George Cobb.  I'm an environmental analytical chemist studying fate and transport and exposure assessments as well.  I'm here at Baylor University in Waco, Texas. 
                  DR. DANIEL SCHLENK:  Thanks, George.  Dr. Davies.
                  DR. HOLLY DAVIES:  Hi, I'm Holly Davies.  I'm a toxicologist at the Washington State Department of Health. 
                  DR. DANEIL SCHLENK:  Great.  Dr. Doucette.  I think you're on mute, Bill.
                  DR. WILLIAM DOUCETTE:  Right.  I thought I hit it.  One more time.  I'm Bill Doucette, environmental chemist and recently retired Professor at Utah State University and previous member of the SACC Committee.
                  DR. DANIEL SCHLENK:  Thanks.  Dr. Ferry.  
                  DR. JOHN FERRY:  My name's John Ferry.  I'm a chemistry professor at the University of South Carolina.  I'm an environmental chemist, and I do research in the reactive attenuation of organic materials.  
                  DR. DANIEL SCHLENK:  Thank you.  Dr. Gribble.
                  DR. MATTHEW GRIBBLE:  Hello, my name is Matthew Gribble.  I'm an associate professor of epidemiology at the University of Alabama at Birmingham School of Public Health.  I'm an environmental epidemiologist and also a diplomat of the American Board of Toxicology.  
                  DR. DANIEL SCHLENK:  Great.  Thanks.  Dr. Heiger-Bernays.
                  DR. WENDY HEIGER-BERNAYS:  Wendy Heiger-Bernays, professor of Environmental Health at the Boston University School of Public Health.  My expertise is in risk assessment methods with a focus on vulnerable and susceptible populations.  
                  DR. DANIEL SCHLENK:  Thank you.  Dr. Henneman.
                  DR. LUCAS HENNEMAN:  Morning.  Lucas Henneman.  I'm an environmental engineer, assistant professor at George Mason University.  My background's in air quality modeling and health assessments. 
                  DR. DANIEL SCHLENK:  Thank you.  Dr. Johnson.
                  DR. MARK JOHNSON:  Hello, everybody.  My name is Mark Johnson.  I'm director of toxicology for the Army's Public Health Center.  My background's environmental toxicology and human health in its applications to risk assessment.  I'm a fellow of the Academy of Toxicological Sciences. 
                  DR. DANIEL SCHLENK:  Thanks.  Dr. Kissel.
                  DR. JOHN KISSEL:  Hi, I'm John Kissel and I'm Professor Emeritus of Environmental and Occupational Health Sciences at the University of Washington in Seattle.  I'm an engineer by training and a human exposure scientist by practice.  
                  DR. DANIEL SCHLENK:  Thank you.  Dr. Li.
                  DR. LI LI:  I'm Li Li.  I'm assistant professor of environmental health at the University of Nevada, Reno.  I'm leading a research group that develops computational models, fate and exposure models to assess how chemical substances reside, travel, and change in the modern media environment and how they get into the human beings.
                  DR. DANIEL SCHLENK:  Thank you.  Dr. Messerlian.  Sorry.
                  DR. CARMEN MESSERLIAN:  That's okay.  My name is Carmen Messerlian.  I'm a professor of environmental reproductive epidemiology at the Harvard Chan School of Public Health, and I'm the director of the scientific early life environmental health and development program at Harvard Chan.  And I study how environmental chemicals and the environment defined more broadly impacts fertility, pregnancy, and child health.  
                  DR. DANIEL SCHLENK:  Thank you.  Dr. Przybyla.
                  DR. JENNIFER PRZYBYLA:  Good morning.  I'm Jennifer Przybyla, an environmental epidemiologist at the Agency for Toxic Substance and Disease Registry.  My expertise are environmental epidemiology, human health risk assessment.  
                  DR. DANIEL SCHLENK:  Thanks.  Dr. Reif?
                  DR. RICK REISS:  Hi, this is Rick Reiss.  I'm a group vice president in principle scientist at Exponent, and my expertise is in exposure and risk assessment and dispersion modeling.  
                  DR. DANIEL SCHLENK:  Okay.  Thanks.  Dr. Reif, please?  I think you jumped the gun a bit there.  No worries.
                  DR. DAVID REIF:  A couple letters off.  Yeah.  I'm David Reif.  I'm a professor at North Carolina State University.  I sit in the bioinformatics center, and I'm in the department of biological sciences.  My lab studies environmental health sciences, data integration, data science applications, and computational toxicology.  And my background is in statistics and human genetics.  
                  DR. DANIEL SCHLENK:  Thanks.  Dr. Rowlands.  I think you're on mute, Craig.  Do we have Dr. Rowlands?  No, I guess not.  I guess we'll skip him.  Dr. Sathyanarayana.   Sathyanarayana.
                  DR. SHEILA SATHYANARAYANA:  Hi, I Sheila Sathyanarayana, and I'm a pediatrician and epidemiologist at Seattle Children's Research Institute in the University of Washington.  I'm a professor that focuses on environmental exposures in early life and human health outcomes and have focused on translation to policy.  
                  DR. DANIEL SCHLENK:  Thanks.  Dr. Unseld.
                  DR. MONICA UNSELD:  Hi, Monica Unseld.  Executive director and founder of Until Justice Data Partners here in Louisville, Kentucky.  My background is in endocrine disruption and environmental signaling.  I also have a master's in public health.  For almost 15 years, I've worked with fenceline communities to see how we can better get modeling and algorithms and data to fit the reality of daily life in these communities.  
                  DR. DANIEL SCHLENK:  Thank you.  And Dr. Vorhees. 
                  DR. CHIP VORHEES:  Hi, Chip Vorhees.  I'm a professor of neuroscience at the University of Cincinnati and Cincinnati Children's Hospital in the division of pediatric neurology.  My research is on animal models of ADHD and developmental neurotoxicity, particularly of pesticides.  
                  
INTRODUCTION AND WELCOME
                  
                  DR. DANIEL SCHLENK:  Thank you, everyone.  Thanks for going through that.  At this point in time, we will have some introductory material that will be presented by various members of the Agency.  Our first presenter will be Mark Hartman who's the deputy director for management at EPA OCSPP.  Office of Pollution and Prevention and Toxics.  Mr. Hartman.
                  MR. MARK HARTMAN:  Thank you, and good morning, everyone.  I am Mark Hartman, I'm the Deputy Office Director for Office of Pollution and Prevention and Toxics.  It's a pleasure to be with you today as we're very glad to welcome back those of you who have previously served on the Committee as well as welcoming our new members to the SACC experience.  It's hard to believe that the last time the SACC met was back in June of 2020.  We're thankful for the important role the SACC plays -- has played and continues to play in our risk evaluation process under TSCA.  
                  Thank you for your time, your consideration for what we are presenting here today, and the thoughtfulness of your input.  We're proud of the EPA team that has worked so diligently on this effort and look forward to your feedback on this very important work.  It is also my pleasure today to introduce to you the Office of Chemical Safety and Pollution Preventions System Administrator Michal Freedhoff.  Dr. Freedhoff has more than 20 years of government experience, most recently as the minority director of oversight for the Senate Environment and Public Works Committee. 
                  She began her career of congressional service in 1996, in then-Congressman Ed Markey's office as a congressional science and engineering fellow after receiving a Ph.D. in physical chemistry at the University of Rochester.  Dr. Freedhoff has also served on the staffs of the House of Science Committee, House Select Committee on Energy Independence and Global Warming, the House Energy and Commerce Committee, and the House Natural Resources Committee.  
                  With environmental expertise spanning a range of policy areas for legislative work includes the 2019 legislation to address PFAS contamination, the Fuel Economy Provisions, and the 2007 Energy Independence and Security Act, and allowing the creation of an online database potential consumer product safety defects.  However, much of her time was spent on the 2016 reauthorization of the Toxic Substances Control Act.  
                  She played an integral role in drafting this legislation and now brings that expertise to EPA to lead TSCA implementation under the Biden/Harris Administration.  In the year-plus that I've had the pleasure of working with Dr. Freedhoff, I have witnessed her strong commitment to scientific integrity using the best available science to drive decision making and her support for EPA's career staff.   Welcome, Dr. Freedhoff.
                  DR. DANIEL SCHLENK:  Thank you.  Dr. Freedhoff. 
                  DR. MICHAL FREEDHOFF:  Thanks so much.  Thanks very much, Mark.  Can you all hear me okay?  
                  MR. MARK HARTMAN:  Yes.
                  DR. DANIEL SCHLENK:  Yes.
                  
WELCOME AND INTRODUCTORY COMMENTS
                  
                  DR. MICHAL FREEDHOFF:  Great.  Thanks.  Well, good morning.  I'm Michal Freedhoff, the assistant administrator of the EPA's Office of Chemical Safety and Pollution Prevention.  And thank you so much for your participation in this peer review of EPA's Approach for Assessing Exposures to Fenceline Communities.  Your support and commitment as both SACC members and as ad hoc expert reviewers is critical in helping EPA to continue to meet its mission.  
                  Part of that mission is ensuring that science and scientific integrity remain the backbone of our regulatory work.  And that's why the peer review that SACC provides is so critical.  And we also greatly appreciate the SACCs continuing assistance with completing reports as expeditiously as possible so that we can incorporate your feedback into the chemical safety protections we expect and hope to provide to communities all across America.  
                  As you all know, under the last administration science on certain exposure pathways -- like exposure through ambient air, water, and disposal -- were excluded from most risk evaluations.  And what that effectively meant is for purposes of TSCA it didn't count if you drink it, and it didn't count if you breathed it.  But that's not what TSCA says.  TSCA tells EPA to conduct risk evaluations to determine whether a chemical substance presents no reasonable risk to health and the environment under the conditions of use, including an unreasonable risk to relevant potentially exposed or susceptible sub-populations.
                  You've actually all told the Agency that over and over again.  For example, in the peer review report for 1,4-Dioxane, you noted that the lack of an exposure assessment for the general population may leave substantial portions of the population at risk, which is particularly concerning for drinking water exposure.  And also, during that peer review meeting, the Committee observed that if each office at EPA says someone else is assessing the risk, the U.S. public will never get a comprehensive risk assessment.  
                  As a second example, in both the carbon tetrachloride and the perchloroethylene (phonetic) reports, the Committee said that excluding multiple routes of exposure from the risk evaluation could not be justified by saying that some other part of the Agency regulates them.  And similarly, in your review of 1-BP, you state, and I quote, "The lack of consideration for general population exposures excludes the vast extent of the U.S. population who are exposed to 1-BP, perhaps on a daily basis.  The lack of consideration of the general population of exposure is concerning given the strong evidence of widespread exposure to a chemical that may be 1-BP based on biomonitoring data."
                  That report goes onto say the exclusion of the general population, quote, "does not instill confidence that objectivity is being maintained in Agency assessments as part of TSCA," end quote.  We agree with you, and that's why we reversed that policy.  So as a very first step to understanding risks to the general public via these exposure pathways, we've developed this version 1.0 of a methodology designed to assess any potential risk in the air and water exposures that were excluded from the risk evaluations to fenceline communities or those communities within close proximity to chemical facilities. 
                  It's important to be clear about what this screening methodology is and what it is not.  We're charged under TSCA with providing chemical safety protections once we find unreasonable risk in a risk evaluation.  A great deal of science and analysis was done in those risk evaluations despite some notable policy deficiencies associated with them, and unreasonable risks were found across almost all uses of all of the chemicals. 
                  We feel a strong sense of urgency and a strong sense of responsibility to note quickly to address those risks.  But we also don't want to leave communities out.  We want to be sure that the rules we write are as protective as they need to be and are also scientifically and legally defensible.  So, the version 1.0 methodology is just that.  It's an initial attempt to develop a meaningful screening-level approach which will assist the Agency in making go or no-go decisions on whether health and environmental protection is best served by either proceeding quickly to rulemaking for a chemical or by formally supplementing the risk evaluation. 
                  If the results of this screening methodology show there are no likely added fenceline community risk for a substance, or if the rule were contemplating for that substance based upon the existing risk evaluation would also address those risks, we'll continue our rule-making process quickly.  As a very extreme example, if the previously finalized risk evaluation supports a complete ban or phase-out of a chemical, clearly no further revision of the risk evaluation should be needed.  
                  However, if the refined screening methodology tells us that the rules supported by the last administration's risk evaluation is not going to be sufficiently protective of fenceline communities, we will perform additional analysis and supplement the risk evaluation.  We've already made the decision that we'll need to do that for 1-dioxane, in part because we agree with the Committee, as well as with the many stakeholders whose express concern is the lack of consideration of all exposure routes to 1,4-Dioxane including as a byproduct in a number of both occupational, as well as consumer uses.
                  But the implications of formally supplementing the risk evaluations are significant because the 9 to 15 months it would take us to do that for each chemical would also push our rule-making for that chemical into 2025 or even later.  These rules are where the rubber meets the road to realizing the great promise of TSCA, and we're all eager to get there.  So, I want to take just a few more minutes to be really clear about what version 1.0 is and is not.
                  It is a proposed screening level methodology using reasonably available data, information, and models to quantify environmental releases, evaluate exposures, and characterize risks associated with such releases and exposures.  It is clearly not the more comprehensive analytic approach that the Agency intends version 2.0 to be that we'll develop and use in future risk evaluations.  Version 1.0 doesn't include a method to address broader potential environmental justice concerns, nor does it attempt to quantify aggregate exposures.
                  We recognize that these and other considerations are important, and we look to expand our capacity to evaluate these concepts in the next 20 risk evaluations and beyond.  But in light of this, my ask of you is two-fold.  One, under what circumstances can this draft screening level approach be used to help us make our go/no-go rule-making decisions?  And two, for the next iteration of this approach, what could we add, build upon, and further develop to make this more comprehensive so that it can be used as one of our scientific building blocks during risk evaluation for the next 20 chemicals?
                  Peer review's a cornerstone of EPA's work, and your work ensures that EPA uses sound science for decision making by honoring innovation and fostering meaningful stakeholder good feedback.  Each of these, and you, are essential for EPA to promote chemical safety in this country.  Thank you, once again, for your efforts, especially during these challenging times.
                  We greatly appreciate your dedication, your sacrifice, and your critically important role in helping EPA to implement this new methodology to understand chemical exposures to communities, particularly fenceline communities, who've been disproportionately exposed to pollution for generations.  Thank you.
                  DR. DANIEL SCHLENK:  Thank you, Dr. Freedhoff.  We are ahead of schedule.  A couple of questions of clarification.  Dr. Kissel, I see your hand is up. 
                  DR. JOHN KISSEL:  So, in the previous incarnation of SACC during the Trump administration, we were explicitly told that spills are not conditions of use and therefore are not considered as toxic releases.  Given the importance of the groundwater pathway in the superfund world generally, my question is has that definition of conditions of use been revisited, and can we expect -- obviously, it's not in this -- in the 1.0 version of the document we're dealing with today.  But can we anticipate that the groundwater will be considered in version 2.0?
                  DR. MICHAL FREEDHOFF:  I don't think we've made specific decisions about 2.0 yet.  I think we're hoping to use some of your feedback to inform that.  But I would agree that reasonably foreseeable disposal conditions of use are within scope of TSCA risk evaluations and need to be considered.  I think that's about all I can say with regard to when a disposal action is reasonably foreseeable and when it is not because that's something that we're currently discussing pretty actively within the Agency. 
                  DR. DANIEL SCHLENK:  Okay.  Thanks.  Dr. Sathyanarayana.
                  DR. SHEELA SATHYANARAYANA:  Hi, thanks.  Great to hear the background on this.  In the previous iteration, we had a lot of discussion about the regulation allowing for the ability to go back and ask industry for data to fill holes for risk assessment.  And it seems like the regulation allows for that.  But in version 1.0, I still don't see that, and I'm just wondering what the Agency's thoughts are on this piece because there are many chemicals where we don't have data to truly inform risk assessment.
                  DR. MICHAL FREEDHOFF:  I mean, this is a bit separate from this particular methodology, but I would agree entirely that the Agency's authority to obtain data from industry was not as expansively utilized as it could've been in the first few years of TSCA implementation.  And we're looking at a number of different ways to expand upon that.  One is the order authority under TSCA that I'm sure you're very familiar with, under Section 4.
                  But the other thing that we've recently begun to explore is a way to kind of standardize information collection activities under a rule-making that would inform the Agency that conditions of use or health and safety studies that are in the possession of industry and a range of other baseline information.  And so, what we've been working on -- and we did have hold a public meeting on that several months ago -- is a way to say that if you're being considered as a high-priority chemical, then as part of CDR reporting you need to provide this additional data set.
                  If you're undergoing a risk evaluation, then that data set might expand to include other information, and when EPA is done with the risk evaluation, then those additional data requirements would disappear.  Since I'm sure you know what was sort of happening in the first few years of the program in the constant budget crunch because no additional funding had ever been requested for implementing the new law -- is that the Agency scientists would get far along into a risk evaluation and then realize that the data gaps existed late in the process, which made it very difficult to use some of those data gathering authorities to inform the risk evaluations and also make the deadlines. 
                  So, we're looking at going forward as a way -- at ways to sustainably ensure that we're getting the baseline data early in the process, that we're writing the TSCA test orders early in the process and that all that information would then be available as we move through the risk evaluation process.  
                  DR. DANIEL SCHLENK:  Great.  Thank you, Dr. Freedhoff.  
                  
OPPT TECHNICAL PRESENTATION  -  OVERVIEW OF DRAFT TSCA FENCELINE METHODOLOGY
                  
                  DR. DANIEL SCHLENK:  Without any further questions, let's go ahead and move forward with our technical presentation, which is the Overview of Fenceline Community Exposure Screening Level -- the approach.  This'll be presented by Kevin Vuilleumier and Rehan Choudhary.  Hopefully, I got your name right there, Kevin.
                  DR. KEVIN VUILLEUMIER:  Thank you, Dr. Schlenk.  You got pretty close.  I've even got that French aspect to it, right?  At the end.  Yeah.  But, yeah, it's Kevin Vuilleumier, so thank you.  So, what we're going to do is we're going to share my screen.  Okay.  Okay.  Can everyone see the screen okay?
                  DR. DANIEL SCHLENK:  Yeah.  Yes.
                  DR. KEVIN VUILLEUMIER:  Okay.  Great.  Thank you.  So, I want to start by saying good morning to the Scientific Advisory Committee on Chemicals, public commenters, and stakeholders.  My name is Kevin Vuilleumier, and I am the assessment lead for the fenceline team.  Our management leads are Rehan Choudhary and Yvette  Selby-Mohamadu.  I'm fortunate to be part of a very dedicated, knowledgeable, and talented team whose work is reflected in this presentation, as well as a draft fenceline report currently undergoing review.
                  Today I'll be presenting an overview of the fenceline work on behalf of the team.  Before we dive into the presentation, I want to remind everyone the draft fenceline methodology report was released to the public on Friday, January 21st, and is nearing the end of its 60-day public comment and review period which ends March 22nd, 2022.  With that, let's get started.
                  Over the next hour, I'll walk you through the Draft Toxic Substances Control Act, or TSCA, fenceline methodology, including some background information.  I'll begin with a brief overview.  Next, I will describe the proposed fenceline methodology in three sections: the air pathway, water pathway, and hazard and risk characterization methodology.  I will close out the presentation by briefly discussing the three case studies and associated findings included in the draft report, as well as anticipated next steps for the fenceline work.
                  Before continuing, I do want to be clear that the three case studies included in the draft report and this presentation are intended to be illustrative examples of applying the proposed fenceline methodology and the efficacy of such application.  While the case studies consist of three real chemicals to which EPA published risk evaluations in 2020 and 2021, the results and associated findings as presented do not represent final Agency action and will not be used for purposes of risk management actions or rule-making at this time.
                  I want to start by establishing a level playing field and common understanding of the background leading to the fenceline effort, as well as the intended purpose of the fenceline methodology.  The Office of Pollution, Prevention, and Toxics, or OPPT, published the first ten risk evaluations under the amended TSCA in 2020/2021 timeframe.  At the time of publication, a policy decision was in place which resulted in certain pathways not being assessed because they fell under the jurisdiction of other EPA administered laws, such as the Clean Water Act or the Clean Air Act.  
                  That policy decision was reversed in June 2021, leading to a targeted effort to assess certain pathways previously excluded from the published risk evaluations.  The targeted effort is the fenceline effort and includes development of the fenceline methodology.  
                  With that background in mind, the purpose of the fenceline methodology includes conducting screening-level evaluations to ensure potential exposures and associated risks were not overlooked for fenceline communities for seven of the first ten chemicals for which OPPT has published risk evaluations; also, to focus on certain ambient air and water pathways previously not assessed in the published risk evaluations; and third, to inform risk management actions and rulemaking for those seven published risk evaluations.  
                  Turning briefly to the table on the right on this slide, you'll see the two pathways included within the fenceline methodology and the seven chemicals for which we intend to conduct a screening-level analysis for fenceline communities.  You'll notice two of the chemicals have a red X under the water pathway which indicates a screening-level analysis is not planned for that chemical for the water pathway.  
                  Why is this the case?  For 1,4-Dioxane, EPA is conducting a supplemental and risk evaluation which will address the water pathway, and therefore screening level analysis is not warranted.  For 1-BP, the water pathway is not a concern based on review of P-chem and fate properties, as well as extremely low releases -- about one pound per year for all facilities -- and this is further discussed in the 1-BP published risk evaluation.  
                  In the previous slide, I reference a term fenceline community several times.  So, what is a fenceline community?  For the purposes of the fenceline methodology, fenceline community consists of members of the general population that are in proximity to air emitting facilities or receiving waterbody and who therefore may be disproportionately exposed to a chemical undergoing risk evaluation under TSCA Section 6.  
                  For the ambient air pathway, proximity goes out to 10,000 meters from an air emitting source.  For the ambient water pathway, proximity does not refer to a specific distance measured from a receiving waterbody but rather to those members of the general population that may interact with the receiving waterbody and, thus, may be exposed.  
                  Slide five outlines what is not included as part of the fenceline work presented here or in the draft report.  The key message we want to express here is a proposed fenceline methodology is intended to be a starting point, or springboard, from which we can build and expand beyond the limits we set for this initial work.  I also want to draw your attention to the footnote associated with the final two bullets on this slide.  
                  As stated, although aggregate\cumulative exposures, as well as identification of potential environmental justice concerns, are not addressed in this current work, EPA is seeking SACC input on potential applications of the proposed methodology and built-in flexibilities to evaluate aggregate\cumulative exposures and potential environmental justice concerns as part of the charge for SACC review of this work.
                  Now, let's move to the discussion of the specific methodologies developed for the fenceline effort beginning with the air pathway.  Here I'll give you an overview of the air pathway starting with the graphic on the right.  We start by looking at the air emissions from a releasing facility, or the source, which may be either, or both, stack and/or fugitive in nature.  Next, we use the release data to model ambient air concentrations at select distances from the releasing facility via the pathways.
                  For purposes of the air pathway fenceline work, we focus on only the inhalation route as the route of exposure and identify exposures and associated risks to fenceline communities with receptors for that route of exposure.  The general approach for estimating air releases from a source is to use 2019 Toxics Release Inventory, or TRI data.  If there are data gaps in the 2019 TRI reporting, we try to identify TRI surrogate data for the use and scenario under consideration.  If data gaps remain, we rely on our existing suite of models and release estimation methods used to support the first ten published risk evaluations. 
                  Ambient air exposure concentrations are estimated at select distances extending out to 10,000 meters using AERMOD.  AERMOD refers to the American Meteorological Society/Environmental Protection Agency Regulatory Model.  One additional item I'd like to mention, when we do not have release data from TRI, we estimate releases as described above and use those estimated releases as inputs to model a series of exposure scenarios considering various factors as shown in the estimated release boxes on this slide. 
                  Two case study chemicals were selected for the air pathway methodology: 1-bromopropane, or 1-BP, and methylene chloride, or MC.  In order to support the evaluation of receptors proximal to facilities that may release chemicals undergoing risk evaluation, we extracted air release data from the 2019 TRI for the air pathway.  
                  EPA followed the five-step approach on this slide for estimating air releases, only deviating from this approach when evaluating occupational exposure scenarios for which no 2019 TRI data existed.  Step one begins with extraction of the chemical-specific release data from the TRI basic plus files which contain the relevant information for the release analysis including data elements such as releases, chemical activity and uses, and other facility-specific information. 
                  Steps two and three, with those steps we associate each facility release with an occupational exposure scenario, or OES, and the corresponding release days both obtained from the published risk evaluations.  Steps four and five involve estimating releases from an alternative approach for OES that have no 2019 TRI data and summarizing all release results for use in the exposure modeling.  
                  The next several slides will focus on steps two, three, and four.  I'd like to take a moment to describe OESs and how they relate to the conditions of use, or COUs, in the published risk evaluations.  COUs, as defined in the risk evaluations, are the circumstances under which a chemical is expected to be manufactured, processed, distributed, used, or disposed.  For the purposes of identifying and using similar assessment approaches based on expected exposure and/or releases, COUs may be grouped or mapped into broad categories referred to as OES.
                  In some cases, this mapping may be fairly simple where one COU maps directly to one OES.  However, in many cases, there isn't a one-to-one mapping.  In such cases, multiple COUs may sit under one OES, or alternatively, one COU may be mapped to multiple OES due to distinctly different exposure scenarios that would not result in similar releases and exposures.  
                  Slide ten discusses mapping TRI use information to an OES, which involves evaluation of the documented uses and sub-uses as reported to TRI using the TRI form R.  Uses and sub-uses are reported on per chemical, per facility basis.  Alternatively, facilities meeting certain requirements may be able to report basic site information using TRI form A.  TRI form A, however, does not require the reporting of use and sub-use information.  
                  So, EPA uses a North American Industry Classification System, or NAICS, code along with information from company websites to determine the use and sub-use information for form A reporting facilities.  The use information is compared to the list of industrial function categories as reported for the chemical data reporting rule, or CDR.  
                  The industrial reporting category describes a specific function that a chemical provides when used in the formulation of a product or used with an industrial process.  A similar mapping was performed between COUs and OESs when developing the published risk evaluations.  The final mapping step uses the CDR industrial function codes as a bridge to bring together the TRI to CDR mapping and the COU to OES mapping to establish the link between the reported TRI facility use information and the OESs from the published risk evaluations.
                  The third step in the release estimation process is estimating the days of release.  Since the TRI release information is reported on an annual basis, estimating the days of release are necessary to combine with reported annual TRI releases.  This combination produces a daily release estimate used for exposure model.  The daily release estimates used in the fenceline work are from the published risk evaluations, and they're provided here for context. 
                  The rationale for the estimated days of release are also provided to show estimates may vary across OES based on underlying assumptions and supplemental release information sources.  For an OES where a model from the published risk evaluation was used for the release days estimate, there may be a distribution of release days provided, as shown in the last row of this table for the aerosol spray degreaser and cleaner OES rather than a single value.  
                  This slide outlines a hierarchy decision tree developed to estimate releases for OES without 2019 TRI data.  When there is no 2019 TRI data, level one starts the hierarchy by considering prior TRI reporting year data, in this case 2016 through 2018 data.  The second level in the hierarchy relies on air release estimation modeling already completed in the published risk evaluations or new modeling using our existing suite of models to estimate releases. 
                  The third level in the hierarchy considers existing literature sources used in the published risk evaluation.  The fourth level in the hierarchy considers use of surrogate data.  This uses 2019 TRI data from another TRI reporting facility which would have been mapped to a somewhat similar but decidedly different OES.  That other TRI facility acts as a surrogate facility and is a source of the release data modeled.  The final level in the hierarchy covers remaining options.  If this level's relied upon for the fenceline work, it is discussed in the chemical-specific case studies.  
                  Closing out the air release portion of the air pathway, this slide shows several assumptions and uncertainties which could have potential quantitative impacts on the release estimates.  The TRI database only contains information on facilities that are subject to TRI reporting and meet the reporting requirements.  As a result, not all sites releasing a TRI chemical will report to the TRI.
                  Those facilities will neither be captured in the TRI database nor be included in the fenceline release summary.  The facility use information as reported to TRI is limited, and therefore may not contain adequate information needed to confidently map facilities to a corresponding OES.  This could impact the estimated days of release and associated daily releases to the ambient air. 
                  Finally, a primary requirement for form A is that the combined facility releases are below 500 pounds per year.  However, actual releases are not required to be reported.  For these facilities, EPA assumes an upper bound of 500 pounds per year for releases, which factors into how exposure modeling is performed for form A reporters.  
                  Moving into the exposure proportion of the air pathway methodology, this slide provides a visual roadmap of the three methodologies used to evaluate exposure via the air pathway for the fenceline work.  I will speak to each of these methodologies in more detail in the coming slides.  But in general, this slide visually displays some of the differences between the approaches as they relate to releases, exposure scenarios, and models used.  
                  Slide 15 provides a brief comparison and explanation of how each methodology is applied for purposes of the fenceline work.  The pre-screening methodology, as applied in the fenceline work, is independent of facility and condition of use.  Findings from the pre-screening methodology are intended to inform whether a full screening analysis is warranted based on whether pre-screening does or does not identify potential risks to select receptors at three predefined distances within the IIOAC model.
                  In contrast, the full-screening methodology is both facility and COU-specific.  Additionally, while we limit our use of the full-screening methodology in the current work to screening-level analyses for fenceline communities, the capabilities of the full-screening methodology are not as limited.  Additional, more detailed analyses can be performed with the full-screening methodology, although such analyses require, among other things, more detailed facility-specific data which may or may not be reasonably available information.
                  The co-resident methodologies is separate from the pre-screening and full-screening methodology in that it is designed for unique case specific conditions of use and receptor configurations.  Additionally, the proposed co-resident methodology looks at indoor air transport phenomena rather than ambient air directly.
                  Beginning with the pre-screening methodology, this flow chart shows the approach and exposure scenario components applied to the fenceline effort.  As shown in the roadmap, the prescreening methodology uses EPA's IIOAC model.  Starting at the left of this slide, the pre-screening methodology uses two air release values from the TRI data set for model inputs: the maximum release value, which is the highest individual facilities reported total release value for the chemical undergoing risk evaluation among all facilities reporting that chemical to TRI and the average, or mean release value, which is the arithmetic average of all facility reported total release values for the chemical undergoing risk evaluation across all facilities reporting that chemical to TRI.
                  Moving left to right, we built out a series of 16 exposure scenarios for each release value considering the release type, topography, meteorological data, and the release scenario.  Each of these inputs and the basis for selection are described in more detail within the draft report currently undergoing review.  
                  For purposes of risk calculations and identifying potential risks, the pre-screening methodology selects the highest exposure concentrations from all exposure scenarios modeled based on the pre-screening work performed for the fenceline effort so far.  The scenario resulting in the highest exposure concentrations follows the exposure scenario highlighted orange in this diagram.  
                  This slide lists some of the assumptions and uncertainties associated with the pre-screening methodology.  The key point to remember is the pre-screening methodology is designed to maintain a conservative approach for estimating exposures as it is intended to inform the need for a full-screening analysis.  As a result, we do not want to miss potential risk and screen out the need for a full screening analysis prematurely.  To retain the conservative nature of the pre-screening methodology, EPA recognizes the default values for stacked parameters and plume characteristics represent the low, slow-moving, non-buoyant plume, which tends to lead to more conservative exposure estimates at the model distances. 
                  This slide closes out the pre-screening methodology by sharing some strengths and limitations of the proposed methodology.  For strengths, the IIOAC model is an Excel-based tool which readily defines necessary inputs as relatively easy to learn.  The model allows quick evaluation, which can be conducted in-house without the need for specialized expertise, saving both time and level of effort.  
                  The primary limitation is the construct of the model itself.  The model is built on pre-run scenarios created and run through AERMOD, which inherently limits the inputs, defaults, and meteorological data to those used for the pre-run scenarios.  
                  Moving to the full-screening methodology, this slide introduces details about the approaches used for the fenceline work using AERMOD.  The first bullet describes the overall purpose and goal of the full-screening methodology which is to estimate ambient air concentrations and associated exposures at varying distances and receptor locations from a facility releasing the chemical undergoing risk evaluation.  
                  The full-screening method evaluates exposures at eight finite distances: 5, 10, 30, 60, 100, 2,500, 5,000, and 10,000 meters, and one area distance, 100 to 1,000, meters from a releasing facility.  For each finite distance, receptors are placed in a polar grid at equal distances around the associated distance ring: every 22.5 degrees.  This results in a total of 16 receptors around each distance ring.  Visually both the distances and receptor locations can be seen in the diagram in the top right of this slide.
                  Finite distances are represented by different colored rings.  The area distance is represented by the shaded donut ring.  Receptor locations are represented by the boxes placed around the ring.  For the one area distance evaluated, receptors are placed in a cartesian grid between approximately 200 meters and 900 meters from the releasing facility at 100 meters spacing.
                  This results in a total of 456 receptors with a daily and annual average exposure concentration estimates for the area distance represent the arithmetic average, the mean exposure concentration, across all 456 receptors within the area distance for each day, and across an entire year.  The remaining bullets on this slide provide some other parameters considered as part of the full screening methodology approach and associated inputs for the model.
                  Slide 20 summarizes the outputs obtained from full-screening methodology based on the distances and receptor locations evaluated.  The left box shows a total number of modeled exposure concentrations obtained for the two types of release estimates provided.  When 2019 TRI data is available, we estimate exposure concentrations using one year of meteorological data resulting in a total of 5,856 separate daily averaged and 16 annual averaged exposure concentrations around each distance ring evaluated.
                  When alternate release estimates are provided, we estimate exposure concentrations using five years of meteorological data.  Since the default meteorological stations are pulled from IIOAC, which uses five years of met data, this results in 29,216 separate daily average and 16 annual average exposure concentrations around each distance ring evaluated.  
                  Moving to the right box, post-processing script is used to extract various statistics and percentile concentrations from the base concentration distributions obtained from AERMOD.  A key component to this effort includes extraction of three percentile concentrations: the 10th, 50th, and 95th percentiles, which are used for purposes of risk calculations and identifying associated potential risks.  In essence, this provides a low-end, central tendency, and high-end concentration-based risk estimate for purposes of risk characterization for each facility at each distance evaluated.  
                  Here I highlight some of the assumptions and uncertainties associated with the full screening methodology.  The key point to remember here is the full screening methodology as presented in the draft report, is used for screening-level analyses.  While we limit user-defined inputs to several key parameters of particular interest for screening level purposes, the capabilities of full screening methodology allow inclusion of many additional user-defined inputs which can be considered and included in a more detailed analysis or an expanded analysis beyond screening level. 
                  Closing out the full-screening methodology, this slide outlines a few strengths and a limitation associated with the full-screening methodology.  The primary strengths of the full-screening methodology revolves around the capabilities of the model used and the potential options for additional more detailed analysis in the future when and if data is available.  However, AERMOD is a complex model which requires specialized expertise to build scenarios within the model, to run the model, and to extract desired data for evaluation.  
                  Moving to the final air pathway methodology, this slide provides an overview of the co-resident methodology and approach presented in the draft report.  The application of the co-resident methodology within the draft report is limited to only one case study and only the dry-cleaning condition of use.  
                  The co-resident methodology utilizes IECCU, which is a deterministic model used to simulate effects of sources in unconditioned zones, a releasing facility, on the indoor environmental concentrations in condition zones in the residences or apartments.  Since the effects on condition zones depends on the building configurations, for example, how the zones are or are not interconnected, the draft report includes analyses for two building configurations: architecturally connected or architecturally separated.     
                  The figure on the right provides a general building schematic showing the primary inputs for the IECCU model.  This example shown here represents a building configuration where the two zones are architecturally connected via a staircase.  So, we're on the left side here.
                  The second bullet provides the mass balance equations used for the simulations.  These provide a concentration per unit time in the condition zones, which are then adjusted to the appropriate averages needed for purposes of evaluating exposure concentrations, risk calculations, and associated risks when compared to the benchmarks.  
                  This slide provides a few assumptions and uncertainties associated with the co-resident methodology, which they are discussed in more detail within the draft report.  Slide 25 closes out the co-resident methodology as well as the air pathway discussion by identifying some strengths and limitations of the co-resident methodology.  
                  General strengths revolve around IECCU being an indoor air pollutant transport model with multiple modules and capabilities to consider sources and syncs with the indoor environment, as well as a variety of potential exposure scenarios.  Limitations are primarily focused on the complexity of the model which requires specialized expertise to run.  
                  Additionally, since there are no default values included within the model, model inputs and limitations of such inputs often are dependent on the accuracy and strengths of the literature values or the capabilities of other models to provide accurate and representative estimates of values, which are then used as inputs to the IECCU model.
                  Now, I will move to the water pathway methodology.  Here I'll give you an overview of the water pathway, starting again with the graphic on the right.  We start by looking at the water releases from a releasing facility, the source, which may be either or both direct and/or indirect in nature.  Next, we use the release data to model ambient water concentrations resulting from the facility releases, via the pathways.  For purposes of the water pathway fenceline work, we focus on the dermal and oral ingestion route of exposure and, again, identify the exposures and associated risk to fenceline communities' receptors for each route of exposure.  
                  The general approach for estimating water releases for the fenceline work relies upon water release information from the published risk evaluations.  The release information include develop releases scenarios representing known direct and indirect chemical releasers.  These direct and indirect releases represent known industrial facilities and wastewater treatment plant releases.  
                  The releases are modeled in the Exposure and Fate Assessment Screening Tool -- specifically E-FAST 2014 -- to predict environmental exposure concentrations in the published risk evaluations.  During this process, ambient water concentrations are modeled, and drinking water concentrations and doses are auto-calculated.  
                  EPA uses the modeled surface water concentration to evaluate both incidental dermal and oral ingestion to fenceline communities.  EPA extracts the auto-calculated drinking water data for use in evaluating ingestion from drinking water, again, to fenceline communities.  The modeled surface water and auto-calculated drinking water data is adjusted, as applicable, to incorporate various 2019 exposure factors handbook input information and age group considerations including intake rate, ingestion rate, body weight, skin surface area, and/or exposure time to evaluate exposures. 
                  One additional item I'd like to mention, EPA did search for available monitoring information for the water pathway work within the fenceline effort.  This is discussed in more detail within the draft report.  Two case study chemicals were selected for the water pathway methodology.  Those are N-Methylpyrrolidone, NMP, and methylene chloride.  
                  E-FAST 2014 is a tool which estimates chemical concentrations in various media, including ambient water resulting from discharges to both free-flowing and still water bodies.  The tool uses upper percentile and/or mean exposure parametric values that result in possible conservative exposure estimates.  Advantages of this tool are that it requires minimal input parameters and has undergone extensive peer review by experts outside of EPA.  
                  This slide shows the inputs and associated calculation within E-FAST 2014 to determine surface water concentrations.  Among the inputs used for this calculation are a number of release dates, the chemical release to wastewater, chemical removal from wastewater treatment, and surface water flow information.  
                  Release days represent the number of days per year that a chemical is discharged and is used to calculate a daily chemical release to wastewater amount based on known annual releases and loading information from either or both TRI and discharge monitoring reports, or DMR, when available.  Since direct discharging facilities are not required to report the number of days associated with chemical releases, release scenarios developed in the published risk evaluations are used to provide an upper and lower bound of release days used to calculate the associated surface water concentrations.
                  Surface water flow information is included within E-FAST 2014 database.  However, flow information is dependent on whether the release comes from a known or unspecified location.  For those locations where there is a known national pollutant discharge elimination system, or NPDES permit, for the discharging facility, the E-FAST database is searched by the NPDES permit number, name, or known discharging waterbody reach code to obtain relevant flow information. 
                  Where a site-specific NPDES code is unavailable, a surrogate NPDES code for a nearby facility that discharges to the same waterbody may be used.  If there is no known NPDES code, or the exact location of a chemical loading is unknown, the standard industrial classification code -- SIC option -- within E-FAST is used.  This option uses a 10th and 50th percentile receiving 7Q10 stream flows for dischargers in a given industry sector.  The most representative SIC for an evaluated release is used. 
                  Slide 30 outlines the approaches and various inputs used for estimating drinking water and recreational oral/dermal exposures for the fenceline effort.  Starting with drinking water exposures in the left box, drinking water exposures are at the water body of release with water treatment set at zero percent.  For acute exposure, modeled stream concentrations are based on 30Q5 flow information and 95th percentile consumer data from the 2019 exposure factors handbook for drinking water intake rates.
                  For chronic exposure, modeled stream concentrations are based on the harmonic mean flow information and mean per capita data from 2019 exposure factors handbook, which is used for the drinking water intake rates.  Moving to recreational oral/dermal exposures -- or it's also referred to as incidental oral/dermal exposure -- in the right box, approaches for recreational oral and dermal exposure follow those originally undertaken in the published risk evaluations for 1,4-Dioxane and NMP.  Chemical-specific skin permeability coefficients are used for the dermal evaluation.  Estimated surface water concentrations use a previous E-FAST facility release scenarios and modeled 30Q5 and harmonic mean concentrations for acute and chronic dose estimations, respectively.  
                  For all water pathways, exposure concentrations are estimated across various age groups ranging from infants to adults, although results presented in the body of the draft report are for the more sensitive chemical-specific populations.  All age group calculations are included in the supplemental materials to the draft report.  
                  This slide closes out the water pathway methodology by identifying some assumptions and uncertainties associated with the water pathway methodology.  The key point to remember here is the proposed screening level methodology for the water pathway is designed to maintain a conservative approach for estimating exposures.
                  A couple key assumptions which help maintain this conservative approach include, estimating the surface water concentrations at the point of release without consideration of post-release environmental fate or degradation, assumptions associated with recreational oral/dermal exposures occurring at the point of release without the consideration of transport, illusion, or treatment.
                  One final note, the applied streamflow distribution is a key driver of estimated results within E-FAST 2014.  However, the age of the streamflow distribution dataset within the E-FAST 2014 tool, and the selection of representative flow data, brings in some uncertainties which can impact the representativeness of the overall modeled result for more current release data.  
                  I'll now present an overview of the human health hazard and risk characterization methodology.  This slide summarizes previously identified hazard endpoints from the published risk evaluations used for each of the three case study chemicals included in the draft fenceline report.  For the fenceline analysis, EPA started with the same human health endpoints -- endpoints of departure -- as were derived in the published risk evaluations for each chemical and only adjusted the human equivalent concentrations or human equivalent doses to a continuous exposure basis so they could be applied to evaluate continuous fenceline exposures.  
                  As you can see, 1-BP and methylene chloride both have acute, chronic non-cancer, and cancer hazards; while NMP has acute and chronic non-cancer but no cancer hazard identified.  This analysis uses the most sensitive endpoints from each published risk evaluation that was the basis of risk determination.  In several cases, they were based on effects during sensitive life stages.  
                  To calculate risks, EPA used the same approach described in the published risk evaluations.  Non-cancer risk was calculated using a margin of exposure of approach where the hazard value was divided by the predicted human concentration.  EPA interpreted the MOE risk estimates in reference to benchmark MOEs.
                  Benchmark MOEs are the total uncertainty factor for each non-cancer POD.  The MOE estimate is interpreted as a health risk if the MOE estimate is less than the benchmark MOE.  Cancer risk is calculated by multiplying the predicted human exposures body inhalation unit risk for inhalation exposures or by the cancer slope factor for oral and dermal exposures.  The cancer risk estimate is interpreted as a health risk if the cancer risk estimate is greater than the benchmark of one times ten to the minus six for fenceline communities.
                  For the water pathways, cancer risk is estimated both for individual life stages and integrated across lifetimes.  EPA also applies age-dependent adjustment factors, or ADAFs, to carcinogens acting to a mutagenic mode of action -- IE methylene chloride -- to account for increased risk from early life exposures via the water pathways.  
                  Slide 35 depicts an overview of the land-use evaluation considerations and associated decision tree.  As part of the risk characterization for the air pathway, the fenceline methodology includes a land-use evaluation around facilities where risk is indicated.  This evaluation is used to determine whether an actual inhalation exposure and an associated potential health risk is expected to fenceline communities within the radius around the facility where risk is indicated.  For all the facilities with TRI-reported releases, location information in the form of latitude and longitude -- we used ARC-GIS to map facility locations and create buffer rings around each facility for each distance evaluated. 
                  We then use ARC-GIS and Google Map to visually examine the land use within the farthest distance from the facility where there is an indication of acute, chronic non-cancer, and/or cancer risks for low, central, and high tendencies.  For residential, industrial, commercial-end businesses, or other public spaces are present within that distance, EPA considers those receptors within the fenceline communities and therefore reasonably expects a potential exposure and associated potential risk to fenceline communities.  When the farthest distance that at which risk is indicated falls within the boundaries of facility property, or includes only uninhabited areas, EPA does not reasonably expect an exposure or an associated risk to fenceline communities.
                  This slide presents some strengths and limitations associated with the land-use evaluation methodology.  A few key takeaways from this slide, it's a simplified method which can be performed using a Google Maps search engine and provides a quick visual image of the area around a given facility.  EPA only applied the land-use analysis methodology to the air pathway in this current fenceline work.  Although, it has potential for use with other pathways, such as the water pathway, as well as additional or more detailed analyses.  Most of the limitations with the land use analysis methodology involve the reliance on certain information and maps data outside of EPA's purview.  
                  This slide closes out the risk characterization methodology by identifying some assumptions and uncertainties related to the hazard and risk characterization for the fenceline to work.  There are several assumptions and uncertainties to keep in mind for the risk characterization overall, including specific strengths and limitations of the analysis.  First, this analysis assumes that an individual living near a facility will be exposed to a chemical at a similar concentration for all hours of the day.  That means it is most relevant for individuals in the fenceline community who spend all day at home or very nearby.  
                  The chronic lifetime cancer risk estimates are most relevant for people who remain in the fenceline community for years and do not relocate.  Second, the precision of the risk estimates is limited by a couple of factors.  Because modeling for the air pathway focused primarily on finite distances from the facility --  for example, we evaluate risk at 60 meters and 100 meters but not in between -- there is some uncertainty about what the risk may be in between those distances when risk is indicated at 60 meters but not at 100 meters. 
                  In addition, for facilities with physical locations, we were able to evaluate land-use patterns.  However, from modeled theoretical facilities with no physical location, we are not able to evaluate land use.  Finally, considered duration of sensitive life stations and subpopulations is consistent with what is described in the published risk evaluations.  Since hazard values are based on PODs derived in the published risk evaluations, they incorporate the same considerations for potentially exposed in subpopulations.  
                  In depth discussion of the assumptions and uncertainties associated with the chemical-specific PODs can be found in the published risk evaluations for each chemical.  For oral and dermal exposures via the water pathway, risks are calculated based on life stage specific exposure scenarios.  For inhalation exposures via the air pathway, risks are calculated based on air concentrations and therefore do not incorporate any life stage differences in dosimetry.  This is consistent with Agency guidance and assumes that the ten times interspecies uncertainty factor accounts for any life stage specific differences in dosimetry.
                  Next, I will briefly discuss the case studies we included in the draft report, followed by a short summary of anticipated next steps for the fenceline work.  Here's a quick recap of the case studies I'm going to discuss.  We include three case study chemicals in the draft fenceline report: two for the air pathway, 1-BP and methylene chloride; and two for the water pathway, methylene chloride and NMP.
                  The purpose of these case studies is to provide illustrative examples of the application and efficacy of the proposed methodologies described in the draft report with the goal of identifying if there are potential risks previously not captured due to the exclusion of certain pathways from the published risk evaluations.  While the case studies do represent three chemicals for which EPA has published risk evaluations, the results presented in the draft report and in this presentation, again, do not represent final Agency actions. 
                  Slide 40 begins the 1-BP case study, which was only evaluated for the air pathway in the draft report.  This case study will include a bit more detail than the other two because I'll talk through slides with results for the first time and provide an example facility which walks through the entire methodology, including land-use analysis.  
                  Here is a tabulated snapshot of the results obtained for the release assessment and exposure assessment through application of the proposed methodologies for the air pathway.  While the ranges of release data and exposure concentrations are shown here, a full set of releases are included in the draft report and accompanying supplemental files.  
                  The left two columns present each OES evaluated along with the number of facilities within each OES evaluated.  Where you see a dash under the TRI facilities column header, it means there is no TRI-reported data available for that OES.  As such, the releases are estimated using the alternative release estimation hierarchy described earlier.  The next two columns show the range of estimated annual air releases obtained for the release assessment for both fugitive and stack releases.
                  The last four columns show a very small subset of the daily averaged and annual averaged modeled exposure concentrations obtained through application of the full screening methodology using AERMOD.  For context, these minimum and maximum concentrations represent only the minimum/maximum 95th percentile exposure concentrations across all facilities within a given OES across all distances modeled for a given OES.
                  For purposes of risk calculations, we present and use the minimum, mean, and maximum 95th percentile exposure concentrations across all facilities within a given OES.  Those values and associated risk calculations are presented by OES and distance within the draft report.  
                  This table summarizes the results of the risk calculations for cancer risk based on the maximum 95th percentile exposure concentrations by OES and distance.  Overall, 14 occupational exposure scenarios were evaluated for 1-BP inhalation risk.  Thirteen of the 14 OES indicate excess cancer risk as far out as the area distance of 100 to 1,000 meters from a facility releasing 1-BP to the ambient air.  Three OES indicated risk from acute exposures.  Two OES indicate non-cancer risk from chronic exposures.  
                  One quick note related to 1-BP, it was just recently designated as a hazardous air pollutant, or a HAP, under the Clean Air Act.  Breaking down the results of the fenceline methodology a bit more for 1-BP, this slide provides an example facility to which fenceline methodology has been applied for the air pathway.  All this information is provided within the draft report and accompanying supplemental files to the draft report.  
                  To begin, there are three main components to the fenceline methodology: the release assessment, exposure assessment, and risk characterization.  The first two boxes are tied to the release assessment component showing the facility-specific mapping of OES and COU as well as the total releases and release type.  The third box is tied to the exposure assessment component presenting the range of modeled exposure concentrations across all nine distances modeled, as well as the three percentiles used for purposes of risk calculations: 10th, 50th, and 95th percentiles. 
                  The fourth box is tied to the risk characterization component presenting the estimated MOE or cancer risk for acute, chronic, non-cancer, and cancer respectively, as well as the exposure concentration percentiles and associated distances indicating risk.  Following the indication of potential risk at one or more evaluated distances from the example facility based on a comparison of the estimated MOE or cancer risk to the respective benchmarks, this slide shows application of the land-use evaluation methodology to the example facility. 
                  In this particular example, risk was indicated from 5 to 1,000 meters to a releasing facility.  A quick look at the map shows the area surrounding the facility, in particular within the distance of 100 to 1,000 meters radius.  Within that distance is included functional zoning containing mixed residential, commercial, industrial, institutional, and recreational areas.  As examples, we see residential areas to the north and south and a school -- which in this case the community college -- to the west among other land uses. 
                  Based on this visual review of land use around the example facility, receptors within the fenceline communities do live and work within the radius of indicated risk.  With that, we determine there is an expected potential exposure to, and therefore associated potential risks to, fenceline communities.  
                  Slide 45 closes out the 1-BP case study by summarizing the key results from applying the fenceline methodology, including land use evaluations.  EPA identified risks from fenceline air concentrations for 52 of the 62 TRI reporting release facilities covering 13 of 14 OES.  Based on land-use considerations, actual fenceline community exposures are expected for 39 of the 49 GIS located facilities for which risk was indicated.  
                  These risk conclusions are based on the 95th percentile modeled exposure concentrations representing a conservative screening-level analysis.  EPA expects these estimates sufficiently capture any risk to fenceline communities.  For most facilities, risk is also indicated at lower percentiles as well, mitigating some of the uncertainty.  Although not included in this presentation, risk is also identified for co-residences of dry-cleaning facilities under all modeled scenarios.  And you can see that in the draft report.  
                  Now, I'll move to the methylene chloride case study which includes both the air and water pathways.  As with 1-BP, this slide provides a snapshot of the results obtained from methylene chloride from the release assessment and exposure assessment through application of the post-screening level methodologies for the air pathway.  This table summarizes the results of the risk calculations for cancer risks, again based on the maximum 95th percentile exposure concentrations by OES and distance from methylene chloride for the air pathway.  Overall, 17 exposure scenarios were evaluated for methylene chloride inhalation risk.
                  Eight of the 17 OES indicate excess cancer risk at distances as far out as 100 meters from the facility releasing methylene chloride to the ambient air.  Two OES indicate risk from acute exposures.  Three OES indicate non-cancer risk from chronic exposures.  This slide provides a snapshot of the number of releases modeled and results from the exposure assessment through application of the proposed methodologies for the water pathways for methylene chloride.  
                  This table shows the number of releases obtained from the release assessment for two release scenarios, 20-day and maximum days, using both 2016 TRI and DMR data.  The last three columns summarize the ranges of modeled exposures for each released scenario for all three routes evaluated.  The ADR, ADD, and LADD for drinking water are provided with respective risk calculations.  The ranges provided here are combined across respective age classes.  
                  The full set of estimated exposure concentrations in doses, and associated risk calculations, are provided in the draft report and accompanying supplemental files to the draft report.  For purposes of risk calculations, we present results by OES and age class within the draft report.  
                  Slide 50 closes out the methylene chloride case study by summarizing the key results from applying the fenceline methodology, including land-use evaluation for the air pathway.  The EPA identified risk at fenceline air concentrations for 14 of the 195 real facilities assessed, covering 8 of 17 OES for the air pathway.  Based on land use considerations, actual fenceline community exposures are expected for 2 of the 14 GIS located facilities for which risk was identified.
                  Again, these risk conclusions are based on the 95th percentile modeled exposure concentrations and, again, representing a conservative screening level analysis for the air pathway.  For the air pathway, the EPA expects these estimates to efficiently capture any risk to the fenceline communities.  For half of the facilities, risk is also indicated at lower percentiles as well, again, mitigating some uncertainty.  EPA also identifies risk via drinking water for one recycling and disposal facility based on acute non-cancer risk to infants and lifetime cancer risk.  Risks are not identified via recreational contact with water, however.  
                  For the final case study, I'll briefly discuss NMP.  This slide provides a snapshot of the number of releases modeled and results of the exposure assessment through application of the proposed methodologies for the water pathways from NMP.  While this slide provides a snapshot of the results, again, the full set of releases, estimated exposure concentrations, doses, and associated risk calculations are provided in the draft report and accompanying supplemental files to the draft report.  This table shows the number of releases obtained for the release assessment for two release scenarios, 12-day and maximum days, using only TRI data from both 2015 and 2018 TRI reporting years.  
                  One thing to point out for NMP, in addition to adults, infants, and youth age classes, NMP includes the age class of pregnant females due to the reproductive and developmental hazards identified for NMP.  The last three columns summarize the ranges of modeled exposures for each release scenario for all three routes evaluated.  
                  Closing out the NMP case study, EPA did not identify any risks from NMP for fenceline communities via either drinking water or recreational contact with water.  Exposures were greater than 10-fold below levels which would result in risk for any exposure scenario.  Based on these findings, EPA feels this represents a health-protective assessment and EPA has increased confidence in the conclusions of no risk via these water pathways.  
                  Slide 54 briefly touches on next steps for the fenceline work.  The first step, revising and finalizing the fenceline methodology -- following public and peer review, EPA will review comments, recommendations, and improvements received.  EPA will modify the post-screening level methodology, as appropriate, and finalize the screening methodology as a framework to conduct screening level analyses.  
                  One revision already planned for the air pathway is to revise the current cancer risk calculations in the draft report to consider a 33-year residential exposure duration from the exposure factors handbook, adjusted to lifetime for cancer risk per EPA's cancer guidelines.  This will be in the current methodology in line with the methodology applied for the water pathway and EPA's cancer guidelines.  The current methodology assumes a full lifetime of exposure, or 78 years, via the air pathway for calculating cancer risk.
                  For the fenceline considerations for seven of the first ten risk evaluations, the final screening-level analysis methodology framework will be used to conduct screening-level analyses for seven of the first ten chemicals for which EPA published risk evaluations between 2020 and 2021 to help determine if there are potential exposures and associated potential risks to fenceline communities from the air and water pathways that were previously not assessed.  For future TSCA or risk evaluations, the final screening-level methodology framework can also be used for future chemicals undergoing risk evaluation under TSCA Section 6.  
                  And this concludes our presentation of the fenceline methodology and associated case studies.  I'd like to than the SACC panel, public, and stakeholders for taking the time to listen, review, and provide comment on the draft report and the fenceline screening methodology.  I just want to say thank you.  This lists the fenceline team members as well as the management leads I mentioned at the beginning of the slide.  Thank you.  
                  DR. DANIEL SCHLENK:  All right.  Thank you, Kevin.  Appreciate that presentation.  Before taking questions or clarification, I think let's go ahead and take a quick 15-minute break.  I just want to remind the Committee, if you do have questions of clarification, please raise your hand, and I'll get to them in order as we go.  But at this point, let's go ahead and take a 15-minute break, and then we'll come back for questions.  Thanks.  So, return at 45 past the hour.

                                    [BREAK]
                                       
SACC QUESTIONS ON OPPT TECHNICAL PRESENTATION
                  
                  DR. DANIEL SCHLENK:  Okay.  Kevin, I guess you are present.  Looks like I see your name there.  Yeah.  Good.  Thanks.
                  DR. KEVIN VUILLEUMIER:  Yup, I'm here.
                  DR. DANIEL SCHLENK:  We've got a few questions of clarification.  Before we get started, we do have another Committee member joining us.  At this point, Craig, if you wouldn't mind just introducing yourself and your area of expertise if that's okay?  Dr. Rowlands, you on now?  Dr. Rowlands?  Okay.  I see you listed on the participant list.  Maybe you haven't gotten back to your screen yet.  Okay.  Let's go ahead and move forward then with questions.
                  Let me just remind the panel a couple things.  First of all, the slides are available from the presentation.  Alaa will send you the link directly to that if you don't have it directly.  But if you would like to peruse the slides, particularly this evening, prior to your deliberations for tomorrow those will be available.  Also, let me just point out -- particularly for our ad hoc reviewers -- that, again, this is a period of questions of clarification, not necessarily for comments.  
                  The comments, obviously, will be provided during the question period which will follow this.  So please use this time for questions to the EPA -- for specific questions of clarification of their presentation and of materials that you've been presented at this point and hold your comments until the time when those are available for the questions.  Okay.  I have -- 
                  DR. KEVIN VUILLEUMIER:  Dr. Schlenk. 
                  DR. DANIEL SCHLENK:  Yes?
                  DR. KEVIN VUILLEUMIER:  This is Kevin, sorry.  I just wanted to point out we're going to work with -- Rehan Choudhary is going to kind of field this portion of the comments and clarifications, as well as the questions and comments that come in later on.  So, we'll have Rehan pulled up as well.  We'll both be on, but he's going to receive it and manage it so the whole panel has one point of contact.  Does that make sense?
                  DR. DANIEL SCHLENK:  Are you talking about right now?
                  DR. REHAN CHOUDHARY:  Yes.
                  DR. KEVIN VUILLEUMIER:  Yeah, right now and moving forward.  Yes.
                  DR. DANIEL SCHLENK:  Okay.  Yeah.  The only thing I would say is just make sure you state your name prior to the response for the written record.  Also, too, for panel members as well, please -- I'll call on your name, but please state your name before you make your question or any comment so that we get that on the record upfront.  Okay.  Okay.  Dr. Chaisson, if you want to go first.
                  DR. CHRISTINE CHAISSON:  Oh, thank you.  Thank you for the presentation.  It was really helpful.  I had been trying to follow the use of data or values throughout the different mathematics in your algorithms -- or presumably in your algorithms.  But I sort of got lost in that effort, so maybe you could help me with this.  Where in the -- when you're using quote "available data" or default values or assumptions or any value applied to an algorithm, would the model of that values that are averages or other middled values from a distribution and apply those to what you would call the maximum calculations?
                  So, for example, if you're using an exposure handbook value, is that a middled value, or is that somehow unique?  Or is that the full distribution?  So that's where I lost the thread, and maybe you can help me understand that part.  Thank you.
                  DR. REHAN CHOUDHARY:  Dr. Chaisson, this is Rehan Choudhary from the EPA.  My apologies, parts of your questions were blocking out, and I could not hear them in entirety.  Could you please repeat what you're focusing on?
                  DR. CHRISTINE CHAISSON:  Right.  I'm focusing on the values within distributions for any metric used in the algorithms in the screening models.  So, my question was I understand when you're using specifically as you pointed out maximum values for the concentrations that are expected or amortized across time.  But in doing the calculations to exposure you're also using values or assumptions from other sources -- for example, the exposure handbook.
                  Are those values middled values somehow, or are they also representing the spectrum -- the distribution of values within that metric?
                  DR. REHAN CHOUDHARY:  Okay.  So this is again Rehan Choudhary from the EPA.  So, we've got two pathways here, one the air pathway and one the water pathway.  I will first pivot to Kevin Vuilleumier for the air pathway so he can comment on that, and then I'll pivot to Jason Todd to see how he can respond to your comment for the water pathway.  Kevin, go ahead.
                  DR. KEVIN VUILLEUMIER:  Okay.  Thank you, Rehan.  This is Kevin Vuilleumier with the EPA.  Yeah, the input values I believe are where you're trying to get to for the models.  In particular, IIOAC has default stack heights -- the fact velocities out the stack.  We also assume some meteorological data.  The data sources vary from where they come from.  In the case of the exposure factors handbook, sometimes it's an average.  Sometimes they give you a range.  And then within the model and the documentation behind the modeling they generally explain what values they use as default and where they come from.
                  So, there may be some instances where an exposure factor is a mean that's used in a model parameter.  There may be other times when it tends to pull out a higher-end, or you may be able to have both of them.  Okay?  So it's the way we'd go about doing that is where the data comes from.  You'd have to look at the manuals and kind of see what the default value is, and then you can look up that reference and find out is it a range, is it a maximum value or something like that, okay.  So, the inputs vary.  
                  The outputs that we use to do the calculations, as you had said, were a bit clearer where we used 95th percentile.  We used a mean.  So that's where the data comes from.  Does that help?
                  DR. CHRISTINE CHAISSON:  Did you -- well, you're zeroing in on where I lost the trail, essentially, because I didn't understand if you had chosen to -- where you had the choice to use a range or an upper.  If you look particularly at the beginning, say the pre-screening methods, are you employing the upper end for each of these values when you do have, in fact, the choice of doing that, or are you systematically using the average number?
                  What are your methodologies and criteria for choosing any of these other values that are going to be part of the algorithm?
                  DR. DANIEL SCHLENK:  That was Dr. Chaisson.
                  DR. KEVIN VUILLEUMIER:  And this is Kevin Vuilleumier.  In the case of the model for pre-screening IIOAC, the default values are established within the model itself.  So they don't change with some of the parameters.  For a stack release, we have different types of stack releases.  We'd only focus on the stack release though instead of like incinerator.  But that stack release is set at ten meters high.  It has a set velocity.  And we outline those defaults in the draft report itself.  Okay?
                  Where it comes from, I'd suggest -- because they vary, I'd recommend we would need to go into the manual itself to see where each value came from.  Generally speaking, I think some of the stack parameters and all were taken across like a national average.  Okay.  But we go to the source -- we go to the manual to find out where it's coming from.  
                  DR. CHRISTINE CHAISSON:  Thank you.
                  DR. DANIEL SCHLENK:  Okay.
                  DR. REHAN CHOUDHARY:  Thank you, Kevin.  This is, again, Rehan Choudhary from the EPA.  And I'll pivot to Jason Todd to see if he has any inputs and clarifications to your question for the water pathway with respect to default inputs or parameters so that it can help you identify what those are.  Jason, go ahead.
                  DR. JASON TODD:  Hi, this is Jason Todd from EPA.  My answer would be very similar to Kevin's on the air side.  On the water side, it's dependent on the input that you'd be asking about.  But generally speaking -- and those are detailed both in the -- at least, on the water side we relied mostly on the use of the E-FAST tool, which Kevin outlined in his presentation.
                  And the inputs -- the default inputs for those are found both within the report and in the manual for that tool.  I'd also refer you to the supplementary Excel files for both the case studies that outline the inputs that were used for the evaluation of the calculated or estimated exposures there.  And so, it would be somewhat dependent on this specific input you're asking about.  But in some cases, we used more conservative values, and others we used more mean values.
                  And so, if you have specific inputs in mind that you're asking about, we can look into that.  But I generally refer you to both the supplemental files and the tool handbook. 
                  DR. REHAN CHOUDHARY:  Okay.  Thank you, Jason.  This is, again, Rehan from the EPA.  I think we can move on to the next question, Dr. Schlenk.
                  DR. DANIEL SCHLENK:  Okay.  Dr. Chaisson, has your question been answered there?
                  DR. CHRISTINE CHAISSON:  Yes.  Thank you very much. 
                  DR. DANIEL SCHLENK:  Okay.  Dr. Doucette?
                  DR. WILLIAM DOUCETTE:  Yes.  I think I got two what I think are clarification questions.  The first one is on the TRI data.  Looking at some of your spreadsheets, if you look at the details, there are multiple ways that industries are allowed to estimate the TRI data.  For example, they can do it by mass balance calculations.  There's engineering best judgment, monitoring data.  And I'm trying to get a handle on how you compare those different TRI results since they're made using different estimation techniques and what the variability associated with that.
                  In other words, I'm worried about garbage in/garbage out.  And I'm wondering if you could just kind of explain to me how you assess that variability.
                  DR. REHAN CHOUDHARY:  Okay.  Thank you for that question.  This is, again, Rehan Choudhary from the EPA.  You are correct that there are basis codes in TRI that help you understand what a company or reporter is saying what the basis for their numbers are.  And I think we commented on the uncertainty related to the basis that is used.  So, I'm going to pivot to Franklyn Hall who is our expert on the release side, so he can comment on your question.  Franklyn, go ahead, please.
                  DR. DANIEL SCHLENK:  We're not hearing you.  You might be on mute.
                  DR. FRANKLYN HALL:  Sorry about that.  Good morning.  This is Franklyn Hall.  So, Dr. Doucette, as Rehan had just indicated, the TRI does require that submitters provide a basis of estimate, and as you've indicated it can be done in a number of different ways.  At this time, we've just provided an explanation of those bases of estimates for context, but we have not done any analysis on the variability or the impacts of that variability on the actual estimates as they've been provided on facility-level or even as they've been aggregated at the OES level.
                  However, that is something that we are considering looking at moving forward.  As indicated early on, this is just a screening-level approach, so this is just one of the ways that we're going to try to better characterize the release estimate information by using those bases of estimates and providing some kind of context to provide readers with an idea as to uncertainty with some of those estimates that are provided by facilities.
                  DR. WILLIAM DOUCETTE:  Thank you.
                  DR. REHAN CHOUDHARY:  Thank you, Franklyn.  This is, again, Rehan from the EPA.  And just to add to that, Dr. Doucette, we do recognize there are various bases, and internally we started to talk about maybe should there be some sort of hierarchy that we implement based on what basis a reporter is saying.  Is it a measurement?  Is it a mass balance estimate?  But I think we would also be looking forward to any feedback that the SACC Committee has on setting up a hierarchy or dealing with different basis or different ways.  
                  DR. WILLIAM DOUCETTE:  Okay, thank you.  And my second clarification question was dealing with a case study for methylene chloride.  You looked at water exposures for methylene chloride which I was a little surprised given the volatility or Henry's law constant for methylene chloride.  And you talked about recreational exposures in water.  
                  Did you consider or at least discuss the possibility of exposures in the same way through bathing and showers?  It would seem like that would be more of a likely water exposure for something like methylene chloride than recreational use.  
                  DR. REHAN CHOUDHARY:  Okay.  Thank you, Mr. Doucette.  This is, again, Rehan Choudhary, from the EPA.  I'm going to pivot to Jason Todd to see if he can clarify that question.
                  DR. DANIEL SCHLENK:  Not hearing you, Jason.
                  DR. JASON TODD:  Yeah, sorry.  There was a lag in my video starting.  Again, this is Jason Todd.  Yeah, good question.  Thank you for that.  We did not assess the exposures due to bathing.  That is something we are considering moving forward as kind of a 2.0 level analysis.  We welcome any thoughts or considerations from the panel on ways to evaluate that or moving forward.
                  But we did not look at that particular pathway for this fenceline analysis.  I'll hand it back to Rehan to see if he has any additional comments there.  
                  DR. REHAN CHOUDHARY:  Thank you, Jason.  Nothing additional.  I hope that's helpful, Mr. Doucette.
                  DR. WILLIAM DOUCETTE:  Yes, it is.  Thank you very much.  And I also greatly appreciate the presentation, which I thought was very well done and helped clarify the document itself.  
                  DR. REHAN CHOUDHARY:  Thank you very much.  
                  DR. DANIEL SCHLENK:  Thanks, Bill.  Mark Johnson.
                  DR. MARK JOHNSON:  Thanks, Dan.  Yeah, admittedly, I'm not a modeler of this type, but the devil's always in the details; right?  So, I've got a question that relates to the air pathway and then water pathway.  I'll start with the air first.  Does the model estimate wet deposition and dry deposition?  I mean, maybe not for these compounds but does it do that?
                  DR. REHAN CHOUDHARY:  I think from a modeling capability perspective, AERMOD -- yes, it can take that into account.  Are you asking whether that was actually incorporated into our estimation method? 
                  DR. DANIEL SCHLENK:  That was Dr. Choudhary. 
                  DR. MARK JOHNSON:  Yeah, I was asking if the model does account for wet and dry deposition to estimate environmental load, the soil? 
                  DR. REHAN CHOUDHARY:  Okay.  Again, this is Rehan Choudhary.  Kevin, could you please field that?
                  DR. KEVIN VUILLEUMIER:  Yes.  Thank you, Rehan.  And good question, Mr. Johnson.  The modeling -- as Rehan said, AERMOD can consider deposition of multiple types.  We did not do that for the fenceline effort, but it is something we can consider moving forward, especially with some of the future chemicals which may not all be so volatile.  Right?  So you can have a bit more deposition to worry about.  But AERMOD is capable of doing that.  
                  IIOAC also has a capability to a degree.  We're still putting together the logic behind what we get from that for prescreening purposes, but for the full screening methodology, AERMOD can consider both.  It can consider deposition, wet and dry deposition, given the right data that you need to be able to calculate that and use them as inputs.
                  DR. MARK JOHNSON:  Okay.  So that kind of answers my second question which has to do with well water.  So, I guess we're not looking at pathways or transport to well water.  We're just looking at releases to municipal water supplies, ultimately for drinking water, correct?
                  DR. REHAN CHOUDHARY:  This is Rehan Choudhary, again.  I'll let Jason Todd chime in with more details, but on the surface, no, we're looking at releases to surface water.  So, Jason, please elaborate as needed.
                  DR. JASON TODD:  Yeah, this is Jason.  Rehan is right.  In that respect, we did not look at potential releases to groundwater.
                  DR. MARK JOHNSON:  Okay.  Awesome.  Thank you.
                  DR. DANIEL SCHLENK:  Thanks, Mark.  Dr. Reiss.
                  DR. RICK REISS:  Yes.  I wanted some clarity on how you're accounting for the property line of facilities.  Is that done in the land use analysis?  Meaning, where you're excluding consideration of concentration estimates that occur on the property line or within the property line -- meaning, not at the fenceline? 
                  DR. REHAN CHOUDHARY:  This is Rehan Choudhary from the EPA, again.  I believe the way the land-use analysis is working we have a lat/long coordinate from TRI, and then we're able to map that and visually inspect what's happening in this vicinity.  Based on the exposure and risk calculations, we can get a sense of how far we are estimating that risk.  So, when we have different boundary or buffers around the lat/long coordinates, we're taking a look at, well, what are the uses around that boundary so to speak.  And visually, we can tell sometimes that we're still on the facility itself, or we are in an area that is officially in recreational areas and things like that.
                  So, it's a visual inspection that helps us distinguish where we think we are as an intial screen.  I'm going to pivot to Kevin to see if he has anything to add to that.  Kevin Vuilleumier, please go ahead. 
                  DR. KEVIN VUILLEUMIER:  Thank you, Rehan.  This is Kevin Vuilleumier, and yeah, I think Rehan pretty much captured it.  It is an initial visual inspection out to the distances where we've found risk.  And on some of the very small properties, it can be difficult to see if it's right on that boundary, right?  Is it two meters away, or is it more than that?  But on a much larger facilities, like on a chemical manufacturing process -- that might be acres -- you can see a clearer delineation of where the property boundaries actually end.  
                  But generally speaking, it's just a visual inspection based on the various distance rings and buffers that we put around it, and then we see within those rings where we find risk.  Do we expect fenceline communities to live there or work there and move from there.
                  DR. RICK REISS:  Thank you.  
                  DR. DANIEL SCHLENK:  Okay.  Dr. Heiger-Bernays.
                  DR. WENDY HEIGER-BERNAYS:  I think Dr. Kissel was before me, but it's up to you.  
                  DR. DANIEL SCHLENK:  He disappeared when I hit your name.  Now he's back but go ahead.
                  DR. WENDY HEIGER-BERNAYS:  Okay.  I'll go, and then Dr. Kissel.  So, thank you.  Wendy Heiger-Bernays.  I have a few questions.  Most of them have been clarified, and the presentation was fantastic.  Thank you for doing such a thorough job.  
                  I have a question that relates to just the previous question, which is regarding the observations, the geo-spatial and where the facility is located.  So, these assume current use considerations and nothing about land use in the future?  And so, that's one question.  I'll start with that.  
                  DR. REHAN CHOUDHARY:  This is Rehan Choudhary from the EPA.  You are correct.  This is trying to take a look at current use.  It does not incorporate local municipalities and their zoning plans or projections.
                  DR. WENDY HEIGER-BERNAYS:  Okay.  And along those lines, when you take a look at the location, if -- and I don't know -- you have seen -- you might have determined where there are multiple facilities within a particular geospatial area, and if there were multiple facilities, how would you address that in the screening assessment for that fenceline community?
                  DR. REHAN CHOUDHARY:  So, right now, yes, when the team or assessors are zooming in visually to see what is in the vicinity of where we see risk, they may make note that there are other facilities in the same buffer.  But right now, the methodology itself focuses on the effects of single sources or single releasors.  It does not get into aggregate exposures or cumulative exposures.  And I think we are specifically requesting feedback from the SACC Committee on how we might expand the capacities of the current approach and take that into account.  
                  So even though visually an assessor may see there's another facility that falls within a buffer of an existing facility, it will be left at that.  It will not be taken further with respect to aggregate approaches or cumulative approaches with version 1.0 of the methodology.
                  DR. WENDY HEIGER-BERNAYS:  Okay.  Thank you very much.  Another question with regard to the water pathway, has the screening assessment incorporated combined sewer overflow events?  There are, according to EPAs estimates, about 860 communities that experience that.  And I'm wondering whether the contribution from the CSOs is included in the discharge and ultimately the risk estimates for the communities around those facilities.
                  DR. REHAN CHOUDHARY:  I'll take an initial stab at that.  This is, again, Rehan Choudhary from the EPA.  If those releases are somehow captured in TRI reporting, then we would be incorporated because they would be reported as direct or indirect discharges to surface waters.  But at this point, I think I'll pivot to Jason Todd to see if he has more -- can elaborate more.  Go ahead, Jason. 
                  DR. JASON TODD:  Yeah, thanks, Rehan.  This is Jason Todd from the EPA, again.  As of right now, we do not include other releases such as that, that would potentially influence chemical concentrations in the water column or in the nearby vicinity.  But, I think, again, I would point you to that this was a screening-level analysis, and if there were information like that that would potentially influence our ultimate estimate, like, that would be part of a 2.0 level of evaluation.  Currently, we do not take those sorts of releases into consideration in this evaluation.
                  DR. WENDY HEIGER-BERNAYS:  Okay.  Thank you.  And one other, I think, quick question.  This relates to the actual risk calculations.  And I'm looking specifically on some of the case studies, for example, slide 49 with the methylene chloride aquatic exposure summary.  And there's looking at 20 days, for example.  And the question I have is what is the averaging time over which that is assessed?  
                  DR. REHAN CHOUDHARY:  Okay.  Again, this Rehan Choudhary.  Jason, do you know that off the top of your head, or should I pivot to the human health assessors?
                  DR. JASON TODD:  Yeah, I might defer to my human health assessors on this one.  But for the 20 days of release, that is the averaging time of the whole release.  So, we have an annual release that's provided, and we divide by those days of release to get a daily release.  But for the risk characterization, I'll defer to my human health colleagues on that one.  
                  DR. REHAN CHOUDHARY:  Okay.  This is, again, Rehan Choudhary.  I'll pivot to Keith Jacobs to see if he can elaborate on that.
                  DR. KEITH JACOBS:  This is Keith Jacobs.  I missed the specifics of the particular question there.
                  DR. WENDY HEIGER-BERNAYS:  Yeah, thank you.  I'm interested in understanding the averaging time for the less than -- I'll say less than daily exposures.  Right.  So, if you've got 20 days, what's the averaging time that you're using in the risk estimates?
                  DR. KEITH JACOBS:  I assume you are referring to for chronic.  For acute scenarios --
                  DR. WENDY HEIGER-BERNAYS:  Yeah, I'm talking about chronic.  
                  DR. KEITH JACOBS:  I will confirm that.  I believe that the averaging time should be the days of release relative to 365 days a year.  Basically, the numerator is release days, and the denominator is days in a year.  I can ask Susanna if she has any clarification.  Susanna Wegner, do you want to clarify anything?  But we can check that also in our files.
                  DR. WENDY HEIGER-BERNAYS:  Sure.  If you could get back to me, that would be great.
                  DR. KEITH JACOBS:  Okay.  Yeah, and Susanna just messaged me that we need to check.  So -- 
                  DR. WENDY HEIGER-BERNAYS:  Okay, thank you so much.
                  DR. KEITH JACOBS:  -- we can get back to you and clarify.  But I'm pretty sure that it's basically release days over days of the year.  And then for cancer, it's a bit different because we also -- as mentioned, typically we account for --
                  DR. WENDY HEIGER-BERNAYS:  Lifetime.
                  DR. KEITH JACOBS:  Lifetime, yeah.  The exposures vectors handbook has a standard value for basically residency time relative to lifetime.  And there were some differences between air and water, but we're going to make those consistent.
                  DR. WENDY HEIGER-BERNAYS:  Okay.  Thank you very much.  
                  DR. REHAN CHOUDHARY:  All right.  Thank you, Keith.
                  DR. DANIEL SCHLENK:  Dr. Kissel.
                  DR. JOHN KISSEL:  Hi, John Kissel.  On page 53 of the version 1.0, there's a permeability coefficient for NMP listed of 4.78 times 10 to the minus 4 centimeters per hour, and it's attributed to Poet.  It's a rat number or it's extrapolated from Poet.  Poet offers a rat number which doesn't have that many significant figures.  It's only 4.7 times 10 to the minus 3.  So, my question is, did you just take a rat number and divide by ten to get a human number, and if so, why are there three significant figures instead of two?
                  And if you didn't do that, what did you do, and why are you using something extrapolated from a rat number instead of a human algorithm which you're using for methylene chloride?  
                  DR. REHAN CHOUDHARY:  Okay.  This is Rehan Choudhary from the EPA, again.  So, if I understood correctly, Dr. Kissel, you are referencing page 53 of the fenceline report?
                  DR. JOHN KISSEL:  Right.
                  DR. REHAN CHOUDHARY:  And you are looking at table 2-7 and asking about the permeability coefficient.
                  DR. JOHN KISSEL:  Yes.
                  DR. REHAN CHOUDHARY:  All right.  And specifically, your question is about we have three significant figures there and how was this parameter incorporated into the risk calculations?
                  DR. JOHN KISSEL:  No, no.  Where did it come from?  So that NMP number, it says in the right-hand column, "Recalibrated from data in Poet."  Poet offers a rat number which is 4.7 times 10 to the minus 3.  So, this might be the rat number divided by ten, which would certainly not be conservative.  But that doesn't make sense because you added an additional significant figure.  So, the origin of that 4.7 times 8 -- times 10 to the minus 4 is mysterious, and that's what I'm asking.
                  DR. REHAN CHOUDHARY:  Okay.
                  DR. JOHN KISSEL:  What is the origin of that number?
                  DR. REHAN CHOUDHARY:  Okay.  Let me first pivot to Jason Todd if he has further clarification on that.  And Jason, if not, we can pivot to our human health assessors. 
                  DR. JASON TODD:  This is Jason Todd, again.  I don't have clarification on that.  That is something that I would have to look at a little bit more to figure out the derivation of that number.
                  DR. REHAN CHOUDHARY:  Okay, Jason.  Let me pivot to Keith or Susanna.  Any input with respect to the number Dr. Kissel is asking about and the Poet and all reference?  I believe the PPK model or so?
                  DR. KEITH JACOBS:  This is Keith Jacobs, EPA.  I think we would -- I would defer to Jason Todd's answer.  We would have to look into how we incorporate it and how we derived that value from the study.  We'd have to look back at all of our Excel files and the derivations of that. 
                  DR. REHAN CHOUDHARY:  Okay, thank you, Keith.  So, Dr. Kissel, I think we'll have to follow up on that question.  But it's been noted.  Thank you.
                  DR. JOHN KISSEL:  Okay.  Thanks.  
                  DR. DANIEL SCHLENK:  Just to follow up, will that information be available this afternoon, or is this something that will require something for tomorrow morning's beginning?  This is to the EPA.
                  DR. REHAN CHOUDHARY:  Well, I think we -- our staff people are trying to look into it as we speak.  So, if they get an answer to us during today, we will relay that back to you.  But if not today, then we would aim to have that available to you tomorrow.
                  DR. DANIEL SCHLENK:  Okay.  Thanks.  Okay, Dr. Calder.
                  DR. RYAN CALDER:  Hi, Ryan Calder speaking.  A lot of the risk calculations turn on parameter values like emission days per year and so on.  And you, in many cases, have maybe one citation for a parameter value like release days per year that are driving all of the exposure assessments.  And the underlying citations don't really seem to have much to do with the specific facilities you're assessing risk from, and they don't even come from the United States in many cases.  And I'm wondering if there's a plan to assess how uncertainty around those values influences screening risk results because, in some cases, they may just be guesses.  
                  DR. REHAN CHOUDHARY:  Dr. Calder, let me see if I understood the correction correctly.  This is, again, Rehan Choudhary from the EPA.  I believe if I refer to the SACC presentation we just gave, slide 11 is kind of talking to the estimating days of release by the various conditions of use or occupational exposure scenarios, and I think what you're saying -- 
                  DR. RYAN CALDER:  Yes -- 
                  DR. REHAN CHOUDHARY:  And you're saying in the report you usually see one reference, or if you dive into it, these are sources that may be international in nature.  I believe the protocol we used here is, we took what we had published in our risk evaluations -- the finalized risk evaluations -- and we carried that forward with respect to assumptions on days of release by various scenarios.  Manufacturing, processing, or other scenarios.  
                  I'm going to pivot to Franklyn Hall to see if he can elaborate on that, but that is my understanding that that is a carry-over from what we did in the risk evaluation.  So even back then the SACC Committee had a chance to review that and comment on that, and we would be looking to the Committee as well to see if you could identify additional sources or methodologies where we could get/have more reflective numbers of those various scenarios or industries.  But let me pivot to Franklyn Hall to see if he wants to add to what I've said.
                  DR. FRANKLYN HALL:  Hi, Dr. Calder.  Yes, so as Rehan said, these release days, or estimated days of release, are provided or presented on an OES basis, and they are from the published risk evaluations.  And primarily the releases that are provided from TRI are provided on an annual basis.  So, we use these estimated days of release from sources such as generic scenarios and emission scenario documents, which again are from the published risk evaluations, to try to develop a daily release.  
                  We are certainly open to getting further feedback on that approach.  Hoping that's answered your question.  If not, please certainly follow up if I have not answered your question adequately.
                  DR. RYAN CALDER:  Okay.  Thank you.
                  DR. DANIEL SCHLENK:  Okay.  Dr. Apte.
                  DR. UDAYAN APTE:  Yeah, hi.  This Udayan Apte.  My question is about the fenceline definition of 10,000 meters for air and then the water.  I was looking at the report, and it basically says that this was decided because beyond 10,000 meters other EPA jurisdiction takes over.  It also says in the introduction that this is associated with professional opinion that beyond 10,000 meters there is less concentration.  
                  I'm just wondering what kind of data were used to come to that conclusion based on -- what was it based on, basically?
                  DR. REHAN CHOUDHARY:  Thank you for the question.  This is Rehan Choudhary from the EPA, again.  I will provide an initial response to that and then pivot to Kevin Vuilleumier to see if he wants to elaborate.  You are correct.  In the report, or the presentation itself, we lay out what we consider to be fenceline communities.  And I believe you're asking on the air pathway side what kind of helped us to come to initially 10,000 meters. 
                  DR. UDAYAN APTE:  Yes, sir.
                  DR. REHAN CHOUDHARY:  I think we mentioned in the report that based on past modeling experiences, having done past assessments, the professional judgment was that people usually see the risks dying out around, I believe, 1,000 meters.  But because we had consulted other offices at EPA, they suggested going farther out to characterize, well, even if it's dying out, going further out would help you to better understand how quickly or slowly it dies out.  
                  So, we took that professional judgment of about of 1,000 meters, and we took it out of an order of magnitude.  So that was the genesis behind that.  Kevin, do you want to add to that?
                  DR. KEVIN VUILLEUMIER:  Thank you, Rehan.  This is Kevin Vuilleumier from EPA.  Rehan pretty much captured it.  One thing I'll add to it is we chose 10,000 meters.  We didn't indicate that anything farther than that would be addressed by other statutes or other programs.  We just selected that as a limitation for our boundary of fenceline community.  However, with regards to the fenceline methodology itself, it's not limited to only 10,000 meters.  We can go out much farther and see what the impacts are farther out.
                  One thing that you may be driving toward is you can sometimes see risks much farther out that you don't see closer in.  That's dependent on the stack parameters.  If you have a much higher stack, it's going to carry much farther, right?  So, in that aspect, since we have limited our stack heights to the defaults of ten meters of low plume, that's why we also kept it within the bounds of 10,000 meters.  But we can go out farther, especially if, like, risk is indicated out toward that distance and recognize that it can be affected with much larger stacks.  
                  DR. UDAYAN APTE:  I have one related question to this, again, and then this is really about double exposure in a way.  So, there is possibility of a lot of those workers occupational exposure, that are having occupational exposure in the facility, may live within the fenceline community.  And so, they essentially are double exposed.  I was wondering has that been considered?
                  DR. DANIEL SCHLENK:  That was Dr. Apte, again.
                  DR. REHAN CHOUDHARY:  Okay.  This is Rehan Choudhary, again, from the EPA.  So, you are correct in that those kinds of exposures can happen where someone may be exposed while they are working at a facility and then they live close by -- they're part of fenceline community.  The version 1.0 does not take that into account.  Right now, it's delineating what the exposure would be if you're within this fenceline distance.  We have not attempted to aggregate those exposures from those various conditions.
                  DR. UDAYAN APTE:  Thank you.  That is very -- that solves my problem.  Thank you.
                  DR. DANIEL SCHLENK:  Okay.  Dr. Li.
                  DR. LI LI:  Li, thanks.  So, I have two clarification questions.  Of course, thank you so much for the fantastic presentation.  Of course, this is very thorough and lots of considerations, and you handle this very well.  So, I have two questions.  The first question is my understanding is that the assessments were largely based on the 2019 TRI data, but you also mentioned a case that you don't have the 2019 TRI data.  But you have multiple years of TRI data before 2019.
                  So, I'm not sure whether you have some general rules for us to select the data between the different years other than 2019.  For example, in some cases you use the maximum data for previous years, but in the case of 1-BP you select the central tendency -- that's the 50th percentile -- and the maximum of the data for the past years.
                  So, I wonder, for example, in terms of the future assessment whether these two data points are recommended for use in the future assessments or whether the risk assessors have their own descriptions to prioritize the data selected for the future assessments.  
                  DR. REHAN CHOUDHARY:  All right, Dr. Li.  Thank you for your question.  Again, this is Rehan Choudhary from the EPA.  I believe you're first asking about use of 2019 TRI, and then in certain instances, other data sources are used to estimate releases.  I believe slide 12 of our presentation helps you to understand what we do and the general hierarchy we follow when we don't have 2019 TRI data.  That slide 12, specifically, refers you to the section in the report that also elaborates on the hierarchy that is used.  
                  So that'll give you a good understanding of when we don't have 2019 data how we go about the various steps and logic to reference other data sets or sources.  I believe you're also asking about, in some cases, we use central tendency and maximum release estimates.  But it goes back to what Kevin Vuilleumier was presenting.  
                  There's a prescreening methodology, and there's the full screening methodology.  And I believe in the prescreening methodology where they're using the IIOAC tool, they take a look at TRI reporting.  They kind of characterize central tendency and high or maximum release, and they put that through their prescreening result to try and understand whether we should proceed to the full screening.
                  So that's my understanding of your question.  I'm going to pivot now to Kevin Vuilleumier to see if he wanted to add to what I've said with respect to the prescreening versus full screening. 
                  DR. KEVIN VUILLEUMIER:  This is Kevin Vuilleumier from EPA.  Yes, Rehan, I think he answered it well.  Did that answer your question, Dr. Li, that you were pursuing?
                  DR. LI LI:  Yes.  I understand the difference between the 2019 data and the years before 2019.  So, I was wondering if you have multiple years of data before 2019 and how did you decide which one should gain the priority?
                  DR. REHAN CHOUDHARY:  Okay.  So, let me pivot to Franklyn Hall to focus on that aspect of it.
                  DR. DANIEL SCHLENK:  That was Dr. Choudhary.
                  DR. FRANKLYN HALL:  Hi, Dr. Li, this is Franklyn Hall, EPA.  So, as Rehan has indicated, we would first try to extract 2019 TRI data.  If that data's unavailable, then we looked at previous years, I believe, from different TRI, and we would go back sequentially.  So, if there wasn't 2019 data, we'd look for 2018, 2017, et cetera.  So that is generally how we would approach trying to fill the data gaps for TRI data that was not available for 2019.  
                  However, I believe that we are asking the Committee to provide comment on whether or not one year's of release data is appropriate, or whether or not there are suggestions or proposals to incorporate previous years of TRI data to encompass -- I think what you're trying to get at -- which is the variability that could occur over multiple reporting years.  Does that answer your question?
                  DR. LI LI:  Yes, yes, yes.  That answers question.
                  DR. FRANKLYN HALL:  Okay.
                  DR. LI LI:  Yeah.  So, I have another question.  The second question is so, of course, you mentioned when 2019 TRI data are missing, and you recommend to give the priority to modeling results to compare to the existing literature resources, for example, in published risk assessment.  So, for example, you gave the higher priority to modern results rather than the trinity consult report used for 1-BP.  So, I was wondering about the justification for the higher priority given to the modeling result.
                  DR. REHAN CHOUDHARY:  Okay.  This is, again, Rehan Choudhary from the EPA.  I believe the hierarchy you're referring to the -- correct, use of modeling is then presented after use of past year data, and I believe the genesis behind that is the models themselves are incorporated in the risk evaluations that were completed.  So, they completed peer review.  So that's why, I believe, they were placed higher in the hierarchy.
                  And then, if there were references or sources cited in the risk evaluations, we then turn to those.  But let me pivot to Franklyn Hall to see if he wants to elaborate or correct me if I've misspoken on any items.
                  DR. FRANKLYN HALL:  I think Rehan has captured it appropriately, Dr. Li.  It's exactly as he's indicated in terms of the preference for model data versus what we cited in literature.
                  DR. LI LI:  Okay.  Thanks.  I have no more question.
                  DR. REHAN CHOUDHARY:  Thank you.
                  DR. DANIEL SCHLENK:  Okay.  Thanks.  Dr. Unseld.
                  DR. MONICA UNSELD:  Yes, this is Monica Unseld.  Again, thank you for the presentation.  You did a great job.  And I understand that this is just a starting point.  I would like to know how much or how often did you engage with disproportionately impacted communities, or fenceline communities, to make sure that the assumptions in your models and the equations were reflective of real life.  
                  I just was trying to see, if the modeling is beginning and it's already at a point where it's so far away from reality, are we going to have to take some back steps here to make it more robust?
                  DR. REHAN CHOUDHARY:  So, thank you for the question.  This is, again, Rehan Choudhary from the EPA.  I believe when the effort launched, we made efforts to consult with the Office of Environmental Justice, Office of Air, Office of Water to try and learn from their experiences and share our thoughts on how we were structuring the approach.  As the approach became more concrete, so to speak, in that we had something to put on paper and we started -- and we had draft results, we then did meet with various stakeholder groups to relay and communicate what we were finding.
                  And based on those interactions, we received feedback on, well, the current approach doesn't maybe take a look at one-time events.  It would be good if you can elaborate and take a look at one-time events and the acute exposures and risks that occur from that.  They commented on the use of TRI data and how just taking annual releases and dividing by the number of days may not appropriately capture these one-time events.  So, that's the nature of the interaction we've had so far.
                  It's a start, and we hope to engage much more with those stakeholders as we've entered this public comment and SACC review phase.  
                  DR. MONICA UNSELD:  A follow-up question -- this is Monica Unseld again.  Are you considering looking at some of the emerging models to integrate lived experience data in order to capture that?  Are you considering that for version 2.0?
                  DR. REHAN CHOUDHARY:  This is Rehan Choudhary from the EPA, again.  This is, again, something we're looking forward to understanding, based on what the SACC Committee itself says and what the public provides to us.  What we've provided is that version 1.0 -- it's through readily available data and methods that were available to us, and I think we're relying on the SACC Committee itself and experts in the public to drive our attention and focus to newer capabilities, emerging capabilities for version 2.0.
                  DR. MONICA UNSELD:  Thank you.  That answers my question. 
                  DR. DANIEL SCHLENK:  Thanks.  Dr. Ferry.
                  DR. JOHN FERRY:  I have a question, not so much about what you showed in your presentation, which I really appreciated, but something that I wonder about might be missing.  I didn't see any consideration of transport venues off-site that you -- I guess I didn't -- sorry, I'm not expressing this very well.  I was curious about criteria that you used to reject consideration of some factors.  So, for example, in the model you're presenting this for version 1.0, we have transport through the gas phase.  We have transport through the aqueous phase, but there's no transport, for example, say, associated with dust which could be very significant for some other contaminants, not necessarily in this.
                  So, I was curious.  Could you explain a little bit about how you decided to reject looking at some pathways?
                  DR. REHAN CHOUDHARY:  This is, again, Rehan Choudhary from the EPA.  I think this is largely a scope and pathway kind of question in that there was a policy shift and that we had not looked at certain pathways when we completed the risk evaluations a year or two ago.  And we know there are more pathways that we did not examine.  But in this version 1.0, the initial thought was to focus on certain air pathways and water pathways with many of the substances we're looking at from the first ten risk evaluations being volatile solvents.
                  I don't think we've excluded the notion of examining dust emissions and what dust would do.  It just wasn't relevant to the case studies and chemicals we're focusing on right now.  And I think if you're able to focus in on the methodology and capability itself and drive to our attention how it could be expanded to address scenarios you have in mind, we would certainly welcome that.  Let me pivot to Kevin Vuilleumier to see if he wants to add to your question about the dust pathway or the settling of dust or things of that nature.
                  DR. KEVIN VUILLEUMIER:  Thank you, Rehan.  This is Kevin Vuilleumier from EPA.  Yeah, Rehan kind of hit the nail on the head.  When we're looking at the air pathway, most of the solvents for the first ten that were taking the screening level approach to look at are VOCs; they're volatile compounds.  However, one of the benefits of the methodologies that we put together and using AERMOD as we noted to a previous comment, it can factor in considerations of dust.  It takes in -- AERMOD can consider deposition.  It can consider evaporations from lakes.  So, there's a lot of other factors that we can take into account moving forward as it applies to different chemicals that maybe need to be evaluated. 
                  So, in the initial approach, the focus was on the seven chemicals we were doing which were mainly VOCs, so we didn't really look at particulate.  But we have the capabilities to look at that moving forward.  As you noted, other chemicals that aren't so volatile thus can be very large contributor.  So, we are able to do that, and that would be considered on a chemical-by-chemical basis as we move forward as to where you may have different impacts from different phases of the chemical.
                  DR. JOHN FERRY:  Okay.  I guess -- and I'm sorry if I'm not articulating it well.  But what I'm curious about really is did you start off with a goal?  So, are (audio skip) export parameters from the site that account for say 90 percent of the releases; 95 percent, 50 percent?  Could you help sort of clarify that a little, please?
                  DR. REHAN CHOUDHARY:  This is Rehan Choudhary from the EPA, again.  I think goal-wise it's based on the scope that was provided to the team.  It was framed as let's examine the ambient air pathway and the surface water pathway.  And so, when we had that framed that way, we took a look at the risk evaluations and as we had published them, right?  We took a look at aquatic exposures in those completed risk evaluations.
                  So, we reused the release assessments from those completed risk evaluations for the water pathway to take a look at surface water concentrations and impact to humans.  In the previous completed risk evaluations, we didn't take a look at the air pathway -- the ambient air pathway.  So here, we took a look at what are some readily available sources?  We gravitated towards the TRI, and we took a look at fugitive and stack releases from TRI.  And we characterized what ambient air concentrations look like from these releases to estimate what the impacts on receptors may be nearby.
                  So that's how the scope to the team came about and how they focused on elaborating on that scope and getting initial draft results in place.  
                  DR. JOHN FERRY:  Thank you.  
                  DR. DANIEL SCHLENK:  Okay.  Thanks for the questions.  Any other questions of clarification that we can bring forward to the Agency?  Okay.  With that in mind, at this point let's go ahead a take an East Coast break for an hour.  So, let's reconvene at 40 past the hour -- one hour from now -- and then reconvene for our public commenters period.  Thank you.  
                    
                                 [LUNCH BREAK]
                  DR. DANIEL SCHLENK:  Okay.  I have 20 minutes till.  Let's go ahead and reconvene the Committee.  At this point in time we'll go ahead and do a roll call for Committee members.  So if you could just answer present, that would he fantastic.  Let's begin with Dr. Apte.
                  DR. UDAYAN APTE:  Present.
                  DR. DANIEL SCHLENK:  Great.  Dr. Baker.
                  DR. MARISSA BAKER:  Present.
                  DR. DANIEL SCHLENK:  Dr. Blystone.
                  DR. SHERI BLYSTONE:  Present.
                  DR. DANIEL SCHLENK:  Dr. Calder.
                  DR. RYAN CALDER:  Present.
                  DR. DANIEL SCHLENK:  Dr. Chaisson.  Dr. Chaisson.  Hello?  Okay.  Dr. Cobb.
                  DR. GEORGE P. COBB:  Yep.
                  DR. DANIEL SCHLENK:  Dr. Davies.
                  DR. HOLLY DAVIES:  Present.
                  DR. DANIEL SCHLENK:  Dr. Doucette.
                  DR. WILLIAM DOUCETTE:  Present.
                  DR. DANIEL SCHLENK:  Dr. Ferry.
                  DR. JOHN L. FERRY:  Present.
                  DR. DANIEL SCHLENK:  Dr. Gribble.
                  DR. MATTHEW O. GRIBBLE:  Hello.
                  DR. DANIEL SCHLENK:  Dr. Heiger-Bernays.
                  DR. WENDY HEIGER-BERNAYS:  Present.
                  DR. DANIEL SCHLENK:  Dr. Henneman.
                  DR. LUCAS HENNEMAN:  Present.
                  DR. DANIEL SCHLENK:  Dr. Johnson.
                  DR. MARK JOHNSON:  Present.
                  DR. DANIEL SCHLENK:  Dr. Kissel.
                  DR. JOHN KISSEL:  Present.
                  DR. DANIEL SCHLENK:  Dr. Li.  Dr. Li.  Okay.  Dr. Messerlian.  Dr. Messerlian.  Okay.  Dr. Przybyla.
                  DR. JENNIFER PRZYBYLA:  Present.
                  DR. DANIEL SCHLENK:  Great.  Dr. Reif.  Dr. Reif?  Dr. Reiss.
                  DR. RICK REISS:  Present.  
                  DR. DANIEL SCHLENK:  Dr. Rowlands.  Dr. Rowlands.  Okay.  Dr. Sathyanarayana.  Dr. Sathyanarayana.  Okay.  Dr. Unseld.
                  DR. MONICA UNSELD:  Present.
                  DR. DANIEL SCHLENK:  Dr. Vorhees.
                  DR. CHARLES V. VORHEES:  Present.
                  DR. DANIEL SCHLENK:  Great.  Let's go back up.  Dr. Chaisson.  Dr. Chaisson.  Okay.  Still not, and Dr. Li?  Have you joined us yet?  Dr. Messerlian.  Dr. Reif.  Okay.  I think we have enough for a quorum to proceed at this point.  Dr. Rowlands, have you joined us yet?  Still not there.  Okay.  At this point in time, it is time for our public commenting period.  We have a number of public commentors that I've been provided a list of.  
                  Let me remind the public commenters that we basically have to hold you to a five minute presentation time period.  If you exceed that, I'll just let you know ahead of time when that's coming.  And we can move forward with that.  Okay.  With that in mind, let's go ahead and begin with our first public commenters.  This is going to be Dan Baker, who's from the Environmental Reaction Engineering Experts Consulting.
                  
PUBLIC COMMENTS
                  
                  MR. DAN BAKER:  Hi.  My name is Dan Baker, and I am currently consulting with a consortium of stakeholder chemical companies.  For over 30 years I have been involved in air quality programs serving as the committee chair for the American Petroleum Institute and for the coordinating research council.  I have evaluated hundreds of projects with one of the criteria being their likelihood of delivering a credible and useful end product.  
                  In my professional judgement I would not have released this version in its current form.  The reasons why will become clear as I go through the charge questions.  I'll focus on questions 2 and 3 to be brief, while my written comments will cover all four questions.  Regarding Charge Question 2, while I do believe that all potential risk will be captured through the screening approach, I don't think a definitive answer can be given because, in my judgement, the range over which this ambitious screening approach is intended to encompass is much too broad in multiple ways.  I'll mention one here.  
                  The types of TRI reporting facilities are too broad, ranging from large multi-emission source manufacturing facilities, many with green space buffer zones, to small one or two emission source specialty businesses embedded in populated neighborhoods.  It is unreasonable to expect a generic fugitive and stacked dual characterization to represent the full diversity of facilities.  Consequently, this screening approach, version 1.0, does little to inform on risk.   
                  Specifically, it does little to differentiate between real potential for risk and highly improbable potential for risk.  Additional tiers of refinement focusing on emissions, source characterization, and population activity patterns are all needed to substantially reduce uncertainty before considering risk-based decisions that would likely result in misutilization of limited resources.  
                  For Charge Question 3 there are several much needed improvements.  I'll focus on one here, namely source characterization.  The EPA is well-aware that stack height has the greatest impact on predicted concentrations of air pollutants, as cited in EPA documents from the 90s that reviewed stack heights by SIC codes, with median heights as high as 40 meters.  For comparison, a 40 meter stack height compared to a 10 meter median stack height reduces peak concentration by a factor of 20.  And the peak occurs four times further downwind.
                  Stack height upper and lower quartiles were not provided, just medians in those documents.  A full display of the data could be available if those records were retained.  In addition, a simple two stack non-merging plumes scenario with a median height of still 10 meters, centered around the facility midpoint, reduces downwind concentration significantly over the entire receptor field, except the very near field.  The combination of potentially misrepresenting stack heights and their spatial distribution can result in roughly two orders of magnitude of uncertainty.
                  Furthermore, if the emissions are actually from a flare at 40 meter height -- and TRI chemicals can have significant flare emissions -- then the peak concentration is reduced two orders of magnitude and occurs five times further downwind.  Clearly flares, as reported in TRI Part 2, Section 7A, Column B, need to be distinguished from stacks.  With regard to TRI chemicals that are also hazardous air pollutants, these are already well modeled using a hybrid approach and air tox screen.  
                  All sources are considered, which allows for model to monitoring data comparison, a key ground truthing step that unfortunately is not part of this current effort.  Finally, other overlapping EPA and state programs could play a much needed role in restructuring and improving this current effort to avoid focusing on highly improbable potential for risk.  Thank you.
                  DR. DANIEL SCHLENK:  Thank you, Mr. Baker.  Any questions from the Committee?  Okay.  Our next presenter is Xavier Barasa (phonetic) from the EJ Leadership Team.  Mr. Barasa?  I'm not hearing you.  Okay.  I guess we will go to the next speaker, which is Uni Blake from the American Petroleum Institute.  Mr. Blake, or Ms. Blake.  There you go.  Oh, thank you. 
                  MS. UNI BLAKE:  So, thank you members of, yeah, here I am.  Thank you.  So thank you members of the SACC and EPA for hosting this meeting.  My name is Uni Blake.  I'm a senior policy advisor here at the American Petroleum Institute.  So API is the only national trade association representing all facets of the oil and natural gas industry.  As such, all members are affected by many of EPA's activities under the amended TSCA.  
                  We applaud EPA's desire to continue advancing the Agency's capabilities to improve methodology to ensure scientifically rigorous approach is used to evaluate risk.  So we support the development and use of sound and well-defined methods for identifying potential health risks associated with fenceline exposures.  However, incorporating exposures for fenceline populations has introduced a layer of complexity into TSCA risk evaluations that are potentially beyond this program's scope, for example, the influence of local specific factors.  
                  So, as defined by the EPA, fenceline exposures occur within 10,000 meters of a facility.  At those distance, local specific factors, such as stack height -- like the previous speaker talked about -- topography, meteorology influence, atmospheric concentrations of a facilities emissions -- these factors are essential input parameters into AERMOD, which is the program that EPA is using.  They influence the dispersion of the emissions.  And so pairing a sophisticated air model with generic assumption can lead to a labor intensive exercise with results that could not reliably support risk management options.  
                  We are also very concerned about the data that's being inputted into the models.  TRI data are typically used across several different EPA risk screening models to provide a broad perspective of potential risk, typically in the context of prioritization.  There are known limitations related to the use of TRI data, as identified by the EPA in their draft document.  Therefore, the data should not be used for making risk determinations.  
                  EPA should consider confirming exposure data information directly with the affected facilities and confirming any extrapolation assumptions that they made when the TRI data was missing or unclear.  The Agency also needs to clarify how they interpret and use the risk findings.  For example, if a second level screening assessment resulted in only one facility having potential risk indicators for an OES, what will the next steps be?  
                  What if there are cases where risk estimates from a second level screening result in sufficiently high exposures across a majority of facilities?  Will a more refined assessment be necessary?  The Agency could consider developing a decision tree that illustrates how EPA could utilize different risk results in a risk management paradigm.  We urge EPA and the TSCA 9 to consult and coordinate with other agency programs as well as other federal and state offices to avoid duplicative requirements.  
                  For example, fenceline exposures are already regulated under the Clean Air Act Section 1112.  As under Section 1112, a substance can be added to the air toxic either by petition or on the administrators determination.  So, in closing, we are asking EPA to clarify how the Agency intends to address uncertainty and complexity introduced into the fenceline screening method by data limitations and the varying exposure profiles that results, in some cases, in differences in orders of magnitude.  
                  We also urge EPA to continue engaging with industry as the industry can serve as a resource to develop practical and streamlined approaches to screen out condition of uses that do not present risk and help identify the remaining COUs for which additional data or modeling is needed to make risk determinations before recommending risk management measures.  Again, thank you very much for this opportunity.
                  DR. DANIEL SCHLENK:  Thank you.  Any questions from the Committee?
                  DR. MONICA UNSELD:  I have one.  This is Monica Unseld.  You mentioned several -- more than once that the EPA should engage with facilities and industry.  I was wondering how often industry is engaging with the communities -- the fenceline communities, so we can see if we can get a data set that tells the entire story.
                  MS. UNI BLAKE:  Thank you very much for your question.  We do have community engagement programs in place for our members that they utilize to engage with the community.  Most of our facilities are located in communities.  They are, for example, CAT programs that refineries use to engage with the communities.  There are several different avenues that the industry has used.  I will gladly share that information with you once I get off this opportunity.  Thank you for the question though.
                  DR. MONICA UNSELD:  Yes, and as a follow-up, could you also, if you have it available -- how you would deal with discrepancies in what the communities are reporting and what the industry is reporting?  So, if you have that available, please make that available.
                  MS. UNI BLAKE:  Yeah, of course.  Thank you.  Thank you for the questions.
                  DR. DANIEL SCHLENK:  Any other questions?  Yep, Dr. Doucette?
                  DR. WILLIAM DOUCETTE:  Yeah, I had a related question regarding fenceline monitoring.  There are fenceline monitoring requirements for refineries, specifically benzene and, in Canada, benzene and a variety of VOCs.  In your opinion, do you think this data could be used to evaluate or validate the screening approach that EPA is proposing?
                  MS. UNI BLAKE:  I believe in my comments I kind of touch a little bit on that.  
                  DR. WILLIAM DOUCETTE:  I was hoping you could expand.
                  MS. UNI BLAKE:  Yeah.  No.  Okay.  So, yes, I believe yes, it could help identifying exposures that occur at the fenceline.  But I'm not sure which program this would fall under.  Whether it would be the TSCA Chemical Management Program or it'll be through the Air Toxics Program.  What we're just trying to do is avoid duplicative reporting.  It makes it challenging for us to operate.
                  DR. WILLIAM DOUCETTE:  Thank you.
                  DR. DANIEL SCHLENK:  Okay.  Thank you.  With that we'll go ahead and move on to our next speaker, which is Eboni Cochran from REACT.
                  MS. EBONI COCHRAN:  Hello, my name is Eboni Neal Cochran and I'm a resident of the Chickasaw Neighborhood in Louisville, Kentucky.  Chickasaw is one of numerous neighborhoods adjacent to a cluster of Title V chemical facilities commonly referred to as Rubber Town.  For over eight decades residents have been adversely impacted by excess emissions, explosions, fires, noxious odors, and acute and chronic illness and deaths, some of which they attribute to Rubber Town chemical facilities.  
                  This is not to mention railcars parked in neighborhoods and sources of pollution that result in cumulative impacts.  After looking into what the EPA will consider when assessing exposure to chemicals I became concerned.  I'm concerned because the TSCA fenceline assessment tool, as designed now, does not provide a complete picture of how people living, learning, visiting, worshipping, and working in impacted neighborhoods are affected by chemical exposure.  
                  Not considering risk from chemical disasters, facility malfunctions, and other peak emissions leaves my community vulnerable because it doesn't take into effect the numerous instances in which chemical facilities in my neighborhood report malfunctions resulting in excess emissions, not to mention the big incidents, like one in which there was a power outage causing a hydrochloric acid spill in my neighborhood.  
                  My understanding is that the screening tool wouldn't consider this when accessing risk.  Not considering risk from soil and groundwater leaves my community vulnerable.  In Chickasaw Park, chemicals were found in the sediment of the lake and the fish.  Children play there, and people often fish there.  We suspect they eat what they catch.  My understanding is that this exposure would not be considered.  
                  Not far from where I live is a wastewater pool that has a liquid leaking from pipes extending from its side into adjacent ditches.  That liquid is soaking into the soil.  My understanding is that this exposure is not going to be considered.  Not too long ago a woman called me distraught because in her neighborhood chemicals were found to have migrated through the soil into their yards.  That exposure is not being considered.  
                  Think about that.  We know the soil is contaminated, but the EPA is going to turn their backs on this family because why?  Because it's more convenient?  Because they're taking the easy way out?  What is the point of spending time, money, and other resources on a tool when the tool does not reflect what my community and other communities around this country are exposed to?  Why is the EPA willing to work with industry using their numbers to assess risk but not also relying on impacted communities to show them exactly what they are being exposed to?  
                  American Synthetic Rubber Company is a prime example of why the EPA should not rely solely on industry self-reporting.  For years, the company has been considered one of the main contributors of 1,3-Butadiene in the community.  They denied it.  This was back in 2003, I believe.  Then came their period of shutdown.  Air monitoring revealed that levels of 1,3-Butadiene reduced significantly during their shutdown.  And at that point they could no longer deny it.  
                  This is just one of the numerous examples as to why solely depending on self-reported numbers is not a good idea.  We need a comprehensive tool that reflects actual pathways of exposure.  By limiting the pathways to the air and surface, the EPA is watering down the atrocities my community experiences every day.  What we need is for the EPA to be on the ground, working with us to identify all known pathways of exposure.  
                  We need the EPA to begin speaking in terms of cumulative impacts because that is the reality.  We need the EPA to consider the most vulnerable in our neighborhoods, like our elders, our children, and those with ailments that make them more susceptible to chemical exposure.  These are all commonsense asks.  You don't have to be a chemist, biologist, physician, or engineer to understand this.  You just have to have compassion for the people who are being impacted by chemicals they didn't ask to be exposed to.  
                  If TSCA requires the EPA to identify and then eliminate unreasonable risks from chemicals, how will they meet this requirement without the most complete picture?  Please help us, and, with a sense of urgency, please do what you can to ensure all of our communities become safer places to live.  Thank you.  And I do -- I want to say that I appreciate that you all allowed five minutes instead of three because three is definitely -- you know, makes you rush through and all of that.  So, I do appreciate it.  Thank you.
                  DR. DANIEL SCHLENK:  Thank you for your presentation.  Any questions from the Committee?  Okay.  Let's go ahead and move on to -- our next speaker is Dr. Paul DeLeo from the American Chemistry Council.
                  DR. PAUL DELEO:  Thanks, Dan, and good afternoon.  My name's Paul DeLeo.  I'm a senior director in the Regulatory And Scientific Affairs Department at the American Chemistry Council.  ACC is a U.S.-based trade association of about 160 companies, more than half of which are small and medium-sized businesses.  More importantly, our members have facilities in communities across the country that employ hundreds of thousands of Americans.  
                  Our members' facilities in the U.S. are subject to numerous federal statutes and regulations, including the Toxic Substances Control Act.  And ACC strenuously advocated for the 2016 Lautenberg Amendments to TSCA with a desire to foster greater confidence among Americans regarding the safety of chemicals in commerce.  In much the same way, ACC is eager to see an approach adopted for evaluating general population exposures to high priority chemicals that consider exposures to fenceline communities adjacent to facilities manufacturing and using those chemicals.  
                  ACC members manufacture, process, or use many of the chemicals for which EPA conducted the first ten risk evaluations that this Committee has previously reviewed.  Therefore, we look forward to the expertise and insights that SACC can provide to EPA as it refines its fenceline approach.  The SACC has been tasked with conducting a peer review of the recent EPA draft TSCA screening level approach for assessing ambient air and water exposures to fenceline communities.  
                  The review by the SACC is critical to producing a transparent and workable framework as EPA will review the SACC's recommendations and develop a final method.  Finalized screening level approach would be applied to seven of the first ten chemicals for which EPA published risk evaluations between 2020 and 2021.  And the final screening level approach will also be applied to future chemicals undergoing risk evaluation under TSCA Section 6.  ACC has submitted written comments in advance of this meeting, however, we'd like to emphasize several points.  
                  First, understanding general population exposures of which fenceline exposures may be a component is an important aspect of the risk evaluation process.  However, the exposure assessment should be developed in a manner consistent with the current longstanding EPA guidance.  EPA's exposure assessment guidelines recommend completing exposure assessments iteratively using a tiered approach to strike a balance between the cost of adding detail and refinement to an assessment and the benefits associated with that additional refinement.  
                  The same is true with the screening level approach.  EPA should develop a tiered exposure assessment methodology that is part of a larger decision tree that guides the actions that would be taken as part of the assessment.  An explicit tiered approach would provide transparency to stakeholders regarding EPA's decision making process.  We believe the use of a tiered approach would result in efficiencies that would counterbalance potential additional effort associated with higher tier refinement, when needed, and achieve the EPA's mission of safeguarding communities and their surrounding environs.  
                  Second, the screening level approach should include steps where existing data analyses and expertise are incorporated into the assessment.  For example, six of the seven chemicals that are, or will be, subject to the screening level approach are hazardous air pollutants under the Clean Air Act, which means they're existing or pending national emissions standards for hazardous air pollutants for most of these chemicals.  
                  As such, there's a tremendous amount of data, expertise, and activity that can be found within EPA's Office of Air and state agencies implementing the Clean Air Act that should be weaved into the screening level approach.  For example, only two weeks ago the Office of Air released an update to its Air Tox Screen model.  EPA describes the Air Tox Screen model as being part of its new approach to air toxics that provides updated data and risk analyses on an annual basis to assist state, local, and tribal agencies, EPA, and the public in more easily identifying existing and emerging air toxics issues.  
                  The EPA TSCA Office should discuss their current or planned engagement with the EPA Office of Air and other experts as part of the development of the screening level approach.  Finally, the data used in the screening level approach, such as the TRI data, are critical and influential components of the outcome of the analysis.  So those data need to be subject to a data quality assessment so that the variability and uncertainties associated with them are well-understood and documented and accounted for.  
                  We believe that the TRI data, while valuable for some purposes, are not sufficiently reliable to serve as the basis for a determination of unreasonable risk under TSCA.  ACC appreciates the opportunity to provide comments on the screening level approach.  And we'd like to thank you, the members of the SACC, for your contribution to this important activity.  Thanks.  Thanks, Dan.
                  DR. DANIEL SCHLENK:  Thank you.  Any questions from the Committee?
                  DR. MONICA UNSELD:  I do.  This is Monica Unseld again.  Thank you for your comments.  This is more of a request for information, if you have it.  Since we have the health data to know that there is a sense of urgency to protect these communities, could you provide us with any actions that the EPA could take to not delay protecting communities while we refine the methodology?  So, with the tiered approach, how long is that going to take?  If we're not using TRI data, what can we use so that we can protect public health?  Because that is one of the missions points of the EPA.
                  DR. PAUL DELEO:  Right.  Yeah, yeah, and I think that, again, there are many other activities outside of the TSCA Office that are currently in place.  And those are places where you might want to consider looking.  And I'm hoping that EPA will talk a little bit more about how they're interacting with those other parts of its own agency and some state agencies.
                  DR. MONICA UNSELD:  Okay.  Thank you.  This is Monica again.  I was asking because you mentioned the tiered approach, and we are aware of how EPA is working with other offices.  But we just want to make sure that, as we refine this, do you have any tips for us on how we can make it better, more sound science, without people getting sick if they don't have to be?
                  DR. PAUL DELEO:  Right, right.  I think, again, part of the tiered approach is taking efforts -- avoiding spending your time on things that are going to be insignificant exposures and focusing your time on those cases where you might clearly have a concern regarding exposure.  I was just looking today at the data on methylene chloride, and something like 0.03 percent of the 390,000 water samples had levels of methylene chloride above the standard, the MCL. 
                  And I'm just kind of curious.  Is that sufficient to say we don't need to look at drinking water exposures to methylene chloride, or is it even that 0.03 percent is too much to be considered?  I think there has to be some decision making and some criteria on decision making that needs to be incorporated.  Otherwise, you're just spending all your resources going round and round and trying to follow each molecule without getting to those decisions and taking action, as you point out.
                  DR. DANIEL SCHLENK:  Okay.  Thank you.  Dr. Johnson, you have your hand up.
                  DR. MARK JOHNSON:  Yes, sir.  Quick question.
                  DR. DANIEL SCHLENK:  Sure.
                  DR. MARK JOHNSON:  Mr. DeLeo, are you familiar with the guidance documents that the EPA has for incinerator permitting?
                  DR. PAUL DELEO:  Not personally, no, not so much I'm afraid.
                  DR. MARK JOHNSON:  Okay.  I was thinking maybe that was what you were kind of alluding to because they use sort of a tiered process as well.  And they look at worst-case assumptions.  And they don't have TRI data to build from.  So I was just wondering --
                  DR. PAUL DELEO:  Yeah, I think there are a number of federal programs where you have this sort of tiered approach.  I'm more familiar on the food safety side.  You look at exposures and based on the exposures that tells you how much data do I need to go onto the next step and just those kinds of ideas -- marrying understanding of the situation with the level of effort.  I personally would like to see more of that weaved into this process so that there's an efficient use of the Agency's resources.
                  DR. MARK JOHNSON:  Thank you.
                  DR. DANIEL SCHLENK:  Dr. Gribble.
                  DR. MATTHEW O. GRIBBLE:  Thank you.  This is Matt Gribble from University of Alabama at Birmingham as an ad hoc member of the SACC.  I'm just hoping for a clarification on scope.  So I understand that we're responding to all public comments, and Dr. DeLeo's comments are welcome and appreciated.  But a lot of them had to do rather with the programmatic aspects of what EPA might do with limited resources, rather than technical criticism of the draft policy, the screening framework.  
                  And I'm wondering is this conversation for the SACC's summary of the technical review of this supposed to include programmatic considerations of where resources are better spent or worst spent?  It seems like that might be a separate conversation from what we're tasked with focusing on in our charge questions.  But I would defer to EPA staff on whether we're moving a little outside scope.
                  DR. DANIEL SCHLENK:  I can respond to that, Dr. Gribble.  This is a period of time where the public is basically commenting on the presentation that the EPA has made.  So they're welcome to present anything they wish to present at this particular time for five minutes.  You're welcome to incorporate those responses into your comments for the questions that the EPA has provided.  
                  That's the purpose of this particular period right now.  If you have questions for the commenters -- for the presenters regarding information that will help you provide a better assessment of the questions that the EPA has provided to you, then feel free to ask questions about that.
                  DR. MATTHEW O. GRIBBLE:  Thank you for clarifying.  This is my first time doing this.
                  DR. DANIEL SCHLENK:  No worries.
                  DR. PAUL DELEO:  Yeah, and, Dan, if I may real quickly just I think programmatically we expect this assessment to be conducted.  But I think you in the SACC can help in helping the Agency focus its resources by determining criteria to when is enough enough of an assessment?  That sort of thing.  So thanks very much.
                  DR. MATTHEW O. GRIBBLE:  Thank you.
                  DR. DANIEL SCHLENK:  That was Dr. DeLeo.  Okay.  Let's go ahead and move on to our next speaker, Stephanie Herron from EJHA.  No response.  Okay.  Let's move on to Dr. Elke Jensen from Dow Chemical Company.  And I believe you have some slides that need to go up.
                  DR. ELKE JENSEN:  Yes, I do.  Thank you very much.  Hi, good afternoon.  My name is Elke Jensen.  And I am a risk assessor at the Dow Chemical Company.  Dow very much appreciates this opportunity to comment on EPA's proposed screening level approach for assessing ambient air and water exposures to fenceline communities.  
                  Dow is committed to the principles of responsible care.  And we remain dedicated to reducing emissions to a level that meet or outperforms EPA's regulations and our own company's sustainability goals.  Dow's comments focus on three main points.  One, the proposed screening level approach is too uncertain and too conservative for use in risk management or cumulative impact assessment.  
                  Two, the proposed approach should only be used in a tiered framework, such as that shown here in the figure, for screening out low risk scenarios.  And, three, other EPA offices and state pollution control agencies have developed higher tiered data, information, and methods that would better inform community-specific assessments.  First, several important sources of uncertainty in the proposed approach undermine its use generally in the risk evaluation process and specifically for evaluating fenceline exposures.  
                  One uncertainty stems from using toxics release inventory data to estimate air and water concentrations.  Uncertainties in the TRI data include ambiguities around the reported release amounts, lack of information about the number of release days, and lack of knowledge about the specific location and characteristic of emissions, amongst others.  All of these can strongly influence estimates of fenceline air and water concentrations. 
                  Another significant source of uncertainty is the mapping approach proposed to assigned chemical releases to conditions of use.  In many instances the mapping process appears highly uncertain and dependent on professional judgment.  And there are additional uncertainties, which are discussed in our written comments.  Due to the high degree of uncertainty, Dow recommends not to merge chemical exposure estimates from the proposed screening level approach with non-chemical stressors to evaluate combined impacts on fenceline communities.  
                  The recently published EPA Office of Research and Development proposed research plan for cumulative impacts lays out significant gaps in data, information, and methods that are needed to evaluate the combined impact of chemical exposure with other stressors.  Accessing cumulative exposures and impacts is complex.  It requires the knowledge of site and community-specific information, consultation with other stakeholders, and peer review before combined effects of chemical and non-chemical stressors are considered.  
                  Second, screening level assessments are by their very nature intended to help prioritize specific scenarios for additional analysis, and as such, fit into a tiered framework.  Thus, the current proposed methodology may be useful for eliminating low-risk scenarios from further assessment.  However, results generated using screening level approaches should not be considered to represent actual exposures experienced by communities or individuals.  Therefore, the proposed approach should not be used to make risk determinations or risk management decisions relating to potential fenceline exposures.  
                  Third, Dow recommends that community-specific analyses, rather than the general ones based on the proposed screening methodology be used to inform potential fenceline exposures.  Other regulatory authorities within EPA, such as the Office of Air Quality, Planning, and Standards, and state pollution control agencies, already perform higher tier fenceline exposure and risk assessments that may provide a more accurate understanding of fenceline community exposures.
                  For water, for example, EPA and state programs implement water quality standards based on site-specific operations and discharge, along with detailed characteristics of the receiving waterbody and its uses.  The water quality criteria are factored into the development of permit limitations to ensure maximum protection of aquatic life and human health.  Thus, at a minimum, these groups should be consulted so that fenceline exposures under TSCA can leverage existing methods and information developed under those authorities. 
                  If we can move to slide 2, please?  Thank you.  In summary, Dow does not recommend use of the screening level fenceline approach to inform risk management for potentially exposed communities.  These results do not accurately depict risk and should not be used in a public health context to evaluate overall community health.  Furthermore, results based on the proposed fenceline approach should not be combined with other stressors, as there are significant gaps in both data and methods that could lead to incorrect conclusions.  Site-specific information is needed to accurately estimate potential emissions.  
                  And community-specific information is needed to evaluate other potential exposures or stressors.  Communicating the results of an overly conservative screening assessment has the potential to create unnecessary fear in fenceline communities and cause more harm than good.  That concludes my remarks.  I'd like to refer the SACC and EPA to our written comments that we've submitted for additional details.  And thank you very much for the opportunity to comment and for your time and attention.  Thank you.
                  DR. DANIEL SCHLENK:  Thank you.  Dr. Gribble, your hand is still up.  Do you have another question, or was that from last time?  Okay.  Thanks.  Anybody else have a question?  Okay.  Thank you very much.  Let's move on to our next presenter.  This would be Rashmi Joglekar -- sorry if I butchered your name -- from Earth Justice.
                  MS. RASHMI JOGLEKAR:  Thank you.  Good afternoon.  My name is Rashmi Joglekar, and I'm the staff scientist at Earth Justice.  And I'd like to thank the SACC for serving in this critical role and for providing the opportunity to speak today regarding the draft TSCA Screening Level Assessment Approach for fenceline communities.
                  We support EPAs decision to consider impacts to fenceline communities when evaluating and regulating chemicals under TSCA, a change which is needed to comply with TSCA and to fulfill the Biden Administration's Environmental Justice commitments.  However, as currently drafted, the screening methodology fails to account for many of the ways that fenceline communities are exposed to and harmed by chemicals.  And fails to provide a complete or scientifically supported assessment of fenceline community risks and thus understates the harm that residents of those communities face.  
                  As Eboni very clearly described, communities near polluting facilities and contaminated sites are exposed every day to toxic chemicals in the air they breathe, the water they drink, and the soil they live, play, and grow food on.  As a result, fenceline communities face disproportionately high risks of cancer, respiratory illness, and other health harms compared to the general population.  
                  Moreover, in the United States residents of these communities are more likely to be people of color, who experience income inequality, health care inequity, food insecurity, and disproportionate burdens of underlying disease which further increases their susceptibility to harm from chemicals released by nearby polluting facilities.  These communities need regulation that protects them now.  The SACC is charged with ensuring that EPA's screening methodology captures all of the ways that communities are exposed to and harmed by toxic chemicals and, if not, recommending ways that the methodology can be improved.  
                  In doing so we urge the SACC to take the following issues into consideration.  First, EPA does not consider risk to communities exposed to the same chemical for multiple facilities.  This approach effectively assumes that community residents will only be exposed to a chemical from a single facility by a single condition of use.  This is not a realistic assumption, and it is not consistent with the best available science, which shows that polluting facilities are often clustered and concentrated in fenceline communities, leaving residents of those community's exposed to the same chemical from multiple sources.  
                  Next, EPA does not consider risk from communities' cumulative exposures to multiple chemicals from a variety of sources and pathways.  Ignoring the real world exposures and risks faced by many fenceline communities.  This approach is also inconsistent with the best available science and is particularly problematic for chemicals that contribute towards common adverse health outcomes, which could increase the likelihood of harm to exposed communities.
                  For example, TRI data from 2020 indicated that fenceline communities near Geismar, Louisiana, a town situated in the heart of Cancer Alley, were exposed to over 370,000 pounds of chemicals associated with cancer by air emissions from nearby facilities.  These include carbon tetrachloride, methylene chloride, PCE, TCE, formaldehyde and 1,3-Butadiene.  EPA also fails to consider fenceline communities' increased susceptibility to harm.  
                  The best available science shows that people living in fenceline communities are more susceptible to harm from chemical exposures due to both intrinsic factors, such as life stage or underlying disease, and extrinsic factors, such as psychosocial stress from racial injustice.  And people living in fenceline communities often experience multiple intrinsic and extrinsic factors simultaneously.  They're more likely to be low income people of color with reduced access to quality health care and healthy foods.  In addition, they have a higher risk of developing cancer or respiratory illness from air pollution.  Yet, EPA fails to take any of these factors into consideration in the screening methodology.  
                  Next, EPA does not consider all relevant exposure routes and pathways through which fenceline communities are exposed to chemicals and ignores risks from known and foreseen exposure combinations.  And, finally, EPA does not consider complete or reliable chemical release data.  And it fails to consider chemical accidents, spills, and other peak release events, which underestimates risk to fenceline communities from peak exposure events.  
                  In its charge to the SACC, EPA solicited comments on ways that its screening methodology may be expanded to address these issues discussed above.  EPA should not delay the implementation of improvements to its screening methodology that can be made today using existing information and resources to protect communities now.  We urge the SACC to recommend near term revisions to EPA's approach that can be implemented without delaying needed chemical regulation.  
                  These include incorporating additional uncertainty factors to account for risks from cumulative exposures to multiple chemicals and multiple non-chemical stressors that enhance susceptibility to harm.  This also includes using the highest level of TRI reporting over a several year look-back period, supplemented by other available data sources that capture accidental spills and peak release events, including facility and fenceline monitoring data, and chemical incident reports.  And this also includes using models and information already -- 
                  DR. ALAA KAMEL:  You have 30 seconds.
                  MS. RASHMI JOGLEKAR:  Okay.  Thanks.  This also includes using models and information already included in the screening methodology, like the IIOAC and AERMOD, to calculate community exposures from multiple facilities that release the same chemical via multiple and combined exposure routes and pathways.  We also urge the SACC to recommend additional changes the EPA should make before completing any additional TSCA risk evaluations to ensure that EPAs fenceline assessments measures fenceline communities' true exposures and risks.  Thank you for your time and your consideration.
                  DR. DANIEL SCHLENK:  Thank you.  Question from Dr. Calder.
                  DR. RYAN CALDER:  Thank you.  That was a really great presentation.  I have a question, I guess, in the first place for the chair.  The last presentation raised a question that I had -- a technical question that I have that maybe I would like technical clarification on if possible from EPA.  Is that possible to do now, or should I do that later?
                  DR. DANIEL SCHLENK:  That would be at another time at that particular point.  So you can hold off on those.  We'll have another period where we go back to them.  At this point, yeah, please focus on the commentors at this point.
                  DR. RYAN CALDER:  Okay.  Okay.  Okay.  Thank you.  Sure.
                  DR. DANIEL SCHLENK:  Sure.  Okay.  Any other questions?  Thank you.  Let's go ahead and move forward with our next presenter, who is Amy Kyle -- Dr. Amy Kyle, who is an environmental health scientist faculty member.
                  DR. AMY KYLE:  Hello, this is Amy Kyle, retired faculty member in case anyone's keeping track.  I'm sorry I have a little bit of unstable internet, so I can't turn on my video.  But thank you for the opportunity to comment.  I really appreciate the thoughtfulness that we've seen already from the EPA presentations and also from the questions and comments from the advisory panel.  I'm really looking forward to you all's work on these very important issues.
                  And I guess I have two main points to make here.  And the first one other people have touched on, but the methods that are proposed really are not sufficient to capture the experiences of the most exposed communities.  And you've heard this from some other people, too.  One issue is that they don't represent what we know about exposure scenarios that are important to communities but not necessarily at the fenceline.  TSCA doesn't limit this just to fenceline communities.  It's supposed to be all the affected communities.  
                  And I want to highlight three things that I think are important to consider.  One of them are the food chain pollutants -- food chain contaminants.  Those are typically contaminants that are persistent, bio-accumulative, and toxic -- the so-called PBT pollutants.  I mean, mercury and dioxane are two very notorious examples that were admitted primarily to air but distribute in such a way over broader areas that they got into the food chain and led to discontinuing consumption, or limiting consumption, for fish and shellfish in most of the states in the United States.  It was an enormously impactful situation far from some of the sources of these pollutants. 
                  And so, I think those need to be considered.  One of the other speakers mentioned that previously.  One additional concern about that is that the food chain pollutants that become contaminated as the toxics move up the food chain also are often traditional foods for people of indigenous heritage or tribes.  And so, that creates additional impacts from a cultural perspective.  And that's fundamentally very unjust.  It's a very fundamental environmental injustice.  So, I urge you to consider these impacted communities that may be disproportionately impacted but not necessarily immediately adjacent to the facility or the waterbody into which the pollutants are distributed. 
                  Secondly, I wanted to agree with others who said that excluding the groundwater pathways is quite problematic because we know that pollutants are distributed through groundwater.  And so, if you don't consider those, that leaves a very important deficit in the analysis as well.  And then, the third thing I wanted to also point out, and this particularly, I looked into the data here on methylene chloride particularly.  But communities can be effected by the waste management disposal systems that we have, which then in themselves become a source of exposure.  
                  And these systems can effectively concentrate these materials in the areas where the facilities are located.  The TRI data that you all are using requires reporting from certain disposal facilities but not from wastewater treatment facilities.  So I'm wondering if this has maybe been overlooked somewhat partly because of that.  
The National Emissions Inventory, which also includes toxics data for some toxics, air emissions from wastewater facilities of methylene chloride, for example, in Los Angeles comprised almost 30,000 pounds from 80 facilities.  
                  That appears to be missing from the data sources that you all are using.  I don't know why those are excluded from the TRI reporting.  It seems like they should be included.  But my point here is that hazardous waste facilities, landfills, and wastewater facilities are all significant emitters of methylene chloride, as one example.  And so, it seems like, because we know those are concentrated pollutants drawn from a wider area, that those should be included.  Okay.   So then my second major point is that --
                  DR. ALAA KAMEL:  You have 30 seconds.
                  DR. AMY KYLE:  Okay.  Well, I'll be brief on this one then.  We really need the scientists here to look deeply into the scientific infrastructure that we have at EPA for these hazardous air pollutants because it's eroded over the last 30 or so years, since the 1990 amendments, as few or no -- or actually one pollutant has been added as a designated hazardous air pollutant, which then is subject to reporting and management and so on.  
                  DR. ALAA KAMEL:  Please complete your sentence.
                  DR. AMY KYLE:  And I think this Committee needs to look at the underlying infrastructure for designation of chemicals and management of data about them to think about how we could do this better.  So, thank you and thank you for my extra 10 seconds.
                  DR. DANIEL SCHLENK:  Thank you.  Any questions from the Committee?  Okay.  Let's move forward to our next presenter, Sonya Lunder from the Sierra Club.
                  MS. SONYA LUNDER:  Hello.  Thank you all for inviting testimony today.  My name is Sonya Lunder.  I'm the senior toxics policy advisor for the Sierra Club.  I'm speaking today on behalf of our millions of members and supporters and my program's own commitment to ensure that our advocacy supports efforts to address the most severe impacts of chemical pollution on people and their health.
                  As such, we believe that the Agency must quickly and deliberately move toward policies and methods that go beyond the rudimentary quantification of single chemical impacts through single media models.  We believe that EPA already has the methods and tools available to do this better to integrate people's background exposure to the high priority chemicals, add together exposure from multiple sources for just one single chemical, and use uncertainty factors to account for major gaps in knowledge about the intensity of exposure to highly impacted populations.
                  At this point, when the President and his senior advisors are proclaiming a commitment to environmental justice and a move to understanding the complexity of the social and environmental factors that impact environmental justice communities, I suggest that the SACC members ask themselves and the EPA whether the proposed model achieves EPA's legal and political mandate of identifying and hopefully protecting the people who are most exposed to TSCA first ten chemicals. 
                  Sierra Club and other community leaders, advocates, and our legal counsel has always disputed EPA's conditions of use framework for interpreting TSCA's legal mandate and allege that it's an unjust way to narrow the bills original scope.  We've seen positive progress in the administration to broaden the focus -- for example, the Agency's determination that we use a, quote/unquote, whole chemical approach to evaluate the safety of HBCD.  
                  In the face of this progress on TSCA chemical evaluations and the broader commitment to do better in addressing the totality of human exposures to environmental pollution, EPA's fenceline methodology 1.0 is woefully inadequate, as many panelists have already raised questions today about the very narrow framing of the modeling that's been presented.  The current model didn't even attempt to address additive exposures emitted from two adjacent facilities into a community, nor does it add together estimated exposures from air and surface water.  
                  As the other advocacy speakers have detailed or will continued to detail in our public comments, these shortcomings and lost opportunities kind of pile up for fenceline 1.0.  The initial criteria themselves cut out significant and widespread background exposures to TSCA chemicals -- things like CDC's NHANE's biomonitoring data that demonstrate vast disparities in exposure to these chemicals across the population and data about subsistence fish consumption, people living in proximity to disposal sites, and drinking water.  
                  EPA's tacit assumption for these undocumented exposures is that their contribution to overall risk is zero.  EPA has asked the SACC to weigh-in on how this methodology could be identified to expand to include EJ concerns and be used to inform future EJ assessments.  Indeed the model stands in a stark contrast to the fundamental principle of environmental justice, which is to address the complex and multifaceted attack on community health by a variety of pollutant and non-pollutant stresses.  EJ leaders continuously call our attention to their lived experience and the reality that exposure to health harming pollution varies tremendously based on a person's race, socioeconomic status, and ethnic identity, a reality in which there are vast disparities in rates of chronic diseases, access to quality health care, educational opportunities and economic mobility but are also influenced by a person's race, ethnicity, household income, and immigration status.  
                  In the reality we know that fenceline communities are places where people are often living in proximity to multiple polluting industries; have less rigorous permitting and oversight and enforcement of those industries; have less robust drinking and wastewater infrastructure; are subject to harmful spikes in pollution during emergency events, malfunctions, or extreme weather, storms and power outages; and who are more likely to live atop historic pollution sources of all types.  
                  We also know that people in fenceline communities drink water from wells, eat locally caught fish or shellfish, and can be employed by those industries that are emitting pollution into the air.  And as just a demonstration of a very different framework, or way of approaching this problem, I would counter the ACC example that only 0.03 water systems --
                  DR. ALAA KAMEL:  You have 30 seconds.
                  MS. SONYA LUNDER:  -- have excessive exposure to methylene chloride.  And I would say these represent documented exposure to real people and a very easy type of exposure data that EPA could incorporate into its models.  Addressing all these factors in a quantitative model could be a risk assessors dream or maybe their worst nightmare.  So, if the EPA wants to do an accurate and reasonably complete assessment of whole chemical exposure to a single TSCA chemical, it needs to measure and model more exposures and account for major unknowns with uncertainty factors.  
                  One last example is TCE and PERC, which are closely related solvents.  We know that many communities have additive exposure to these two high priority chemicals in their drinking water and their air, and employments.  And we look toward the next 20 chemicals as a place where there are also lots of additive exposures.  Lots of additive exposures in fenceline communities by the group of solvents --
                  DR. ALAA KAMEL:  Please complete the sentence.
                  MS. SONYA LUNDER:  -- (inaudible).  All right.  I'll stop there.  Thank you so much for inviting public testimony today.
                  DR. DANIEL SCHLENK:  Thank you.  Any questions from the Committee?  Okay.  We'll move forward to our next speaker, which will be Lindsay McCormick from the Environmental Defense Fund.  Lindsay McCormick.  Okay.
                  DR. KAREN SLANEY:  She's muted.  Speaking, but she's muted.
                  MS. LINDSAY MCCORMICK:  Can you hear me now?  I'm sorry.
                  DR. DANIEL SCHLENK:  Okay.  Go forward, please.
                  MS. LINDSAY MCCORMICK:  Okay.  Sorry about that.  Good afternoon.  My name is Lindsay McCormick, and I'm a program manager with Environmental Defense Fund.  EDF commends EPA for developing a draft methodology to assess fenceline exposures and risks from chemicals undergoing risk evaluation under TSCA.  However, we have major concerns about the draft approach, particularly related to its screening level scope, underestimation of risk, and troubling implications for risk management.
                  While EPA intends this draft to be a version 1.0 that will be supplanted by version 2.0 in the future, the Agency clearly also intends to use this version to make important risk management decisions, including decisions that specific fenceline exposures do not present unreasonable risk.  EPA's discussion of the possible outcomes of its fenceline approach indicates that if any unreasonable risk is identified that is not already found in the risk evaluation will need to be further substantiated.  
                  In contrast, however, if the fenceline approach estimates there is no unreasonable risk, then the Agency will not require any further substantiation.  EPA's implicit rationale for this asymmetric approach is that it believes its screening approach is conservative.  However, while some factors used in this methodology may indeed be conservative, in reality it systematically underestimates risks overall.  
                  This likely means that EPA will exclude real world exposure pathways as well as underestimate exposures to fenceline communities ultimately undermining effective risk management approaches.  I'd like to take a moment to highlight three specific examples.  And we have provided further examples in our written comments that we have submitted.  One, EPA excluded major environmental pathways of exposures, including from land disposal and deposit, groundwater, plume deposits and vapor intrusion, consumption of contaminated food including but not limited to fish and accidental releases. 
                  Two, EPA did not advocate multiple exposure sources or settings within a given condition of use, such as combined exposures to multiple facilities, multiple pathways, such as air and water, as well as exposures from being both a resident of a fenceline community and a worker who is exposed to the chemical on the job.  Three, EPA did not aggregate exposure and risk across conditions of use.  The real world scenarios in which fenceline community residents may be subject to combined risk from two more conditions of use are not considered. 
                  So, for example, EPA's approach fails to account for the aggregate chemical exposure and risk faced by a person who lives both near an industrial facility and next door to a dry cleaner emitting a given chemical, such as 1-bromopropane.  Further, the approach does not rely in sufficiently robust data.  For example, the use of annual TRI release data will obfuscate peaks such as accidental releases and startup and shutdown events.  Where possible, EPA should integrate real world fenceline air, water, and ground monitoring data to reflect the reality of individual's exposures.
                  Of note, EPA has authority under TSCA Sections 4 and 8 to require or call in such data from chemical companies.  We recommend that in future applications of this methodology, EPA acquires such monitoring data and do so sufficiently early in the process so that it can be fully incorporated.  The many ways in which the draft endpoint approach excludes or underestimates exposures demonstrates the best available science, which is required by TSCA Section 26H, is not being used to estimate risk to fenceline communities. 
                  This is particularly glaring given that individuals in fenceline communities generally have higher than average exposures and are potentially exposed or a susceptible subpopulation, a group identified in TSCA for specific consideration.  EPA had sufficient time to revise the approach before applying it to the six chemicals, given its current proposal, to take the time to further substantiate any unreasonable risk with additional analyses.  
                  At a minimum, EPA should include all appropriate pathways of exposure, aggregate exposures, and incorporate more robust data sources to reflect how individuals living in a fenceline community are actually exposed to these chemicals.  Beyond this, we also encourage the SACC to provide EPA with advice on how the Agency can implement a cumulative risk assessment framework within the context of a fenceline approach moving forward.  EPA's traditional chemical-specific approach, which is a no-risk consideration of how other chemical exposures may impact the risk posed by the specific chemical in question, underestimates actual risk to public health.  This is particularly the case for fenceline communities --
                  DR. ALAA KAMEL:  You have 30 seconds.
                  MS. LINDSAY MCCORMICK:  -- who are often exposed -- thank you.  This particularly the case for fenceline communities who are often exposed to multiple chemicals simultaneously and disproportionately bear the health burden.  Thank you for the opportunity to comment today. 
                  DR. DANIEL SCHLENK:  Thank you.  Any questions from the Committee?  Okay.  Let's move forward.  Our next presenter is Dr. Maya Nye from Coming Clean.
                  DR. MAYA NYE:  Good afternoon.  Can you hear me?
                  DR. DANIEL SCHLENK:  Yes, thank you.
                  DR. MAYA NYE:  Yes, thanks.  Thank you for the opportunity to speak today.  And I want to thank all of you for your service to the Science Advisory Committee on Chemicals.  So, my name is Dr. Maya Nye.  I'm the federal policy director for Coming Clean.  And we're a network of around 150 organizations across the country that are working to transform the chemical industry so that it's no longer a source of harm.  And we are guided by the Louisville Charter for Safer Chemicals, otherwise referred to as the Louisville Charter.  I'm putting a link to that in the chat as soon as I can find it here.
                  And that outlines -- let's see.  Here we go.  It outlines our vision for a safe and healthy environment.  And it calls on the requirement of safer substitutes and solutions, acting with foresight to protect health, and preventing disproportionate exposures and cumulative impacts.  And so, I guess I want to submit the Louisville Charter for Safer Chemicals as a guidepost for policy and scientific decision making.
                  And so, I grew up in a fenceline community, and I went to school as a child in a fenceline community -- all the schools that I went to next to a chemical manufacturing site that was owned and managed by multiple owners that produced multiple different chemicals, all the way from carbamate pesticides to antifreeze.  And I did so from the time that my mother was pregnant with me all the way through adulthood.  And so, I'm really happy to see the EPA is acknowledging that fenceline communities face unique threats. 
                  Unfortunately, as a number of my previous colleagues have pointed out, this methodology falls short of recognizing the realities of the exposures on the ground in my community and in community's like -- that Ms. Cochran from Louisville talked about.  So it really significantly underestimates hazards that are faced by fenceline communities.  And so, in my community we didn't face these hazards one facility at a time, one chemical at a time.  If only we were fortunate enough to say, okay, today I think I'm only going to breathe in the ethylene oxide from the Union Carbide plant in Institute and not the one in South Charleston.  
                  Or, I'm only going to be able to breathe it in in the amounts that are actually reported on the toxics release inventory and not the other emissions that didn't get reported through the TRI.  And just pointing out, I think as some previous colleagues did, that these reported data are reported by industry, and oftentimes it's not validated by state environmental protection agencies or the EPA.  And when I was kid, we went swimming in the Kanawha River on a frequent basis.
                  And, I couldn't say, well, I'm only going to be exposed to whatever -- one of these chemicals that's being emitted from the outflow, the discharge that particular day.  And, oftentimes, those discharges significantly exceeded threshold quantities.  And I didn't see in the methodology where those kinds of peak exposures were really well taken into consideration.  And some other folks had mentioned there are a number of people that still fish for subsistence, particularly unhoused populations in these areas, and as a means for a sustenance.
                  So, considering that the fish in the Kanawha River have -- they are burdened with legacy contaminates, these PBTs, these persistent bio-cumulative toxins, that someone referred to earlier -- the uptake in the system is going to be, contribute to cumulative impacts.  Someone else mentioned not taking into account chemical disasters and malfunctions.  And I can't tell you the number of chemical disasters that have occurred in my community over the years.  
                  And, in fact, one particular disaster, the fenceline monitoring was disabled prior to the incident.  And so, there was, quote/unquote, no detectable quantity that left the fenceline because, literally, there was no way to measure that it was leaving the fenceline.  But that doesn't mean that the community doesn't experience those things.  It also didn't take into account -- so in my community folks were also about -- 300,000 of my neighbors and I, we had our drinking water contaminated from a chemical that was grandfathered in under TSCA that wasn't required to have human health effects acknowledged before being -- entering commerce or entering our drinking water supply.  So the --
                  DR. ALAA KAMEL:  Thirty seconds.
                  DR. MAYA NYE:  -- methodology didn't take into account those kinds of exposures -- or the brown field sites and Super Fund sites in the area.  It also didn't take into account the stresses that I face as a white woman are not going to be the same stressors that are faced by folks who live in Institute right across the river from where I grew up that are on the receiving end of racial discrimination.  So, don't assume that low levels of discharge aren't worth considering because a lot of low level discharges in these communities add up.
                  DR. ALAA KAMEL:  Please end your sentence.
                  DR. MAYA NYE:  Thank you.
                  DR. DANIEL SCHLENK:  Thank you.  Any questions from the Committee?  Okay.  We'll move forward to our next speaker, Dr. Katheline Pierre, and I believe you have some slides to put up.  There we go.
                  DR. KATHELINE PIERRE:  Good afternoon everyone.  My name is Katheline Pierre.  I am both the medical doctor and physical scientist and the director of Foundation Medicine 501(c)(3) Private Foundation.  And I'm going to go ahead and give you a brief overview of some of the takeaways I got from a lot of your comments, as well as a few different points that I feel that we didn't cover just yet.
                  I wanted to start with the first page, going over what you were tasked with.  And that would be upon a recall of materials such as OES, interest was found in a group of COUs.  Now these COUs are easily combined with different molecules, for example, sulfuric acid, H2SO4, and its carboxyl group, CH3O2.  Now some of the methyls that we've been talking about have various what I would say to be components.  For example, when structuring different molecules, you'll notice their biproducts as well as their catalytic decomposition.  
                  Some of it is unbalanced, for example, salt, such as hydrocholorequine, that have been recalled.  That causes gastric acid or hypertension.  They're carboxyl groups.  That would be the hydrochlorics as well as the anticoagulants and the sulfates and sulfides.  The silicone group, that would be much more considered an insulator or an inductor -- the anticonvulsant groups, such as bis-phenyl or hydramine, which has a correlational variable.  
                  The anticonvulsants seem to be much better than the original carboxyl group, mainly because most people refuse to use or are unaccustomed to the anticoagulants.  There is -- for reference, we've been taught how to clean, treat, and protect most diseases or brachial hemorrhages.  We also have to overview zinc sulfates from niacin to magnesium thiamine.  Those are successful substitutes.  The next part I wanted to go into would be finding yourself things that are universal.  The reward is in the risk in terms of capacitance and Ieffa (phonetic).  
                  Now I carry multiple roles in my community, similar to those around me.  Not only am I a student, I'm a medical professional.  I also live in the community and also travel between community's.  Post-pandemic we have to look at the different correlational variables starting from -- and I just want to make sure that you guys can hear me.  That way I'm able to give you guys a comprehensive review.  For example, distance -- variables that we should measure would be distances -- electrical consumption, as well as its effects during meetings. 
                  For example, nylon is a really good substitute for something that may be causing a -- what I would say an index of refraction effect.  And pardon me if I'm not giving you guys the best review.  I am going briefly through this.  I had to do this last minute, and I work all week.  So I have a lot of case files on me as well.  And that's one of the things that is important about Foundation Medicine is that we work with --
                  DR. ALAA KAMEL:  You have 30 seconds.
                  DR. KATHELINE PIERRE:  -- different things.  So one of the, a few important things I do want to stress would be PZ over T or what they would call the molar volumes of these substances -- getting labels for them.  For example, as volume increases, so does pressure -- as well as the, one more minute.  Let me see if I can find my notes on that -- as well as the kinetic theory or Avogadro's hypothesis.  And that would require the molar volumne at STP or A or Calvin, which is equal through a degree Celsius plus 273.15.  For --
                  DR. ALAA KAMEL:  Please finish your conversation.
                  DR. KATHELINE PIERRE:  -- now we have over safety and environmental concerns, such as implementing safer procedures, lubrication post-pandemic, labeling of methods and medical machines.  And, lastly, some of your sources of error -- or sources of error would include --
                  DR. DANIEL SCHLENK:  Can you please finish up your last sentence, please?
                  DR. KATHELINE PIERRE:  Yes.  The PPM or the PPBs, overcrowding and aggregate exposure as the EBF states.  Post-pandemic rations, getting this to the public without extraneous events. 
                  DR. DANIEL SCHLENK:  Thank you very much.  Thank you for your comments.  Any questions from the panel?  Okay.  We will move forward to our next speaker, which is Molly Rauch from the Moms Clean Air Force.
                  MS. MOLLY RAUCH:  Hello.  Thank you so much for the opportunity to testify.  I'm Molly Rauch.  I'm public health policy director for Moms Clean Air Force.  I have three children and live in Washington, D.C.  Moms Clean Air Force has more than a million members across the country and organizers working on the ground in a dozen states.  And our mission is to protect children from air pollution and climate change and other sources of health harms.  Many of our moms and dads and grandmas and aunties who are part of our organization joined us because they are concerned about how toxic chemical pollution is effecting the health of their children and their families.  
                  Many of them live near refineries, power plants, pumpjacks, petrol chemical plants, factories, and other industrial facilities in states across the country.  And they're living on the fenceline.  So it matters deeply to our members what they and their families are exposed to.  They don't care if the chemical is in the air or in the water or coming up through the soil in their home, whether it comes from the playground, the home, or the school.  They care about being protected from all these sources.  
                  It matters to them that someone's paying attention, and it's so important for the EPA to take an approach that is not piecemeal when it comes to looking at what these families are exposed to.  They're whole people and should be treated as such in EPA's approach.  So, we feel that one way to do this is not only to look at all the ways or pathways that can expose fenceline communities to hazardous chemicals, such as through contaminated food and groundwater and from chemical spills, but also to face the reality that these families and communities often deal with exposures from more than one source, which we've heard a lot about already in this hour.  
                  For example, EPA's own data shows that polluting facilities tend to be clustered together.  So fenceline communities will often be dealing with multiple exposures at the same time.  And many members of the community may have a double whammy of exposure because, for example, they live close to facilities and also work at one of them.  And we feel that EPA's plan doesn't properly take such lives into account.  
                  Another troubling aspect of the fenceline screening approach, as it's currently written, is that EPA's approach not only underestimates the risks that fenceline communities face but also appears to trivialize them.  The plan says that if risks from certain chemical uses are identified, then EPA will do a further analysis to confirm those findings.  Although, we don't know what that analysis exactly is.  But, on the flipside, if EPA does not identify any unreasonable risks, the plan says the Agency will stop there and no further investigation is needed.  
                  So we're concerned about this.  It doesn't make sense to us that EPA would second guess a finding of risk to fenceline communities and require more analysis to confirm it while doing the opposite when its initial screening finds no risk, but just presuming in that case that everything is fine.  So, I urge EPA -- on behalf of Moms Clean Air Force and our members, I urge EPA to strengthen its method of analyzing fenceline risks to capture the real lived experience of these fenceline communities.  Thank you very much for the opportunity to testify.
                  DR. DANIEL SCHLENK:  Thank you.  Question from Dr. Unseld.
                  DR. MONICA UNSELD:  Yes.  This is Monica Unseld.  I'm trying to synthesize as much as I can today.  This is a question for Molly Rauch.  In speaking with the communities that you work with, have you ever heard them express concern that maybe we shouldn't look at cumulative impacts or shouldn't look at something because it would create an unreasonable sense of fear and, therefore, perhaps backfire or --
                  MS. MOLLY RAUCH:  We do not hear this.  In fact, we hear the opposite.  We work with families that are already afraid and are concerned that they're not getting adequate information because the analysis of their exposure doesn't take into account the multiple pathways and the cumulative risks.  So we hear the exact opposite.
                  DR. MONICA UNSELD:  Thank you.
                  DR. DANIEL SCHLENK:  Okay.  Thank you very much.  All right.  Our next speaker is Swati Rayasam from the UCSF Program on Reproductive Health and the Environment.
                  MS. SWATI RAYASAM:  Yeah.  Hi.  Hi, everybody.  Thank you so much for sitting on what is going to be a series of very long Zoom calls.  I really appreciate all of your service to the SACC to address this really critically important issue.  My name is Swati Rayasam.  I'm a science associate at the Program on Reproductive Health and the Environment at the University of California, San Francisco, otherwise referred to as PRHE.
                  And today I'll be discussing a number of my organization's concerns around the recently released fenceline screening methodology, as well as kind of the process that the Agency has used in the release of this important methodology that disproportionately impacts those on the margins.  But, primarily, or first and foremost rather, I have no conflicts to disclose.  So, PRHE is among a number of groups who have been actively following TSCA implementation, submitting public comments with support from experts to ensure that the Agency meets its statutory mandate of making decisions about chemical risks based on the best available science, adequate information, and the weight of scientific evidence.  
                  We support the Agency's decision to revisit and evaluate the previous administration's exclusions and exposures to communities surrounding polluting facilities.  However, upon reviewing the methodology, we found a series of both methodological and logistical decisions that, if finalized, would cause this fenceline screening methodology to systematically underestimate risk and adversely impact the health of community's that this document is explicitly stating it wants to support. 
                  In several places in the methodology, as well as in the media, EPA has asserted that this proposed screening methodology incorporates conservative assumptions and provides conservative estimates of risk in the sense of being more likely to overestimate than underestimate.  However, EPA provides little or no justification for these statements.  And, upon assessment of our group, and a couple of the other commentors you've heard from, many aspects of EPA's approach are actually likely to underestimate risk to communities.   
                  For example, understanding ambient concentrations of a chemical at various locations near emitting facilities seems to be a foundational question that this method would be able to answer.  At present though, EPA's approach is designed to address and understand typical ambient concentrations of a chemical across various locations as a result of emissions from individual facilities assigned to specified occupational exposure scenarios.  
                  Thus, the approach doesn't actually consider how multiple facilities may contribute to ambient concentrations of a chemical in a community or aggregate exposure, as addressed by other commentors.  Summary statistics as well reported from EPA's modeling don't present ambient concentration values from individual model receptor locations but instead choose to combine and compile results from multiple receptors, which averages out and, thus, underestimates risk.  So we would strongly recommend that EPA revise its methodology to determine aggregate, ambient concentrations of chemicals at individual receptor locations in fenceline communities.  
                  This revision would not require a major overhaul of the methodology but a reorientation of some steps in the approach.  And we outlined them in detail in our written comments, which will be submitted to the docket.  Additionally, EPA's approach to estimations for facilities lacking TRI data is also not conservative and may, in many instances, significantly underestimate emissions, concentrations, and risk by not accounting for uncertainty while making use of very limited data.  
                  For example, the category of spray adhesives is the only occupational exposure scenario where EPA found no additional risks for 1-bromopropane.  However, this is a category for which there was no TRI data.  And, in the methodology, EPA used data from a single contractor report that provided data for a single facility and said that there were no fugitive emissions from the facility with all emissions going through the stack.  EPA assumed that these data were representative and appropriate for representing this category in the methodology.  
                  However, it seems highly unlikely that this category would have absolutely no fugitive emissions.  And, in fact, the methodology shows that no other OES had zero fugitive emissions of 1-bromopropane.  Therefore, rather than assuming no fugitive emissions for this OES, which likely underestimates ambient concentrations and risks, EPA should have developed a non-zero estimate based on use of data from other OES as surrogates or based on expert engineering judgement.  
                  More generally, EPA should adopt a method to account for uncertainty in emissions estimates for categories with limited data and perhaps make use of the Office of Air and Radiation emission inventories and expertise for emissions estimates.  With regard to 1-bromopropane as well, this methodology indicates that EPA has a plan to employ models from its draft risk evaluations which were conducted under the last administration.  However, our group, and many others on this call, submitted extensive comments, which went unaddressed, about the inadequacy of EPA's model assumptions for 1-bromopropane and --
                  DR. ALAA KAMEL:  Thirty seconds.
                  MS. SWATI RAYASAM:  -- its impacts on PESS.  Thank you so much.  So, specifically, that kind of outlines how EPA would assume that children were only exposed during a four hour period after school, which does not actually address the reality of children from low wealth households whose families own dry cleaners, and similarly makes assumptions about single workers doing single tasks and then later counteracts that assumption by saying, but many workers provide multiple tasks.  
                  And, so, within its model assumptions as well, which this methodology claims to carry forward, we would really recommend the SACC to look back on public comments that were given both oral and written to EPA that have gone unaddressed that would impact fenceline communities.  And I have a series of other things, but I think that --
                  DR. ALAA KAMEL:  Just finish your sentence please, yes.
                  MS. SWATI RAYASAM:  Yeah.  One of the major things that have been recommended or asked by the SACC at this meeting is what can be done now?  I think, Dr. Unseld, you asked that.  And I think that one of the major things that we would recommend is that EPA can put health protected default adjustment factors right now that were recommended 13 years ago by the NAS and Science and Decisions to account for uncertainties in the data.  And, while they do that, EPA can simultaneously have its cake and eat it too and provide a robust screening methodology that accommodates for all the exposure uses and pathways that people will be exposed via --
                  DR. ALAA KAMEL:  Thank you.
                  DR. DANIEL SCHLENK:  Thank you very much.  Any questions?
                  DR. MONICA UNSELD:  Monica Unseld again.  Could you name that -- what you said was 13 years ago, please?
                  MS. SWATI RAYASAM:  Yeah, totally.  There are health protective default adjustment factors, and we would recommend that EPA would immediately incorporate -- or could immediately incorporate these health protective adjustment factors into the risk evaluation process -- we've said this a number of times during the first ten chemicals -- and into its risk management decisions to be able to kind of protect potentially exposed or susceptible subpopulations.  So, in Science and Decisions, which was released in 2009 by the National Academies of Sciences --  And, to date myself, this is the year that I graduated high school -- these were actually recommended for cases where there are known relevant issues, but we actually lack specified data.  
                  And so, we are really trying to understand and sympathize with EPA's predicament, right?  They are under these timeline constraints.  They are under these resource constraints.  However, there are things that can happen now to protect communities who have been experiencing harm via polluting industries, communities that Maya comes from, communities in North Carolina and in Richmond, California, which are next to me in Berkeley over here -- that we can use to protect people right now and make sure that we have methodologies that --
                  DR. ALAA KAMEL:  There's another question.
                  MS. SWATI RAYASAM:  -- well into the future. 
                  DR. DANIEL SCHLENK:  Yes, I see it.  Yes, Dr. Chaisson, please.
                  DR. CHRISTINE CHAISSON:  Thank you for your presentation.  Can you provide the specific reference to all of those default factors you're talking about?  Would you be willing to send those to Dr. Schlenk so that we can take a look at that?
                  MS. SWATI RAYASAM:  Yeah, I'm happy to.  I'll be attaching these oral comments, the written version of them.  We also have written comments we'll put in the docket.  And I'll make sure that I attach our 1-bromopropane comments, which I referenced in my oral comment, and Science and Decisions, the specific chapter.
                  DR. CHRISTINE CHAISSON:  Thank you.
                  DR. DANIEL SCHLENK:  Okay.  Thank you very much.  Okay.  Our next speaker is Kari Rhinehart from If It Was Your Child.
                  MS. KARI RHINEHART:  Hi, my name's Kari Rhinehart.  Thank you for the opportunity to speak today.  I want to talk about how important it is for the EPA to ensure it considers all of the different ways that families that live near the factories and the facilities that pollute are exposed to these harmful chemicals.  I'm the founder of If It Was Your Child, a grassroots effort started in 2015 by parents in response to an alarming rate of pediatric cancer in Johnson County, Indiana, where I lived in the town of Franklin for 20 years.  
                  One of those children was my 13-year-old daughter, Emma Grace.  Emma died December 18, 2014, from a rare brain tumor, an inoperable glioblastoma multi-form that is most common in men over the age of 50.  Three more children within two blocks of our home were also diagnosed with rare brain tumors in the two years prior to Emma being diagnosed.  After Emma died, I was shocked to learn that for the previous 11 years the home we lived in, in Franklin, had been within a half mile of a site that had a 30 year history of TCE and PCE contamination.
                  This groundwater contamination threatens this community to this day.  In 2012, the well field within a quarter of our home was no longer being used as a municipal water source because the EPA designated it a Superfund site, polluted with TCE, PCE, and other toxins.  While it isn't used any longer for city water, many residents continue to utilize the well field for private wells.  And it has also been repeatedly found in homes from vapor intrusion at dangerously high levels above even the most conservative limits.  
                  It has been found under two of our elementary schools, in our creek, running through the city parks.  EPA's proposal for assessing the cumulative exposure and risks to fenceline communities and families like mine would only look at chemical exposures from local air and water.  That means it would not consider the groundwater contamination or the vapor intrusion that invaded our homes, and that is unacceptable.  It does not accurately portray the reality that communities like mine face.  Like the rest of Franklin, like my neighbors, like my daughter, I'm not exposed to these toxic chemicals from just one source.  
                  I can be exposed to a chemical like TCE and PCE from the air and the water.  My body, my children's bodies, especially the vulnerable children -- their bodies do not differentiate which route of exposure allows toxic chemicals into our homes and bodies.  The EPA needs to use the best available science to estimate all of the risks we face from a chemical like TCE and other dangerous substances that are making our kids sick.  EPA has said itself even one brief exposure to TCE can be harmful to human health.  And that was regardless of the route of exposure.  
                  Just look at what happened to Franklin, where factories have contaminated for decades.  We have 17 percent of the population for our county, yet we have 46 percent of the pediatric cancers.  Almost all of those lived within two miles of this TCE contamination.  It's now time for the EPA to act and to deal with towns like Franklin all over this country.  
                  EPA needs to modify its fenceline screening approach so it fully looks out for families like mine.  Please advise the EPA to use the best available science so it understands the full scope of exposures and risks families face and can manage these risks from the chemicals and ensure that communities and children get the protection we need and deserve.  Thank you.
                  DR. DANIEL SCHLENK:  Thank you.  Chris, your hand is still up.  Is that from last time or is that from -- no?  Okay.  Any other --
                  DR. CHRISTINE CHAISSON:  I'm sorry, I just forgot to put it down.  Pardon me.
                  DR. DANIEL SCHLENK:  Okay.  No worries.  Any other questions from the Committee?  Let me just remind the Committee that I do communicate to you directly through the chat box, and I'm not getting any responses.  So please, please check periodically the chat box if you can, which will be part of the public domain as well, just so the audience knows that.  Okay.  Our next speaker will be Jennifer Sass from the Natural Resources Defense Council, and she has some slides as well.
                  MS. JENNIFER SASS:  Sorry, I did answer your chat, and I don't have slides.
                  DR. DANIEL SCHLENK:  Okay.
                  MS. JENNIFER SASS:  But I did see the chat, and I did let them know.  So I was paying attention.  Thank you for the opportunity to speak to you and, also, thank you for your service on the SACC.  I know it'll be a long, hard journey.  But the report and the work that you do is very, very important.  And, as you can see from the lineup of speakers today, many, many people care.  So thank you.
                  I'm a senior scientist at NRDC, the Natural Resources Defense Council.  And I work on the federal chemical policy and regulations across chemicals of all statutes.  My comments, I hope, were circulated to you as a short, roughly eight-page letter or document.  I'm going to just touch on them now.  It's organized by charge question, so I'll just touch on a summary of the response to each charge question.
                  For Charge Question 1 -- I'll keep it short -- we simply recommend to the SACC that the SACC support recommendations from Environmental Defense Fund, Earth Justice, and others that EPA consider using the most recent five years or a broader swath of the TRI data and, also, use the highest reported releases.  I'll talk a little bit about that later in my comments.  For Charge Question 2, I wanted to point out that there is like a fatal flaw in the way the screening methodology is set up right now.  
                  I would call it a poison pill, which is to say that if there is some alerts or concerns that are identified, it goes on to more and more screening.  And I think these delays lead to actual harm to people and communities and workers and others.  And I think the other speakers have spoke to that.  So I'll just say that there needs to be some actionable evidence.  The evidence should be actionable.  It needs to be used to deliver the protections that communities and workers and others have been long denied and that are well-deserved.  
                  So the screen needs to be used to protect communities, not sideline those concerns.  Specifically, I recommend that if conducting a re-analysis if there's new data or new information becomes available, the screen could be used for that.  It could be updated.  It could be advanced.  But for now it's not robust enough to make a determination of not risk.  So we recommend to the SACC that they recommend that if the screen doesn't find an alert, that that is classified into something like an IR group three, unable to determine, or like an unclassifiable, but not be considered no risk.  The screen can't do that. 
                  For Charge Question 3, again, focusing on advancements that should not be delayed, we do recommend some quick fixes that we think could be done to the screen, including incorporating some of the information from other pathways that's available in models from the Air Office and others.  But we also remind the SACC and EPA that these improvements or advancements shouldn't come at the expense of delays and withholding protections so that EPA could apply additional uncertainty factors, as Swati before me talked about.  
                  And these uncertainty factors can provide a margin of protection or a margin of safety where there's gaps and limitations.  In particular, the SACC could identify where gaps and limitations underestimate risk.  That's very important -- not just to identify gaps and limitations but what direction they go.  For Charge Question 4A, yes, there's other data that could be used.  And we suggest using the National Air Toxics Assessment data as well.  The NATA data provides a combined measure of exposures, including to multiple chemicals, so it can be very useful in that area.  
                  For Charge Question 4B, there's a number of things we think would be really helpful that are kind of quick fixes.  It could be incorporated or considered to address EJ issues.  One of them is risk management plans, EPA's RMP plans.  They require that facilities develop RPM plans that create -- that list foreseeable exposure events, including spills, explosions, things like that.  And those are foreseeable exposure events, so they could be included in a screening method.  And they're in the RPM plans.  
                  For example, in my notes I point out that one unlucky zip code in Harris County, Texas, over a period of month, had three such events -- incidents -- chemical explosion and spill incidents in Harris County, Texas, by two different facilities --  
                  DR. ALAA KAMEL:  You have 30 seconds.
                  MS. JENNIFER SASS:  -- all of them requiring fenceline communities to be evacuated.  So they're affected by these.  Extreme weather events everybody agrees are going to increase accidental or other releases, including fires.  And we saw that in Hurricane Harvey in 2017 that lead to disastrous chemical spills.  Again, those are foreseen events.  They should be included.  
                  Peak releases, such as flaring, spills, and explosions can cause both acute and chronic health harms.  An example of chronic is formaldehyde -- or sorry, chronic outcomes from peak exposures is formaldehyde, which National Cancer Institute has reported in epidemiology studies is associated with peak exposures of 15 minutes or less --  
                  DR. ALAA KAMEL:  Please finish the sentence.
                  MS. JENNIFER SASS:  -- can lead to cancer.  Sorry?
                  DR. ALAA KAMEL:  Your time is up.
                  MS. JENNIFER SASS:  Oh, thank you.  Okay.  I'll just say that there are some quick things that I've identified in here, but fundamentally -- and we present a method that I've published in the published literature using IRIS data to identify endpoints that are common, such as cancer or noncancer endpoints, across multiple chemicals.  That is published, and I've just put a summary in my comments here with references.  
                  DR. DANIEL SCHLENK:  Thank you very much.
                  MS. JENNIFER SASS:  And on the last page I've got the databases there.  Thank you.
                  DR. DANIEL SCHLENK:  Thank you very much.  Any questions?  Okay.  We'll move on to, at least on my list, our last presenter, Karen Slaney also from Moms Clean Air Force.
                  MS. KAREN SLANEY:  Good afternoon.  My name's Karen Slaney.  Thank you for hearing my comments today.  EPA needs to look at all the real world chemical exposures people face, in combination, not just one or two in isolation.  Evaluating chemical exposures from the air and the water is important and good but incomplete.  There are more than two ways to come into contact with chemicals.  Today, chemicals are everywhere.  We can be exposed to chemicals from places we work or shop or from the products we buy or use.  
                  The proposed methodology does not consider exposure from all these sources.  Exposure matters.  I was exposed to chemicals at work for some years when I worked at Greater Boston Legal Services in Downtown Boston.  Next door to our pretty refurbished building was a dry cleaning shop, and it turned out that it was venting its waste fumes right into our building.  I and a few others in the office developed health problems, quite possibly as a result.  For the significant and debilitating immune and endocrine problems that I faced, I received social security disability benefits and an end to my legal career.
                  Even if EPA's proposed method would capture the type of exposure I endured at work, it would treat it in isolation unrelated to anything else I experienced from polluted air near my home, other emissions at work, the chemicals that hit me every time I walk into a dry cleaning establishment.  Exposures aren't neatly packaged in isolated and discrete occurrences.  The more someone is exposed to a chemical, the more likely we are to see health impacts.  
                  So it's crucial that EPA consider all the different chemicals and burdens that individuals face.  When we sideline science or fail to use best scientific practices, people, families, and communities living and working near polluting facilities will pay too high a price.  In summary, EPA must consider together all the ways we're exposed, so I ask you, as a science advisory committee, to please advise the EPA how it can evaluate all the real world exposures and risks we face from a chemical in today's world.  Thank you.
                  DR. DANIEL SCHLENK:  Thank you.  Any questions from the Committee?  Okay.  Oh, we have a question from Dr. Chaisson.
                  DR. CHRISTINE CHAISSON:  As the presenters are referring to other publications or something like that, Dan, would you request that they post those somehow so that we can take a look at what they're referring to.
                  DR. DANIEL SCHLENK:  Yeah.  Most of the presenters actually have written comments that are on the docket.  If you are requesting additional information, they can place those on the docket, which you will be allowed access to.  
                  DR. CHRISTINE CHAISSON:  Thank you.
                  DR. DANIEL SCHLENK:  Okay.  That's the last person on my list.  There's a couple unconfirmed public commenters that I just want to read out just to make sure that they're not available.  Debbie Cox, Brandi Crawford-Johnson, Sherri Norris, John Oluwaleye, Paul Webster, or Jane Williams?  Okay.  Having not heard anything let's go ahead and take a 15 minute break at this particular point.  And we'll reconvene and begin our charge questions.
                  
                  [BREAK]

                  DR. DANIEL SCHLENK:  Okay.  We're starting to get folks back.  Alaa, do you want to make a, you said you had a comment you want to make.  You want another couple minutes, or go ahead?
                  DR. ALAA KAMEL:  Yeah, just a quick announcement for the public commentors who made oral comments.  I know they left the Zoom link, and if they rejoin YouTube and they can still hear me, if you have a written document on what you have presented orally, it would be great if you can send it to me to my email.  The address is on the agenda.  It is kamel.alaa@epa.gov.  So that whatever you send will be more accurate than the transcription and that way we can have exactly an accurate representation of what you said.  Thank you very much.
                  DR. DANIEL SCHLENK:  Okay.  Thanks, Alaa.
                  DR. ALAA KAMEL:  You're welcome.
                  DR. DANIEL SCHLENK:  So I'm going to try a third time.  Dr. Rowlands, are you on to introduce yourself?  
                  DR. CRAIG ROWLANDS:  Okay.  I think I'm unmuted now.  This is Craig Rowlands --
                  DR. DANIEL SCHLENK:  Yay.
                  DR. CRAIG ROWLANDS:  You can hear me?
                  DR. DANIEL SCHLENK:  Yes.
                  DR. ALAA KAMEL:  Yes.
                  DR. CRAIG ROWLANDS:  Okay.  Good.  This is Craig Rowlands with Underwriters Laboratory R&D, toxicologist that has a background in molecular toxicology with a focus on cancer.  And I do risk assessment for various businesses at the UL and focus a lot on medical devices.  And glad I was able to introduce myself.  Thanks.
                  DR. DANIEL SCHLENK:  Thanks.  Thanks for doing that.  Appreciate that.  At this point in time I believe there were a couple Committee members who had some additional questions or clarification for the Agency.  So, before we read the questions into the record, I was wondering are Kevin and Rehan around that they could actually answer some of the questions?
                  DR. REHAN CHOUDHARY:  Good afternoon.  This is Rehan Choudhary from the EPA.  Yes, the team is still available, so if there's some additional questions, we can do our best.
                  DR. DANIEL SCHLENK:  Okay.  Let me just, at least to give some information to the Committee, especially for some of the newer ad hoc members.  Once we go into the charge questions, we try to not necessarily have a banter back and forth with the EPA.  So, again, the questions that you do have please try to ask them now before we get into the charge questions.  
                  I will, after each charge question, ask the EPA if they are satisfied with the answer or have questions or clarification for us.  But we try to avoid the banter back and forth between the Agency and the Committee.  So please, at this point in time, if you have, again, questions of clarification before we move into the charge questions, please do so at this point.  Dr. Calder.
                  DR. RYAN CALDER:  Hi, thank you.  Ryan Calder speaking.  So we heard from a number of commentors about the importance of considering both exposure to multiple contaminants and exposure from multiple sources.  And I had thought, at least for the air exposure pathway, that the methodology does consider the super imposition of multiple sources.  I thought that was the rationale for using quite a long radius from each receptor.  Can you clarify that?  If the screening methodology considers via influence of multiple, simultaneous sources for a given contaminant?
                  DR. REHAN CHOUDHARY:  So this is Rehan Choudhary from the EPA.  Currently the approach is estimating ambient air concentrations through a single source -- release source.  It is not aggregating concentrations due to multiple release facilities.  
                  DR. RYAN CALDER:  Okay.  Thank you.
                  DR. DANIEL SCHLENK:  All right.  Any other questions or clarification?  Okay.  
                  DR. LUCAS HENNEMAN:  This is Lucas Henneman raising my hand in real life, not virtually.
                  DR. DANIEL SCHLENK:  Okay.  Thank you.
                  DR. LUCAS HENNEMAN:  Just a quick clarification on the TRI data, so are there two mediums of release total in the TRI data, air release and water release?  I know there are different pathways associated with that, but are those the total of the TRI release types?
                  DR. REHAN CHOUDHARY:  So this is Rehan Choudhary from the EPA.  The TRI database itself is multimedia, so in addition to releases to air and water it also encompasses releases as reported by facilities to other pathways, either offsite waste management or to landfills or underground injection, and things of that sort.
                  DR. LUCAS HENNEMAN:  Thank you.
                  
CHARGE QUESTION 1
                  
                  DR. DANIEL SCHLENK:  Okay.  So let's go ahead and move forward into the charge question answering period.  At this point we usually have the agency read the question into the record.  Usually that's on a slide, so yep, there we go.  So, Rehan or Kevin, do you want to read that into the record for us?
                  DR. REHAN CHOUDHARY:  Yes, not a problem.  This is Rehan Choudhary from the EPA.  The first charge question we're posing to the SACC Committee: Is EPA screening level approach (Version 1.0) for assessing ambient air and water exposures to fenceline communities clearly communicated and are you able to reproduce results that are relevant to your review?  In your response, please provide examples or explanations to support your conclusions or suggestions. 
                  DR. DANIEL SCHLENK:  Okay.  The lead discussant for question 1 is Dr. Cobb.
                  DR. GEORGE P. COBB:  Thank you, Dr. Schlenk.  I've endeavored to pull together the responses for all the discussants and other Committee members who sent me comments.  So I will do my best to read this into the record.  It's relatively long.  So I'm just going to go ahead and get started.  The Committee commends the Agency for drafting a complex document that does a good job explaining the procedures to have been followed to assess exposures that may be experienced by humans residing in fenceline communities.
                  This document is well-organized and generally well-written.  In general, discussants can reproduce results that are relevant to the understanding and review of the document.  Of course, with any draft document, there are improvements that can be included.  Let's begin with a few overview thoughts.  It would be helpful if EPA provided an explanation of how the case study chemicals were selected.  There should be some explanation of why some chemicals were -- excuse me, the same chemicals were not used for air and water pathways.
                  The draft TSCA screening level approach should be validated with appropriate fenceline monitoring data.  Until validation is done, it may be premature to evaluate the reproducibility of this screening approach.  For example, in some cases there are ten orders of magnitude difference between minimum and maximum predicted air concentrations.  Chemical use data from benzene monitoring programs associated with refinery emissions to evaluate and validate proposed screening approaches could be useful.
                  Broadly speaking, steps in the approach are clear.  The process follows logical steps to obtain the information for air modeling, including emissions, discharge estimates, which are the most challenging input to obtain.  So, with those big picture questions in mind, let's move forward to more specific responses to some of the portions of question 1.  Calculations are mostly reproduceable to the extent that data is provided.  However, that is not always the case.  In the 2019 TRI data for air, for 1-BP and for methylene chloride in Washington State, these data could not be reproduced.  
                  The EPA spreadsheet for 1-BP has four facility's in Washington, but the TRI data has five.  The air appears to be involving the Protective Coatings Incorporation in Kent, Washington.  The stack release was 21,617 pounds, so it wasn't too small to include.  Perhaps the fugitive emissions being small was the reason.  The EPA said they used both stack and fugitive emissions.  They ended up only using fugitive emissions, and it's not clear why.  There was insufficient time to review and evaluate all the supplemental files and to try and decipher this.
                  Using mass balances to total masses used versus reported releases could be helpful in determining the fraction of any chemical that is unaccounted for in a given assessment.  There were other places in the document where it is unclear what is done.  For example, in the 1-BP case, there are 15 OESs in Table 3-3.  The few sections later there are 14 OESs evaluated in Table 3-5.  No rationale is provided for excluding one of the OESs.  And there's indication of which OES was omitted.  This situation was noted.  There are other cases as well.  
                  EPA did not provide the AERMOD input files, which would have been needed to verify if AERMOD was run correctly.  One discussant found that opening Excel files caused errors when brining up linked files.  Excel data sheets are highly technical and can be understood by scientists but difficult for others, including fenceline communities, to interpret.  It will be helpful to develop an internet application to look at these tables and important data.  
                  It would also be useful to include calculations in Excel cells.  Some have this, but others do not.  The discussants suggested that the executive summary and introduction sections more clearly articulate the intended or targeted users of the screening level approach and the intended range of chemicals, or classes of chemicals that would be assessed through this approach.  The current methodological document provides rather limited information on the intended targeted users and the scope of this methodological document.  
                  It would be useful for EPA to define the audience and user base for this approach.  The definition provided for a fenceline community for the purposes of this report is clearly stated.  However, the process to identify fenceline persons and populations is vague.  The approach identifies programs that were used but does not outline the methodology.  EPA should provide some background on how this has historically been approached for general population exposures at the fenceline.  
                  On pages 10 and 11, the exclusion of groundwater wells from consideration of the scope leaves this document incomplete.  The report would benefit from including descriptions of relative risk of exposure pathways not assessed by the approach, for example, from contaminated soil or groundwater.  The current methodological document articulates the exclusion of exposure pathways other than air and water.  It does not consider concepts of aggregate cumulative exposures.  
                  While the document states that the design of the proposed methodology presented is flexible enough to allow addition of expanded capacities, on page 18, discussants could not find any information through the document on how the flexibility is embodied or implemented in the screening level approach.  EPA has the discretion to exclude exposure pathways.  It is also impractical to include all exposure pathways.  
                  However, decisions to exclude an exposure pathway should always be based on relevance to overall human exposure to the chemical.  And such a decision should be specified in the chemical's properties, uses, and releases.  Perhaps exposure pathway considerations should be part of the problem formulation process.  Another weakness in the approach is the lack of explicit considerations of race and economic disparities, cumulative impacts, and occupational exposures. 
                  A short description of A and R, designations within TRI forms, would be helpful to make the methods of this document clearer.  Something like most facilities report on the R form, but some facilities use the shorter A form.  TRI estimates for 1-BP release to ambient air were made using several different approaches: mass balance, monitoring, best practices, best judgement.  How do the accuracy and variability of these approaches compare?  Is it appropriate to compare fenceline concentrations obtained using these vastly different release estimation techniques?
                  Annual TRI releases were used along with the estimated number of days per year that a process is implemented in order to predict daily exposure concentrations.  It doesn't seem likely these releases would occur in this manner.  How would larger, less frequent or single larger releases impact the assessment?  Also, is there any information that would indicate a typical variability associated with TRI chemical release?  How would this variability impact the resulting estimated fenceline air and water concentrations?
                  I might point out that those questions I just mentioned aren't questions we anticipate the Agency answering here today.  They're things to be addressed in the document.  One would assume that many facilities use and release multiple chemicals or change chemicals over time.  Even facilities that use a single solvent likely release other chemicals, perhaps as impurities in bulk solvents.  How would co-contaminants be addressed, and how many chemical facilities that provide TRI data do so for multiple chemicals?
                  So let's move on to estimating emissions and mapping to OES.  It's challenging to use TRI emissions to map to OES, and the descriptions and process need to be explained, including discussions of uncertainty.  There's an interesting admission in page 86, which reads, "In addition, information on the use of chemicals at the facility in TRI and DMR is limited."  Therefore, there's some uncertainty as to whether the mapping of each facility to the OES does in fact represent specific OES.  The uncertainty is quite a bit larger than the word "some" applies here.
                  Mapping emissions to the OES is very challenging, and the process is complicated.  EPA appears to have done an admirable job using the available information.  A broader description of what is and is not in TRI would be helpful.  A crosswalk in Appendix C was very helpful in understanding how the TRI data would map to OES.  Significant elements of professional judgement appear to be involved, which may diminish the objectivity and credibility of this method.  More text is required to explain these decisions.
                  Much of the execution of the methodology is in tables without text descriptions.  While tables are helpful, it would be better to have more supplementing text.  EPA should consider demonstrating the validity of this method by selecting an example where conditions of use are known and then applying the methodology to see if it reproduces the result.  It is not clear why EPA did not leverage the National Emissions Inventory data, which contained additional relevant data on stack parameters.  One limitation that is noted is that TRI would have more recent data. 
                  While that is true, it's unclear that recent data outweighs the use of the larger NEI data set.  So, the methodologies do build largely on the TRI datasets from 2019 and other available data for previous years, but the use of single years versus multiple years needs to be specified as to how that is selected and how the decisions are made for which of the multiple years are used.  One should be aware that emissions data may vary or fluctuate dramatically over years because emission and assets are proportional to total tonnage of chemicals used in a given year.  
                  Discussants (audio skip) were assessing when TRI data are not available for multiple years of TRI.  Justification for higher priority given to modeling results compared to the existence of literature sources used in published risk evaluations -- modeling results are not unconditionally superior to literature-based report estimates.  The 500 pound threshold for reporting should be explicitly stated as the default value for small users in the Agency's general and detailed descriptions of the approach.
                  Discussants found that AERMOD was a reasonable selection at this level of sophistication.  Within Figure 2.1, the emission source icon looks like a cooling tower, which is probably not representative of the sources of toxics.  Actual data are needed from industries that are generating or using the chemicals in question.  That refers to information on page 24.  In Figure 2.3 the approach used here must be to obtain data, not to implement model-based results that are based on unexplained or non-existent data.  
                  If data are unavailable, users should provide them under strict quality control.  It was quite disappointing today to hear that many commentors representing trade groups are criticizing the EPA for an approach that does not have data.  And these data are ones that the trade associations could have easily provided in the interim between the time that this process began and today.  It is not clear how the Agency can model environmental concentrations without input data.  
                  Any such exercise will require the use of adjustment factors or uncertainty factors to avoid a false negative result.  The Agency should describe which safety factors are used.  And if there are no safety factors, then the Agency should provide an explanation for why there are not.  The Trinity Consultant's report was rather lengthy, but it appeared to be a survey of users and not a comprehensive inventory of emission from all users.  I could be mistaken there, but that was my take on that.  
                  Also, the methodology for screening level ambient air pollution has a static distance of 10,000 meters from the point source.  And the comment was made that many air pollutants would have an isotropic plume of exposure depending on the prevailing winds and not all contaminants have similar environmental transport characteristics.  Thus, 10,000 meters may not be as protective for some compounds as for others.  The 10,000 meter distance is arbitrary, but it does seem to protect most contaminants.  But there could be some that could be improved by a larger distance.
                  Deciding which emission types are most hazardous is essential for outcome of fenceline risk evaluations.  Modeling fugitive and stack emissions and selecting the worst-case would seem to be the most conservative approach.  The extent to which an emission type is hazardous would be location and population dependent.  A need for the recommended type of placement would be to have actual emission points located along with stack dimensions and operation conditions. 
                  Mapping facilities to OES from internet searches does not follow typical standards of reproducibility, and it would be preferable to have each company provide operational facility locations, not administrative locations.  The open top degasser inclusion is a good aspect of the approach.  However, release durations and patterns are needed.  And, without data to this effect, worst-case release or high centiles of worse-case releases should always be included.   
                  EPA's integrated indoor/outdoor air calculator does predict concentrations at 100 meters and beyond.  But it's inadequate for measuring estimates nearer to the sources.  And this is important for fugitive emissions.  Exposure scenarios were well-described and well-depicted in Figure 2.5 with a few exceptions.  Does West Coast imply mountainous or hilly terrain?  Maybe flat terrain?  How are building densities and heights considered?  And are the Xs in Figure 2.5 the only areas model, or are all 16 points at 2.5 degree spacing modeled at all distances?  
                  The different kinds of landscapes could vasty influence chemical transports.  Including high centile chemical atmospheric release values, on page 29, would be preferable, maybe something like a 90th or 95th percentile as well just to make sure that that distribution is somewhat well-understood.  This would ensure that the max is not too high and is not unreasonable.  On page 30, the threshold of ten to the minus six for cancer risk is appropriate.  It does seem that some tables later in the assessment use less protective thresholds.  And the more protective thresholds are the ones that are needed. 
                  Also, citations for this cancer benchmark should be provided on lines 595 through 601.  The ability to model multiple atmospheric scenarios is good.  If empirical data are not available, adjustment factors or uncertainty factors should be needed.  Appendix D has release heights that may not represent actual release scenarios.  For example, ten meter heights may not be appropriate for a dry cleaning operation or small machine operation.  Worst-case scenarios may, in fact, be different depending on the topography, building characteristics, or densities, as well as population distributions.
                  The discussants were interested whether land use was considered and land use changes.  There should be ways to operationalize land uses and their considerations using visual analyses.  The visual examination was a good aspect of the assessment.  Maximum emission values were modeled now at only 95th and higher centiles.  Detects need to be harmonized, and inclusion of both maximum and high centile values would be useful.  The modeling approach on page 37 was good and had informative graphics there in Figure 2.7.  Guys, I'm about halfway through.
                  The description of the approach to modeled area sources is confusing in Figure 2.8.  And we've talked about whether these Xs are all the receptor model locations or if there are more.  The IECCU model, wall losses are not included in this model.  This may be an aspect needed for higher tier refinement.  Not including wall losses may be conservative, but that should be explicitly stated in the document.  So, as we move on to drinking water, drinking water exposures are estimated for public water supplies six-year EPA data, but they're only available for some contaminants.  
                  Also, private wells are not considered.  This is a concern since private well users may be exposed to higher concentrations of contaminants removed by certain public health drinking water processes.  And fenceline communities may not have the financial resources to expect individual household level remediation of their water.  The estimation procedures for incidental oral exposures from swimming and incidental dermal exposures from swimming were clearly articulated.
                  Data are needed in these assessments, however.  These data should be gathered by users.  I've talked about uncertainty factors already.  The formulas for risk characterization for non-cancer risks, i.e. benchmarks margin of error, and for cancer risk are presented clearly.  These elements are calculated similarly for other EPA projects.  So, in Line 573, there was a question as to why not use the ADJ_U for 2011 to 2015 data.  The reason provided is unclear and without a citation.  
                  On page 56, it's unclear how the census data related to the number of facilities releasing specific chemicals.  That should be clarified.  Distances of 5 to 60 meters for atmospheric exposures are good inclusions for this approach, but it doesn't match the distances in the IIOAC, as EPA outlined.  Inhalational risks really do need to be modeled at these distances, something like 5, 10, 30, and 60 meters, to capture the shape of the risk profile near the 10 meter fugitive emission threshold and then out to the 100 meter IIOAC minimum distance.  
                  EPA should provide an indication of exactly how close is close enough to pass the prescreen for exposure concentration.  It may be better to modify the IIOAC or develop a supplement rather than to try to predict concentrations closer than 100 meters through the processes that EPA is currently using.  Concentrations at ground level from stack emissions may tend to peak near 100 meters, but that estimate will surely depend on stack height, effluent velocity, and wind.  
                  On page 58, even with a peer-reviewed model, there are many uncertainties and specific evaluations using observations -- for instance, the NATTS network for toxic chemicals -- would improve confidence.  Conservative plume characteristics are appropriate at this level, and should refiners be necessary, operators can provide empirical data related to specific facilities or accept these conservative assumptions.  Having only data for methylene chloride in drinking water is unacceptable.  These chemicals have been under review for several years now, and these data are easily obtainable by initiating or expanding monitoring programs.
                  The discussants noted that water exposure release was ruled out for 1-BP based on physical chemical properties and release data.  Please better define how and what properties are used to evaluate potential risk pathways and the exclusion mentioned above.  For example, what are the cutoff values for Henry's Law of Constants that would be used to eliminate a compound from consideration?  Could or should any environmental compartments be eliminated in a fashion similar for other chemicals or future chemical considerations?
                  There is significant uncertainty related to emissions to air and how much of that will be partitioned into water.  This was pointed out in previous SACC meetings, and a figure will be provided in the written comments.  This is the reason that monitoring data are essential.  Based on volatilization assumptions of wastewater treatment plants, airborne releases from these facilities would perhaps serve as sources of toxicants of concern in water.  This is important for compounds like 1-BP that degrade slowly in air and can be transported long distances and partitioned back into water.
                  On page 63, the cancer slope provided in that table should be explained a little bit.  What is the point of departure?  Is it zero with a slope of four times ten to the minus three per part per million?  In Table 3-38, the lower bound of the OES for chemical processing, excluding formulations, should not be 0.91 kilograms per site per year.  This is due to an apparent misuse/mismatch within one of the files, "SF_FLA_Water Path Exposure Data for NMP."  
                  Also, 59 sites reported to be releasing NMP, on page 63, but how many users were there?  Is this 59 of a small number or 59 of a very large number?  It's important to know what fraction of users are providing data.  Additionally it would be important to know the fraction of the chemical use that is reported that would go towards mass balance.   Also, on page 67, data are needed to feed this model.  And the survey from the Trinity Consultant report may not be comprehensive enough to provide that. 
                  On page 69, the statement that Appendix B includes model parameters and output is misleading.  Appendix B simply includes a list of files that are then linked in the document.  So the format's not really very helpful there.  Also on page 69, the estimated data needed to be comprised of submitted use and release data from users or trade associations.  To improve the scientific defensibility of this approach, data should be required as part of review of these chemicals under TSCA.  
                  To assist the reviewers and better facilitate use of screening approaches by non-EPA personnel the panel suggests adding more comments on specific cells to the Excel models or data sheets.  For example, the fugitive basis description column and the environmental releases to environmental ambient area for 1-BP list best engineering judgement.  What does that indicate?  Please ensure that definitions are provided for abbreviations used as column headings for input tables in the supplemental files.
                  Risk data in Table 3.9 predict risk for the 10th and 50th centile emissions in at least one scenario for each OES.  This should be stated explicitly so as not to leave the impression that only high centile releases generate risks.  On page 90, Table 3-12, the cancer risk of 1 in 10,000 is used, not 1 in a million.  The more protective value is needed.  Also, the conversion of gaseous concentrations from milligrams per cubic meter to parts per million assumes ideal gas at standard temperature and pressure.  
                  And this may be sensitive to results of to -- excuse me, oh, my goodness.  My cursor just got hit.  Hold on, guys.  I just hit about a hundred carriage returns.  So we need to make sure that we don't have a calculation error at higher altitudes.  Pardon me for that.  I hit -- I did.  I hit about a hundred carriage returns and had to find my place.  Okay.
                  And, more broadly, from my perspective at least, the unit of part per million bpm is problematic.  I would say that microgram per cubic meter is preferable.  But if we're gonna use bpm, you should be clear as to whether that unit is mass per mass, volume per volume, or mass per volume.  Just be explicit with that.  Okay.  On page 91, the statement regarding under- or over-prediction of risk from varying exposure durations is misleading.  
                  There are likely data to suggest whether a 1.5 hour exposure duration under or over predicts carcinogenicity of chronic exposure to chlorinated or volatile compounds.  This should be evaluated in the next revision.  Also, it would be useful to include more info on the six-year review and the EFAST data since these concentrations drive the rest of the aquatic analysis.  Omitting estuaries, bays, lakes should probably be more clearly justified in the introductory materials.  There's a question as to whether ambient water samples were collected near any of the facilities that were discharging methylene chloride.  
                  If the monitoring data were not near any methylene chloride facilities, then the water monitoring are at best meaningless and, at worst, misleading.  So monitoring data near facilities discharging these chemicals are what's needed for these type of assessments.  The data in Table 319 need to be revised to include a better approach to handle the wide range of limits of detection.  We came across this in previous SACCs, and there's such wide range of limits of detection that some very serious treatment needs to be done with this.
                  Note that the 10th and 50th centile releases also demonstrate risk exceedances for several scenarios, on page 125.  And that point should be explicitly stated earlier, much earlier in the document.  Data in Table 326 are difficult to reconcile with spreadsheets for the file "Raw_Data-all_cals" and "Summary_Risk_Found" because these spreadsheets have different sorts, and so the data are not in the same columns or the same -- or perhaps the same rows.  So that makes reconciling difficult, not impossible, but more difficult. 
                  On page 143, knowing how much of a reported NMP is released is important.  But of equal, if not more, importance is knowledge about unreported amount of NMP.  What fraction is unreported?  Does an 87 percent release of reported amounts represent 80 or more percent of the total releases or less than 0.8 percent?  We simply don't know.  This same comment goes for all chemicals and all aspects of TSCA risk determinations.  
                  It would be important to know how NMP concentrations in water compare to possible partitioning from air, as was raised in previous SACC meetings.  The highest annual outdoor air concentrations on page 190 are predicted values and should be identified as such.  And this is a general comment for all modeled and predicted estimates.  So there could be some additional clarity in some of the mitigation options.  One discussant mentioned that risk conclusions should not be yes or no but rather maybe or no.  And that's because this is a screening level analysis, and a yes gets you to another level of screening perhaps.  
                  Outcome 5 suggests refinements will be considered in some cases when a COU exceeds risk levels.  Clarity is needed here to determine what to do if refinements are not possible.  An action may not be appropriate if a regulated community were to provide data to fill data gaps.  The recourse afforded users should be included in the proposed use.  Excuse me, in the proposed rule.  Let me read that again.  The recourse afforded users should be included in the proposed rule.  Guys, I'm almost done.  I'm down to uncertainties now.  
                  The approach has large uncertainties, many of which are noted in Section 2.4.  For most areas with uncertainty -- for example, in incorporating incomplete emission data -- EPA takes a conservative approach but not always the most conservative approach to quantifying risk.  But it's often unclear how reliable even the conservative assumptions are.  It may be useful to implement a formal uncertainty analysis to explore how variability in the inputs will introduce variability into the results.  
                  Discussants suggest including aggregate emissions, emission distributions through the year stack and fugitive source heights, temperatures and velocities, as well as meteorology at different times of the year.  Large uncertainties also exist when using predictive models that use results from other predictive models.  For example, estimated 1-BP releases from particular processes were used as input into other models used to estimate fenceline air concentrations.  How did these uncertainties compound themselves?  
                  Emission estimate uncertainties should be described, and the uncertainty and emission estimates and mapping to OES are likely to be large.  But there's no attempt to quantify that.  There are underlying uncertainties in all emission estimates, some of which may be large.  EPA might consult the academic work of Dr. Chris Fry, the current ORD administrator.  Substantial things are missed without a specific -- let me read that again.  Substantial things are missed without a site-specific analysis which goes to whether the methodology is sufficient to act on alone without further refinement.  
                  Aspects would be terrain, nearby buildings, specific information on emission velocity and modeling of separate release points.  There may be other factors that are not listed here.  More information on the availability of these screening tools to predict observed toxic concentrations and sensitivities to output would be very valuable to the interpretation of EPA's screening tool.  Given the uncertainties, this approach may not -- this approach is not appropriate for a full risk assessment and should be exclusively for screening.  As many of the public comments suggest, it's unclear the amount of information added by the ambient prescreening methodology.
                  The IIAOC, which likely produces results with greater uncertainty than the full AERMOD runs, may underestimate risk from certain CES, which would exclude them from the final analysis.  That would not be a good outcome.  It seems resources would be better spent streamlining the process for running the full AERMOD module for all of the CES.  Step 3 of the environmental air release section makes many assumptions with already uncertain annual emission totals.  It would be helpful to present more information on the sensitivity of these results on the assumptions.
                  Finally, a couple of general comments.  There are a few typos and missing references in the text.  Those will be included in our final response.  And there were places were rounding numbers in tables could potentially cause miscalculations if rounded figures were used directly in calculations.  With that, chairman, I will give you the mic back, gladly.
                  DR. DANIEL SCHLENK:  Thank you, George.  Appreciate that synopsis.  Let me go down the list here with associates to see if there's any further additions or discussant.  Dr. Doucette?
                  DR. WILLIAM DOUCETTE:  Thanks, Dan.  I think -- I hope George covered everything in that long-winded summary.  I just wanted to bring up two items that I felt were important and may not have been clearly presented.  I read this document, and I thought a more fundamental question might be is the proposed screening level approach truly useful, given the limitations in the release estimates and the lack of corroborating monitoring data?  
                  So, I mean, from a fundamental point of view -- and I think this has been brought up in the public comments too.  And I know EPA's stuck between a rock and a hard place in doing this, but it's just a consideration.  Are we spending a lot of time generating or looking at these screening models, and it really doesn't improve our estimate of risk?  There might be some -- and I know there is'-- some fenceline monitoring programs for refineries that we might be able to use -- or could be used potentially to help validate or at least evaluate how accurate this screening technique is.  
                  And, then, the other comment that I wanted to make too was how important it is to consider individual chemicals and look at how they are used and what their most likely route of human exposure would be, for example, dry cleaning solvents, 1-BP included.  But we're going to run across TCE and PCE.  The most likely source of human exposure is probably vapor intrusion from groundwater contamination.  And that was also brought up by several of the public comments.  
                  And I think that's critical to, and maybe we can eliminate some of the pathways to look at if we look at the ones that are most important and focus our resources there, if we don't have monitoring data.  The related point I want to make to that is related to co-contaminants.  I've probably have been on dozens of groundwater contaminated sites and measured indoor air contamination related to vapor intrusion.  And if I'm looking at a TCE-contaminated site where that is the main solvent, typically we find another 20 compounds -- 20 related solvents within our analysis.  
                  So it's that whole idea of co-contaminants that I realize is hard to get a grasp on, but that might be dealt with with expanding the uncertainty factors in the toxicological assessments.  And, then, finally -- and I think this is the appropriate time to bring this out -- I keep thinking that without good input data it's hard to have good output data.  And maybe the way would be to turn this around and use the model in a different way.  
                  Under what circumstances, what meteorological conditions, what stack height, what emissions would give a concentration that would be risk?  So, in other words, turn the model around instead of trying to predict a fenceline concentration that we can't really predict very accurately.  Turn it around and what scenarios would be there that would result in a fenceline concentration that would likely be risk?  And that might be a way to start focusing on facilities where we could actually get monitoring data.  So I don't know if I was able to articulate that very well, but those are some of the comments that -- the more general comments that I had.  
                  DR. DANIEL SCHLENK:  Okay.  Thanks, Bill.  Dr. Henneman.
                  DR. LUCAS HENNEMAN:  Yeah, I think George did a really good job capturing my comments.  I guess my primary comment is just to encourage EPA to really look at the uncertainties and the sensitivity of the model to these uncertainties and really give us a picture of, okay, is the information coming out of this screening approach useful for the things that we're trying to screen for?  And other than that, everything was captured, so thanks.
                  DR. DANIEL SCHLENK:  Thank you.  Dr. Li.
                  DR. LI LI:  Oh, yes.  I think George has done a very great job in capturing everything, including my responses.  So I just want to bring another point to everybody's attention, which is about the property of the chemical because I just realized that all the three case chemicals in this report just are very hydrophilic and volatile chemicals.  So, I'm not sure whether EPA just wanted this document designed specifically for these chemicals, the hydrophilic and volatile chemicals or EPA wants it to be a generic practical guideline for other chemicals in TSCA, for example, hydrophobic or minimal volatile organic chemicals, because this is something I think super important in terms of exposure pathway.  
                  So, we just did a comprehensive review, which shows bio-cumulation of a chemical is not likely happen for chemicals that are very hydrophilic, very volatile, or highly unstable.  So this is of course the case for three case studies in this report, but I'm not sure if this is also the case for other chemicals if you want to include other chemicals in the future -- for example, if you want to do the assessment for dioxanes, for mercury, for chemicals that are highly hydrophobic, minimally volatile, or highly persistent, or PBT chemicals.  
                  So maybe the first step to screen the property of the chemical and then determine which approach would be best suited for chemicals with certain properties, it would be better.  Yeah, that's my point.
                  DR. DANIEL SCHLENK:  Okay.  Thank you.
                  DR. LI LI:  Yeah, thank you.
                  DR. DANIEL SCHLENK:  Dr. Reiss?
                  DR. RICK REISS:  Yes, thank you.  I think George did a great job of summarizing a lot of information from all the discussants.  A few things I wanted to comment on, expand on a little bit.  The idea of fenceline monitoring is an interesting one.  I don't know if a dataset is out there that would be helpful, but, I mean, I think a lot of us were left wondering -- the approach wasn't really validating.  You're left wondering whether or not it's really screening things out, one, or whether it's underestimating or vastly overestimating to the point where it's not useful.  
                  So, I mean, if there's any monitoring data out there that could be used for validation purposes, I think that would be really useful.  But I do acknowledge -- I mean, I've been involved in a number of fenceline monitoring initiatives, and those programs are very challenging to design, and very expensive.  So I'm not sure if that's going to be possible.  The other thing I wanted to do is comment a bit on the mitigation.  There is this implication that you could act on this alone -- I mean, this screening level analysis alone, if I read that correctly.
                  I mean, in all EPA kind of guidance documents you generally hear of screening level analysis.  The next step would be refinement, not a proposed rule.  So I'm left a little confused as to how this is different, especially because there's just -- the EPA has an enormously challenging problem here to model all these different facilities with so many data gaps.  And I know you're trying to develop a process where you're inputting conservative assumptions on top of conservative assumptions to make sure you're not underestimating.  
                  But there's some very large -- I mean, Mr. Baker pointed out that you're using this 10 meter stack height.  The stack height can be quite a bit larger in many facilities and especially for high emitters.  And that could have orders of magnitude difference in concentration.  So that's just one example where you could be potentially significantly overestimating.  
                  So, I mean, if you're going to propose acting on this screening level analysis, again, I don't think it's as consistent with the general risk assessment paradigm from EPA.  But I think you would have to be -- want to be more explicit about what you think the criteria would be that you would act versus not act -- act versus not go to a more refined risk assessment first.  So those are the comments I wanted to add.  Thank you.
                  DR. DANIEL SCHLENK:  Thank you.  Okay.  Let's open it up to the rest of the Committee.  First on the list, I've got Dr. Johnson.
                  DR. MARK JOHNSON:  Okay.  Thanks, Dan.  Yeah, just some quick ones.  First of all, this one comment alludes to something I kind of discussed earlier is I would suggest they make it explicit that these criteria are based on exposures to surface water, right?  That could potentially be used -- or would be used by drinking water facilities from municipal treatment facilities to provide drinking water.  So that's the drinking water pathway.  
                  And maybe a conceptual site model would help describe that process.  We're not talking about groundwater here.  We could.  Maybe other chemicals would be more appropriate to do so, but for these two, we're talking about surface water releases that could wind up to drinking water through municipal treatment facilities.  The other comment I have here is regarding the use of TRI data that are yearly estimates of mass.  
                  And maybe others have alluded to this as well, but I'm wondering about peaks and valleys, about spikes and how spikes are considered.  Maybe that's something that we can just discuss in terms of uncertainty, but you may want to discuss that in terms of how that may influence any unreasonable determination of risk.  And that's all I had.
                  DR. DANIEL SCHLENK:  Okay.  Thanks.  Bill, if you don't mind, I'm going to go to Dr. Kissel first, if that's okay?  I'll come back to you afterwards.
                  DR. WILLIAM DOUCETTE:  No, I don't mind.
                  DR. JOHN KISSEL:  Okay.  John Kissel.  I interpreted question 1 to be with respect to clarity and reproducibility of the document.  And I focused primarily on the dermal stuff because that's what I do.  And the dermal approaches are quite limited and straightforward.  So it's easy enough to follow.  That's different than declaring that they're technically good.  I haven't found any errors in the calculations so far, but I caveat that with I'm still doing spot checks.  So I reserve the right to come back to that.  
                  On clarity, I have some kind of correction sorts of things.  I noticed -- and this is limited to things that have to do with dermal because that's where I was poking around -- that a citation of Shenk et al is in the reference list.  But it's not cited anywhere in the text.  So I don't know why it's in the reference list.  In Spreadsheets 13 and 14 of supplemental files 13 and 14, in the equation tabs the units are mis-specified for permeability coefficient and for exposure time.  Permeability coefficient should be centimeters per hour, not liters per hour.  And exposure time should be hours per day, not hours.  
                  But those same variables are specified correctly in the input files or input tabs.  And so, they don't seem to be having any effect on the calculated result.  But it is confusing to have the wrong units on the equations spreadsheet.  And in Supplemental File 14, under NMP, that same permeability coefficient that I queried about earlier, because it's mysterious to me, the source is cited not as Poet (phonetic) as in the text, but as Atkinson (phonetic), which doesn't seem like a likely source.  So I have no idea why that reference is given there.  Those are the specific comments I have.
                  DR. DANIEL SCHLENK:  Thanks, John.  Dr. Davies.
                  DR. HOLLY DAVIES:  Yes, hi, this is Holly Davies.  I wanted to mention a little bit of what Bill was talking about with fenceline monitoring and also kind of flipping and looking at risk and where do we see the risk because that's really what our air quality program does in our environmental agency, right?  They know the facility.  They're looking for -- they have monitoring data, and they look -- is there risk at the fenceline?  Is it possible for a member of the public to be in an area where it's close enough to see risk?  And I see this exercise from EPA as being different than that.  
                  Although, all the data that the states have would be good for validating it because they certainly do have a lot of monitoring.  We have oil refineries here.  We also have chemical plants.  We have a lot of pulp and paper mills.  So we do have a lot of large facilities with a lot of data on the fenceline monitoring.  Something that George mentioned, one of the comments, the notion of how useful or not useful this exercise is, I just didn't want to let that sit.  
                  That seems like an important thing for the Committee to discuss, right, as we're going over these few days.  I wouldn't put a pronouncement on now, but I think that's important for us to talk about and get either consensus or not to consensus.  And, lastly, I would start with mass balance if I was trying to look at where everything is.  I would start with how much methylene chloride is produced, how much is captured by TRI?  All those questions, again, that someone had given George that he brought up are really good questions to answer.
                  DR. DANIEL SCHLENK:  Okay.  Thank you.  Dr. Chaisson.
                  DR. CHRISTINE CHAISSON:  Thank you.  First, my complements to the lead and the associates.  That was incredibly thorough.  And I'm just really impressed.  I wanted to sort of present my big concerns that have to do about data or values used, even if they weren't from data, in both the screening tool itself or the models on which it relies for other values that were mentioned.  I had asked EPA -- I can't -- I tried to go back and take a look at kind of what was the magnitude and the variabilities or what are we talking about?  Are we using average data, or are we using some kind of central tendency?  Are we using maximums or whatever? 
                  There doesn't appear to be a standard of use -- best practices of use for applying any of these values or even knowing what kind of values were used by EPA or, for that matter, anybody who uses it.  So I have sort of three levels of concern about the values that I'd really appreciate hearing the discussants address this.  The first one is this term that keeps showing up, including in the assistant administrator's presentation today, which was this idea of readily available information.  
                  I mean, I think we all have some kind of picture of what that probably is, but I can't find any standards which require a reviewer or an assessor to go out and find the data.  And clearly we've heard many, many instances, including from the public comment, where information's been supplied to EPA which is usually coming in through their comments on individual assessments.  
                  But it's just not accrued for application on the next assessment, or somehow it's ignored.  I mean, the National Tribal Council has, I know, very frequently supplied information to EPA which goes unused, and I'm sure there are many other groups, including industry, which could say the same thing.  So, two points on that, one, what do people think would be sort of a minimum package of where you should go?  
                  There must be information about many of these metrics from the states or from other groups who are compiling information.  And, also, what about some kind of very formal EPA portal through which groups, whether it's industry or communities or whatever, provides actual information detailing the pedigree, if you will, of that information which can be reviewed.  And then, once it's reviewed, it will be used somehow with some guidance and best practices for this kind of thing.  
                  Now that's not just as a matter of contamination values or emission values.  It could also be very definitely on the many other factors which go into the calculations and are sometimes hardwired in these algorithms in these models and which also should include the values that would be employed in the routes of exposure not included in this because I'm going to argue strenuously for inclusion of dietary, for example, as part of this.  
                  And, also, as I think the transparent standards for best practices, should you be defining -- or definition of the value, are you using a point value or using a point from a distribution?  What was the genesis of that value?  Was it modeled and further monitored -- should accompany every evaluation, so every value that's in an algorithm I think should be listed and be transparent so we know what kind of numbers were used here because sometimes the ranges are orders of magnitude.  
                  So, whether you're using -- if you're using a central tendency, that's going to really throw the calculation one way or another.  Or, if you're using an accumulation of values that are either maximum or central tendency, you're going to be able to jerk these answers around a lot and affect the outcome.  And it won't be visible without listing that.  And, by the way, I think that needs to be stipulated before Bill Doucette's suggestion could be executed, which I thought was really a great idea, Bill.  So, anyway, that's my -- Dan, I'll send you those points if you would like them.
                  DR. DANIEL SCHLENK:  Actually -- yeah, you need to send them to George, actually.
                  DR. CHRISTINE CHAISSON:  Oh, okay.  Okay.
                  DR. DANIEL SCHLENK:  All of the people that haven't --
                  DR. CHRISTINE CHAISSON:  Oh, yeah, that's right.  I forgot.
                  DR. DANIEL SCHLENK:  -- been assigned to those questions should be sent to George.  And he will compile that.
                  DR. CHRISTINE CHAISSON:  George, I'll send you those comments if you like. 
                  DR. DANIEL SCHLENK:  Okay.  Yeah, let's, I've got Dr. Gribble, Dr. Ferry, and then hopefully we'll get Bill in here before 5:00.
                  DR. MATTHEW O. GRIBBLE:  Thank you.  This is Matthew Gribble, temporary member of the SACC from University of Alabama at Birmingham.  I appreciated the summary that Dr. Cobb provided of most of my comments on the charge questions provided to him prior to the meeting.  I did want to highlight a few issues that have not gotten a ton of discussion.  The first is the issue of the 10,000 meter buffer being an arbitrary equidistant circle around the polluting facility and the need for incorporating environmental fate and transport considerations for actual fenceline community definitions.  
                  So, Dr. Li highlighted that there were chemical properties of the example chemicals that were consistent, but for non-reactive longer dispersion air pollutants there may be a longer distance than 10,000 meters, potentially still qualifying as downwind of the polluting facility.  So I thought that that consideration might require specific consideration of those site and environmental contaminant characteristics for more case-by-case risk assessment, rather than just drawing a one-size fits all circle.  
                  The second comment was that the example data that they were talking about was EPA six year review data authorized under the Safe Drinking Water Act.  Unfortunately, that's only available for a very limited number of contaminants.  And for unregulated contaminants, only a limited number are sampled through the unregulated contaminant monitoring rule data.  So there's a lot of chemicals that'll be assessed under TSCA.  And I thought it was unclear for some of the emerging contaminants what the data sources might be.  And I'm aware that there are non-regulatory datasets, for example, within the U.S. Geological Survey, for environmental surface water monitoring that may or may not be useful to Agency staff as they're looking to do these fenceline community assessments.  
                  But I thought that relying on six year review data would be unrealistic for a lot of emerging contaminants.  And my last issue for this is just noting that the focus on surface water direct releases into a receiving water body is, as has been discussed and I'm sure will continue to be discussed in later charge questions, a very narrow definition of water pollution and concern for communities that maybe are relying on the water body for subsistence fishing or for groundwater or other non-potable uses.  I think it bears further consideration by Agency staff. 
                  DR. DANIEL SCHLENK:  Okay.  Thank you.  Dr. Ferry.
                  DR. JOHN L. FERRY:  Hi there.  One thing that struck me -- and it has struck me all day -- is listening to people ask questions about the validity of the base data used to construct the models.  And I have noticed -- because EPA has a wonderful tool, the CompTox Dashboard, where they just have a really thorough compilation of data and molecular models together used to generate simple things like solubility, vapor pressure -- that, although they are simple, are still at the center of these exposure risk models.  
                  And the few pieces of those data that seem to be reported in the Excel spreadsheets did not agree with the values on the CompTox Dashboard.  And, in fact, I couldn't find any citations of the CompTox Dashboard in the document itself.  Some of the variations were significant, differences greater than, say 15 percent, between the Dashboard and the citations used in the document.  So I just thought I'd point that out with respect to the question about repeatability here, George.  It would be nice to see some consistency for the data sources here.  And they've already got a wonderful source with that Dashboard to re-cite themselves.
                  DR. DANIEL SCHLENK:  Thanks for pointing that out, Dr. Ferry.  Bill, can you get us out in five minutes?
                  DR. WILLIAM DOUCETTE:  I can get us out sooner than that.  So, Dr. Ferry just brought up the physical-chemical properties, and there is a table, Appendix A1, for the physical-chemical properties used in the case study chemicals, which was brought forward from the previous SACC reviews for those individual chemicals.  So I think they're consistent that way.  The other comment I wanted to make was to address Dr. Li's comment about all these compounds being -- I thought hydrophobic you said, or did you say hydrophilic?  
                  DR. DANIEL SCHLENK:  I think he said hydrophilic.
                  DR. WILLIAM DOUCETTE:  Hydrophilic.  And, again, that's a relative term.  And I think in our previous review of the ten chemicals, the only one that I would consider very hydrophobic was a dye.  What was it?  PV, purple violet 29, and I think the reason that EPA didn't use this in the case studies is that there was no data available to describe its behavior.  And certainly no monitoring data.  
                  So it would have been nice to include a compound that was more hydrophobic.  One was hydrophilic.  One was in the middle being volatile, but I don't think they were trying to pull it from the previous ten chemicals.  And I don't think that there was a big difference, other than that particular compound. 
                  DR. DANIEL SCHLENK:  Okay.  Great.  Thanks, Bill.  So we're looking right at 5:00.  I don't want to shut off discussion completely.  I think what we'll do today is we've had a fairly long day with the presentation and the public commentors, et cetera.  And before I go back to the Agency to ask them for questions or clarifications, let's go ahead and stew on this for tonight.  And then, we'll begin with a discussion in the morning.  
                  You can view -- George, if you --I'm sure you've circulated your comments to your associate discussants.  But, again, for those of you that have provided -- we can't send those out to the entire panel, but to those that have provided comments if you want to look at some of those -- the written document to see if you want to add in or chime in on some of those points, where we can change discussants to Committee members and see whether or not we can get consensus on any of those points.  That would be great.  
                  And, George, if you could, again, assimilate these in bullet points at some point where we could make it a little easier for us to get to the executive summary, that would be great.  If you guys could kind of rank those in terms of importance, that would be fantastic.  And if we can start on that in the morning, and then -- yeah, then we'll go back to the Agency and ask them for questions or clarification at that point and then move forward.  How does that sound?  
                  DR. GEORGE P. COBB:  When do you want those bullet points, Dan?  By the report or for tomorrow?
                  DR. DANIEL SCHLENK:  You know, as soon as you can get them.  But I think at this point it's just out for discussion, if we can actually get those things, but that would be -- at this point get it -- I think getting your written comments out to everybody who had comments today, and then, after that, then we can assimilate.  Maybe after the discussion tomorrow you could get the bullet points off of that.  Yeah.  Okay?  With that, let's go ahead and adjourn for today.  And we'll start bright and early tomorrow.  
                  If you guys could be here at 6:45 -- or sorry, 9:45 Eastern, there's a couple things I'd like to sort of talk about, particularly with the chat box components there.  Some of you, I guess, don't know that you can have direct contact with the chat box, and it doesn't necessarily have to go to everyone.  But let's meet -- if we can do that beforehand, that would be fantastic.  
                  DR. ALAA KAMEL:  Thank you very much, Dr. Schlenk, for chairing the session today.  Thank you for the SACC Committee Members and for the ad hoc reviewers.  And thank you for the public commentors today and thank you for the EPA presenters that made presentations today.  And we hope to see you again tomorrow.  And today the meeting will be adjourned.  Thank you very much.
                  DR. WILLIAM DOUCETTE:  Thank you.  Bye.
                  DR. ALAA KAMEL:  Bye.
                  
                        [MEETING ADJOURNED FOR THE DAY]

OPENING OF MEETING - DAY 2 
                  
                  DR. ALAA KAMEL:  Good morning, everyone.  My name is Alla Kamel, and I will be serving as the Designated Federal Official to the U.S. EPA Science Advisory Committee on Chemicals for this morning.  For this meeting and in my role, I will be opening the second day of the public meeting on EPA's draft TSCA Screening Level Approach for Assessing Ambient Air and Water Exposures to Fenceline Communities Version 1.0.  
                  I'd like to repeat that SACC meetings are subject to all FACA requirements.  These include open meetings, timely public notice of meetings, and document availability to the public.  All documents are available to the public in the docket at www.regulations.gov.  Also note that this meeting is being webcast, transcribed, and recorded, and a live stream of today's meeting is available on YouTube.  See the link on the meeting website.  Also, there is a link to yesterday's meeting on the same website.  
                  We had a very successful opening day yesterday.  I would like to thank EPA's assistant administrator, Dr. Michal Freedhoff, for her welcome and introductory comments.  I would also like to thank the Deputy Director for Management of the Office of Pollution Prevention and Toxics, Mark Hartman, and, also, would like to thank Dr. Kevin Vuilleumier and Rehan Choudhary for OPPT's presentation on the methodologies and the responses to the SACC questions.  Thanks are also due to the public commenters for all their presentations.  
                  Yesterday, the Committee responded to Charge Question 1, and I would like to thank Dr. George Cobb, the lead discussant for this Question 1, and the associate discussants, Dr. Bill Doucette, Dr. Lucas Henneman, Dr. Li Li, and Dr. Rick Reiss.  Now, I would hand the meeting over to the Chair, Dr. Daniel Schlenk.  Thank you.
                  DR. DANIEL SCHLENK:  Good morning, everybody.  I'd like to begin today's meeting with a roll call of the Committee members if that's possible.  If you're here, just please answer "present" or "here."  I'll just go alphabetically through our list.  Dr. Apte.
                  DR. UDAYAN APTE:  Present.
                  DR. DANIEL SCHLENK:  Dr. Baker.
                  DR. MARISSA BAKER:  Present.
                  DR. DANIEL SCHLENK:  Dr. Blystone.
                  DR. SHERI BLYSTONE:  Present.
                  DR. DANIEL SCHLENK:  Dr. Calder.
                  DR. RYAN CALDER:  Present.
                  DR. DANIEL SCHLENK:  Dr. Chaisson.
                  DR. CHRISTINE CHAISSON:  Present.
                  DR. DANIEL SCHLENK:  Dr. Cobb.
                  DR. GEORGE COBB:  I'm here.
                  DR. DANIEL SCHLENK:  Dr. Davies.
                  DR. HOLLY DAVIES:  I'm here. 
                  DR. DANIEL SCHLENK:  Dr. Doucette.
                  DR. WILLIAM DOUCETTE:  Present.
                  DR. DANIEL SCHLENK:  Dr. Ferry.
                  DR. JOHN FERRY:  Present.
                  DR. DANIEL SCHLENK:  Dr. Gribble. Dr. Gribble?  Okay.  Dr. Heiger-Bernays.
                  DR. WENDY HEIGER-BERNAYS:  Present.
                  DR. DANIEL SCHLENK:  Dr. Henneman.
                  DR. LUCAS HENNEMAN:  Present.
                  DR. DANIEL SCHLENK:  Dr. Johnson.
                  DR. MARK JOHNSON:  Here.
                  DR. DANIEL SCHLENK:  Dr. Kissel.
                  DR. JOHN KISSEL:  Present.
                  DR. DANIEL SCHLENK:  Dr. Li.
                  DR. LI LI:  Present.
                  DR. DANIEL SCHLENK:  Dr. Messerlian.
                  DR. CARMEN MESSERLIAN:  Here.
                  DR. DANIEL SCHLENK:  Okay.  Gotcha. Dr. Przybyla.
                  DR. JENNIFER PRZYBYLA:  Present.
                  DR. DANIEL SCHLENK:  Dr. Reif.
                  DR. DAVID REIF:  Present.
                  DR. DANIEL SCHLENK:  Dr. Reiss.
                  DR. RICK REISS:  Present.
                  DR. DANIEL SCHLENK:  Dr. Rowlands.  Dr. Rowlands?  Okay.  Dr. Sathyanarayana.
                  DR. SHEELA SATHYANARAYANA:  Here.
                  DR. DANIEL SCHLENK:  Dr. Unseld.
                  DR. MONICA UNSELD:  Present.
                  DR. DANIEL SCHLENK:  Dr. Vorhees.
                  DR. CHARLES VORHEES:  Present.
                  DR. DANIEL SCHLENK:  Let's go back.  Dr. Gribble.
                  DR. MATTHEW GRIBBLE:  Present.  Sorry about that.
                  DR. DANIEL SCHLENK:  No worries.  Dr. Rowlands.  Dr. Rowlands?  Okay.  Hopefully, he doesn't have the audio issues again there.  Okay, thank you for that.  
                  
PANEL MEMBERS: FOLLOW-UP ON PREVIOUS DAY
                  
                  DR. DANIEL SCHLENK:  The plan for today, as I mentioned yesterday, was we'll finish discussions on Question 1 that was provided by the Agency.  Some of the comments that were presented and discussed, I would like to sort of finalize that discussion, and then move forward to the Agency and ask them for questions or clarification at that point.  Let's continue the discussion of Question 1.  Dr. Cobb had presented a fair amount of information.  There were some other comments that were provided after that.  
                  At this point, do we have consensus, I guess, at this particular point?  Is there some discussion about some of the points raised in terms of whether or not those are part of the consensus?  How many Committee members feel strongly about those points?  At this point, let's go ahead and continue that.  Does anybody have any further input for Question 1 at this time?  A little sleepy this morning, I guess?  Any other comments?  
                  Okay.  I guess, George, you have what you have.  Yeah, if you can put that together, that would be fantastic.  At this point, then, let me go to Rehan and ask if he has any questions regarding the comments that were made yesterday, questions or clarification.
                  DR. REHAN CHOUDHARY:  Good morning, everybody.  This is Rehan Choudhary from the EPA.  I think the first charge question was really focused on clarity and us trying to understand what we could enhance and revise if reviewers, such as yourselves, were trying to look through something, reproduce something, and you weren't able to do so.  I think the way you provided and laid out that feedback is very helpful to us.  The way it was being presented, it felt that, if -- section this, line this, this could use improvement or enhancement.  
                  If that's the way it comes to us, I think it'll make it very easy for us to go through it and try and tackle and address those items and hopefully make those items clear.  The only thing I would highlight is -- I know the first question was focused on how the report and technical aspects were presented, whether they were clear.  There was a lot of focus or discussion around uncertainty of the approaches yesterday.  We'll see how that carries over into subsequent charge questions.  
                  But that's really something we are looking forward to hearing from the SACC panel itself, with respect to the expertise you bring.  Does the uncertainty lean conservative?  Do you think it's not conservative enough?  What particular or specific actions could the EPA take to address those uncertainties?  I think that would be very helpful to us.  I think I'll stop there. 
                  DR. DANIEL SCHLENK:  Okay, great.  Dr. Johnson, you have your hand up?
                  DR. MARK JOHNSON:  Yes.  Sorry, Dr. Schlenk.  It took me a while to go through my comments to see if I missed anything.  But there was one for clarity that you may want to consider.  On page 25, Figure 2.3, if you follow the logic in the figure, if the data do not exist, either analytical or modeled, further evaluation and refinement is called for.  If you just look at the figure, it's unclear.  You have more explanation in the text.  So I suggest maybe the language in the last box be changed to "consider evaluation of alternative or surrogate data sources or collection of further data" just to be a little more explicit to the reader for that figure.  
                  I do have some other suggestions, but I think they fit better under other questions.  I'll just wait on those to get to those questions to provide that.  Thank you.
                  DR. DANIEL SCHLENK:  Dr. Blystone.
                  DR. SHERI BLYSTONE:  I've been debating whether to bring this up for Question 1 or somewhere else.  But I think, because it's clarity, I'll bring it up here.  This is very general around the title of the document and the use of "fenceline communities."  I know the EPA does define fenceline communities in there, but I think, when you say that, people get a picture in their mind.  
                  So I think there could be some further clarity around the scope of what this document covers, going from an industrial facility with a fence that people might think of when they're talking about fencelines down to those small commercial facilities that might be in a neighborhood.  It was brought up a couple of times yesterday.  But I think that the EPA could perhaps make it more clear, the broad scope of things that they're trying to cover with this guidance.
                  DR. DANIEL SCHLENK:  Great.  Dr. Davies.
                  DR. HOLLY DAVIES:  Since Sheri brought this up, I'm going to agree with her.  When telling people I was looking at this fenceline document, a lot of quizzical looks, people not knowing what it was.  I think it would be good to have more explanation around that, more descriptive.
                  DR. DANIEL SCHLENK:  Okay.  Now everybody's waking up, I guess.  Dr. Unseld.
                  DR. MONICA UNSELD:  Yes.  I wanted to also support Dr. Blystone's comments.  I think if people look at it in terms of disproportionately impacted or something with a little more clarity, we understand that it's going to bring in other routes of exposure, not necessarily just living next door.  If it's disproportionately impacted, that's one way you can bring in the fact that you may have a Dollar Tree that has more toxic products instead of a Target in your community or your diet or something like that.
                  DR. DANIEL SCHLENK:  Okay.  George, hopefully, you're getting these comments as well.
                  DR. GEORGE COBB:  I am.  I'm capturing these.  I'm putting notes in the document now.  Sheri and Holly -- and I'm sorry I wasn't looking at the last speaker -- thanks for those comments.
                  DR. DANIEL SCHLENK:  Dr. Unseld.
                  DR. GEORGE COBB:  Some of this is already there, and we'll just double check to make sure it's sufficiently detailed for your needs.
                  DR. DANIEL SCHLENK:  Great.  Okay.  Any other comments on Question 1 before we move on?  Dr. Choudhary, please.
                  DR. REHAN CHOUDHARY:  Yes.  Some of my teammates brought to my attention one thing we did want to bring forth for the panel again is the way the opening was done yesterday with Dr. Michal Freedhoff.  This screening level approach, Version 1.0, it has a specific purpose, to try and address seven of the first ten risk evaluations.  It's been put forth in such a way where we think we can expand its capacity for subsequent risk evaluation.  
                  That's a dichotomy that I would really like to reemphasize and remind everyone that we're trying to do something with seven of the ten risk evaluations that have already been completed.  Is the methodology as is?  What can it do for that?  Then how can it be expanded for newer risk evaluations we do?
                  DR. DANIEL SCHLENK:  Great.  Thank you for that comment.  
                  
CHARGE QUESTION 2
                  
                  DR. DANIEL SCHLENK:  Okay.  Let's go ahead and move on to Question 2.  If we can, put that up and read that into the record.  Thank you, Mr. King.
                  DR. REHAN CHOUDHARY:  All right.  This is Rehan Choudhary from the EPA.  Charge Question 2 to the SACC Committee: "For instances where EPA is focused on the potential impact of a single release source, air or water release, for a given condition of use, or COU, is it reasonable for EPA to use this screening-level approach, Version 1.0, to conclude that chemical exposure from a single-release source for a given COU is not a concern if exposure results of the methodology, when compared to relevant toxicological benchmarks, do not indicate any potential human health risks to fenceline communities?  
                  In your response, please provide examples or explanations to support your conclusions or suggestions." 
                  DR. DANIEL SCHLENK:  Okay.  Our lead discussant for that is Dr. Przybyla.
                  DR. JENNIFER PRZYBYLA:  Good morning and thank you for everyone who commented on this question.  I collated and summarized the responses as best I could.  Any omission was purely my mistake and not intentional.  Please feel free to, at the end of this, speak up if I unintentionally left out any of your responses.  SACC members have identified several major limitations to using a single-release source for the screening-level approach, including first, as we recognize that as a screening approach, it is best used as a first step in a tiered assessment to identify areas where a more detailed review may be called for.  
                  At least one Committee member noted that, as there are numerous conservative assumptions in the approach as drafted and it could reasonably be used to focus further risk evaluation on areas where a concern is indicated for the pathways and receptors included, the lack of consideration for cumulative exposures, multiple-source exposures, or additional risk factors, such as stress, poverty, and/or diet, that can synergistically affect environmental exposures may underestimate the adverse effects from the environmental exposures in fenceline communities.  
                  Also, there is a concern that there are sources that are not reporting emissions, yet still contributing to exposures.  Additionally, there is not the ability to incorporate existing background concentrations of contaminants when conducting the single-source analysis.  These are complex issues, and the Committee recommends that any changes to EPA's approach to include such issues go through the peer-review process.  
                  The current screening process does not address fenceline communities that rely on private domestic wells as groundwater contamination is possible.  The water pathway exposure assessment focuses solely on surface water, which may underestimate exposure.  Additionally, the E-FAST model may underestimate concentrations because it assumes an equilibrium between water and the atmosphere when concentrations of organic contaminants may be influenced by absorption to soils.  
                  Similarly, there is a significant uncertainty related to emissions to air and how much of that will partition into water, as was pointed out in previous SACC meetings.  This is a reason that monitoring data are essential.  Based on volatilization assumptions of wastewater treatment plants, airborne releases from these facilities would serve as sources for toxicants of concern.  
                  The screening analysis relies heavily on one type of data for each medium with many assumptions for modeling that does not represent all communities, especially tribal and indigenous communities.  Concerns were raised about the accuracy and completeness about the data used to conduct the screening analysis.  Specifically, there is concerns about the accuracy of TRI and NIEI data and that the TRI data lacks inclusion of emerging contaminants, such as PFOS.  Also, exact discharge locations must be known.  
                  Otherwise, a worst-case scenario for release points should be used.  There's a concern about using circuit data instead of monitoring data at the full-screening phase.  Additionally, the SACC members identify that the models used to estimate exposure failed to account for societal shifts, like the recent increase of working and schooling from home, and the meteorological models failed to incorporate potential changes or disasters driven by climate change.  
                  At least one member suggested closer distance should be modeled for inhalation risk.  Field analysis does not include conclusions on fenceline risks to animal or plant populations, which is unlikely to be captured by TRI data.  There is a lack of explanation on how limited toxicological evidence for health endpoints or benchmarks is addressed.  Because the TRI data has zero-emission dates, it is unclear how noncontinuous exposure is addressed and if this could be an overestimation of risk by averaging in zero-emission days into exposure days.  
                  Because of these reasons, it was suggested that EPA does not make definitive conclusions using single-release source analysis unless there is a high degree of uncertainty that there is truly a single source and instead make conclusions about the screening including both "failed to detect" and "indication for concern," or that a chemical can be "reasonably anticipated" to cause a health effect.
                  DR. DANIEL SCHLENK:  Okay.  Thank you very much.  Our associate discussants for Question 2 are Sheri Blystone.
                  DR. SHERI BLYSTONE:  Hello.  Jennifer did a great job.  I have nothing to add.
                  DR. DANIEL SCHLENK:  Thanks.  Our second associate is Sheela Sathyanarayana.
                  DR. SHEELA SATHYANARAYANA:  I think that was a great summary, and I had submitted my comments before.  The only thing that I would add is that there were some differences of opinion I saw in the comments that came in.  I think one of the things you read is that "the Committee recommends," and I'm not sure that that was really the case for that comment.  It was just one person who recommended that.  I'm just trying to make that clear, that sometimes there are differences.  
                  That was with respect to combining environmental exposures and nonchemical stressors, which is an emerging area of science and certainly an emerging area of risk assessment and deserves significant attention with respect to fenceline communities.  I just wanted to raise that one point.  
                  The other point that I wanted to make is that Rehan had talked about how do we apply this to past chemicals, so at least to the first chemicals that have already been reviewed?  One of the things that's come up with some of the chemicals is that sometimes there's no health data at all on those chemicals.  Then they're making conclusions based on no health data or trying to make conclusions based on no health data.  There was a lot of discussion about how to do that in past SACC meetings.  There was no discussion of that in this report.  So it would be great to see that here in terms that Version 1.0 and moving forward is incorporating an approach there that reflects, maybe, some of the comments from SACC in the past.
                  DR. DANIEL SCHLENK:  Okay.  Great.  Thanks.  Dr. Vorhees.
                  DR. CHARLES VORHEES:  Yes.  I think Jennifer certainly captured all my comments, and I don't have anything further to add.
                  DR. DANIEL SCHLENK:  Dr. Ferry.
                  DR. JOHN FERRY:  I don't have anything to add.  Thank you.
                  DR. DANIEL SCHLENK:  Okay.  Any other Committee members?
                  DR. MONICA UNSELD:  I have a question.  This is Monica Unseld, and this is just a clarification.  When saying recommendations from past SACCs, are you saying that, when Version 2.0 comes out, they should mention that previous SACCs have asked for this?  I just want to make sure I'm on the right page.
                  DR. DANIEL SCHLENK:  Who are you directing the question to?
                  DR. SHEELA SATHYANARAYANA:  Probably me.
                  DR. MONICA UNSELD:  Yeah.
                  DR. DANIEL SCHLENK:  Okay.
                  DR. SHEELA SATHYANARAYANA:  This is Sheela.  I guess, what I was saying is that, when there's been no health data -- basically, at different times we've suggested, or certain members have suggested -- that you cannot make necessarily a risk determination when you have no data in front of you.  That has been put into previous SACC assessments.  It's taking that into consideration or at least adapting an approach.  Certainly, the suggestion is not to not do a risk determination but certainly to take that information into account to create a new approach when there is no health data.
                  DR. MONICA UNSELD:  This is Monica again.  Thank you.  I know yesterday people had commented that SACC had already received this.  I just wasn't sure if the process was SACC says something, and then it goes into the oblivion, or should we expect the next version to reflect that SACC said something.  Thank you.
                  DR. DANIEL SCHLENK:  We all have our opinions on that comment sometimes, I think.  Dr. Kimmel.
                  DR. JOHN KISSEL:  Kissel?
                  DR. DANIEL SCHLENK:  Oh, sorry. Sorry about that.  Yes.
                  DR. JOHN KISSEL:  There is a Kimmel, or was, at one time.
                  DR. DANIEL SCHLENK:  Yeah.  I know.
                  DR. JOHN KISSEL:  I guess my first point in response to the question is, is this useable?  I would say that, first and foremost, I don't know where the Committee's going to come out.  If there's a dissenting opinion, I want to be on that side.  I don't think it's usable because I think it leaves out too many pathways.  Screening is supposed to be conservative.  
                  The first reason that this is not conservative, although individual assumptions might be conservative within the pathways that are actually considered, there's so many pathways that aren't considered that it, overall, can't be considered conservative.  In particular, I'm concerned that we still aren't getting to groundwater.  The history of groundwater contamination near industrial facilities and commercial facilities is so extensive that ignoring it is just not acceptable at this point.  
                  That would include both groundwater transport and consumption of the groundwater and soil vapor transport in the vadose zone.  I would point out that EPA has online something called the Regional Screening Limits calculator, which you can go use, and it has both a soil-to-groundwater and a fish pathway in it.  So EPA already has existing methods for addressing some of those concerns and chose to ignore its own methods in putting together what we've seen in this document.  
                  Again, I'm particularly focused on dermal pathways, so I will point out more specifically how dermal pathways are not conservative.  There's no vapor-to-skin in this document.  All we have is the swimming pathway, so recreational exposure to water and then absorption from water into a human being.  As someone pointed out earlier, tap water is also contacted dermally, and so that pathway is not here.  
                  Now, for some of these things, the particular compounds we're looking at wouldn't be very important, but in a screening calculation, you can do that calculation and then demonstrate it.  For instance, in RAGS Part E from 2004, there is a calculation of an oral-to-dermal ratio.  It's actually dermal-to-oral ratio.  It's an EPA methodology.  It already exists, and it allows you to estimate the relative importance of bathing exposure to skin to drinking tap water.  For the compounds that we're talking about here, that number's likely to be low.  Then you can say, okay, we can leave out the dermal pathway.  But you need to do the calculation first and demonstrate it.  
                  The way you do screening is you don't decide to toss stuff out; you do calculations and say we can then toss stuff out.  That methodology already exists in EPA's toolkit, and they ignored it.  The vapor-to skin, which actually is potentially much more important, the methodology was developed by Weshor Nazorov (phonetic) in the early 2010s, and it has now been adopted.  It can be found in the Computer Exposure Model.  
                  EPA has worked up the methodology that Weshor Nazorov developed.  They have it in their own handbooks.  There is something called the DI Ratio, which in the Weshor Nazorov case, is the dermal vapor-to-skin ratio.  The physical chemistry here is a little, maybe, surprising, but there are a few compounds for which the skin actually takes up material from vapor as efficiently as lungs do or maybe even more.  Most chemicals don't work that way, but a few do.  
                  I've been urging EPA, in the TSCA process, to screen all the chemicals for this particular phenomenon.  Last night, I did the calculations for our three chemicals.  Methylene chloride and 1-Bromopropane come in fairly low.  NMP has a dermal vapor-to-inhalation ratio which is much greater than one.  And for compounds like that -- this is the old problem in industrial hygiene -- you just do an inhalation exposure, and you say you're done.  That may or may not be how people are actually exposed.  
                  So the air standards by themselves may be not protective at all.  I think EPA already knows this.  They already have published a method, and they aren't using it here.  That's not conservative.  
                  Two other points, the dermal methodology that is here assumes steady-state absorption, which is okay for compounds with low lag times.  So three-hour exposure would reach steady state if you had a compound that has a lag time for penetration of the skin of about half an hour, which, again, we're talking about solvents.  
                  They go through skin pretty fast.  It's not a bad assumption for these compounds.  But if it's the generic method that will be applied to all compounds coming up later, and you have more lipophilic compounds that are slower to go through the skin that dissolve into the skin relatively easily but then they don't pass through it relatively easily, then a steady-state assumption is a bad assumption and will underestimate total uptake.  
                  If you take a person with clean skin and you expose them to a chemical, the first thing that has to happen is the absorption capacity of the skin has to be filled.  So before you see it and then come out the other side of the skin, you have to fill up the membrane.  That's basically the lag time.  For compounds with a low lag time, then a steady-state assumption will underestimate short-term uptake badly.  So that's a problem.  
                  The last bit is the release days versus exposure days issue, as one of the public commenters point out the other day.  There was a great example in West Virginia, that coal cleaning chemical.  It got dumped into the Kanawha River.  The event lasted not very long because the tank just drained right away.  But once it got into the water distribution system, then the exposure lasted weeks because water distribution systems are very difficult to purge.  The exposure went on for much longer than the number of release days.  
                  Those are the things that I have written down.  I am done for now.
                  DR. DANIEL SCHLENK:  Thank you, Dr. Kissel.  Please, if you can get that information to Jennifer, that'd be great.  Dr. Heiger-Bernays.
                  DR. WENDY HEIGER-BERNAYS:  Yes.  I concur with the presentation that had already been made.  In addition, I do agree with Dr. Kissel's comments and was actually going to make similar overarching comments regarding the utility and reproducibility of the method.  With regard to the reproducibility of the methods, it's really about the lack of inclusion of relevant pathways, specifically because this is a screening assessment where one would screen in order to eliminate irrelevant pathways.  
                  With regard to single COUs, as was specifically asked in the question from a single-release source, it is useful to examine the COU and to understand which of the COUs are the drivers of occupational exposure and risk.  It's also useful for understanding how much additional risk can be attributed to the nonoccupational exposures and vice versa.  
                  The approach as presented does not allow for the well-documented evidence that people who work in these facilities often live nearby, and there are a lot of mobility data that are available.  I'll make this specific in my written comments.  Studies from take-home hazards often do have release data that connect the location or facility with where people are living.  
                  With regard to the toxicological benchmarks, while the POD selection is based on published and vetted literature and prior EPA Committee work, EPA has the opportunity here and the ability to use the recommendations that were suggested in one of the commenter's statements yesterday.  Those are the recommendations of the National Research Council in 2009.  And these include harmonizing the approaches to non-cancer and cancer risk assessment.  
                  Not only is it useful to have a single approach that conveys both the uncertainty in the POD selection and is more readily translatable but also addresses the fact that responses are variable amongst people in the population.  Using this probability approach also recognizes that the epidemiological data on health effects associated with exposure to these three chemicals, but also looking beyond that will be in the TSCA docket, have non-cancer effects at increasing doses but also have a suite of effects that can be formally recognized and should be important, allowing the regulators to make decisions to make exposures below the point of departure.  
                  Now, for screening, that may not be as important.  But, quantifying non-cancer health risks due to environmental exposures is important to contextualize population-level health effects and allow more thorough assessments and allow, frankly, additional information to be gleaned if the screening risk assessment is intended to be used as EPA presents, where it will be used to make more specific analyses.  
                  Second, if the point-of-departure approach is used as demonstrated in the screening assessment, uncertainty and variability do need to be accounted for.  We've heard this in other comments.  But this information should be gleaned from the scientific literature, of which I know that EPA is aware.  Of specific concern is that the selected point of departure needs to be supported in light of the health data, the epidemiological data, the non-animal data, the NAMs that EPA is using, has developed, and certainly has the capability to use in developing and examining that point of departure.  
                  People's sensitivity to chemicals is dependent on biology, and the biological response is a function of health, also, at the time of that exposure.  So for people who are older, who have experienced infectious diseases, young children, and even presumably healthy young adults, respond to exposures with a suite of outcomes.  It could be that, at the screening assessment, there isn't this level of detail but certainly perhaps an uncertainty factor to account for these biologics when assessing risk, particularly for the screening-level approach.  
                  With regard to the NAMs, there has been amazing work and advances done at EPA itself and in, certainly, coordination with NIEHS.  I think that in the interest of moving forward quickly with the screening assessments, since that is the objective here, is not to, I believe, get bogged down so that nothing happens.  But I think that there's an opportunity here.  Maybe the opportunity is to recognize these, I'll call them, gaps in the current screening analysis and apply those, a series of uncertainty factors, directly to the points of departure or to the exposure estimates.  Thank you.  That's it.
                  DR. DANIEL SCHLENK:  Okay.  Thank you very much.  Dr. Davies.
                  DR. HOLLY DAVIES:  Hi.  I wanted to bring up the insufficiency of the way the method goes from this very general TRI data, data that people have mentioned coming from one survey for things, and then going to specific points on a map and just kind of drawing the concentric circles because, once you're at a specific spot on the map with the facility, then you do have so much more information.  You know is this spot in a valley where the air is going to behave differently.  
                  I think, of course, of Washington state where the Columbia moves, and the air patterns change very locally there.  Then, it's not sufficient to say, through these circles, we don't see risk out to this point.  So, then, we don't see risk because there could be when you're talking about specific places.  So I don't think that's a sufficient way of doing it.  
                  As I think someone mentioned yesterday, it doesn't take into account the changing land-use patterns.  To say there's currently no houses there doesn't take into account potential risk moving forward because TSCA's not about land-use patterns; TSCA's about chemical uses and what chemical uses are allowed.  
                  The other point I wanted to bring up was -- I haven't done this yet, so this is kind of a placeholder -- looking at, basically, how we do permit and permit criteria and comparing that to the PODs.  I understand why EPA decided to take the PODs that we discussed for the initial risk evaluations and move those forward.  But of course, we have levels.  When we're looking locally for permits, we take into account other things.  But we look at what level it is as opposed to like where the risk is, how far out it is.  We'll look at the fenceline, how does it compare to the criteria?  Just as a note, I was going to compare the two different methods.  
                  Although, of course, in some of our water quality criteria, we do take into account fish consumption, other pathways that people have mentioned here.  Thanks.
                  DR. DANIEL SCHLENK:  Okay.  Thank you.  Dr. Sathyanarayana.
                  DR. SHEELA SATHYANARAYANA:  I just wanted to make one point of clarification that Dr. Kissel's comments reminded me of.  They asked, "Is this sufficient," in the question.  I think, from the totality of the comments, the answer is no.  And I just wanted to clarify that I agree with "the answer is no" for a variety of reasons, many of which were brought up yesterday.  Often, when you're looking at the health characterization, it is so dependent on accurate exposure characterization.  
                  In response to Question 1, there's been many, multiple comments about the exposure characterization not accounting for the multiple pathways, cumulative exposure, burden, and I think that that's what leads to the answer being no here.  I just wanted to clarify that point.
                  DR. DANIEL SCHLENK:  Okay.  Got that.  I lost you.  Bill, you had your hand up.  Got your question answered, I guess.  You're on mute.
                  DR. WILLIAM DOUCETTE:  I was going to let it go, but I thought maybe this is an okay time to bring it up.  It's been obvious to me through the last ten chemicals and this session here that there's a significant overlap in the responses to the general charge questions.  It keeps happening over and over again, and I'm not sure the best way to deal with that.  But part of it is that the questions are -- they're like leading questions.  
                  I wonder if a section-by-section review is appropriate so that the general question might be, what are the main strengths and weaknesses of the document, and does it achieve its overall goal?  That way, we wouldn't keep repeating the same things over and over again.  That's just a comment based on, I guess, my frustration with the last ten meetings.  I thought we had discussed how the charge questions kind of focus you on areas that maybe they really shouldn't.  So I just thought I'd bring that up now, Dan, and I apologize for rambling on like that.
                  DR. DANIEL SCHLENK:  No worries.  I think what we've done in the past, Bill, if you recall, we usually have a comment period at the end where we say, yeah, maybe it'd be better to ask questions this way and make those recommendations.  I think we will do that again at the conclusion.  Again, I see your point in terms of the redundancy of the answers that are there, so we'll definitely do that at the end and make sure that that's a component of the report.  Yeah.  Dr. Johnson.
                  DR. MARK JOHNSON:  Thank you.  I also agree with the previous comment.  I want to point out that this really isn't a risk assessment; it is a screening assessment.  It does not estimate the probability of an adverse event occurring, which is the definition of risk.  There's no probabilities here.  We have quotients, or we have MOEs.  But I think the overall process is a reasonable one, specifically for these two chemicals.  
                  If we have things that have different chemical/physical properties that we expect may be persistent, may not volatilize as readily, we may also want to consider other pathways that were discussed earlier, like wet and dry deposition and infiltration of the groundwater.  Maybe there's some adjustments that could be made, some of the ones that were brought up earlier by other commenters.  But I think the overall process is a relatively reasonable one.  
                  You don't want to get bogged down into too much quantitation because I think it gives a false perception of precision.  Risk assessment by nature is one that uses a lot of assumptions.  It was definitely used a lot of assumptions here.  We've got to be careful not to take it too far as being precise.  It is not.  I think, overall, it roughly achieves the correct objectives, maybe requires a little more tweaking here and there.  I may want to make specific caveats given specific chemicals that have different chemical/physical properties.
                  DR. DANIEL SCHLENK:  Okay.  Thank you, Dr. Johnson.  Dr. Chaisson.
                  DR. CHRISTINE CHAISSON:  I think these have been great comments.  I just wanted to, once again, raise this.  When we're talking about something being conservative as an answer or not conservative enough or whatever, I do not think we actually know whether or not these calculations are conservative or not for two key reasons.  We don't know what the data or value choices were for many key components of the algorithms.  We do not know when they take a concentration in the air or in the water or whatever, and they start. 
                  Then the process has many other factors in the algorithms that are chosen from handbooks or other sources.  We don't know if there was some kind of amortization across time.  I'm not criticizing it.  I'm just saying it's completely opaque.  So the summation of the effect of all of these other factors going into the algorithm could bring what initially looked like a conservative estimate down to something that is clearly not going to be viewed as conservative in its summation.  
                  So in order to even have a sort of gut feeling as to whether it's conservative, at a minimum, all of those factors need to be identified and need to be defined as to where the value point was chosen.  Was this some kind of averaging number?  Was this an extreme?  Was it unique for a particular?  Was it a model number?  The reliance on other programs and just saying to somebody, you can go look it up, well, I tried looking some of this up, and it's laborious to begin with.  But it's completely opaque.  
                  The second point is, especially when we don't know what health endpoints are going to be most critical for different life stages, we do know that there is an averaging or assumptions about how long the release is and over what period of time will the exposure be?  So that has a tendency to, if you will, dull down the spike events.  That is something that I think is a real concern in a screen.  Now, later on, in the more detailed risk assessments, that can be dealt with.  But in a screen, I question whether it's always appropriate to reduce by amortizing.  
                  You can't tell the difference in those numbers whether you've got a long-term lower exposure or whether you have spikes.  I just want us to keep an eye on the ball when we're talking about whether it's adequate, whether it's reflecting upper bounds, or whether it's really conservative because I do not think the way it's constructed right now that we know the answer to that.  Anyway, that's my opinion.  Thanks.
                  DR. DANIEL SCHLENK:  Okay.  Again, let me also just remind folks to get their written comments in to the lead discussant as you're making these oral comments.  Dr. Choudhary, I'm going to get to you after I get through the Committee, okay?  At that point, we'll go back to you for questions of clarification.  Dr. Unseld.
                  DR. MONICA UNSELD:  Yes, this is Monica Unseld.  This is my first time being on an ad hoc committee, so maybe this is a clarification point.  We've said multiple times that the reality is that people are not exposed to a single use and that this is just not reflective of what reality is.  
                  So it may be beneficial to say, like, and for purposes of screening before we get to risk assessment, this is why we are looking at one chemical, because I'm having difficulty seeing how you can look at one chemical and say that's a great screening method.  And then, let's just say, we take it out of the test tube, and it's chaos because it's not reflecting what's really going on.  So I'm not confident.  Again, this may just be a need for clarification as to how this screening is going to fit into reality.  
                  As others, I also have many concerns that there are so many assumptions and estimates when some of these could be refined by just engaging with stakeholders and asking, where is the POD?  Where is the facility boundaries?  Are you in a river valley?  These sorts of things.  
                  I wonder, when it comes to defending this, should it have to be that way?  Should we have a method of -- look, we have peer-reviewed literature, but we also have direct engagement with stakeholders.  So that's my comment.
                  DR. DANIEL SCHLENK:  Okay.  Any other comments from the Committee?  Dr. Chaisson, your hand is still up.  Do you have any -- no.  Okay.  If there's no further comment at this point, let's go back to the Agency and provide time for questions or clarification.  Dr. Choudhary.
                  DR. REHAN CHOUDHARY:  Yes.  Good morning, everybody.  This is Rehan Choudhary again.  As the discussions were ongoing, various technical members of the team wanted to clarify certain things.  I think there was a portion there that maybe got the TRI data being very general, and then how do we go from TRI data being general to identifying points around a facility, and are those representative of that particular geography?  The team wanted to clarify that, when we have TRI-reported data, we also have lat/long information for that facility.  
                  The full screening methodology on the air side then tries to pick the closest meteorological data and stations and use those as being representative for those particular facilities.  So there is an attempt to go from -- okay, you've got TRI-reported data.  This is the geographical coordinate.  We pick the closest or most representative meteorological data or met data, and that's how we model those conditions.  I know the pre-screen does it a little differently, so we wanted to clarify.  The full screening methodology is more granular than the pre-screen.
                  DR. DANIEL SCHLENK:  So is that a question that you're providing or more information?
                  DR. REHAN CHOUDHARY:  It's a clarification because, like I said, based on the discussion, it felt like people were thinking the approach or TRI is generic, and how do you take into account geographic-specific information?
                  DR. DANIEL SCHLENK:  Sure.  I think that's their reading of the document.  So I just want to caution you in terms of trying to influence the Committee based upon additional information at that point.  At this point, they're reviewing the document as written, so they provide those comments to you.  I can't allow sort of a back and forth between the Agency and Committee at this point.  If you have questions of particular comments that require clarity, I can provide that.  It's not appropriate to banter back and forth.  I hope you understand what I'm getting at there.
                  DR. REHAN CHOUDHARY:  That's all right, Dr. Schlenk.  We just wanted to attempt to clarify, but we'll make note of that.  Thank you.
                  DR. DANIEL SCHLENK:  Thanks.  Any other comments?  Jennifer, I think you've got most of the info from folks.  Again, same type of approach here.  Just to provide this also to the lead discussants as well, this is during the discussion where you can modify your output to say, the majority of the Committee felt so and so.  Certain Committee members felt so and so and provide that as the initial document.  Then we can actually go forward with that aspect.  Again, I'd welcome the Committee to, again, view that document when it comes forward.  
                  If you agree with a certain position and it says, one Committee member felt so and so, and you felt you agreed with that, you can say, several Committee members, and edit that when it comes to that particular point in time so that the clarity is portrayed in terms of whether there's a majority or consensus for that question.  Yeah, Dr. Vuilleumier.
                  DR. KEVIN VUILLEUMIER:  Thank you, Dr. Schlenk.  One clarifying question -- and it is asking for clarification just so we understand what the comment was.  
                  DR. DANIEL SCHLENK:  Sure.
                  DR. KEVIN VUILLEUMIER:  One of the commenters indicated that they thought we should model at closer distances.  I want to clarify in what methodology is that referring to for pre-screening.  This is described in the report.  We did 100 to 100,000, 1,000 meters because that's the limitations of IIOAC.  For a full screening, we did five meters and then went out from there.  In what context were they referring to we should do nearer the releasing facility?
                  DR. DANIEL SCHLENK:  Is that Dr. Davies, or who made that particular comment?  I was looking for my notes.
                  DR. JENNIFER PRZYBYLA:  I believe that was George who made that comment.
                  DR. HOLLY DAVIES:  I don't think that was mine.
                  DR. DANIEL SCHLENK:  Okay.  George?
                  DR. GEORGE COBB:  I think that was me, Dan, but that was yesterday.
                  DR. DANIEL SCHLENK:  Yeah.  Okay. 
                  DR. GEORGE COBB:  When you try to couple those models, and you've got one model that predicts concentrations down to a hundred meters, and then you're trying to model exposures inside that -- excuse me, risk inside that when you've got exposures, you don't know what those exposures are.  A better description of how that was done and trying to actually model something rather than choosing values is -- it needs to be better explained.  
                  It would be better it if could be actually modeled in the package that exists.  It was unclear to me how that was done inside of a hundred meters.
                  DR. DANIEL SCHLENK:  Does that answer your question there, Kevin?
                  DR. KEVIN VUILLEUMIER:  I believe so.  It sounds like it's referring to the pre-screening methodology which is limited by the model.  For the full screening, we used AERMOD, which isn't limited to that, and we did model 5, 10, 30, 60, and so on out.  So it was much closer to the facility.  Thank you.
                  DR. DANIEL SCHLENK:  Great.
                  DR. GEORGE COBB:  I think you're right, Kevin.
                  DR. DANIEL SCHLENK:  Okay.  Any other questions from the Agency or clarification?  Okay.  At this point, we've been at it for an hour.  Let's go ahead and take a ten-minute break before we move onto Question 3 if that's okay.  Let the coffee move through, and we'll take a ten-minute break and come back for Question 3 at that point.  Let's go back at ten minutes past the hour. 

                  [BREAK]
                  
                  DR. DANIEL SCHLENK:  Okay.  Is everybody back?  Don't see any pictures; I'm just seeing names.  There we go.  Okay.  I just wanted to make a little point of clarification here too.  This is based on Dr. Choudhary's comments here.  I'm sorry to cut you off there, but if the Committee would like questions or clarification, they can ask the Agency for those points of clarification.  So if during your discussions and deliberations you've come up with additional questions, then that is totally okay.  
                  You can then ask for that information from Dr. Choudhary or Dr. Vuilleumier.  If there's certain comments or questions that come up that you would still like additional information, then that is okay to ask for those points.  I just wanted to make sure you guys were aware of that, that that's a possibility at that point.  So before we go to Question 3, does anybody have any questions to the Agency in terms of more clarification?  Is everybody back?  Okay.  Thanks, George.  
                  
CHARGE QUESTION 3
                  
                  DR. DANIEL SCHLENK:  Okay, so with that being said, let's go ahead and move forward, then, to Question 3.  We can put that on.  Thanks.  Dr. Choudhary, if you could read that into the record, that'd be great.
                  DR. REHAN CHOUDHARY:  All right.  Good morning, everybody, Rehan Choudhary from the EPA.  Charge Question 3 to the SACC Committee: "Keeping in mind that EPA's intent is to develop a screening-level approach, please provide any practical suggestions you may have for enhancing Version 1.0 of EPA's screening-level approach with respect to air and water release estimation, ambient and indoor air exposure estimation, and ambient surface water exposure estimation."  
                  DR. DANIEL SCHLENK:  Okay.  Our lead discussant for that is Dr. Blystone.
                  DR. SHERI BLYSTONE:  Yeah.  Thanks.  I'm going to apologize upfront that I'm probably not as organized as Dr. Cobb or Dr. Przybyla was.  So forgive me in advance for skipping around a little bit.  I'd also point out, like Dr. Doucette said, some of these things may be duplicative of what you've heard in previous comments as well.  But we'll try to keep that to a minimum or just mention them again as necessary.  With that being said, I'll just dive right in.  This is my comment.  
                  Since there's a lot of talk about TRI data throughout this process, the risk evaluation process in general, and I'm always sort of amazed at the level of contortions that EPA goes through to try to figure out how to box that information for that facility.  It seems like there's an opportunity there in a very simplified, standardized way, maybe through the web.  You've already identified facilities through TRI that you could go and say, here's an opportunity to provide this additional clarifying information that we need on this chemical.  
                  You can do that for the ones under review, for the ones you're thinking about reviewing, for the next priority, and have that in advance, whether you use that in the pre-screening or the screening or final risk evaluation.  That would keep you from having to guess, which seems to happen quite a bit on what that facility is doing with that chemical.  
                  There has been talk a couple of times about data that may be available at the state, particularly through permitting for some of the larger facilitates and those reporting for TRI.  They probably have permits, and there's probably information there that could be used to help you clarify all of this information as well.  There's been talk about a need to validate the screening results versus actual monitoring data.  I think that was brought up yesterday by Dr. Doucette, something that could be useful and enhance the tool as it is, the approach.  
                  From a reader perspective, if you look at the non-technical summary and the tables that EPA is putting out there to show the results of their assessment through this approach, it might be useful to put a little bit more detail in there about when they're saying, "additional risk was identified," what that was.  For instance, if it's 1,000 meters plus or 0 to a hundred meters or whatever that might be and how many facilities, that might be something that would be useful to the non-technical reader to try to help them understand what that risk might be.  
                  I'm not sure that this has come up specifically yet, but it probably has.  In addition to validation and the sensitivity assessment, when you're changing the variables in this approach, like which ones are the ones that are most important that might help you key into what you would need to ask those facilities for is for additional clarifying information.  So that sensitivity analysis could be useful.  
                  There was a comment that EPA proposed to identify occupational exposure scenarios based on CDR reporting, consumption codes, which are in turn derived from TRI data, conditions of use, sources of ambiguity, and errors in the tools to facilitate database crosswalks.  EPA should explain how it interprets conflicting information gaps, et cetera, so as to provide a conservative high estimate for exposure.  So some further explanation of that could be useful.  
                  On page 21, EPA talks about the 10,000 meters for exposure assessment.  It seems to imply that EPA is considering the influence of multiple sources.  I think a couple of us had the impression that the approach actually was looking at where -- if you're looking at two sources, and you're drawing the circles, and there's overlap in those circles, that we were looking at that.  From what we heard yesterday, apparently, that's not true.  I think that's maybe something practical that could be added to the approach as it is.  
                  If two of the facilitates do have overlapping exposures, then you can look at that as another potentially exposed subpopulation, for instance, and look at that exposure from both sources.  
                  I think in the water side -- you may already be doing that -- looking for if they're discharging into the same body of water, that you're adding that information together.  If you're not, then perhaps you should be.  
                  There was a comment that we have heard many opinions to the effect that the screening framework may identify sources as meaningful risks due to data limitations and modeling assumptions.  But the point of the screening tool is to identify protentional risks that may warrant further study.  Therefore, it's important to have a low probability of missing real risks.  It is more important to have a low probability of missing real risk than it is to exclude non-risks.  
                  This commenter believed that the screening framework report makes that clear, that the output of the screening model is not intended to be interpreted as definitive findings of risk.  Since some people are still having questions about that, maybe there's some clarity that could be added there.  
                  There was a comment that the document should provide a conceptual overview of resources and explain what data will be extracted, clearly identifying simplifying assumptions, for example, mapping each condition of use to occupational exposure scenario combination, from the initial risk assessment to one IFC code or TRI use/subuse, even if the facility reports multiple uses or subuses.  
                  EPA should comment on sources of error or uncertainty in these other resources that may affect exposure calculations in the screening methodology.  
                  There was a comment, and I've had this as well.  What happens when chemicals under review aren't on TRI?  What approach is EPA going to take then?  Right now, there's a heavy emphasis on TRI data.  So what happens if you're looking at chemicals that aren't on TRI and what all those other data sources might be using.  This particular commenter talked about maybe there's consulting reports or other facility-specific information that could be used by the Agency.  
                  A very specific comment, that there was a sentence on page 19, lines 127 to 130, that seemed incoherent and that the Agency might want to take a look at that and clarify.  
                  Also very specifically, on Table 3-1, there was a question. Does "benchmark" refer to benchmarks margin of exposure for the first two rows?  Is margin of exposure based on the NOAEL or the LOAEL in the third row?  Is this the benchmark probability of additional cancer?  Please clarify.  
                  There was a comment, page 37, using 1.8 meters tall for receptors might be a bit tall for females or children.  Maybe there's some clarity or some adjustments that could be made to using that as a benchmark for the receptors.  
                  Page 46, the lack of ambient NMP data in water is a glaring data gap that needs to be filled at locations near several point sources.  I think that's been brought up before as well.  
                  I think this was also brought up by Dr. Kissel earlier.  It's unclear that dermal exposure will not pose significant risk relative to inhalation.  There's another commenter that supported that.  
                  On the land-use side -- and this is on page 32, 33 -- we've got rural.  We've got urban, but what about suburban?  How should that be managed?  Perhaps there's an opportunity there.  
                  This is specific to page 45, but the SACC established in previous reviews that, for many of the scenarios presented, air emissions could not be decoupled from the assessment of water as the concentrations emitted to air from multiple sources were predicted to be much higher and would cause portioning of volatile chemicals back into water as significant concentrations relative to the direct emissions of water.  I remember Dr. Cobb saying those comments many times.  
                  There's also comments here about the hundred meters and that something nearer.  I think that may have been clarified earlier this morning.  
                  On page 111, limit of detections, there was a question about or comments that those are not handled properly.  All values with the limited detection above ten must be included if half the limited detection is used for statistical thresholds.  Otherwise, all the data from these higher LODs should be excluded and that this was a serious loss.  
                  For me personally, I also had struggled with the LOD.  I think I came at it from a different perspective.  It feels like the way the Agency handled how they are managing non-detects, if you will, and then using LODs needs some clarity.  
                  Again, there's no assessment of partitioning from air to water, and this needs to be fixed.  
                  Many of the exposure assessments, and therefore risk conclusions, depend on assumptions inputted into the various calculators and models.  The proposed methodology uses the most conservative assessments to be most protective of health, which is appropriate in a screening phase.  Additional modeling efforts, such as those done when no data is available, would help increase the confidence in the 2019 TRI data.  A threshold of action could be implemented.  That, if reached, could result in greater inquiries about characteristics into the AERMOD to ensure accurate information is being inputted.  This could depend on the population density in areas of greatest interest.  
                  A similar approach could be taken for water release estimation, ambient and indoor air exposure, and ambient surface water estimation, as all conclusions depend heavily upon conservative input.  If a very high risk is detected, thresholds to be decided, that could result in further investigation of input to help improve the accuracy of the risk estimate.  
                  Another comment about the Agency sustaining open and accessible relationships with the fenceline communities as a stakeholder to ensure methodologies are adapted and replaced as needed to protect public health.  This will reveal routes of exposure in realities not represented in Version 1.1.  
                  Uncertainties and improvements to screening methods must not be used to delay protections by not closing the door on chemical risk classification.  The EPA can continue to pursue and utilize the best possible science.  The methodology must also be adaptable to the impacts of climate change release and dispersal.  Yearly averages may hide accidental releases and acute exposures on any given day.  
                  Communities may not be exposed to the chemical at the same concentrations each day.  The AERMOD and IIOAC software used in Version 1 allow for analysis to include exposure to multiple facilities, which we talked about earlier.  The commenter recommended that EPA expand the application of this software in pursuit of the best possible science.  
                  Also, comments, again, on cumulative impacts has been brought up a few times already. The commenter also specifically called out the comments by the National Tribal Toxics Council that note that the use of geospatial analysis may underestimate the exposure of tribal and indigenous communities.  The commenter supported those comments.  
                  Again, talking about the limiting of the approach to only air and surface water releases, compounds like TCE and PCE groundwater contamination and vapor intrusions are likely important pathways into fenceline and other communities.  Other potential exposure routes, such as food chain contamination, could also be important for some chemicals.  
                  A detailed step-by-step example calculation of the estimated fenceline air and water concentrations would be useful for interested parties attempting to reproduce the calculations.  
                  Another comment in support of sensitivity analysis so that the reader can better understand how variabilities in input data impact the predicted concentrations at the fenceline.  
                  As mentioned in previous SACC discussions, better highlight or emphasize model limitations, such as the lack of degradation and volatilization processes in E-FAST and discuss if the model limitations result in appropriately conservative estimated concentration.  It was also brought up, I believe, yesterday and then maybe earlier today, maybe by me, that you could use the monitoring data to validate the results of this approach and that there might be sources of those data available.  
                  There's some links here that we will provide.  The Agency could illustrate how this draft's screening approach could be expanded to consider the impacts of multiple chemical exposures, releases from multiple industries in the same location, co-contaminants, et cetera.  
                  Back to the 10,000-meter static buffer, it may be helpful to consider circumstances under which available data will support an alternative to the assumption of a 10,000-meter buffer to instead be something reflective of the environmental fate and transport characteristics of the contaminant's behavior in the local setting.  If a pollutant is expected to be dispersed farther than 10,000 meters, then the definition of the fenceline community with respect to that contaminant seems like it should be extended.  
                  Again, communities making use of the receiving water bodies for a drinking water source, accounting to the extent to which populations rely on public water supplies versus alternative water sources, like wells, is an important data point.  There is limited spatial data available on this from the 1990 census, with updates available from the U.S. Geological Survey, for spatial estimates in different years of the number of persons relying on private wells, benefit-to-risk assessment to consider whether drinking water is largely consumed from private wells near a receiving water body.  
                  Additional site-specific characteristics, like three-dimensional groundwater or hydrological dynamics, would be pertinent if this is sociologically a zone where human populations are reliant on the groundwater as a drinking-water source.  
                  That is it for what I've received.  My apologies to anyone who sent me stuff that I didn't report correctly.  I'm sure you can correct me now.  Thank you.
                  DR. DANIEL SCHLENK:  Great.  Okay.  Let's move down the associate discussant list.  Dr. Przybyla.  I'm not hearing you.  Are you muted?  Dr. Przybyla, do you have any other comments?  Okay.  Still not hearing you if you're muted.  
                  DR. ALAA KAMEL:  She said she is having connection errors, and she's trying to log back into the meeting.
                  DR. DANIEL SCHLENK:  Okay.  We'll get back to her then.  Thanks, Alaa.  Next on the list, then, would be Dr. Calder.
                  DR. RYAN CALDER:  My comments are reflected.  Thanks.
                  DR. DANIEL SCHLENK:  Fabulous.  Dr. Unseld.
                  DR. MONICA UNSELD:  I have nothing to add. 
                  DR. DANIEL SCHLENK:  And Dr. Doucette.
                  DR. WILLIAM DOUCETTE:  Yeah.  I thought Dr. Blystone did a great job at summarizing the comments.  One that I've just sent her -- and I think it's been discussed before -- any screening efforts should incorporate background VOC concentrations from consumer products, building materials, et cetera, in any indoor air assessment.  So that adds, potentially, an additional factor to the exposure concentration since, for most VOCs, they're typically five to ten times higher indoor than outdoor.  Thank you.
                  DR. DANIEL SCHLENK:  Okay.  Thanks.  Dr. Przybyla, are you back?
                  DR. JENNIFER PRZYBYLA:  Apologies.  I had some network issues. 
                  DR. DANIEL SCHLENK:  No worries.
                  DR. JENNIFER PRZYBYLA:  I have no further comments.
                  DR. DANIEL SCHLENK:  Okay.  Thanks.  Okay, with that, we'll open it up to the rest of the Committee.  Dr. Reiss.
                  DR. RICK REISS:  This is Dr. Reiss.  This is my first experience on the Panel.  I've been on the other side of these.  There's a lot of great comments.  I also feel like it's easy to make a lot of these suggestions and maybe a little bit hard for EPA to implement many of them.  
                  I have experience in dispersion modeling and dealing with emissions data.  I think we just have to acknowledge what EPA is trying to do here is really, really hard.  I mean, there are hundreds of HAPs, hazardous air pollutants.  There are tens of thousands of facilities.  The complexity here is just massive.  I might have made a simpler screening methodology.  I might've also tried to use the NEI to get the real stock data.  
                  EPA did what they thought was right here.  While it's complex, it's dealing with a massively complex and challenging problem.  Hopefully, we can distill this down to a few good items that we can recommend to make this better.  
                  Just an acknowledgment by EPA that some of this stuff is not there yet, in terms of other pathways, and that there's going to be a 2.0.  This is tailored toward the specific properties of the three chemicals that are in here.  I don't know.  I think that, just as an overarching comment, that strikes me.  
                  I also think, given all that, the other overarching comment is that this is a screening approach.  I think EPA should keep to their general paradigm for a screening approach is that refinements need to be possible before you move onto a rule or something like that.  We're being good at pointing out all the different uncertainties here.  Of course, there are a lot of uncertainties.  
                  In terms of whether this is conservative or not is really one of the rubs, the real questions here.  There's reason to think because there are some pathways that are not included, you have some questions there.  Like I said, I'm the dispersion modeling expertise.  Just the stack height assumption alone, I think, adds a tremendous amount of conservatism to this.  
                  Just in terms of whether it's conservative or not conservative, which is what a screening-level approach needs to be, I think it's conservative.  But, of course, that's my professional judgment.  It's just professional judgment.  If there's some kind of methodological way that that could be demonstrated with an available dataset, I think that that would strengthen this process.  Those are my comments. 
                  DR. DANIEL SCHLENK:  Thanks, Rick.  Appreciate that.  Dr. Davies.
                  DR. HOLLY DAVIES:  Hi, again.  Thanks to Dr. Blystone for her list.  We've talked about the overlap.  This topic has been mentioned before; it will be mentioned again.  But I think it is important to include PBTs in how this will be because none of these chemicals chosen are PBTs.  Some of the first ten -- I guess I'm thinking about HPCD.  In the future, this will be applied to chemicals that are persistent, bioaccumulative, so it's important to include that and how to include that.  
                  I was really interested in what Dr. Reiss just said, interested in his simpler ideas of how to get this down.  Sheri also mentioned this, the importance of "is this conservative?"  I think that's agreed that that's an important question for the Committee.
                  DR. DANIEL SCHLENK:  Yeah.  That definitely seems to be -- how we are going to define conservatism, basically, seems to be a fairly -- something where consensus is a little bit lacking, I would say, at this point.  Dr. Doucette.
                  DR. WILLIAM DOUCETTE:  Just one additional point, it's important also to remember that the chemicals that this screening approach is being applied to have a history of environmental releases.  I realize the challenge -- and this was brought up in a previous speaker -- the challenges that EPA faces with all the multiple pathways.  But to ignore a pathway for TCE, PCE, or even 1-BP through vapor intrusion seems -- since there's so much history and so many case-study examples of that, that seems to be a big hole in the approach.  
                  So I think because these chemicals have such a history, that helps us decide what pathways likely are going to be important or have been important in the past.  And to ignore that, I think, is an issue.  We can use that information to make judgments on which pathways are likely to be most relevant for these specific compounds.  Thank you.
                  DR. DANIEL SCHLENK:  Great.  Thanks, Bill.  Dr. Kissel.
                  DR. JOHN KISSEL:  Apropos my comments on Question 2, in under the Question 3 rubric, I would add the specific references to the Regional Screening Level online calculator to the computer exposure model and to RAGS Part E, all of which have methodologies that are not addressed here.  
                  DR. DANIEL SCHLENK:  Okay.  Again, yeah, please get your information into Sheri for that.  Thanks.  Any other comments from the Committee on Question 3?  Dr. Li.
                  DR. LI LI:  Yeah.  I just want to add some about my two cents.  Because we are talking about how to make these documents practical and easily applicable to everybody, so maybe we can do two things.  The first is to keep everything comprehensive.  For example, we can try to include as many exposure pathways as possible because some exposure pathways may be important for some chemicals, with chemicals with some physical/chemical property.  At the same time, some exposure pathway may be important for some subgroup population.  
                  For example, food chain bioaccumulation contamination may be important for some people who rely on locally produced food, or for example, the mouth immediate ingestion.  That is, you touch a dirty surface, the ground, and then put your hands into your mouth, may be important for some in the fenceline communities.  This is why we have to keep in mind that all exposure routes would matter in terms of the total exposure.  So that's my first thought.  
                  The other thought is can we try to keep everything simple?  For example, at this moment, we use a AERMOD for the full-screen level, for the air pollutions.  But I think that the model is too complicated.  You have to rely on a lot of site-specific data to run the model, which is not available to many local communities or local authorities.  If the fenceline communities want to do the simulation for themselves by themselves, this is no way to do.  
                  Maybe we can get rid of some very complicated, very sophisticated approach and just keep it simple.  So I'm not sure whether it is okay to keep this site-specific, or we just go back to the generic simulation, for example, for air pollutant.  Just the two cents, keep it comprehensive and keep it simple.  Yeah.  That's all.
                  DR. DANIEL SCHLENK:  Okay.  Thank you, Dr. Li.  I think you might have some discussion on that comment.  Dr. Unseld.
                  DR. MONICA UNSELD:  Yeah.  I agree with Dr. Li.  I just thought, reflecting on the repetitiveness of the responses to the charge questions, if there have been previous SACC comment or recommendations, they could be used to simplify this.  I think they should be used to simplify this because it sounds like there may have been some things in the past that could make this a little easier.  We have to do what we can do now to protect the public health, but we also need to keep in mind that there's a long game here where we need to, overall, just improve the entire process.  
                  I think we just need to be cognizant of what's on the long term, building up capacity, independent monitoring, all of the things that can make the entire process, screening process, regulatory process, more effective, but at the same time making sure that it makes sense and that it's reliable enough to do something now.  If there are things on record that can do that, I hope the Agency does that.  Monica Unseld.
                  DR. DANIEL SCHLENK:  Thank you.  Dr. Gribble.
                  DR. MATTHEW GRIBBLE:  Hi, this is Dr. Gribble, a temporary member of the SACC from the University of Alabama Birmingham.  I would slightly disagree with Dr. Unseld and Dr. Li on this about the importance or lack of importance of complexity.  So many of my comments are geared towards the opinion that incorporating additional exposure pathways and incorporating potentially chemical site-specific information and, if you're going to add groundwater as an exposure pathway, three-dimensional hydrological modeling would be value added for screening community risks in a comprehensive way.  
                  I think that a question I have is the onus of doing this analysis.  It's been assumed that this would be done by EPA agency staff with limited EPA agency staff resources.  Potentially, this could be a polluter-pays situation where sites seeking to demonstrate a lack of excess hazard from discharge of a known toxic chemical could be responsible for demonstrating through compliant analysis that they were not creating excess risk for the community.  
                  It was also suggested that fenceline communities themselves wouldn't have the bandwidth to do this.  I don't know that it should be the responsibility of a fenceline community that often will have limited resources to do this screening assessment or contest the EPA screening assessment through their own analysis.  
                  So I was wondering if it was something that the SACC could consider for its recommendations about who would be responsible for this because, if there is an army of environmental consultants out there doing this kind of assessment, it might be more technical and feasible to do a more comprehensive assessment than if it was Agency staff doing it and if it was community doing it.  I just thought that the who's doing what of this might be something we would want to encourage EPA to think about.
                  DR. DANIEL SCHLENK:  Okay.  Thanks.  Dr. Johnson.
                  DR. MARK JOHNSON:  Thank you.  Yeah, I was just kind of thinking out loud and considering some of the previous comments made regarding simplicity, the fact that this is a screening approach.  I'm wondering if there would be value in the EPA doing a sort of sensitivity analysis thinking about which factors have the greatest influence on predicting risk or predicting hazard.  One example may be dermal exposures through swimming.  I wonder.  We've heard some criticisms of maybe the use of the permeability coefficients.  
                  I'm wondering, really, how much does that affect the overall exposure and the overall characterization of risk?  Again, just to paraphrase, I think there may be some value in doing a sensitivity analysis to see which factors attribute mostly greatly to the final hazard estimate.
                  DR. DANIEL SCHLENK:  Okie doke.  Thank you.  Sheri.
                  DR. SHERI BLYSTONE:  Yeah.  Just reacting a little bit to a couple things.  The site-specific data is going to be important somewhere down the line.  Ideally, we're doing some tiered screening process that eliminates and focuses our resources on things that are of the most concern.  That's what everybody, I think, would agree we're looking for.  We may disagree on the specifics of that, but the process is that we're looking to focus resources there.  But when you get to that higher-level evaluation, you're going to need better data.  That includes the specifics on the site.  
                  I'd also like to mention on the comment of resources and EPA resources because this is critical as well.  I mean this is an agency that has to do it -- they are being asked to be experts in everything related to the commercial production of chemicals in the United States.  From sites and how they work to the markets that they're used in, to how they're used, to exposure to industrial hygiene.  
                  There are experts out there that, I think, the Agency should consider outsourcing some of this stuff when those specific, very detailed questions come up, rather than trying to do it all themselves, which sometimes, in my opinion, it appears they're trying to do.  That's a huge job that is not really possible for any one group of people.  
                  DR. DANIEL SCHLENK:  Thanks.  Dr. Unseld.
                  DR. MONICA UNSELD:  Yes.  I wanted to just clarify my use of the word "complexity."  When I used that term, I feel like, with this screening proposal, the EPA is trying to reinvent the wheel when maybe they don't need to because there are already methodologies, already databases, already recommendations that were in place so we don't have to rely on these estimates and concentric circles and things that are unnecessarily complicating it when we know that we can get some sort of reliable data source to fill those gaps.  
                  In terms of community, I work with many fenceline communities.  I actually live in Louisville, Kentucky, where there's Rubbertown.  We have local control of our air, so the state doesn't monitor our air; the city does.  There are many fenceline communities who already have some independent monitoring data.  They just may not have access to get it to the EPA.  It's not as valued because people look at it as like, oh, it's not coming from such-and-such a place.  
                  There's a great demand.  Even if the EPA could just support and advocate and say, we don't have the capacity to do this, but we need to have an infrastructure in our country of more local monitoring.  That's going to take funding.  That could take consulting.  
                  Here in Louisville, we partner with the local university.  We have our air pollution control districts.  We have our own aspect of the city government to do that.  So there are ways to do that that don't overburden fenceline communities.  
                  But I also want to know that these communities, they may not have the degrees, but they may know more about this than we do because they have to in order to survive.  I don't want it to sound like we don't trust them or we don't think they can do it.  It's they may be too busy, but usually, they already are doing it. 
                  DR. DANIEL SCHLENK:  Sounds like info for 4B, actually, as well.  Dr. Reif.  Reif, sorry.
                  DR. DAVID REIF:  Yeah.  Thank you.  Yeah, I know that's hard with Dr. Reiss as well.
                  DR. DANIEL SCHLENK:  I know.  You guys keep flip-flopping on me.
                  DR. DAVID REIF:  Yes.  But Reif is right.  I appreciate that.  Thank you.  Yeah, this is David Reif.  I think I'm on the docket to talk about Question 4A, but I think the discussion is related here, and I wasn't sure where to send my comments.  
                  I think the idea is that we're discussing about complexity and enhancing what we're calling a Version 1.  I think we maybe haven't talked as much about the difference between -- complexity of the model and everything that goes into it is one thing, but simplicity in terms of interactivity, especially if we're moving to communities, means that interfaces people can use.  
                  And this kind of a boring software question in some way but really important.  I think, in my experience, people will tolerate very complicated models if they can interact with them and actually do something with them.  I think you've seen the same thing with newer approach methodologies sort of being adopted, that once the chemistry dashboard that was brought up by, I believe, Dr. Ferry yesterday -- once people had access to things and they could touch them, sort of new and more complex things that weren't as familiar become more acceptable.  
                  I think for the community aspect of this, I think that's going to be really important going forward.  I'm not throwing shade on Excel, but I am saying that there's some choices one makes when that's how you're going to develop and put forth models.  I think there's maybe a separate consideration then: the complexity, the underlying statistics, and methods themselves.
                  DR. DANIEL SCHLENK:  Great.  Thanks for those comments.  Yeah.  I would also point out, I guess, if we're going to reduce complexity, it'd be very nice to document what those recommendations would be and how to simplify.  It's easy to say, we need to make it simple, or we need to reduce complexity.  But I think the Agency would like very specific, concrete recommendations, sort of like what you mentioned in terms of how that is possible and what things are too complex and what things can be sort of simplified.  That would be fantastic, I think.  Any other comments?  Yeah, Dr. Henneman.
                  DR. LUCAS HENNEMAN:  Yeah.  I apologize a little bit for just sort of thinking out loud.  But some of the discussion yesterday was talking about sort of applying uncertainty factors to the results and accounting for some of the uncertainties that are in the approach.  Then, some of the conversation today is talking about, well, what if the model is too complex?  
                  I guess I'm kind of curious to know whether some very simple approaches, even thinking about the pre-screening approach, if we use the pre-screening approach and uncertainty factors, do we get the same answers eventually that we're going to screen these things in a more thorough way using the full screening approach?  Is there an opportunity to cut out a step that we would do anyways just by looking at sort of a more simple approach to begin with?
                  DR. DANIEL SCHLENK:  Yeah.  I think the tiered approach was brought forward as another possibility of maybe tiering this in some way.
                  DR. LUCAS HENNEMAN:  Yeah.
                  DR. DANIEL SCHLENK:  Yeah.  Thanks.  Dr. Calder.
                  DR. RYAN CALDER:  Hi.  Thank you, Ryan Calder speaking.  I'm reflecting on Dr. Unseld's comments on the importance of involving community knowledge and her observation that, in many cases, communities are already aware of many of the biggest risks, especially -- I guess this is my interpretation -- for air pathways.  I would say that there are still a lot of pathways that sometimes communities are not as aware of, specifically groundwater transport and other kind of subtle pathways that can introduce risks to communities without their knowledge.  
                  This interacts with comments that we heard earlier about the exclusion by EPA of certain transport pathways from the screening framework, notably groundwater transport.  So there's maybe a double whammy in some sense that communities are already very involved in the types of pathways that EPA's screening methodology targets, and the pathways that EPA's screening methodology overlooks or the ones that communities might need more support in proactively identifying because they might not be as evident.  
                  I hope that is an okay interpretation of Dr. Unseld's comments.  So feel free to correct me if I got anything wrong.
                  DR. DANIEL SCHLENK:  I'm sure she's about to.  Dr. Unseld.
                  DR. MONICA UNSELD:  Yes, this is Dr. Unseld.  Again, I think there are some -- I've met community members, not just in Louisville but nationwide, environmental justice organizations, predominately black and brown-led, who have no budget, no resources, and they can school me on some of these pathways because, when you're living in these environments, and you're trying to figure out why you're sick, you start researching.  So I would never say that they are -- they may not have the technical expertise that we have and actually knowing the models and figuring them out and that sort of thing.  But I think they may know different routes of exposure because they know what they do every day.  
                  I think we've seen it in the comments from public comments and the written comments.  They were uplifting things like diet and things that we, the so-called experts, missed in this.  I think my overall point is that we need to continue to engage with communities because I found that that's one of the best ways to uplift potential data gaps and to find new research questions as when you're like, oh, wait.  What?  You're building a school there, and there's people getting sick, and there's this in the soil?  That's a great way to discover that.  
                  I think sometimes, as academics, we will run to the library before we run to a different zip code to just talk to people.  Maybe we need to say that they're both valuable is what I'm trying to say, that they are both extremely valuable.  Before we make any regulatory decisions, we need to make sure all of the stakeholders are involved.  Does that make sense?
                  DR. DANIEL SCHLENK:  Yeah.  I think some strengths and weaknesses sort of discussion on how to employ the fenceline communities would be very useful for sure.  
                  Just want to call attention, there's a couple of comments coming out to everybody on the chat box.  Since this is the first time we've done Zoom, I've been told that those will be on the docket, but I think it might be good just to have them orally presented as well.  So Mark and Dr. Apte, if you could just get that in at some point, I think it'd be good.  Otherwise, everyone can read it too.  Dr. Gribble.  You're on mute.  I'm not hearing you.
                  DR. MATTHEW GRIBBLE:  Yeah, I am.  Hi, this is Dr. Gribble, a temporary SACC member.  I wanted to echo the comments that we saw in the public comments as well as from Dr. Unseld about the importance and value of community consultation, while also wanting to speak a little bit to burden.  Especially during COVID, a lot of communities are very bandwidth constrained, potentially very resource constrained.  And I would be concerned about offloading the responsibility of knowing about risks to communities that maybe don't have technical capacity or dedicated staff to deal with this.  
                  I do think that there's value and importance in allowing community input.  But I would wonder about the implementation about requirement for community input because that could potentially delay protecting communities from exposures that nobody necessarily has time to deal with.  I think that, in response to some of the industry comments from yesterday about EPA resources being limited, maybe the industry could contribute to this risk assessment process if the methodology were EPA established.  
                  Just consideration of the burdens of who's having to do this and who's voices are at the table.  I do think that encouraging community input is a good idea.  I would worry about, especially in the era of COVID, overburdening limited community resources.
                  DR. DANIEL SCHLENK:  Okay.  Thanks.  Dr. Baker.
                  DR. MARISSA BAKER:  Hi, this is Marissa Baker speaking.  I'm kind of changing the direction a little bit, and I hope that's okay because I do value the conversation.  I hope we can do more of it with 4B in particular.  One thing that came up in the public comment that I'm also personally interested is the idea of folks who live in these communities who also may work in these industries.  So I'd like to see a little more attention on folks who are kind of getting the double whammy of both working with essentially a higher exposure and then also coming home and living in those communities.  
                  So EPA asks for practical suggestions.  One idea could be to look at the census blocks that make up these fenceline communities, that 10,000-meter buffer, and look at where the people are working using publicly available BLS data that reports on how many people are working in these industries and using that to kind of identify whether or not the estimates need to be made more conservative given the number of folks who might be working in those higher-risk industries in there.  Thank you.
                  DR. DANIEL SCHLENK:  Thanks.  I've just been informed regarding chat info, "Please hold the chat info to the oral components, so that we discuss that in an oral manner."  So in terms of chatting to everyone, please refrain from that if it has something to do with the question in itself.  We need to get that on the oral record.  Yeah.  
                  Actually, Mark, I think you were first on the chat, so I'll go with you first.  Then, I think, we can follow Dr. Apte after that, if that's okay.
                  DR. MARK JOHNSON:  Yeah, sure.  Consistent with your request, my comment was there's value in simplicity.  It helps in risk communication, describing to others what we're doing.  I think I'm seeing consensus regarding the use of a tiered approach.  I think we need, again, to do some sort of sensitivity analysis to see which factors contribute most to the outcome.  If we have something we all can truly agree is a protective screening approach, then from there, we can go and look for further data to help elucidate to find out what reality kind of looks like, if that makes sense. 
                  DR. DANIEL SCHLENK:  Great.  Thank you.  Dr. Apte.
                  DR. UDAYAN APTE:  Basically, I wanted to completely agree with Dr. Johnson there.  I think there's so many different things going on.  It's important to rank them and find out what is the most impactful because only so much can be done at a given point in time. So having that in front of the Agency to identify the highest risk is probably an important part of the process.
                  DR. DANIEL SCHLENK:  Great.  Thank you.  Holly, I had you down afterwards.  Did you want to get your comment on the record there?
                  DR. HOLLY DAVIES:  Yeah, since I chimed in on Mark's comment in the chat.  Just going back to Dr. Li's "comprehensive and simple."  Of course, we need the practical suggestions for what's in that comprehensive and simple.  I think it was Dr. Kissel who mentioned before including things, doing the calculation, and then saying it's not important, which fits in with Dr. Li's "different pathways are important for different people."  So I think that's the comprehensive part that needs to be in the beginning.
                  DR. DANIEL SCHLENK:  Great.  Then, Dr. Unseld, you're next on the list. 
                  DR. MONICA UNSELD:  Yes, this is Monica Unseld again.  I just wanted to bring up the fact that maybe we're not considering the different ways communities can be engaged.  One, we're not offloading anything to them.  Many times these communities already have this information.  Two, many of them are asking to be involved.  It is not our place, and in fact, it may be a bit paternalistic for us to assume that, with COVID, they cannot be involved because, even before COVID, they didn't have time to be involved.  They had no money.  They had no budget, no volunteers, no staff.  They were just asking for help and figuring things out on their own.  
                  But there are plenty of options on how we can engage them.  Some of that is just saying, hey, as a Committee, we support local air monitoring.  That does not mean that the fenceline community has to do it themselves.  That means, maybe, at the state level or at the municipal level, they have to figure it out.  So I think we may need to broaden our understanding of how we engage with these communities and the different options, like the Alaska Committee Action on Toxics.  They've done their own research.  The National Tribal Toxic Council, they submitted comments.  The work is there.  
                  So I think there's potential danger and a potential to continue to erode public trust, particularly between black and brown communities with government entities, if we go ahead and make the decision that they won't be able to do it.  If they tell us they can't do it, that's one thing.  But I don't feel that it's our place to say, we can't do this, especially if they're asking.  
                  What we should do is say, we need to figure out a strategy, an outreach strategy, that does not burden them, but that, again, is going to require their input.  
                  I'm telling you, there are plenty of people that have something to say.  They don't have access to say it.  I think that should be the first step.  We ask them what do they need from us?  How can we get you engaged into this process before we decide they won't be able to do it?
                  DR. DANIEL SCHLENK:  Yeah.  Again, I think these might be a little better for 4B when we get to those discussions a bit on how to involve communities in sort of the process when we get to that point.  Thanks for the comments there.  Dr. Heiger-Bernays, you were next on the chat list.  Then I'll go to you, Dr. Li, after that.
                  DR. WENDY HEIGER-BERNAYS:  Okay.  Thank you.  I see I'm a little foggy here.
                  DR. DANIEL SCHLENK:  You are.
                  DR. WENDY HEIGER-BERNAYS:  It's because the sun's at the top of my head.  Maybe you can't see that.
                  DR. DANIEL SCHLENK:  I can see.
                  DR. WENDY HEIGER-BERNAYS:  Yes, I agree with what others have said here.  But I do think that this notion of a tiered approach is very powerful.  We're talking about a tiered approach.  There can be tiers for different parts of the screening analysis.  The one that I was addressing in the chat was really about having a tiered but flexible enough approach that encourages and incorporates community-generated data.  I absolutely agree with Dr. Unseld who notes that there are data that are out there.  
                  In fact, some of those data come from other federally-funded research programs and projects that would certainly be beneficial, not as a replacement for prioritizing pathways necessarily but for providing those imperial data to justify or to move forward with a set of relevant pathways.
                  DR. DANIEL SCHLENK:  Yeah.  That's very nice.  Again, try to get your comments to Sheri.  Hopefully, Sheri, you're taking some notes on this.  I know Alaa is for sure.  Please, yeah, just get your comments into Sheri for this.  Dr. Li.
                  DR. LI LI:  Yeah, this is Li speaking.  I just want to share more thoughts on the more specific definition or the thought of "simple."  In my mind, we have three things that need to be considered for simplicity.  The first thing is input parsimonious.  That means we try to identify the most of things, match it to -- for example, in terms of human exposure, in terms of the environmental contamination, that means we require only those parameters really match.  
That means we need to do the sensitivity analysis or uncertain analysis first and identify the most important parameters, important piece of information required by the model, and we try to require only this information in the simulation.  That's the first thing.
                  The second thing is we try to make the approach or the model user friendly.  So I like the idea that we use the models coded in Excel.  Maybe if you want us to code it in other language, we try to make something user friendly to you and I, so the local communities, the local fenceline communities, local authorities or the state level or municipal level can use it in a user-friendly way.  
                  The third thing is maybe we can try to make the models more intuitive.  So this has nothing to do with the complexity of the model algorithm.  Of course, we can incorporate a lot of advanced, more complicated, more sophisticated algorithms behind the model.  
                  We try to make what people can see simpler so they can interact with the model, so they don't have to dig into very complicated -- a black window.  You have to code a lot of codes, a lot of letters, a lot of fractions, and you get some numbers that are not intuitive to you.  So maybe that's three things we need to consider when we talk about simplicity.  Please, feel free to comment.
                  DR. DANIEL SCHLENK:  Thanks, Dr. Li.  I think the more specifics we have, the better.  Dr. Chaisson.
                  DR. CHRISTINE CHAISSON:  I wanted just to elaborate on two good comments that I heard and particularly on Mark's idea of doing sensitivity analysis.  Dietary and even screening and sophisticated systems for doing dietary exposure assessments and risk assessments have been around for three or four decades now.  Even from the beginning of those kind of modeling exercises, one of the things that was standard was an assessment of the contribution from any one food or groups of foods into the overall risk was considered as a percentage of the overall calculation of exposure or risk.  
                  So it was, if you will, sensitivity analysis for every run.  That kind of approach could be, I think, relatively easily put into a screening model like this.  It's really not a very complicated algorithm to do that.  So you could see what percentage of the overall risk was being contributed by any of the components, if you will.  That really guides a lot of issues ranging from where do you put money for additional research to putting some perspective?  
                  There's another very big component to this whole idea of sensitivity analysis, and that is not a mathematical consideration; it's a relevance consideration.  We can have pristine mathematics and sensitivity and uncertainty and variability calculation or whatever, but if what we're looking at is not relevant to the population in question, then we really, really missed the boat here.  
                  There are two points in this.  I'm going to bring this up again later when we're talking about Question 4B, but I wonder, how many swimming pools are in the backyards of the people who are fenceline-community livers?  Yet just because we have already figured out how to do that kind of calculation, we stuck it in there.  I am not suggesting we take it out.  But I chuckle at the idea, a couple things, like these people are fish eaters, and they go swimming, probably not really characterizing this group of people very well.  
                  So one of the things that I think is necessary is when -- just like Dr. Unseld was talking about, the involvement of the community in terms of relevance -- or are these assumptions we're making that are sometimes hardwired into the assessment software that we traditionally use there?  
                  It doesn't make any sense to the populations we're dealing with.  You don't have to be able to do the calculation in order to opine on whether or not how the calculation is done makes sense to that community.  I've been a part of several NIH research groups where communication --  actually, leadership by the community was the philosophy behind those research grants.  In other words, the science was serving the community, not imposing it upon the community.  
                  Every time we made an assumption, every time we made critical calculations, we had to reveal two things; where did you get the data that you used for the calculation?  And I'm talking about the specific values and the ranges of the distributions for any metric.  Show that, verbally show that, to committees made up of the community.  They made up the committees.  You know if they all started laughing, then we figured we might not have this right.  Going in opining on swimming pool exposures would probably generate a bit of a chuckle for some of these communities.  
                  On the other hand, the absence of some of these routes of exposure will, I believe, far outweigh the statistical precision of the calculations that we are doing.  We'll get to that later on.  But I do think that, if we are much, much more transparent -- and I know it's a pain in the patush (phonetic).  I've developed software and sitting down and writing out the characteristics of the values that are used for any of these metrics is painful.  
                  But I think it's the way that you make communities understand whether or not the calculations reflect their real-life situation.  It's a simple way.  In some ways, it allows you to validate, if you will, some of these data, both in terms of whether you need more resources or whether or not you just need a new look at the way you apply them.  So I do believe there are some really good ways for complicated science to be presented as a task in the confirmation toward using the answers that are calculated. 
                  DR. DANIEL SCHLENK:  Great.  Again, I think this would be great information for 4B, when we get to 4B for sure.  Sheri. 
                  DR. SHERI BLYSTONE:  One last thing quickly.  This whole conversation reminded me there was -- at least I believe I saw in the public comments and other people have referred to some of the existing, publicly available tools that EPA has where you can go online and plug in your address and kind of get an assessment of what your exposures might be.  Now you're having another approach that's also estimating exposures.  The Agency should be aware that they will need to address any inconsistencies between those two tools that are publicly available.
                  DR. DANIEL SCHLENK:  Okay.  Had quite a bit of discussion for Question 3.  Any other comments?
                  DR. MONICA UNSELD:  I just wanted to add -- I accidently put it in the chat.  Sorry, I forgot.  If you have comments for 4B, since we already have dived into that, you can send them to me at monica@untiljusticedatapartners.org.
                  DR. DANIEL SCHLENK:  That was Dr. Unseld.  Thanks.  Anybody else have anything?  Again, I'd recommend to get your comments as you can to Dr. Blystone, and we'll try to assimilate that into some bullet points at the end that we can actually get out to the Agency for sure.  Again, I would again stress specific recommendations that can be made in terms of some of the comments that were made.  
                  Okay.  With that, I guess you've heard quite a bit of discussion.  Dr. Choudhary, do you have any questions of clarification regarding the comments made?
                  DR. REHAN CHOUDHARY:  Good afternoon, everybody, Rehan Choudhary from the EPA.  We've listened to the discussion, and I think we can use clarity or we have question around -- we heard, I think, Committee members saying they didn't think the current approach was adequate for screening.  Here's where we're getting confused.  We're seeing one take that is more holistic and that we're missing pathways.  We're grasping that portion of it.  
                  We didn't get a clear picture on -- well, here's the air pathway, and here's the water pathway portion of that.  Are those approaches themselves -- what are the members or Committee members' thoughts on the air methodology or the water methodology?  I think the team as a whole is feeling like, well, if we build it out and made it more holistic, we still have components to it.  If the Committee members can elaborate or clarify their position on that, that would help us.
                  DR. DANIEL SCHLENK:  Great.  Thanks.  Dr. Davies.
                  DR. HOLLY DAVIES:  I can clarify right now that my PBT comment was meant to the air and water pathways, in addition to the rest of the pathways that are missing.
                  DR. DANIEL SCHLENK:  Sure.  I think we'll get to that in 4C, actually, for some of those other -- at least for groundwater, anyway.  As Bill mentioned, there will be a component where we can actually throw in recommendations that are not listed as questions, as well, at the conclusion.  Okay.  With that, let's go ahead and take our break, our east coast lunch break.  Let's try to reconvene at 12:20.  Monica, I'm going to send you a direct message to see if you're available for 4B this afternoon, if we can get that in.  Is that possible?  You're on mute.  Yeah, go ahead.
                  DR. MONICA UNSELD:  Unless anyone thinks that they would like to send me something.  I have the comments that I have already.  But if someone wants to send me something, if you can, send it as soon as possible.
                  DR. DANIEL SCHLENK:  Okay.  Well, let's see what happens with 4A.  We'll try and see if we can sneak in 4B.  Dr. Chaisson.
                  DR. CHRISTINE CHAISSON:  The conversation on 4B I think is really important.  I have a feeling there are going to be a lot of comments on it.  Personally, I'd like to see, if Dr. Unseld wouldn't be able to harvest the existing thoughts from the full panel before summarizing that and maybe we can begin the day tomorrow and devote -- I think a lot of the conversations from 4B and 4D will be very similar.  Hopefully, there will be perspectives from everybody here.  
                  DR. DANIEL SCHLENK:  Okay.  Well, we'll see what the timing works like that.  I get your requests.  Dr. Apte, do you have another comment?
                  DR. UDAYAN APTE:  We are starting with 4A after this, after the lunch break?
                  DR. DANIEL SCHLENK:  Yes.  After lunch break, we will be doing 4A and see how long that goes.  If that goes quickly, then we can start 4B, maybe not conclude 4B but at least we can start since it's already been started already.  We don't necessarily have to conclude 4B today.  We can actually continue that tomorrow morning once we get that.  Okay.  Yeah.  We've gained another three minutes.  Let's reconvene at 25 past the hour for our afternoon session.
                  DR. ALAA KAMEL:  So 1:25 eastern time?
                  DR. DANIEL SCHLENK:  Eastern time, yeah, 25 past the hour.  Exactly.
                  DR. ALAA KAMEL:  Thanks.
            DR. DANIEL SCHLENK:  Okay.
            
            [LUNCH BREAK]
            
                  DR. DANIEL SCHLENK:  Okay.  Welcome back, everyone.  At this point, let's go ahead and I'll take a quick roll call for folks, and we'll move forward from there.  So begin alphabetically again.  Dr. Apte.  Dr. Apte.  Okay, Dr. Baker.
                  DR. MARISSA BAKER:  Present.
                  DR. DANIEL SCHLENK:  Thank you.  Dr. Blystone.
                  DR. SHERI BLYSTONE:  Here.
                  DR. DANIEL SCHLENK:  Dr. Calder.
                  DR. RYAN CALDER:  Present.
                  DR. DANIEL SCHLENK:  Dr. Chaisson. Dr. Chaisson.  Dr. Cobb.  Dr. Cobb.
                  DR. GEORGE COBB:  Here.
                  DR. DANIEL SCHLENK:  Gotcha.  That mute button's tough, isn't it?
                  DR. GEORGE COBB:  Oh, I got a -- I got a bar that pulls up when there's something alerting to me.  So --
                  DR. DANIEL SCHLENK:  Watch out for those alerts.  Dr. Davies.
                  DR. HOLLY DAVIES:  I'm here.
                  DR. DANIEL SCHLENK:  Dr. Doucette.
                  DR. WILLIAM DOUCETTE:  Virtually present.
                  DR. DANIEL SCHLENK:  Virtually present.  Haven't heard that one before.  That was your standard one last item actually, wasn't it?
                  DR. WILLIAM DOUCETTE:  Yep.  Thought I'd reuse it.
                  DR. DANIEL SCHLENK:  Dr. Ferry.
                  DR. JOHN FERRY:  Present.
                  DR. DANIEL SCHLENK:  Dr. Gribble.
                  DR. MATTHEW GRIBBLE:  Here.
                  DR. DANIEL SCHLENK:  Dr. Heiger-Bernays.  Dr. Heiger-Bernays.  Okay.  Dr. Henneman.  Dr. Henneman.
                  DR. LUCAS HENNEMAN:  Present.
                  DR. DANIEL SCHLENK:  Gotcha, thanks.  Dr. Johnson.
                  DR. MARK JOHNSON:  Here.
                  DR. DANIEL SCHLENK:  Dr. Kissel.
                  DR. JOHN KISSEL:  Present.
                  DR. DANIEL SCHLENK:  Thanks.  Dr. Li.
                  DR. LI LI:  Present.
                  DR. DANIEL SCHLENK:  Great.  Dr. Miserlian.  Dr. Miserlian.  Dr. Przybyla.
                  DR. JENNIFER PRZYBYLA:  Present.
                  DR. DANIEL SCHLENK:  Great.  Dr. Reif.
                  DR. DAVID REIF:  Present.
                  DR. DANIEL SCHLENK:  And Dr. Reiss.  I got it right that time.
                  DR. RICK REISS:  Present.
                  DR. DANIEL SCHLENK:  Great.  Thanks.  Dr. Rollins.  Still no Dr. Rollins.  Okay.  Dr. Sathyanarayana.  Okay.  I think she might be out today at this point.  Dr. Unseld.
                  DR. UNSELD:  Present.
                  DR. DANIEL SCHLENK:  Got it.  And Dr. Voorhees.
                  DR. CHARLES VORHEES:  Present.
                  DR. DANIEL SCHLENK:  Got it.  Let's go back.  Dr. Apte.  Dr. Apte.  Okay.  Dr. Chaisson.
                  DR. CHRISTINE CHAISSON:  Present.
                  DR. DANIEL SCHLENK:  Gotcha.  And Dr. Heiger-Bernays.  Dr. Heiger-Bernays.  Okay.  Dr. Messerlian.  Okay.  We've got a few missing there, but we've got enough for a quorum.  So we'll go ahead and move forward.  So what we're going to try to do today is we'll start with 4a, see how we proceed through that and begin, probably, 4b and see how we go through that.
                  I've been asked by the staff if the members of 4c and 4d wouldn't mind making comments on those questions today to try to end early.  But I think based upon discussions before lunch that there was sort of some interest in pursuing this tomorrow as well.  So I'll leave that up for a survey.  If folks are interested in ending early today or pursuing this tomorrow, please let me know.  You can do a direct response on the chat box.  That would be great.
                  So again, just let me know whether or not you would like to end today or pursue this tomorrow.  That would be great.  Okay.  So let's go ahead and put question 4a on the -- and, yeah, I guess because these are subparts of the question, would it be possible -- let's go ahead and read all parts in together.  And then we'll just address the subparts as we go rather than having to read the first part.  
                  Because I don't know if you have slide -- that first part in every subpart of the slide.  If you do, then we'll just read this first one.  If you don't, then we'll just go ahead and -- let's go ahead and do a, b, c, and d all together.  Just --
                  MR. WILL KING:  A, b, c, and d are set up exactly like this one.
                  DR. DANIEL SCHLENK:  Oh, perfect.  Okay.  So let's just read them separately then.
                  MR. WILL KING:  Right.
                  DR. DANIEL SCHLENK:  Great.  Dr. Choudhary, do you want to read that into the record?
                  
CHARGE QUESTION 4a
                  
                  DR. REHAN CHOUDHARY:  All right.  Good afternoon, everybody.  Rehan Choudhary from the EPA.  Charge Question 4 to the SACC Committee:  "Please propose and describe approaches that EPA can take into consideration for the purposes of expanding the capacity of the proposed screening methodology (Version 1.0) presented in this work.
                  Some possible examples may include but are not limited to, subpart a, how the proposed screening level approach may be expanded to evaluate aggregate/cumulative exposures and whether additional sources of environmental release information (beyond the Toxics Release Inventory or TRI) should be considered for such enhancements (such as the National Emissions Inventory or NEI)." 
                  DR. DANIEL SCHLENK:  Great.  Our lead discussant is Dr. Johnson.
                  DR. MARK JOHNSON:  Okay.  I haven't had much opportunity to put these comments in order, but I will provide them as they're presenting.  And as we interpret this question, 4a, is really asking about subsequent tiers, what they would look like, and any additional sources or data beyond the TRI.
                  And so, the issue of cumulative impacts is very important for fenceline communities.  In many fenceline communities, members of the community also work at polluting facilities and may also have occupational exposures as well and may also contribute to cumulative body burdens of contaminants, thereby additional potential risks.  
                  The current screening approach excludes occupational exposure assessments.  But an improved version of the screening tool is focused on cumulative impacts that would take a more holistic view of lived experience of fenceline communities would benefit.  
                  Dr. Nicky Sheats established a pathway to provide cumulative impact approach.  The State of New Jersey passed the Environmental Justice Policy, NJ S232 -- that's 20r -- that includes cumulative impacts and establishes a potential protocol for working with impacted communities on policy.  Promoting the use of apps like Smell MyCity and other encouraging local air monitoring will highlight potential gaps in the TRI data.
                  The EPA should also analyze more than one year of TRI data.  Analysis of five years of TRI data would provide greater clarity than one year use in version 1.0.  Dr. Unseld goes further to mention that as a resident of Louisville, Kentucky, she's very familiar with the Rubbertown area with multiple chemical facilities.  Homes may be a chain-link fence away from the facility property, less than a hundred meters.
                  I've personally noticed changes in odor reports, even on holidays such as Christmas.  I was in one of the neighborhoods surrounding Rubbertown on Christmas Day.  You could smell the odors from Rubbertown facilities.  Residents of Louisville can report odors via Smell MyCity app.  Local data like this can enhance EPA's estimation of exposure and may highlight releases not found in one-year TRI data averages.  
                  Another commenter notes that there are examples of compounds for which a given year's TRI or other inventory may not be sufficient to evaluate aggregate or cumulative exposure.  These include some of these so-called emerging contaminants that have strong historical exposure component, such as the case with PFAS.  For some compounds like this, the Agency should consider additional sources of information such as dose reconstruction from new water or epi sampling data.
                  To address aggregate cumulative hazard aspects, new approach methods could be considered to fill in tracks of missing data for compounds in a given aggregate exposure set.  These methods may be especially appropriate for use at screening levels.  
                  I think that we also need to be explicit with discussions of the simplicity to complexity spectrum to specify whether it's data or methods or software or communication.  Complexity underlying methods may be tolerated if interfaces for interacting with data are useful.  Examples include the EPA chemistry dashboard, Cal info screen, the interfaces for specific models developed as spinoff applications.  The interactivity may be key to communication of the screening level approach to fencelike community.  And on a practical level, public data can be scraped into more automated fashion that a multi-step hand curation procedure introduces the opportunity for errors.
                  For the current Version 1, the hand curation is appropriate for development.  As the approach expands, it will be important to automate the collection and apportionment of data in well-documented open-source code.  This will also serve to aid model evaluation and revision over time, including any sensitivity analyses.  
                  For aggregate and cumulative exposure assessment, a majority of the fenceline communities will be exposed to several different chemicals at the same time.  Many of these chemicals may have different or the same target tissues where they induce adverse effects.  Many of these chemicals will affect receptors using water pathways: air, water, dermal.  Thus, going forward, developing a framework for cumulative exposure assessment is highly recommended.  
                  Cumulative exposure assessment will be able to determine the total exposure of the fenceline communities to multiple chemicals via multiple routes of exposure.  These exposure assessments will be able to determine the total eposome (phonetic) of the fenceline communities which is very critical in getting better comprehensive risk assessment.
                  Cumulative exposure is likely to reveal new chemicals that were not included in the current screening approach and may not be part of the TRI or NEI.  This is likely to complicate the risk assessment process but a necessary step.  In this individual's opinion, it's more than aggregate exposure assessment; cumulative exposure assessment would be more relevant and informative for risk assessment for fenceline communities.
                  And for nonchemical stressors, fenceline communities generally have a disproportionate burden of nonchemical stressors such as lack of healthcare, pre-existing untreated disease such as obesity and diabetes.  It is critical to include these in the modeling going forward.  This is similar to including potentially exposed or susceptible subpopulations in the risk assessment process.
                  Using additional sources beyond the TRA, this commenter notices that there are other sources, to include self-reporting and self-monitoring by fenceline communities at the municipal city level.  Academic centers that work with fenceline communities and tribal councils may also have data or information, and this could be integrated.  
                  Another comment: the EPA needs to reach out to states and ask what data they may have available and not passively wait for states to contact the EPA.  These are some examples from Washington.  Other states and territories may have similar data sources.  NEI has been mentioned as a source of information that this commenter goes to for identifying major sources of a chemical.  In Washington, we have priority pollutants for water, and permittees do a priority pollutant scan.  This is broader than the EPA's Washington list.
                  I am not an expert in water quality permitting, but my understanding is that large industrial facilities monitor for these pollutions once per year.  These data go into our PARIS database.  I don't think data flows to EPA automatically.  
                  Methyl Chloride is on the Washington priority pollutant list, but NMP is not.  I look, and there is no additional MECL detections.  A small amount of data and assessment was built.  It only makes it important to look for other data.
                  Fish tissue data is a source of information for the level of pollutants in water bodies.  This is in addition to looking at fish tissue for fish consumption estimates.  In Washington, we use fish data to identify impaired water bodies.  Obviously, this is more important than PBTs.  We don't have MECL in our fish, but most of our fish have unsafe levels of PCBs, for example, and I would imagine mercury as well.  Washington and other states' governments have databases on fish tissue the EPA may find useful.  
                  For air quality, Washington has a list of state toxic air populates which list pollutants that are not federal hazardous air pollutants.  Washington has data on taps and other sources of information.  Other states and local area agencies may also have some information as well.  
                  State and local governments have information on small businesses.  For example, King County information on dry cleaners is mentioned in previous SACC meetings.
                  This draft report is used for the training report for emissions and assumed dry cleaners using third-generation machines based on age of dry-cleaning machines in King County and that one BPE is a drop in the replacement for PERC. The assumption that they're all third-generation's machines is not conservative.
                  And one additional comment that I had is, if you're thinking about looking at additional tiers, one approach I've seen in the environmental health field, I haven't seen used for human health yet, is the use of Bayesian networks to begin to think about ways to integrate probabilities of different exposure pathways such as oral inhalation, air exposures, and ones from surface water releases.
                  I could show you an example if you'd like to see an example figuratively of what a Bayesian network sort of looks like.  But basically, the understanding is that Bayesian networks take distributions of what you think these certain contaminants may follow, it could be geometric, logarithmic, Gaussian distribution.  You have limits.  You pretty much have ranges or boundaries on those data and use sort of monocular (phonetic) analysis and you link these together.
                  You can link adverse outcome pathway data together if it shares a common mechanism mode of action.  And you can do this for the tox side, you can do this for the exposure side, and you can do it for the different pathways.  And so I'll just stop there pending any questions.
                  DR. DANIEL SCHLENK:  Okay, thanks, Mark.  Our next discussant is Dr. Apte.  Dr. Apte.
                  DR. UDAYAN APTE:  Yep.  
                  DR. DANIEL SCHLENK:  There you go.
                  DR. UDAYAN APTE:  Can you hear me?  Yeah. 
                  DR. DANIEL SCHLENK:  Yep.
                  DR. UDAYAN APTE:  Well, I think Dr. Johnson covered most of my comments, and I'm going to wait and see what others have to say.
                  DR. DANIEL SCHLENK:  Okay.  Dr. Reif, you're next.
                  DR. DAVID REIF:  Yes, same here.  My comments were covered by Dr. Johnson as well.
                  DR. DANIEL SCHLENK:  Great.  And Dr. Unseld.
                  DR. MONICA UNSELD:  I have nothing to add.
                  DR. DANIEL SCHLENK:  Okay.  Open it up for other Committee members.  Dr. Reiss.  I got it right this time.
                  DR. RICK REISS:  Thank you.  I appreciate it.  So it's maybe a little bit tangential to this but I, you know, take EPA's comment about helpful suggestions on, you know, how to maybe streamline this or provide a better screening approach.  The question mentions the NEI, the National Emission Inventory, which unlike the TRI has stack data, information about stack heights, and exit velocities and diameters, which are very useful for modeling.
                  You know, in lieu of that, not being in the TRIs, you know, the EPA used some conservative assumptions for those.  And, you know, those can make very dramatic differences, particularly, I think, with the large facilities and big emitters, which may have stacks to mitigate downwind pollution.  
                  So I just wonder whether you could use the NEI combined with the screening level approach.  So you have that screening level approach which is must simpler to implement and has a conservative aspect to it in terms of using worst-case meteorological conditions.  It uses the worst-case site but then add the realism of NEI.  
                  You know, maybe it doesn't make a difference with these chemicals, but when you start to go down the more -- maybe less toxic chemicals through these full lists, it would be nice to have a screening methodology that actually screens some stuff.  And I think combining the NEI with the pre-screening approach might be one way to do that.
                  DR. DANIEL SCHLENK:  Okay.  Thank you, Dr. Reiss.  Dr. Chaisson.
                  DR. CHRISTINE CHAISSON:  Thank you.  I was wondering if it's possible, as part of the screening process to have a very formalized problem formulation step at the very beginning before any calculations are run of any kind, which establishes that the Agency is going to run a screen on a given chemical for fenceline communities and laying out any other details on the intended analysis, and at that stage making it public and soliciting from the fenceline communities, or industry, or anybody, the states, the local groups, and whatever, information about other sources that are important to those places or other data sets that people already have.  That would make it available also to researchers who may have data or approaches or any kind of information that's relevant to the question and giving the Agency an opportunity to harvest what could be quite important up-front information before they have to put an analysis of any kind, screening or otherwise, out there for public comment.  
                  So it gives the public and any interested stakeholders an opportunity to contribute to either modification of the problem formulation or any way to inform the assessment.  Is that possible?
                  DR. DANIEL SCHLENK:  Is that a question for --
                  DR. CHRISTINE CHAISSON:  Well, no, I meant --
                  DR. DANIEL SCHLENK:  -- Mark Johnson -- oh.
                  DR. CHRISTINE CHAISSON:  I mean, rhetorically.
                  DR. DANIEL SCHLENK:  Oh, okay.
                  DR. CHRISTINE CHAISSON:  I think that was not a specific answer to what the sources of information should be.  But I think that one of our problems is that we don't necessarily know, I mean, where all the information could be for any given chemical or what, you know, may be very prescient information or data are being generated.  
                  And so, that also brings the opportunity to the fenceline communities for their participation, not after everything is said and done, but at the very beginning of the process.
                  DR. DANIEL SCHLENK:  Okay.  Any other comments?  Dr. Sathyanarayana.
                  DR. SHEELA SATHYANARAYANA:  Okay, thanks.  So I think there are two parts to this question.  One was how could you look for other sources of information and data?  But then the other part was, how do you aggregate that data and consider cumulative exposures?  And Dr. Johnson mentioned Bayesian networks, but there's a whole field of science devoted to aggregate and cumulative exposure and NIHS has had multiple workshops on this.
                  There's a number of methods like weighted quantile regression.  There's the Bayesian method.  There's G-Quantile computation.  There's just a number of others.  And, Mark, I'm happy to send you some references to those so that it could be incorporated.
                  DR. DANIEL SCHLENK:  Great, thanks. After we get the comments, he actually has a slide apparently that he can talk about some of the Bayesian stuff.  So, Dr. Heiger-Bernays.
                  DR. WENDY HEIGER-BERNAYS:  Yes, thank you.  I was actually going to say what Sheela had mentioned.  But the other point that I have actually is with regard to the upfront statement of the problem -- the problem formulation.  So not to take away from what we've actually been asked to evaluate, but around clarity of what that assessment or this screening model will actually be able to do.
                  I do think it is important to understand, as EPA has asked, what are additional sources of data and information that can be useful to this effort?  And I think that there are other data sources that exist, certainly all the data around hazardous waste sites that EPA has in its possession sort of from that line of thinking which is -- ATSDR has those documented, where they have done their assessments.
                  I think there are ways to construct the screening analysis so that for those chemicals for which there are a lot of data, you're going to have this what we're hopefully going to get to as a tiered approach.  But it's almost weight of evidence.  Like there is a lot of this stuff out there.  And for these things, here is a way we can proceed, but we don't want to miss the big, I'll call them, data sources that are already at EPA and ATSDR, right.
                  So we should be able to use those, pull those in, and almost provide some sort of I'll call it weight of evidence, that, you know, for these chemicals.  Certainly, for the first 20 chemicals, there are good environmental data that are out there.  
                  And then the second is, you know, how to access and gain the data from the fenceline through -- well, both the environmental data and also the data on behaviors and human characteristics of people living around these locations.
                  And I think that these are sort of two different buckets, and they're going to inform each other.  So what I worry about is, for the data that may be coming from communities -- and I'm talking environmental data now -- I would like not to see that there is almost a can't look at those data because they're not validated.  We can't look at those data because they don't go through the same level of QA/QC that contracted data go through, right.
                  And so I think it's useful to recognize that this might be an issue.  It's not an issue to prevent using those data; it's an issue to prevent, at some point, somebody, somewhere, saying can't use those data.  So it's almost what are the questions that EPA could ask or the steps that they could take to be able to use those data?  And that's all I have.  Thank you.
                  DR. DANIEL SCHLENK:  Great.  Thank you.  Bill, I guess you put your hand down so -- oh, you're back up again.  Okay.
                  DR. WILLIAM DOUCETTE:  Actually, the data quality aspect is really interesting, and what data would EPA be allowed to use at a screening level.  And I think that's very important.  And it kind of stole my topic; that's why I lowered my hand.  But I got involved in several field projects that -- both of them lasted about five years.  And we collected, you know, hundreds of samples and data.  
                  I had the opportunity, or I had the ability because of my lab to not only collect the samples but actually analyze them.  And in some cases -- this one in particular was for the Air Force, they had a contractor do the QA/QC for my data -- in other words, an independent review -- and that's fine.  But generally, the other projects that I've been involved with, they hired an academic lab to generate data not because -- instead of a contract lab mainly because the parties involved, the residents around the sites, wanted someone independent to do that.
                  So they didn't trust a consulting engineer hired by the Air Force to do that, but they felt comfortable with that academic lab.  And the problem is with many academic labs -- mine included -- we didn't always -- I think the quality of the data was great but didn't necessarily check all the -- or dot all the i's and cross the t's and sometimes what outside reviewers would consider appropriate quality assurance.
                  So I totally agree that there are lots of data out there.  I'm not sure what EPA would consider using given their quality control requirements.  And that's a question and a comment.
                  DR. DANIEL SCHLENK:  Okay, thanks.  Dr. Apte.
                  DR. UDAYAN APTE:  Yes.  So about the data usage, I mean, of course, there are other sources of data out there that could be used, and there is this question about vetting them.  And I was going back to a couple or three of the individual chemical risk -- the draft assessments that SACC has done in the past where I served as an ad hoc.  And I remember there was this process set up upfront by EPA to select which data they will use for that particular chemical risk assessment, right.
                  So there was a framework design.  And there was a lot of discussion about that framework, I remember.  And so something similar can be possibly put in here to use data that are not in TRI or in NEI.  A framework that can be considered by EPA, okay, are these data good for our assessment or not.  And they need to clearly define why they are or why they are not.
                  And if that can be put in, then this question about whether they can be used or not can be easily answered.
                  DR. DANIEL SCHLENK:  Okay.  Thanks.  Dr. Chiasson.
                  DR. CHRISTINE CHAISSON:  I think we have an opportunity here to influence the thinking on the adequacy of information that's going to be used and screened.  I'm not sure if this has been done in a regulatory framework before.  I can't think of anything right off the top of my head.  But while I think it's really important to have -- or to pay homage, if you will, to the efforts EPA has made in establishing the pedigree of data that's going to be used in a definitive risk assessment that's going to proceed to a regulatory statement and consequences, a screen is a little bit different.
                  I'm not saying that you put junk into it.  I'm not advocating for just tossing anything in there.  But sometimes, you know, the canary dies in the coal mine.  That's not a very analytical precision, but it's a clue.  And so, in some of the kinds of information that you can glean during a problem setting phase is going to have to have that kind of quality assurance.  Perhaps we could suggest some relaxation, if you will, to the pedigree.
                  But it's also going to include, I think, a much broader sort of education of the Agency as to what the communities or the state or regional area authority -- scientists, researchers, whatever -- see as contributing causes, significant issues, that might be missed by the Agency because it, as somebody else said, they can't know all things.  And that kind of information or even the application of certain kinds of health effects information, whatever, these are all good science clues.
                  And I think we have an opportunity here to embrace all of that kind of science clues as part of a screen with an acknowledgment that, when proceeding to a formal regulatory consequence decision, it doesn't necessarily adopt the same levels of inclusion and information as it could as you set up a preliminary screening event.
                  DR. DANIEL SCHLENK:  Okay.  Thank you.  Dr. Cobb.
                  DR. GEORGE COBB:  Yeah.  I just -- quickly point out that on this data quality issue, we had these discussions a year or so ago about some of the data inputs and the relative quality of various types of data and quality controls.  And there are approaches out there for weighting different studies based on those data quality criteria.  And I was just trying to dig one or two of those references out to make sure that they are included, and I will share that with the lead discussant for this topic.
                  DR. DANIEL SCHLENK:  Okay.  Great.  Thanks.  Dr. Reif.
                  DR. DAVID REIF:  Yeah.  So I wanted to say I'm glad that the data source thing is being discussed.  I wasn't sure where in Question 4 it was going to show up but I'm glad it's here.  Because I think as this charge question seems quite forward-looking, you know, there's a lot of movement from the very high levels of the Agency about data sources and things like use of animals going forward.  And I think it's certainly time to start pivoting toward those.
                  You know, the draft report or the Version 1 report cites a lot of NTP studies and guideline studies and those kinds of data.  And I think, if we're talking about how to expand this proposed approach, now is the time to start thinking about those methods.  And I'll offer for all the weight of evidence and things like that approaches, I think some of the Bayesian methods that are -- a couple of the commenters have already brought up and are going to discuss more are good approaches to build those kinds of things in because one can build both preferences of data quality but also preferences of preferred or priority data sources, right.  
                  So either sort of method is available with that.  So I'm glad we're having this discussion, and I'll try to contribute some specific sources of both data sources and perhaps methods when I see the other comments so we can have some specific guidance for EPA.
                  DR. DANIEL SCHLENK:  Great.  Good segue into Mark's slide.  Mr. King, can you make Dr. Johnson available for a slide to share his screen, or is he already available to do that?
                  MR. WILL KING:  He's all set.
                  DR. DANIEL SCHLENK:  Okay, thanks.  Go ahead, Mark.  George, do you have another question?  I see your hand still up.  Is that -- okay, thanks.  Go ahead, Mark.
                  DR. MARK JOHNSON:  Okay.  So you do have to use your imagination with this.  Okay?  And this may also dovetail with a comment I think I heard earlier about showing a conceptual site model, which would be very helpful as well.  So people can easily see the pathways you're looking at through water releases, air release, and so forth.  But this is an example for actually salmon in a river in determining how much effects can the salmon actually experience without adverse effects.
                  But in this particular example, we have organic phosphate pathway which we know occurs through inhibition of acetylcholinesterase.  And this can be integrated within each of these different blocks you see, which are independent networks, and they can all be linked.  And so the math isn't that difficult, and I think we can certainly do something like this for human health as well.
                  But the devil is in the details.  If you look really deep here you can see percentages, and you can get an idea of what the distributions look like.  They are embedded within each of these networks.  But this kind of gives you an idea about what I was talking about.
                  DR. DANIEL SCHLENK:  Okay.  Any other --  
                  DR. MARK JOHNSON:  So I'll stop sharing.
                  DR. DANIEL SCHLENK:  Okay, great.  Any others -- Dr. Unseld.
                  DR. MONICA UNSELD:  Yes, I just wanted to clarify.  So when we use the Smell MyCity app, it's kind of two-fold.  One is to demonstrate that the facilities may be operating outside of times that they're reporting.  So they say they're not on Christmas Day or they say they close at 5:00 p.m., and we can say, no, they're not.
                  And the second reason is because, once you submit data to that app, someone from the air pollution control district or the University of Louisville will actually go to the area to investigate to see what's going on.  So it may not be like the hard-core numbers, but it flags some potential data gaps.
                  DR. DANIEL SCHLENK:  Okay, great.  Any other comments from Panel members on -- yeah, Mark?
                  DR. MARK JOHNSON:  Yeah.  I just want to add to Dr. Unseld's comment.  We were discussing there's a report, I think, from American Industrial Hygiene Association where they looked at inner thresholds and just to ballpark the levels at which sublethal effects occur.  And more often than not they do.  If you can smell it, that's usually about the region where sublethal effects may be experienced at some chronic levels.  And so, I'll try to provide that reference as an example.
                  DR. DANIEL SCHLENK:  Great.  Dr. Heiger-Bernays.
                  DR. WENDY HEIGER-BERNAYS:  Yes.  I actually think this might be a way at getting at some of the concerns that have been raised earlier about aggregating or averaging over time and not really capturing the peaks or the peak emissions, the malfunction releases.  I think that this might be a way to do that.
                  We have seen this in the communities where we have worked where there are observations that are made.  Again, it's not quantitative data but it's qualitative, and it may be very useful for deciding sort of how to proceed.
                  DR. DANIEL SCHLENK:  Okay.  A lot of suggestions there.  Any other comments for 4a?  Okay.  I thought someone, maybe it was -- Dr. Doucette, did you want to ask EPA a question regarding data quality or is that something that we've already dealt with?
                  DR. WILLIAM DOUCETTE:  I mean, we did discuss the approach that EPA used to assess the data quality when we were doing the original assessments before this field line report was put out, and they were fairly well defined.
                  DR. DANIEL SCHLENK:  Okay.
                  DR. WILLIAM DOUCETTE:  And I think we've also addressed that maybe they could allow us some flexibility in the screening approach for field data, for example, that didn't go through their quality review since it's probably useful data, especially in a screening scenario.  So I don't know how they should articulate that.
                  You know, you worry about okay, so they use that data in a screening method, and then maybe industry or someone else comes back and say that data is no good.  You can't make a decision based on that.  However, if it's articulated properly and it is just a screening approach, I think a lot of that data could be used.  That's my only other comment.  So it's a comment/question.  Maybe EPA could come up with a way to express that.
                  DR. DANIEL SCHLENK:  Okay.  But that's a recommendation that you're going to make.
                  DR. WILLIAM DOUCETTE:  Yeah.
                  DR. DANIEL SCHLENK:  I'm just wondering whether or not you want to ask them since we have them in the room, so to speak, if that is how they would do it or not.
                  DR. WILLIAM DOUCETTE:  Well, okay, that's the question then for EPA if I can do that.
                  DR. DANIEL SCHLENK:  Oh, yeah.  We can ask, again, them a question for that if you want.  
                  DR. WILLIAM DOUCETTE:  That would be a question.
                  DR. DANIEL SCHLENK:  I just wanted to make sure.  Okay.  Let's go through the rest of the comments first, and then we can do that at the end.  So, Dr. Davies.
                  DR. HOLLY DAVIES:  Oh, I just wanted to add onto this data conversation.  This is just a comment to the Committee that this is relevant for our systematic review discussion at the next meeting -- what data they use.
                  DR. DANIEL SCHLENK:  It sure is.
                  DR. HOLLY DAVIES:  Right.
                  DR. DANIEL SCHLENK:  It is.
                  DR. HOLLY DAVIES:  And great here too.
                  DR. DANIEL SCHLENK:  Preemptive strike.  Yeah.  Dr. Chiasson.
                  DR. CHRISTINE CHAISSON:  Just commenting on Dr. Doucette's comment.  When considering how perfect the data set is or the information in whatever format that's being presented, the other risk is that you completely miss a clue or you completely miss a key element of what could be exposure.  So there is a certain risk, if you will, in terms of -- about assessment in throwing away information if its pedigree is not deemed to be sufficient.
                  DR. DANIEL SCHLENK:  Thanks.  So any other comments before we go to the Agency?  So, Dr. Chaudry, if you're on.  Bill, can you just rephrase your question to him so that he can answer that?
                  DR. WILLIAM DOUCETTE:  Rephrase it.  Okay, I'll give it a shot.  I guess for a screening exercise, what data criteria would be considered acceptable for use in that particular screening model situation?
                  DR. DANIEL SCHLENK:  Dr. Choudhary.
                  DR. REHAN CHOUDHARY:  This is Rehan Choudhary from the EPA.  I think that it's correct that some people have already said that this is next in the queue, so to speak, with respect to your SACC meeting on the systematic review protocol.  I think what I can say, it depends on the purpose of a screen.
                  With the fenceline screening approach, it is intending -- let me step back and say, if the screen is intended to inform more thorough evaluations which will then eventually lead to determinations, the sources we're relying on have to follow the suit of best available science.  And so, we have a systematic review protocol in place to ensure the information sources we are relying on meet certain minimum criteria.
                  So I think that's where I'd like to leave it, that there is a protocol in place and when we know a screening approach is going to be informing determinations, meaning the rulemaking, we need to rely on that protocol to ensure what we're using meets minimum criteria.
                  DR. WILLIAM DOUCETTE:  Okay.  A follow-up then, if you don't mind, Dan.  Is that all right to follow up?
                  DR. DANIEL SCHLENK:  Sure.
                  DR. WILLIAM DOUCETTE:  So what if the data were used exclusively just to illustrate potential pathways?  In other words, there's a set of data that looks at a food chain contamination into plants.  I've done a lot of plant uptake work.  And you might not think that that data meets your data quality, but it suggests that that pathway might be important in determining your conceptual model for a particular chemical.  Could it be used in that way?
                  DR. REHAN CHOUDHARY:  You know, it gets broader.  There is a systematic review protocol that acknowledges certain types of sources go through a rating and evaluation process.  Then there are sources that don't go through that kind of rating and evaluation process, but they're incorporated into a broader weight of the scientific evidence.
                  So that flexibility, I believe, is there so that, if you have some other sources that don't fit nicely into going through that systematic review protocol, they can become mined together to come up with an overall weight of scientific evidence, which would then be informing approaches and methods or direction that the Agency takes.
                  DR. WILLIAM DOUCETTE:  Thank you.
                  DR. REHAN CHOUDHARY:  And by all means, I'm not the expert on that systematic review protocol, but I think you'll get more in about a month or so.
                  DR. DANIEL SCHLENK:  That's the truth.  More than we want to know, I think, probably.  Okay.  So at this point, any other comments that we have before we go to Dr. Choudhary?  Dr. Apte.
                  DR. UDAYAN APTE:  Yeah.  I just wanted to bring up the nonchemical stressors for a minute here in terms of their effect on fenceline communities.  And I think what I got from EPA before and discussion that that has not been included in this particular version.  But, you know, I strongly suggest that those interactions should be included going forward maybe in Version 2.0.
                  Because as more and more research is showing, these stressors, their combination effect is a lot more important than just individual chemical exposures at this point.  So I just want to put that on the record here.
                  DR. DANIEL SCHLENK:  Yeah.  That was just brought up at the SAB meeting a couple weeks ago, actually, combined stressor impacts.  So I'm sure that's being circulated at this point.  But thank you for that comment.  Any other comments?  Okay.  So let's go to Dr. Choudhary.  Any questions that you have regarding the comments that were made for 4a?
                  DR. REHAN CHOUDHARY:  I don't see any particular questions that the group wants to elevate to the SACC Committee members.  Based on the discussion we were hearing, we simply wanted to clarify that the dockets for the next 20 or so chemical risk evaluations are still open with the discussion centered around, if people have data, can they submit it to us?  They certainly can.
                   DR. DANIEL SCHLENK:  Great.  Doctor -- I can never get your name.  Zoom cuts off your name, Kevin.  So I can't get the full -- it cuts it straight about half off.
                  DR. KEVIN VUILLEUMIER:  That's okay.  You don't want to say it anyway.  Just one small clarification I wanted to ask.  Early in this question, they mentioned rather than using one year of data, to use five years of data for TRI data.  I'd just like a little clarification on how they view using those five years of data.  Is it modeling individual years across five years and then averaging those results?  Which gets kind of to Dr. Chaisson's comments about where the data comes from.  Is it averages and so on?  
                  Or are we talking about taking five years of data, averaging it together, and then modeling it and then taking averages?  So if we can get clarification on what your thoughts are in that line of -- that train of thought, that could be beneficial.
                  DR. DANIEL SCHLENK:  Okay.  I don't recall who actually made that particular comment.  Do you, Dr. Johnson?
                  DR. MARK JOHNSON:  No.  I don't think it was me, sir.
                  DR. DANIEL SCHLENK:  Okay.
                  DR. MONICA UNSELD:  It was me -- Monica.  
                  DR. DANIEL SCHLENK:  Oh, okay.  Okay.
                  DR. MONICA UNSELD:  So my thinking was, you know, one year average as has been stated before is not going to tell you peak releases as much.  But if we see five years, maybe we can at least get some shifting.  Maybe we could catch some trends of what's happening.  So I guess it would be an average, but hopefully, it would just add some more weight because every year's not the same, especially with the shifting climate and shifting land use.  My thinking was five years would just provide more weight to the equations.
                  DR. DANIEL SCHLENK:  Does that answer your question, Kevin?
                  DR. KEVIN VUILLEUMIER:  Yeah.  And I see Dr. Chaisson's hands up too.  She might have more to add.  So yeah, thank you.
                  DR. DANIEL SCHLENK:  Okay.  Dr. Chaisson.
                  DR. CHRISTINE CHAISSON:  Yeah, thank you.  I think that the issue Dr. Unseld was talking about is very, very important.  Because if you can only see amortized data, you don't know what the contribution of the changes are, Monica.  In other words, it could have been fewer releases with greater spikes, or it could be a whole lot of smaller releases, which themselves could be consequential depending upon the exposure opportunity that precedes the adverse health effect.
                  So, you know, this really goes hand in hand.  And back to the point, you might have average data from multiple sources that's then modeled, then you take the 50th percentile.  That's an extremely different kind of data set to be used.  However, once again, we're in the weeds of the data utility and the statistics.
                  And I want to refocus this back to the relevance question so that this upfront process, which we're going to get to talk about much more in a month or so -- but I think it's very, very important for this particular question.   I think that the screening method would be greatly enhanced if there was a formal process ahead of time in the problem construction, not just EPA making an announcement and saying send me your data.
                  That is wholly insufficient, completely insufficient for setting up the problem to be addressed.  I think the communities need to have a much broader input -- and researchers or community members, states, counties, whomever -- to look at the problem formulation in its entirety, not just have the EPA determine they're going to use this tool, we're going to have this chemical looked at, send me your data.
                  So I want to make -- I'm obviously emphasizing that problem formulation is not just dumping data into the Agency.
                  DR. DANIEL SCHLENK:  Okay.  Thank you.  Dr. Heiger-Bernays.
                  DR. WENDY HEIGER-BERNAYS:  Yes.  I do concur with Dr. Chaisson.  I think we've heard two -- well, there's two things I want to say.  One is we're heard about problem formulation which is really important in setting this up.  And the other is the site conceptual model, right.  These are two terms that risk assessors use.  But I think it's a very -- those are two very important, I'll call them formatting, really explanations.  And it will be very useful in providing that kind of framework for fenceline communities.  So that when data or when there are decisions made about what kind of data, whose data, there is a place where those go.  
                  The other thing is, I do want to refocus us.  This is screening.  It's a screening-level assessment, right.  So, you know, we are looking not for the lower percentile in the hazard concentrations, right.  We're asking, are there data that support these concentrations that are being emitted that are problematic, right?
                  So I guess I am less concerned about have we gotten the -- I don't know, the right five, ten years.  I think the question is, is there evidence that there are these higher concentrations that are out there that have been documented?  And we need to capture those.
                  DR. DANIEL SCHLENK:  Okay.  Dr. Blystone.  You're on mute, Sherri.
                  DR. SHERI BLYSTONE:  I am muted.  Sorry.  I've got too many buttons to hit.  This is an aside.  Just a comment in general because we're talking about problem formulations.  So just to remind people on this Committee and the public that may be listening.  There is an entire process for risk evaluation of chemicals that includes a problem formulation step that allows public input.
                  So that if you are interested in these, I would highly encourage you to follow what the EPA is doing and use those opportunities to put your input in.
                  DR. DANIEL SCHLENK:  Okay.  Great.  Thank you.  Okay.  Well, we've sort of gone around a bit back to our original question.  Our point for Dr. Choudhary was to ask questions and clarification.  So I guess you've gotten some more comments to question, perhaps.  Is that where we're at here?
                  DR. REHAN CHOUDHARY:  So while this was happening, some additional core members have highlighted clarifications.  I think during this discussion, there was mention of nonchemical stressors.  And staff members are saying that if the Committee members, relevant Committee members who are thinking along those lines know of sources or methods to incorporate nonchemical stressors, we would very much like that to be part of your documentation and report and sources that you bring to our attention.
                  DR. DANIEL SCHLENK:  Great.  Thanks.  
                  DR. REHAN CHOUDHARY:  And I believe there is one more question trying to get a little more clarity on use of multiple years of data.  For example, when we say let's use multiple years of TRI data, with the recent pandemic or effects of the pandemic, do the Committee members have any thoughts on whether these kinds of occurrences should be a basis for excluding that kind of data from data sets when you're looking at multiple years or averages?  
                  So again, it's not intended more as -- we don't intend for you to be able to clarify this on the spot.  But when you're writing this up and that's incorporated into your recommendations, if you can also incorporate your thoughts on pandemic related, these kinds of occurrences, that will help inform us as to how to proceed as well.
                  DR. DANIEL SCHLENK:  Okay, thanks.  Sheela, can you state your chat info for the verbal record, please?
                  DR. SHEELA SATHYANARAYANA:  Yes, sorry.  I just said that I would send some sources on combining chemical and nonchemical stressors. 
                  DR. DANIEL SCHLENK:  Thanks for that.
                  
CHARGE QUESTION 4b
                  
                  DR. DANIEL SCHLENK:  Okay.  I think we're ready to move on to 4b at this point and begin that discussion.  So Dr. Choudhary, can you read that into the record, please?
                  DR. REHAN CHOUDHARY:  Yes.  Good afternoon, everybody.  Rehan Choudhary from the EPA.  Charge Question 4, subpart b being posed to the SACC Committee: "Please propose and describe approaches that EPA can take into consideration for the purposes of expanding the capacity of the proposed screening methodology (Version 1.0) presented in this work.  Some possible examples may include but are not limited to, subpart b:  how the proposed screening level approach may be expanded to identify potential environmental justice or EJ concerns and inform future EJ analyses that can assess racial and economic disparities in exposures."  
                  DR. DANIEL SCHLENK:  Okay.  Our lead discussant for this question is Dr. Unseld.
                  DR. MONICA UNSELD:  Hello.  This is Monica Unseld.  I just got some of these comments during lunch, so I will try my best to present what was provided to me.  If there was consensus in the comments, it was what we've been hearing all of this time.  That we would like the Agency to take more information into consideration for the revision of Version 1.0.  That was the consensus statement if we have one, and the next will be individual discussant comments.
                  So the Agency should not delay using available data and methodology to protect the public, particularly for disproportionately impacted communities.  And yesterday we heard in the public comments about the health-protective default adjustment factors.  Once that's submitted, we would like that to also be used by the Agency for reference.  
                  We would like to uplift -- I should stop saying we -- include relevant health data that was mentioned earlier today, I believe, especially in terms of earlier SACC recommendations.
                  In terms of the best possible science, it may be nice for the EPA to define that, especially since science can kind of be a moving target as we get better tools and better ways to analyze things.  That can maybe help set expectations not only for the SACC Committee but for the public and all stakeholders.  
                  We've talked about nonchemical stressors, cumulative impacts.
                  I have provided seven linked resources on how to potentially incorporate lived experience data.  So they're linked in my notes.  So these are resources, these are examples, these are also discussions of the pros and cons of trying to incorporate lived experience data.  So hopefully, the Agency will be able to overlook this information and decide how it might be adapted to improve the methodology, especially before we get to risk evaluation.
                  Note that there is a delay in publication.  So while we do rely on public peer-reviewed research, we still need to keep that open channel of communication open with communities and with stakeholders.  And right now the EPA's outreach method is lacking both for stakeholders and the community.  As we saw in the comments, it was stated that people felt like they didn't have enough time to comment.  And again, the input should really be solved at the beginning of the process and not in terms of just providing revisions.
                  This could help route the models and the estimate into reality and could help us not rely on estimates and assumptions that may no longer be real for what's happening in our society.  As stated before, it's a rapidly changing society, and we can't assume that things will go back to normal, whatever normal was.  So we need to make space for, what if we do stay in a work from home culture?  Climate change doesn't seem to be going away.
                  So how can we keep those open channels of communication sustained so that the EPA can best know how the published literature, which is delayed, can actually fit what's be happening?  So this is mapping, routes of exposure, conditions of use.  It may be helpful for the EPA to provide the community and stakeholders just with an Agency map.
                  So let's say if you call the regional office, what happens then?  How does it move through the EPA?  Yesterday we learned that there were different offices.  So they talked to the Office of Environmental Justice to learn.  How is that information getting from the Office of Environmental Justice to this office?  And so how can people and stakeholders be assured that their comments are getting to the place where they need to be?  And I think that can also help build or possibly rebuild trust between the Agency and the public and stakeholders.  
                  The Union of Concerned Scientists has some resources on community-based participatory research.  I will provide links for that.  I'm not suggesting that the EPA uplift this and do this itself, but this could be a resource that those who are coming to the EPA could say, hey, if you want to learn how to do this, here's a link so that you can help us help you.  
                  Scrolling though.  We need more independent data and data validation.  And then, that could just be to uplifting the need for local monitoring.  And that doesn't have to be strictly run by the EPA.  We can look for some creative ways to approach that.  
                  We need to anticipate age-related exposure.  So consider sensitive sub-population groups within these "unique communities".
                  In terms of water, the EPA focuses on public drinking water and recreational swimming.  As we heard earlier today, that's not a reality or a part of daily life in many fenceline and communities of color of lower economic status.  
                  Once again, uplift the National Tribal Toxic Council.  They had some great recommendations.  They uplifted roots of exposure in terms of fish, diet, bioaccumulating substances.  So we need to consider cultural differences and how that may impact routes of exposure.
                  Include noncommercial exposure sources.  And again, that's diet, subsistence food.  And I would think we now need the impact of climate change on that because we know the arctic, the chemicals are bioaccumulating at the poles, and these are also communities that are eating a lot of those fishy mammals and whales and things.  So their exposure may be a little different than what you may have here in Louisville, Kentucky.
                  Let's see.  Let's consider brownfields and disposal and garbage pits.  Fenceline communities, there should be automatic safety factors assigned to the communities in the widest use of the term.  This is to acknowledge enhanced exposure and susceptibility to the people, especially as compared to populations living commercially defined, middle-class lives and diets reflected in many EPA exposure factors, focused research, and assumptions.
                  The lack of knowledge/understanding about exposure and enhanced susceptibility to toxic chemicals is unto itself an imposing fact which should be acknowledged by conservative safety factors until such a time as such conditions are detailed and understood for risk assessments.  This uniqueness of such communities should be acknowledged as a data gap and dealt with as risk assessors detail untested missing toxicology endpoints, metrics, and apply safety factors until such time information is produced.
                  And there are some bullet points under that, so it talks about intrinsic stressors which can amplify exposure.  You may miss sources of exposure, which has been said a lot these past two days, and the extrinsic stressors to amplify susceptibility.  
                  So some examples of these exposures that we haven't spoken of before.  So we're looking at the entire lifespan, the multiple life stages to the whole community and not necessarily just like the 11 to 15 age range or pregnant women but multiple life spans.
                  Short-term, high exposures which would be unusual or accidental or illegal intermittent exposures to any and all life stages.  If the screens do not catch these situations, it's pretty unlikely that subsequent work will include such scenarios.  Research the issues, seek data on the unknowns, or in any meaningful way protect these people who have been systemically erased and they will remain indivisible.
                  And I will add to that, that if we do not try to address these issues now, we're going to just keep kicking the can further down the road, and it's just going to make the problem even more complex.  
                  In terms of algorithms of screening metrics, the use of average data points or conversions to represent time durations, there's a point where a contaminant value is mathematically reduced to comport to the algorithm's required metric.  And I'll ask for clarification on that at the end.
                  And there are assumptions and defaults on key exposure factors.  We're also uplifting the public comments by the National Tribal Toxic Council.  And don't forget home-based industries -- weaving, art.  And if you can consider recreational swimming, then consider cultural traditions in other communities.  
                  Let's see.  So we talk about not only potential cumulative exposures but synergistic exposures.
                  Let's see.  I'll read this sentence. I'll just quote it.  "If populations in unique communities such as fenceline communities are more likely to experience multiple chemical exposure scenarios than people in general commercial, non-special communities represented in most regulatory paradigms, is their location, lifestyle, et cetera, more likely to have situational elements that are likely to deliver exposure to different chemicals and stressors?  And has that been studied or documented?"  And then there's some clarification on that which I will ask the commenter to provide.
                  Let's see.  And again, it's saying, if we don't try to catch these situations now, it may make things more difficult down the road.  And if I'm paraphrasing that incorrectly, please let me know.  
                  Let's see.  So it says, needs for future work of EPA, especially to design data assumption scenarios of exposure, default factors.  And there should probably be some discussion about this.  
                  Okay.  There are some more bullet points.  So it says, "excellent idea for insertion into the screen.  Will be valuable element in a screen to highlight need for more refined assessment.  Justify requests for better data, et cetera."  So whoever's bullet points these are, please feel free to clarify them because I'm pretty sure I'm not saying it in a way that makes sense.
                  Sensitivity analysis, showing percent contribution of a given exposure source. Total exposure is a standard element of most dietary exposure assessment models in use by EPA over the past four decades.  It would be a great addition here and easy to program.  
                  And another key point to add is a sensitivity assessment which must be more than a mathematical task.  For a screening tool intended to provide protection to invisible communities, relevance is essential.  And it points to comments from myself and Dr. Heiger-Bernays and others that emphasize the need for community engagement.  This is Dr. Unseld commenting.  We need to examine the outreach strategy because, putting up a notice on the website, it shouldn't be that difficult for stakeholders and community groups to find out that this process is happening.  So putting up a notice on regulations.gov seems to not be enough.
                  And here it says something that was said earlier today, the science here should be in service to the community, not imposed on to the community.  
                  All right, next commenter.  The most obvious way to address environmental justice economic disparities is to analyze the data around the facilities included in the screen.  Each census block group contains data on race, ethnicity, and percentage of low-income households.  The EPA could analyze this data within 10,000 meters of the facility and compare it to national averages to assess disproportionate impact.  These data are contained in the EPA's EJSCREEN tool.
                  And then bullet points.  There are several limitations that should be considered.  While the screening level analysis estimate risk associated with specific facilities, it is not really site specific, because the stack parameters are not specific to the site but rather selected to be conservative, as well as other factors to just not considering local terrain and nearby buildings.  It should also be noted that census track data are estimates, and there is more uncertainty at the block level.  EJSCREEN includes this caveat.
                  The second important limitation is that EJSCREEN relies on demographic and environmental estimates that involve substantial uncertainty.  This is especially true when looking at a small geographic area such as the single census block group.  A single block group is often small and has uncertain estimates.  A buffer that is roughly the same size as a block group or smaller will introduce additional uncertainty because it has to approximate the locations of residences.
                  Therefore, it is typically very useful to summarize EJSCREEN data for a larger area covering several block groups in what is called a buffer report.  As explained later in this document, there's a tradeoff between resolution and precision.  
                  Detailed maps at high resolution can suggest the presence of a local hot spot but are uncertain.  Estimates based on larger areas will provide more confidence and precision but may overlook local hot spots if not supplemented with detailed maps.  Doing analysis at the 10,000-meter range and averaging would be most reliable.
                  Next commenter: once a community is classified as a fenceline community by meeting the definition for air and/or water exposures, its demographics can be evaluated with respect to EJ considerations.  However, this is complicated for water exposure since the definition of fenceline community is contingent on human behaviors.  The proposed methodology focuses on place as a determinant of whether a community is a fenceline community for the purposes of air pollution exposures, i.e., does the person reside within 10,000 meters of the pollutant source?
                  And on behavior as a determinate of whether a community is a fenceline community for the purposes of water pollution exposures, the definition of water exposure fenceline community refers to persons using the receiving water body as a drinking water source or as recreational use water from which incidental oral and dermal exposures are possible.  
                  This definition of a water fenceline community notably lacks consideration of seafood contamination.  But many racial-ethnic minorities, including tribal nations, depend on subsistence harvest of seafood resources.  So this is uplifting the dietary concerns.  It also mentions the domestic whales, bottled water supplies for drinking water.  And it only focuses on public water supply and not these other ways of being exposed to water.
                  There is systemic underrepresentation in fenceline community definitions of persons whose interactions with the receiving water body are mediated through seafood or have turned to private drinking water sources due to perceived contamination that the water body might lead to distortions in subsequent environmental justice analyses due to selection biases.
                  Economic evaluations of environmental justice, e.g., definitions of disadvantaged communities and severely disadvantaged communities based on regional median income are sensitive to modifiable spatial area unit problems and economic data may be spatially aligned with a buffer around the air pollution exposure.  
                  Fenceline community definition: the behaviorally defined fenceline communities for water pollution exposure may be spatially diffused and not have income information as readily available for environmental justice analyses.  It may be important to think about how to characterize economic status of behaviorally defined fenceline communities.  I also received a link to a ProPublica article, which I have linked in the notes, where they use RESI data.  I'm not sure how to pronounce that.  But that link is in the notes.
                  Some other comments that came over the break.  And it talks about, what is a state?  So TSCA includes Washington, D.C., Puerto Rico, Guam, Virgin Islands, et cetera, as states.  But this draft mentions the 50 states.  D.C. and Puerto Rico are in AERMOD, so what about people living in other territories?  So they would like for this method to be addressed for their -- or this method needs to address their potential exposures and risks.  So we need to address the territories and not just the 50 states.
                  Let's see.  So EPA should consider an interpretation for unreasonable risk specific to contaminates it evaluates that accounts for cumulative risk faced by communities affected.  The draft analysis suggests EPA is considering a uniform value for unreasonable risk of one extra cancer per one million for carcinogenic endpoints.  This results in higher overall risk for populations already exposed to multiple stressors including multiple stressors potentially regulated by TSCA.  This does not account for nonchemical stressors that aggravate risk, such as lower access to health care or potentially poorly understood synergies between chemical exposure.  
                  The EPA should consider exposure pathways that are likely to provide new information about hazards as opposed to hazard information that fenceline communities are already providing.  Many exposure pathways become clear only after epidemiologists or community members themselves identify clusters of rare diseases.
                  This was exemplified by testimony to the SACC by Carrie Reinhardt from, If It Was Your Child, who described her community's experience discovering TCE contamination of groundwater following a cluster of pediatric brain cancers.  "In my opinion" -- this is this commenter's opinion -- "the main benefit of the screening methodology is proactively identifying previously unknown or unappreciated hazards before adverse health outcomes are observed.
                  "This is especially true because most environmental exposures result in outcomes that are not highly specific, i.e., cancers that cannot be conclusively tied to a single environmental exposure or increased risk of vascular disease, et cetera.  Currently, the EPA is excluding from its screening methodology many of the exposure pathways that are likely to go unnoticed by affected communities.
                  "Conversely, the EPA should establish a methodology or protocol for receiving, aggregating, and analyzing information received from fenceline communities about perceived risk.  And they cite me as how many communities already have this data.  And this can maybe go along with this providing a community a means, like, where does the information flow through the EPA?  How do they access it, and how can the EPA improve its outreach so that you don't have to necessarily have regulation.gov bookmarked in your browser?
                  And it says, "In some cases, fenceline communities may have better information than EPA and they may be able to uncover by applying generic modeling strategies to national databases.  This is especially the case for the exposure pathways the EPA is considering in its draft framework for air and ambient water."
                  And this commenter says, "Nevertheless, in my opinion, it is still important for EPA to screen chemical exposures to communities even if these communities are already aware of environmental hazards because the potential to uncover previously unknown or underappreciated risk" -- let's see.  And then it cuts off.  Sorry about that.  So whoever's comment that way, please finish that sentence.  I apologize.  I can go get it from my email.
                  And then I wanted to tag Dr. Reif because he said that he might have some comments; he just may not have had time to get them to me over lunch.  
                  DR. DAVID REIF:  Oh, sorry.  I can talk.  I wasn't sure if we're -- I was raising my hand.  I wasn't sure if we were doing the -- you're muted, Dr. Schlenk, I'm sorry.
                  DR. DANIEL SCHLENK:  Not yet.  Let Dr. Unseld finish.  We'll go through the associates, and then we'll go to the Committee in general.
                  DR. DAVID REIF:  Yep.
                  DR. MONICA UNSELD:  I am finished.  Again, I apologize for cutting off that last sentence.  I'll try to get it from my email.  But I'm finished.
                  DR. DANIEL SCHLENK:  That's fine.  Thanks.  I'm sure that whoever gave it to you will have the opportunity to do that at this point.  So thanks for the comments.  Okay.  So let's move through our associate discussants.  Dr. Gribble, you're next. 
                  DR. MATTHEW GRIBBLE:  This is Matthew Gribble, a temporary member of the SACC.  First of all, thank you, Dr. Unseld, for summarizing like a gazillion comments.  That was heroic.  I would like to clarify because I think that two of the comments that I had inserted might have been a little bit less clear reading through the whole thing.
                  The first is this idea of the distinction between how you're considering the air exposure pathway as centered on the location and drawing a buffer around that.  Versus the water fenceline communities are defined by whether they engaged with the water body, regardless of whether they are residentially proximate or not.
                  And so, it's a behavioral definition of a water fenceline community.  And whether or not they engage with a water body is shaped by things like chemical risk perceptions.  If people are concerned about a surface water being unsafe, they might not engage with it which would sort of impose a selection bias of those communities might not meet the definition for the screening process of an environmental justice fenceline community specifically because the water body was impaired, which is kind of backwards.
                  A second point, which I didn't put in my prior written comments to Dr. Unseld is that we need to be careful for conceptual clarity about the distinction between fenceline community and an environmental justice community and environmental justice practice as coded in EPA guidance.  So environmental justice is both the need for equitable participation in the policy and decision-making process and achieving equitable outcomes.
                  And so some of the earlier discussion and response to some of the previous charge questions was about how to engage effectively with communities, how to elevate their voices without necessarily penalizing communities that are under-resourced and can't be burdened with having to contribute that information -- otherwise, it doesn't happen -- while also respecting the need for equitable outcomes.  Communities, whether or not they've had technical assistance funding, whether or not they've had a research partner should have protection from environmental insults.  
                  The second issue about how we're defining fenceline communities.  We're already having two definitions of that in this.  Neither of those is tied to the racial, ethnic, or economic dimensions of an EJ community.  It's kind of understood that often fenceline communities will be enriched for low-income or communities of color.  But those are separate considerations from spatial considerations of whether this is a fenceline community.  
                  And so I had suggested that the EPA consider that as a secondary concern.  First, define what are your fenceline communities?  Who are these people?  And then consider their characteristics as persons either as members of a minority racial-ethnic group or as members of a financially marginalized community.
                  There was a somewhat important mispronunciation, which it's totally understandable because there were like a gazillion things to read through.  But my point was there's actually potential spatial misalignment, not alignment, between the spatial definitions useful for economic data and the buffer being drawn around these communities based on the site of the hazardous air pollutants.
                  So if you have economic data that aren't exactly aligned, there are technical challenges that can potentially change your inferences about how to classify regional income.  And so I thought that this was an important spatial methodology question for EPA to resolve.  If you're figuring out who's a fenceline person based on this buffer or some modified version of that, like a plume for that contaminant, and then you are evaluating that community's economic data, making sure the spatial boundaries are aligned is important.
                  And I thought that the economic evaluation could be very challenging for behaviorally defined communities if they're spatially diffused.  So, for example, if you have an oil pipeline and that has a discharge into an aquifer that a lot of people are tapping into, currently this is completely not part of the screening process.  But it might be that all of those communities around the aquifer drawing in that water for their groundwater could be considered fenceline communities for that contaminate at that site.
                  And how that gets handled if your population that you're trying to protect is spatially distributed in a weird way, how do you do that with EJ, I thought was kind of an open question.  Those are my comments.
                  DR. DANIEL SCHLENK:  Okay thanks.  Dr. Reiss.
                  DR. RICK REISS:  Yeah.  Monica summarized my comments.  I just had recommended looking at the EJSCREEN tool, which I'm sure EPA is aware of; it's their own tool.  And they just upgraded it to Version 2.0 recently.  You know, at least from the dispersion modeling facility-oriented concentration exposures, that tool and the associated census track data obviously would be, I think, quite useful to look at these kinds of problems.
                  But you have to acknowledge, one, the uncertainties associated with the fact that some of these census block estimates are -- I'm sorry, data are actually estimates and, you know, there's some uncertainty in those.  And then the general uncertainty associated with dispersion modeling, this is not really a site-specific analysis because you're not using all the kind of site-specific data you have on stacks and things like that.
                  And then even so, even if you did a site-specific analysis, you know, the general rule of thumb with dispersion modeling is, if you have good data, you may be there by a factor of two accuracy in getting the maximum impact.  But you don't necessarily predict the location of the maximum impact correctly even in the best circumstances.
                  So just giving all those kinds of caveats, I think you can use that census track data on a larger level around the five or six miles, the 10,000 meters.  And I think that would be the way to go.
                  DR. DANIEL SCHLENK:  Okay.  Thank you.  Dr. Chaisson.
                  DR. CHRISTINE CHAISSON:  Thank you.  Dr. Unseld, that was a great summary put together in just a few minutes.  So thanks for that.  
                  I was the one who had sent you the comment about the sensitivity analysis.  And actually, that was part of my response, comment for Question 3.  But it kind of segues into Question 4b.  Dr. Johnson had talked about the need for sensitivity analysis.  And that first sentence that Dr. Unself read was referring to the sensitivity analysis to be used as part of a screen.
                  And I personally think that's an excellent idea.  It will be a valuable element in the screen to highlight the need for more refined assessments and justify requests for better data if we know that we are looking at, at least theoretically, a significant contribution to the overall risk.  The sensitivity analysis approach that I just described has been being used for almost four decades at EPA in doing their dietary exposure and risk assessments, and it's pretty easy.
                  However, for purposes of this screen, which is focused to already a very unique kind of population under unique circumstances, is that the sensitivity assessment has to be more than just a mathematical task.  It needs to include, in fact maybe begin with, the whole idea of whether the screen is relevant and whether the relevant exposure sources are even being considered.
                  The worst thing I think a screen can do is look like it's being conservative and encompassing and then declare no risk or no sign or no evidence of concern.  I think that's a huge disservice to the community and in fact in total contradiction to the introduction that we heard on day one from the assistant administrator, Dr. Freedhoff.  I think her charge to us and to EPA was to address what EPA has recognized as sort of an underserved problem in science.  And the approaches up until now didn't quite meet the mark.
                  So just as Dr. Freedhoff said, we no longer can accept that we dismiss a particular source or exposure because somebody else is doing it because it's covered under some other assessment or whatever.  No, we've got to bring it together into a holistic, if you will, evaluation, particularly for communities that almost by definition are already surfacing a plethora of health effects that are rare in neighborhoods like I live in and which I'm assuming most of you live in too.
                  So the point, the challenge, I think, is that we absolutely have to address these other sources in order to even begin to meet that challenge, if you will, that she's put forth.  At this point in the design of the screening tool, relevance of the source of the exposure seems the most lacking and debilitating problem to the utility of the tool.
                  Indeed, it may be a public relations debacle to refine the mathematics of a swimming pool exposure filled with nice tap water, while ignoring chemical spill events, dietary exposure, exposure consequential to living and working within the zone or cultural practices and other everyday realities for the people who live in these areas, who work in these areas.
                  And so I think the science has got to service those kinds of communities to meet even minimal level of application.  Thank you.
                  DR. DANIEL SCHLENK:  Okay.  Thank you.  All right.  We'll open it up to other Committee members.  I've got Dr. Calder listed first.
                  DR. RYAN CALDER:  Oh, hi.  Yeah.  This is Ryan Calder speaking.  So I was the bullet point that I think might have gotten cut off.  I was looking at the bullet point, and it wasn't cut off.  I think it was just written weirdly.  There was maybe a missing word or something.  I had just said, "Nevertheless, in my opinion, it's still important for EPA to screen chemical exposures to communities, even if those communities are already aware of environmental hazards because of the potential to uncover previously unknown or underappreciated risks."
                  And just for context, to loop back to the previous line of thinking that was in the previous bullet points, I was just, I guess, reaffirming Dr. Unseld's comments about how, in many cases, fenceline communities can have more information than EPA in some cases about certain exposure pathways.  But, yeah, just to reemphasize that it's still important for EPA to live up to its mission to identify potential risks that communities may not be aware of.  Thank you.
                  DR. DANIEL SCHLENK:  Thanks.  Dr. Apte.
                  DR. UDAYAN APTE:  Yeah.  I have more of a question for EPA.  And I don't know if this is the right place or not, but I'll ask anyway.  I can see the rationale behind the 10-kilometer, the 10,000-meter radius thing for the air pathway.  But I'm still struggling to figure out why the water pathway is defined the way it is instead.  And that was kind of referred to earlier where, you know, the communities engage with the resource.  I mean, that would mean anything from anybody drinking, swimming just recreationally, putting their feet in that water, to water being drawn out and provided to the community.  And how far are you going to go?  
                  I mean, are you going to go to the next town down after that because the rivers flow, right?  And the chemicals will carry -- I'm trying to get a handle on why that was defined the way it is.  And if I can -- I couldn't find a good clarification of that in the document.  And so I just want to put that out there for -- maybe EPA could comment.
                  DR. DANIEL SCHLENK:  Sure.  Actually, if you don't mind, we'll do that at the end after we kind of go through the --
                  DR. UDAYAN APTE:  That is totally fine.
                  DR. DANIEL SCHLENK:  Yeah.  And then before we turn to the Agency, that kind of at least logistically makes sense in that regard.  Dr. Gibble.  
                  DR. MATTHEW GRIBBLE:  Hey.  So this is just a post-op clarification afterthought.  So my question, like Dr. Apte just said about the behavioral definition of a water fenceline community, my understanding is that the intent of the EPA is to be attentive to the fate and transport of contaminants when thinking about who's exposed.  And I think that a hybrid definition that's not either/or but -- well, I guess is either/or not and -- wait, setting up the conjunction, that's right.
                  If a person lives next to a body of water that they're afraid to go in, I think that kind of person should be able to be considered part of the fenceline community.  Because they live there and the reason they're not engaging is because they think it's an acid lake or they think it's a toxic drinking water source or they think it's something where they would have been engaging with the water body if not for the pollution issue.  I think that omission of that people is a problem.
                  At the same time, I do think it's actually a strength to have a more open mind.  Because as Dr. Apte was saying, there are multiple communities potentially directly downriver of a discharge site.  And all of those communities might be affected by the contamination flow.  So, again, I think that thinking of the fenceline community definition in terms of fate and transport and affected persons is critical.  
                  DR. DANIEL SCHLENK:  Great, thanks.  Dr. Reif.
                  DR. DAVID REIF:  Yes, thank you.  Wanted to close the loop on -- I had an email exchange with Dr. Unseld before.  And I wanted to make sure some of the things got covered that I think actually did in comments both by her and by Dr. Reiss.  And it was about the tools that already exist.  Some of them from EPA, like EJSCREEN and the Superfund Program which has some EPA component to it, a lot of those has an overlay for this and expand to disparities that already exist.
                  So perhaps there's not additional work, but those tools are already in place, and the existing system could essentially be overlayed.  Or if you think about it the other way, those tools can be overlayed over the top of it to address some of these concerns.  And so I think that's been noted, but I wanted to close that loop since I was mentioned earlier.  So thank you.
                  DR. DANIEL SCHLENK:  Great, thanks.  Dr. Przybyla.
                  DR. JENNIFER PRZYBYLA:  Building on tools that already exist because of our discussion about engaging in communities, I did want to point out a recently published ATSDR document, a Community Engagement Playbook.  I'd be happy to send that to Dr. Unseld and also put it in the chat.
                  DR. DANIEL SCHLENK:  Great.  Thanks for that.  Send it also to Dr. Alaa too, if you don't mind.  That would be good.  Dr. Unseld.
                  DR. MONICA UNSELD:  Yes.  Dr. Gribble brought up something that I would like to just uplift.  There are many fenceline communities that do not go by the EPA's definition of environmental justice because, one, there's a lack of trust that the EPA is going to actually do something to help them.  And two, they were not consulted.  As like, what does it mean to have justice?  So if you're looking at climate justice, you have to ask, what does it mean to you?
                  So I think when we're talking about engaging with communities, those channels and stakeholders -- so that includes industry -- the channels of communication should be clear and accessible.  And we need to trust that the communities and the stakeholders will tell us what they need, they will tell us what they can provide, they will tell us what's two and two.
                  So just respect the authority of these communities and not necessarily close the door by assuming that the stakeholders in the community won't be able to do it.  Like, they'll tell us.
                  DR. DANIEL SCHLENK:  Great.  Thanks.  Dr. Davies.
                  DR. HOLLY DAVIES:  Hi.  I wanted to mention another tool.  A lot of people mentioned EJSCREEN and the idea of sending tools for how to incorporate the chemical and nonchemical stressors.  And another tool is Washington's -- our Environmental Health Disparities Map, which looks at those chemical and nonchemical stressors to put this together.  So chemical stressors like lead in housing, diesel particulates, close percentage roadways, and nonchemical stressors -- language, income, race.
                  And so that's another link that I'll send.  And California has something similar.
                  DR. DANIEL SCHLENK:  Great, thanks.  Dr. Heiger-Bernays.
                  DR. HEIGER-BERNAYS:  Thank you.  And I will add that Massachusetts has a couple of tools as well that can start to get at that overlaying, again, climate hazardous waste site. Sort of all of these layers where the data are already available and can be used.
                  DR. DANIEL SCHLENK:  Fabulous.  Great.  Any other states have some useful tools out there?  I'm sorry to say I wish California had something like that.  I'm sure there might be, but I'm not familiar with it off the top of my head.
                  DR. HOLLY DAVIES:  We based our Washington Tracking Network on the California model.
                  DR. DANIEL SCHLENK:  There you go.  Good.  Okay.  Any other comments?  Okay.  So, Dr. Apte, you had a question regarding the definition.  Let's go ahead with that.  And, Dr. Choudhary, if you're on?  Dr. Apte, if you could just rephrase that so he can hear, that would be great.
                  DR. UDAYAN APTE:  Sure.  This is Udayan Apte.  I just wanted to find out, how was the water pathway definition set in terms of exposure to communities?  Right now, the way it states that anybody who interacts with the water whatever the influence or the chemicals are will become a fenceline community.  In other words, anybody who either bathes in it, gets the water for it, fishes in it.
                  It doesn't put any distance as it has done for the air pathway.  And that just kind of leaves the definition very open and broad for interpretation.  I mean, one could think about hundreds of miles downstream.  One could think about right after where the factory fluid is, things like that.  So I wanted to find out how that was reached, and what was the rationale behind that?  Thank you.
                  DR. DANIEL SCHLENK:  Dr. Choudhary.
                  DR. REHAN CHOUDHARY:  This is Rehan Choudhary from the EPA.  I'll take an initial attempt at this, and then I'm going pivot to Jason Todd, who is our expert on the water side.  
                  The background here is when we were looking at the air modeling and the water pathway modeling, we could see how proximity is affecting concentration gradients.  And as we consulted with various offices here at EPA, we came to this proximity of 10,000 meters initially on the air pathway side.
                  The approaches we are taking on the water pathway are not -- those exposure estimates by themselves are not affected by proximity.  So we wanted to attempt to be inclusive in that if there are communities or members interacting with an impaired water body, we should consider them initially.  Recognizing that as we get farther and farther away from a body, you may be less likely to interact with it.
                  So that's -- so that's more of a qualitative understanding around defining fenceline communities with respect to the water pathway.  Let me now pivot to Jason Todd to see if he would like to elaborate or actually correct me if I misspoke on something.
                  DR. DANIEL SCHLENK:  Jason.
                  DR. JASON TODD:  Yeah.  Thanks, Rehan.  This is Jason Todd from EPA.  I think Rehan mostly has that right.  I think the idea for this analysis was to provide a screening level approach.  And our thought was that, since our modeling was done at the point of discharge into a receiving water body, almost always that would be the highest expected concentration.  And so to be conservative, independent of how far you may live or work or recreate from that potential exposure point, the idea was that simply interacting with that water body would have an effect.
                  I think in the interest of this 1.0, if risk was identified, we would then potentially take into account other considerations.  How far downstream is an actual drinking water source?  What are fate and transport dynamics?  Additional considerations that would further refine that evaluation.  But in the interest of being conservative, we did take the kind of presumption that the person is physically recreating or drinking from the water body where the point of discharge is occurring.  Does that help?  I'm happy to answer any follow-ups that you might have.
                  DR. UDAYAN APTE:  Oh, no.  It does help.  Just I feel like it keeps the definition very open-ended.  I mean, it's for this Agency to -- it probably is a lot more work for you to honestly keep this open-ended because one could say, I live 50 miles away from the discharge, but there is this concentration.  I interact, I swim in this river, and because of that, I'm now a fenceline community, right.  Technically that's totally fine to say rather than it has a distance definition there.  
                  And so I just thought that should be brought up.  And when you go further thinking about it I guess that hopefully will come up in your discussions.  So thank you for the clarification.  I appreciate that.
                  DR. JASON TODD:  Yeah.  And thank you for the comment from both you, I think, and Dr. Gribble also had points to that nature.  So thank you.
                  DR. DANIEL SCHLENK:  Thanks.  Dr. Chaisson.
                  DR. CHRISTINE CHAISSON:  Yes.  We'll be speaking hopefully during the discussion on 4d about this as well.  But the definition of fenceline community is problematic for another reason, which is linking the definition to a spatial proximity can, by accident, really kind of eliminate the community that's going to suffer the consequences.  Because the community in many of the areas, certainly many of the areas in the west in Alaska and other places, the first contact, if you will, with humans is going to be beyond the scope of what the definition is right now.  
                  And the second thing is, certainly for people doing either recreational or subsistence activities anywhere along those moving surface water bodies could certainly be affected.  When you say people who would be interacting with the water, people eating stuff out of the water is certainly interacting with it in its most profound way -- and not just fish.  
                  We detailed five zones of subsistence diet throughout Alaska, for example.  And there are literally hundreds of things that people eat or put in their foods that come out of waters which were several miles away from where there were all kinds of environmental issues.
                  So with that in mind, maybe the definition of fenceline community could be linked to two things.  One would be any kind of contact with water that has been polluted because of the affluence or fugitive chemicals coming from there, or whatever, and coupled with any kind of higher than a national norm of the occasion of adverse health effects within that community.  That's sort of the, once again, you know, the canary in the mine kind of an approach.
                  But those are certainly two kinds of clues that we have a problem and we're not sure where the problem's coming from.  But there's reason at least to believe that it's from a given source.  And that is almost the underlying philosophy of what a screen is supposed to be.  It's not exactly an indictment, but you can clear the evidence up in subsequent assessments.  
                  But at least starting with that kind of information I think might be helpful.  So maybe that would also help the definition of what a fenceline community could be.  So, thank you.
                  DR. DANIEL SCHLENK:  Thanks for that.  Dr. Cobb.
                  DR. GEORGE COBB:  Thank you, Dr. Schlenk.  I had not intended to wade into this question, but given the discussion, I wanted to point out -- and this is part of the report that will be issued for Response 1, unless we decide to put it somewhere else.  
                  In these previous risk determinations, I looked at some of these calculations for air to water partitioning using the FUGACITY models that EPA has used to justify these approaches.  And in those models, it shows that the chemicals -- and specifically I'm looking at a table for perchloroethylene -- partition into water from air such that it increases the concentration by a factor of 2.6 over what was released or predicted to be released from the wastewater treatment plant.  So what's happening is the models are predicting a large proportion of the contaminant to be released into the air and very little to be released into the water.
                  But there's no consideration of what happens to that once it gets into the air.  And if you actually use the models that EPA is saying they're using to predict what goes into the water, you have to look at what comes back in over time.  And so, I don't agree that that's necessarily the most conservative approach that EPA has used, but I will grant that, if there is a ten-fold margin of safety, which I think I heard -- I don't remember reading that specifically -- that a factor of three still doesn't get you to a factor of ten.
                  But I think EPA needs to be careful in how they use models to justify one side of a discussion but then discount or don't use that model to look at the whole picture.
                  DR. DANIEL SCHLENK:  Thanks, George.  Yeah, I think that probably might fit with C a little bit when we get into some of the other sources that weren't considered.  But thanks for bringing that up.
                  DR. GEORGE COBB:  Yeah.  And I don't feel a need to say this again, and we'll put this wherever it goes in the report.
                  DR. DANIEL SCHLENK:  Gotcha.  I think your point's very clear.  Okay.  Any other comments from the Committee on 4b?  Okay, not hearing any, let me go to Dr. Choudhary and see if he has any questions or clarification regarding the Committee's response.
                  DR. REHAN CHOUDHARY:  Afternoon, Rehan Choudhary here.  If you just give me a moment, I'm going to confer with the team to see if they have any questions they'd like to bring forth with respect to clarification.
                  DR. DANIEL SCHLENK:  Sure.  No worries.  Actually, would you like to take a break?  We can -- we're actually due for a break if you want to take a ten-minute break to interact with them.  Would that be appropriate?
                  DR. REHAN CHOUDHARY:  I think that would work out well.  It'll give us ten minutes to clarify whether there are any follow-ups from our end.
                  DR. DANIEL SCHLENK:  Great.
                  DR. REHAN CHOUDHARY:  And everyone can take a brief break as well.
                  DR. DANIEL SCHLENK:  Yeah.  Let's go for a ten-minute break and be back at 30 minutes past the hour.  That's actually a 12-minute break, but let's go to 30 minutes past the hour.
                  
                  [BREAK]
                  
                  DR. DANIEL SCHLENK:  Okay.  I have 30 past the hour.  Let's check and make sure everybody is back.  Looks like it so far, at least enough for a quorum.  Okay.  So let's go to Dr. Choudhary again.  Having convened with your affiliates, do you have any questions or clarification for the comments made by the Committee?
                  DR. REHAN CHOUDHARY:  Afternoon everybody.  Rehan from the EPA.  No.  We've conferred together and at the time there are no clarifications that we need for 4b.
                  DR. DANIEL SCHLENK:  Great.  Thank you, very much.  So at this point in time, we are scheduled to do 4c, but after getting a few comments back from several members of the Committee I think what we'll do is this.  I think c, particularly, might be a bit lengthy, and I don't think we'll be able to get d, for sure, today.
                  So I think at this point, let's go ahead and defer c until tomorrow morning and adjourn for this afternoon.  It's 3:30 Eastern which -- yeah, I don't think we'll be able to get both in in an hour and a half.  So let's go ahead and adjourn for today, and then we'll start 4c first thing in the morning.  Dr. Kissel, you have your hand up.
                  DR. JOHN KISSEL:  Yeah, John Kissel.  I wanted to say, since this is a kind of a loose end might as well do it now instead of waiting until tomorrow.  But yesterday I asked about the permeability coefficient for NMP, and EPA said they would get back to us offline.  By email, they have shared the origin story for that number, and it turns out it's an optimization from a PBPK model which raises additional questions.
                  So it's from a human trial, and normally human data for a specific compound trumps what you would get from animal studies or from an algorithm that describes regression through a bunch of data.  
                  The problem with multi-parameter PBPK models is that you can get a really nice fit by getting a half a dozen or so parameters wrong because you're compensating errors can make the thing look really, really good when, in fact, some of the underlying assumptions are wrong.  Among the underlying assumptions that they made was to get the number that they're ultimately using was that only 25 percent of the skin is exposed to vapor, which means that you're assuming that clothing is a vapor barrier which is certainly not true.
                  Cotton weave shirts are not vapor impermeable, and basically, whole bodies are exposed.  It might be that there's a little bit of additional mass transfer resistance because of a stagnant air layer under the clothing.  But certainly, clothing does not hermetically seal skin.  
                  So if you start with some bad assumptions and then do multi-parameter fitting, you can get a number.  But I think that the assumption that human trial data trumps other options goes away if there's enough questions about the human trial data and how it was derived.
                  And this gets back to a question that somebody else raised is EPA has multiple estimators for many parameters.  And, you know, how do they choose them?  In this case, this is supposed to be a screening tool, but it's being applied to specific cases.  And you have a specific case where you had some human data that's been interpreted in one particular way.  And maybe that's a plus and maybe it's not.
                  I would think a screening tool -- you know, we've been through this now those of us who are veterans of this process know that the whole process is way too slow to actually deal with the need.  The throughput of the number of compounds we have to deal with, or EPA has to deal with, and the amount of time it takes to do these one at a time kind of analyses, well, you know, conceptually you can say, gee, it's good if we've got some compound-specific data for this compound.
                  Ultimately, EPA's going to have to resort to some type of a machine learning or automated process, and they're going to want to use the same algorithm for 200 compounds and then just start cranking out results.  And so I'm not sure in this case that the permeability coefficient is preferable to another value of the permeability coefficient that could come from a different direction.  And I'm not sure that that strategy is workable in the long run, especially for a screening tool.
                  DR. DANIEL SCHLENK:  So which question would this be more pertinent toward, would you say?
                  DR. JOHN KISSEL:  The original question was Question 1.
                  DR. DANIEL SCHLENK:  Okay.
                  DR. JOHN KISSEL:  Because it was the question of clarity.  And I wanted to know where the permeability coefficient came from.  
                  DR. DANIEL SCHLENK:  Okay.
                  DR. JOHN KISSEL:  So I think that's where it should be added.
                  DR. DANIEL SCHLENK:  Okay.  So if you could, please send those to George.  I think he's lead on Question 1.
                  DR. JOHN KISSEL:  Right.
                  DR. DANIEL SCHLENK:  Perfect.  Okay, thanks.  All right, so let's -- oh, do you have a question, Dr. Choudhary?
                  DR. REHAN CHOUDHARY:  Just a clarification, Dr. Schlenk.  The clarification, the follow-ups we had sent you, those were sent to the SACC Committee members.  I think one of them was that KP question, and the other had to do with adjustment factors.  So those have been relayed?
                  DR. DANIEL SCHLENK:  Yeah.
                  DR. REHAN CHOUDHARY:  Okay.
                  DR. DANIEL SCHLENK:  Yes, those were sent.  Alaa sent those out to the appropriate individual.  So, yeah, we got that.  Okay.  Well, thanks, everybody, for a full day of discussion.  Had a lot of information going back and forth amongst folks.  We'll be ready for tomorrow morning and, hopefully, finish this up.  So thanks again and have a great afternoon and evening on the east coast.
                  DR. ALAA KAMEL:  Thank you, very much, Dr. Schlenk, for chairing today's session as well.  And I would like to thank all of the SACC members for contributing to the charge Questions 2 and 3 and 4a and b.  And we will meet again tomorrow morning.  So today's meeting is adjourned.  Thank you.
                  DR. DANIEL SCHLENK:  Bye.
                  DR. ALAA KAMEL:  Bye.
                  
                  [MEETING ADJOURNED FOR THE DAY]
            
OPENING OF MEETING - DAY 3 
                  
                  DR. ALAA KAMEL:  Good morning, everyone.  My name is Alaa Kamel, and I am serving as the Designated Federal Official to this U.S. EPA Science Advisory Committee on Chemicals.  For this meeting, and in my role, I will be opening the third, and last day, of the public meeting on EPA's Draft TSCA Screening Level Approach for Assessing Ambient Air and Water Exposures to Fenceline Communities Version 1.0.  
                  I'd like to repeat that SACC meetings are subject to all FACA requirements.  These include open meetings, timely public notice of meetings, and document availability of the public.  All documents are available to the public in the docket at regulations.gov.  And as a reminder, this meeting is being webcasted, transcribed, and recorded.  
                  The live stream of today's meeting is available on YouTube as well.  See the link on the meeting website.  The website also has links to the meetings that we had yesterday and the day before on March 15 and 16th of 2022.
                  I'd like to thank Dr. Daniel Schlenk, the chair, for chairing yesterday's session, and to the Committee members and ad hoc reviewers for responding to Charge Questions 2, 3, 4a, and 4b.  Thanks, are also due to the EPA's Office of Pollution Prevention on Toxics team for their responses to all the questions submitted by the SACC.  And now I'd like to hand the meeting over to the chair, Dr. Daniel Schlenk.  Dr. Schlenk.
                  DR. DANIEL SCHLENK:  Thanks, Alaa.  Good morning, everybody.  Welcome to our last day and happy St. Patrick's Day.  We begin by taking a roll call of the Committee.  So, I'll begin in alphabetical order.  Dr. Apte.
                  DR. UDAYAN APTE:  Present.
                  DR. DANIEL SCHLENK:  Dr. Baker.
                  DR. MARISSA BAKER:  Present.
                  DR. DANIEL SCHLENK:  Dr. Blystone.
                  DR. SHERI BLYSTONE:  Present. 
                  DR. DANIEL SCHLENK:  Dr. Calder.
                  DR. RYAN CALDER:  Present.  Sorry.
                  DR. DANIEL SCHLENK:  No worries.  Dr. Chaisson.
                  DR. CHRISTINE CHAISSON:  Present.
                  DR. DANIEL SCHLENK:  Dr. Cobb.  Dr. Cobb?  Got your mute button?  Okay.  Dr. Davies.
                  DR. HOLLY DAVIES:  Present. 
                  DR. DANIEL SCHLENK:  Dr. Doucette?
                  DR. WILLIAM DOUCETTE:  Present.
                  DR. DANIEL SCHLENK:  Not virtually present?
                  DR. WILLIAM DOUCETTE:  Not virtually present.  I'm present.
                  DR. DANIEL SCHLENK:  Okay.  Dr. Ferry.
                  DR. JOHN FERRY:  Present.
                  DR. DANIEL SCHLENK:  Dr. Gribble.
                  DR. MATTHEW GRIBBLE:  Present. 
                  DR. DANIEL SCHLENK:  Dr. Heiger-Bernays.
                  DR. WENDY HEIGER-BERNAYS:  Present.
                  DR. DANIEL SCHLENK:  Dr. Henneman.
                  DR. LUCAS HENNEMAN:  Present.
                  DR. DANIEL SCHLENK:  Dr. Johnson.  
                  DR. MARK JOHNSON:  Present.
                  DR. DANIEL SCHLENK:  Dr. Kissel.
                  DR. JOHN KISSEL:  Present.
                  DR. DANIEL SCHLENK:  Dr. Li.  Dr. Li?  Okay, no Dr. Li.  Dr. Messerlian.
                  DR. CARMEN MESSERLIAN:  Present.
                  DR. DANIEL SCHLENK:  Dr. PRZYBYLA.
                  DR. JENNIFER PRZYBYLA:  Present. 
                  DR. DANIEL SCHLENK:  Dr. Reif.
                  DR. DAVID REIF:  Present.
                  DR. DANIEL SCHLENK:  Dr. Reiss.
                  DR. RICK REISS:  Present.
                  DR. DANIEL SCHLENK:  Dr. Sathyanarayana.
                  DR. SHEELA SATHYANARAYANA:  Present.
                  DR. DANIEL SCHLENK:  Dr. Unseld.
                  DR. MONICA UNSELD:  Present.
                  DR. DANIEL SCHLENK:  And Dr. Vorhees.
                  DR. CHARLES VORHEES:  Present.
                  DR. DANIEL SCHLENK: Great.  Let me go back.  Dr. Cobb?  Okay.  And Dr. Li?
                  DR. LI LI:  Here. 
                  DR. DANIEL SCHLENK:  Okay, got you.  
                  
PANEL MEMBERS: FOLLOW-UP ON PREVIOUS DAY PRESENTATIONS
                  
                  DR. DANIEL SCHLENK:  All right, let's go ahead and move forward.  We've got a lot of discussion in the last couple days on the questions.  Again, thanks to the Committee and participants there.  Seems to be a lot of consensuses, at least on some of the components regarding uncertainty and issues related to model development and assessment as well as data quality discussions.  So hopefully that will be coming out in the minutes for the Agency to peruse.  Today, what we hope to do is finish up Question 4 and start with 4c and then with 4d.
                  Before that, we have a couple announcements.  I believe, Dr. Henneman, you had something you wanted to state just for the record.
                  DR. LUCAS HENNEMAN:  Yeah, thanks, Dr. Schlenk.  This is Lucas Henneman.  This is thinking about communicating uncertainties relevant way to back to Question 1.  I just wanted to note that in Section 2.4, which is the section that goes into depth about uncertainties, I thought it would be useful to include explicit qualitative uncertainty statements indicating most likely direction and magnitude for each assumption or uncertainty.  
                  So, for each source of uncertainty identified, do we expect that to be large or small?  And in which direction do we expect that to push the results to the extent possible?  And that's my comment, thanks.
                  DR. DANIEL SCHLENK:  Great.  Thanks, and yeah, just get that to Dr. Cobb.  I think he's the lead for Number 1.  Yep.  Dr. Johnson.
                  DR. MARK JOHNSON:  Yeah, I just want to agree with Dr. Henneman.  In fact, I was constructing the same statement for 4c when we get to it, but basically, just to acknowledge that there's a difference between uncertainty and variability.  I mean, variability can be reduced by collecting additional data; uncertainty cannot.  And I think we need to be candid, and we need to be honest that in some cases we have no idea what the magnitude of uncertainty is.
                  And so, we just need to honestly state that, that there's some things we just don't know.  And to just arbitrarily slop an order of magnitude of uncertainty factor on it I think is a bit irresponsible.  We need to be careful on how we do that.  
                  DR. DANIEL SCHLENK:  Okay, thanks for that comment.  I guess we'll wait to see here for that in a couple minutes.  Okay, so let's go ahead and get rolling.  At this point, let me go to the Agency to ask if they have any further questions of clarification before we move on to 4c.  Dr. Choudhary.  Yep.  
                  DR. REHAN CHOUDHARY:  Good morning, everybody.  This is Rehan Choudhary from the EPA.  Yes, Kevin and I have been discussing some items, and I'm going to pivot to Kevin Vuilleumier.  I believe there's a clarification that he's seeking.  Go ahead, Kevin.
                  DR. KEVIN VUILLEUMIER:  Thank you, Rehan.  This is Kevin Vuilleumier with the EPA.  We actually had two clarifications that we wanted to kind of mention.  
                  The first relates to a comment, I believe, that Dr. Davies may have raised yesterday on Charge Question 3 about the receptor height we used for the modeling.  We chose 1.8 meters as the average adult receptor, and the discussions yesterday indicated that may not be representative of adult females or children.
                  So, for clarification, the recommendations, we're hopeful that if the SACC has some recommendations for considering the adult female height and children height for receptor height that would be great to have as well as the basis for choosing that as the receptor height can further inform the modeling.  
                  In relation to Charge Questions 4a and 4b, we believe we heard during deliberations yesterday that in some aspects, our geospatial approach to modeling exposures may not precisely align with the way certain data is collected or available.  For example, the census block group set that was mentioned yesterday.  
                  To better inform EPA on the pathways for which we currently have and the proposed methodology for the ambient air and the ambient water pathway, we're hopeful that the written recommendations from the Committee will include suggestions on how we may better align the geospatially modeled exposures to such available data.  And those are the two clarifications that we're seeking.  
                  DR. DANIEL SCHLENK:  Okay, so, Dr. Johnson, did you want to address that since that was 4a?
                  DR. MARK JOHNSON:  It wasn't specifically my comment, so I would be uncomfortable doing so.  But the individual who did provide that comment, if they want to step forward?
                  DR. DANIEL SCHLENK:  I didn't catch the notes to who actually made the comment.
                  DR. RICK REISS:  If you're talking about the latter one, about the geospatial, how to use the census block data given the geospatial resolution of the modeling?  That was my comment.  And I believe that we did provide -- that Monica read it into the record, some recommendations on how to use that.  I mean, the basic idea would be to not do it at the census block level but rather just do it at a broader geospatial level.  The 10,000 meters because then some of those errors would cancel out.  
                  So, that I think, we can have that certainly in the record.  I think it was already read into the comments.  
                  DR. DANIEL SCHLENK:  Great.  Thanks, Dr. Reiss.  Sheri, do you have a comment?
                  DR. SHERI BLYSTONE:  Yeah.  I think the first part of the question about the 1.8 meters was in our comment.  I'm pretty sure it was Dr. Cobb that said that.  We'll clarify exactly what the question is.  I think there was just an observation perhaps that might be high.  But it either will say we need more clarity of where that came from or a recommendation on how that should be changed.  Is that what you're looking for?
                  DR. DANIEL SCHLENK:  It sounds like it, yeah.  
                  DR. KEVIN VUILLEUMIER:  Yes, or if they have suggested additional heights to represent other age groups or something like that. That's where we'd look for the input from SACC.  
                  DR. SHERI BLYSTONE:  Okay, thank you.
                  DR. KEVIN VUILLEUMIER:  Thank you.
                  DR. DANIEL SCHLENK:  Great.  Okay.  No other comments in play here.  Let's go ahead and move forward then.  If we can put Charge Question 4c up on the board and read that into the record.  Choudhary.

CHARGE QUESTION 4C
                  
                  DR. REHAN CHOUDHARY:  Yes, this is Rehan Choudhary from the EPA.  Charge Question 4 to the SACC Committee, subpart c: "Please propose and describe approaches that EPA can take into consideration for the purposes of expanding the capacity of the proposed screening methodology, Version 1.0, presented in this work.  Some possible examples may include but are not limited to, subpart c, how the proposed screening-level approach may be expanded to evaluate exposures from additional pathways such as land disposal or groundwater contamination." 
                  DR. DANIEL SCHLENK:  Thanks.  The discussant for this one is Dr. Davies.
                  DR. HOLLY DAVIES:  Good morning.  So, I have responses from the associates, and I have been making notes during the meeting whenever someone has mentioned other pathways, and I've incorporated these together for a summary.  
                  But first, I wanted to start by thanking EPA for proposing a method to such risk to fenceline communities, especially with all of our critical suggestions last couple of days.
                  So, one thing I've heard from the Committee is the importance of including more pathways to sufficiently characterize exposures and risk.  I've also heard or gotten comments from several people about mentioning the idea of this tiered approach perhaps with different data, different pathways in higher tiers.  And we're going to talk about data evaluation in the systematic review method.  
                  I just wanted to mention this is an opportunity to include information from communities that we've been talking about.  And EPA needs to continue to facilitate charge to protect the public and also providing guidance to communities that they may wish to pursue and submit their independent data and being able to include this in the methodologies for getting data.  
                  One idea is to merge emissions data with available activity data.  So public and private well locations, for instance, to aid in prioritizing sources and communities for more in-depth risk assessment, part of this tiered approach, including targeted monitoring campaigns.  
                  We should incorporate observational data to assess exposure as much as possible for communities mentioned the NATTS network, available groundwater samples.
                  A notice that AERMODs can be applied to estimate deposition of the chemical of interest and the spatial pattern of deposition.  And this air deposition pattern could be used to quantify total chemicals deposited to soil from the facility.  
                  And longer-term abuse would have epi studies to inform this expanded view of the pathways and the data.  
                  So, I believe there's a consensus of including more pathways, the importance of including more pathways, and this does depend both on the chemical characteristics and the relevance of the pathway.  One example is fish consumption is a really important pathway for persistent bio-cumulative toxic chemicals, which are not the case studies we've been looking at here.  
                  Groundwater was mentioned by several people, a very important pathway to groundwater, both vapor intrusion and private well.  Chemical emissions, multiple media may influence groundwater.  And one starting point would be to classify facilities by their total emissions to all media.
                  As mentioned earlier, TRI data isn't just air and water, it also includes other pathways.  And given also that these pathways can be much further, like air deposition can be farther and the groundwater pathway because of the way groundwater moves, it could move long distances.  So, the definition of fenceline communities might need to be expanded to fit that.  
                  So, the movement of chemicals in groundwater is very dependent on the characteristics that would have to be characterized in the higher tiers when looking more specifically at risk and including the chemical transformations that are different in soil and the volatilizations in soil that may be relevant and important for certain chemicals and areas.  
                  We need more groundwater monitoring.  And, of course, just pointing out in terms of protecting fenceline populations, that private wells tend not to be monitored.  We've talked about municipal water systems that are monitored -- not specifically monitored -- but looked at for chemicals and concerns.  So, a lot of people don't know what chemicals that are in their private wells.  
                  There's other pathways, one mentioned the comments from the National Tribal Toxics Coalition about both drinking water, and they mentioned hygienic water for bathing.  This is also mentioned by Committee members.  And also, the ceremonial use to a steam bath and emersion.  And we have to take into account the different cultural practices of different communities.  Not only for fish consumption is important for many chemicals but also game consumption.  EPA should not look at the average person but at specific communities and their consumption practices, especially the communities that have high consumption.  
                  We also have the pathway through biosolids, wastewater treatment plants, and then biosolids that are spread on the fields, which may be important for some chemicals but should at least be looked at.  And related to biosolids is also plant uptakes, both from spreading biosolids and plant uptake from aerial deposition and other ways that chemicals have gotten onto the soil.
                  Another pathway is spills, accidental releases.  We know that these happen and that they should be dealt with in the exposure pathway assessment.  Also, the combined sewer outfall which I put in with these accidental releases in that category.  
                  We also have exposures from household products, whether that's taking into account specifically with household products or with the background factor of we know that people are being exposed to household products also.  
                  And disposals and landfills and, again, something mentioned by the tribes -- especially, in Alaska -- they've given us lots of details.  Both in the comments of this meeting and comments from previous meetings about people's exposures through landfills. 
                   Also I wanted to mention the aggregate and cumulative exposures that we've been talking about.  Rather than looking at specific one at a time, one pathway at a time, one chemical at a time, looking at exposures together.  Occupational exposure, people who get occupational exposure also then live in fenceline communities and the multiple facilities.  
                  And then two comments about hazard assessment.  Looking at the traditional -- not expecting a traditional dose-response curve because that might underestimate risk, especially for chemicals that are endocrine disruptors.  I think these comments are partly because we're looking at a general method that EPA has said they want to use for the chemicals that are currently on the table and in the future.  So, talking about possible future chemicals they'd be looking at.
                  And so, looking at the dose-response relationships with the real-life context and uncertainty and reflecting the missing data.  And also, the non-cancer outcomes, including outcomes from long-term low-dose exposure, must be included in the analysis before the regulatory outcomes are decided.  And we know we have exposures in certain places in the country with multiple facilities and multiple chemicals.  
                  At this point, I'll turn back to Dan to ask the associates.
                  DR. WILLIAM DOUCETTE:  Dan, you're muted.
                  DR. DANIEL SCHLENK:  I'm muted.  I was telling her she was muted.  Dr. Unseld, please.
                  DR. MONICA UNSELD:  I think Holly did a better job explaining my comments than I did, so I have nothing to add.  Thank you.
                  DR. DANIEL SCHLENK:  Great.  Dr. Henneman.
                  DR. LUCAS HENNEMAN:  Thank you, Holly.  I have nothing to add.
                  DR. DANIEL SCHLENK:  And, Dr. Cobb.
                  DR. GEORGE COBB:  Nothing to add.  Thank you, Holly.
                  DR. DANIEL SCHLENK:  Wow.  Fantastic job.  Okay, any other Committee members for this one?  Yeah, Dr. Gribble?
                  DR. MATTHEW GRIBBLE:  Thank you.  This is Matthew Gribble, a temporary member of the SACC.  And I am just wanting to respond to one part of Charge Question C.  How the proposed screening-level approach can be expanded to evaluate exposures from additional pathways?  I agree with all of Dr. Davies' summary of the multiple exposure pathways that may require consideration and the need for a tiered approach or the value of a tiered approach.  
                  One thing that I did not hear in this summary, which I had sent in a written comment to Dr. Davies, is the potential availability of data sources to help support the inclusion of additional pathways. 
                  And for water, the EPA six-year review data set referenced in the draft screening policy is not something that they can use as a methodology for all water contaminants.  There's only a couple of regulated drinking water contaminants that are measured with the EPA six-year review.  
                  So, I thought that if Agency staff could brainstorm a bit about other resources.  There's the UCMR data set.  There are potentially local or state-level water monitoring programs.  There are non-regulatory data sets from the U.S. Geological Survey and some other sources.  And so, I thought that casting a wider net for water data might be helpful, and I thought it might be helpful to discuss as a Committee if there's any other resources that come to mind that we can point EPA to now. 
                  DR. DANIEL SCHLENK:  Great, thanks.  Dr. Johnson.
                  DR. MARK JOHNSON:  Yeah, when you think about maybe integrating other pathways as part of the conceptual site model that we talked about earlier, you can begin to think about this.  And Holly mentioned chemical/physical properties as parameters whether to look at certain pathways.  And so, for things that are unlikely to volatilize that do come out of the stack, then those things may be more important to look at wet and dry deposition to make it to ground water.
                  We also may want to think about affinity to organic carbon, right, and maybe octanol/water partition coefficients to make some generalizations regarding the affinity or probability for bioaccumulation.  I think, if the EPA consults some of the earlier guidance documents on incinerator permitting, a lot of these parameters are already there.  And so I would recommend that maybe TSCA go look at those documents and see what could be gleaned from them to kind of prioritize which chemicals and which pathways to look at given the chemical/physical properties.  
                  DR. DANIEL SCHLENK:  Thank you.  Dr. Heiger-Bernays.
                  DR. WENDY HEIGER-BERNAYS:  Yes.  Dr. Davies, that was very, very comprehensive.  I have two comments.  Actually, one is the previous request from Dr. Johnson, I think, about additional sources for water information and data.  
                  CCR [sic] actually went through this process many, many years ago.  I was on that committee, and we went through what are the data sources that are available, and I think that that is another possible -- another location to find some additional data other than UCMR data and the six-year review.
                  DR. HOLLY DAVIES:  Great.  Could I ask a quick question?  What is CCR?
                  DR. WENDY HEIGER-BERNAYS:  Oh, the Criteria Contaminants Rule.  So, I can send you the specifics and the year that process was revisited.  I'll get that information and put it into the record.
                  The other thing is this question does focus on additional pathways and sources that may be missing.  And I think that it is useful for us to provide as much specific as possible, and I do like an approach that's been proposed that could be used to determine which pathways are likely, I'll say, necessary.  And that wouldn't be the case for all of them.  And I'll just leave it at that, and I'll come back to this point in the next question.  Thank you.
                  DR. DANIEL SCHLENK:  Great.  Anyone else?  I know Dr. Kissel brought up several other components on earlier questions, so I don't know if you want to add anything more to this.  We just may move some of that information from Question 1, I believe it was, to this.  We talked about some of the other pathways.  John, do you have some other comments?
                  DR. JOHN KISSEL:  Yeah, so earlier I noted that the regional screening levels calculator that's online already has a soil to groundwater track in it.  The guidance document for that doesn't seem to be available as a standalone PDF.  You can read it online, but you can't download a copy of it, so it's not as accessible as it should be.  So, I don't know.  I haven't studied the assumptions that went into that pathway, but it's there and EPA has already done it.  
                  I've also looked and there's all manner of regulatory implications of this, but we've had this problem all along is that the environmental regulation in the United States, especially at the federal level, is reactive rather than preemptive for the most part.  And TSCA's supposed to be different in that way.  That was part of the point of Lautenberg was that we would stop waiting until there was a mess.  We would try to incentivize not making a mess in the first place.
                  And in the RCRA world, way back when, when the transition was made from dumping waste willy-nilly to, we're going to do this professionally, a lot of businesses were given the opportunity to either shut down or to go forward as licensed hazardous waste handlers.  And that meant that they had to -- in order to take that next step, which meant they could generate a lot more revenue because all of the sudden the disposal cost per ton went up dramatically once things were specifically legally designated as hazardous waste, that meant that you could charge a lot more to get rid of those things.  And people that were getting rid of them haphazardly were subject to a great deal of financial distress potentially.  
                  But there's a Corrective Actions Plan from 1994, so we're not talking recent history here.  And the 1994 Corrective Action Plan goes through a whole list of things that you want to assess at your facility if you're going to keep it operating.  
                  So, to become a permanent hazardous waste handling facility, you had to do an inventory of things like spills, and among the pathways that are specifically highlighted are soil, gas, and groundwater.  So that's 1994.  And now we're here.  We're looking at this compartmentalization that if we clean up air, if we restrict air releases, then somehow, we've protected everybody when we know damn well from experience that that isn't true. 
                  But currently, the regulatory process for legal businesses and groundwater is that you wait until there's a problem, and then you sue them, which is an extremely ugly and painful and expensive and inefficient process.  This is maybe beyond the scope of the beleaguered EPA employees that we're talking to, but TRI should include some manner of accounting for spills and discharges to groundwater.  
                  They do have to account for discharges to waste handling facilities, but there is no inherent moral right to sit on a piece of property, load up the groundwater underneath it, and then walk away 50 years later having extracted profits and then left a big cleanup for the taxpayer to cover.  That's explicitly stated in the hazardous waste world through the RCRA Corrective Action Plan.  
                  But, so far as I know there is nothing equivalent to that in the -- we're a normal chemical manufacturing facility and we have our permitting requirements and we have to report how much goes to the air and how much goes to the sewers.  But we don't have to report if we're doing casual dumping outside the back door of the facility, for instance.
                  The one famous example is Woburn, Massachusetts.  It was really just a warehouse.  It wasn't even a manufacturing facility, but they had a paint shop and they used solvents for cleaning and for degreasing.  And they had employees that were just basically walking out the back door with a quart or so at a time of solvent, and then they just pitched it out on the ground.  And over decades that wound up to be a groundwater plume.  
                  They also did some shady disposal on the lot where somebody once -- they only admit to this once -- but there was a case in which an employee dug a trench with a backhoe, and they dumped six barrels of solvents into the trump, and then covered it up.  Well, many years later, that contamination reached wells G&H which became a Superfund site.  And somehow normal operating non-hazardous waste facilities have to be held to account because it's inefficient as hell for society to pay for the cleanup after the fact. 
                  The ounce of prevention is worth a pound of cure rule still holds, and it holds, really obviously, in the hazardous waste world.  The evidence is overwhelming, and there should be no inherent right to just discharge the -- to load up the groundwater under your facility and then let people deal with it later.  
                  Ignoring groundwater and soil gas given the history, which is just case, after case, after case in which groundwater and soil gas have been contaminated, we just need to raise our hand and say, okay, this is a tough nut to crack, but you've got to take a stab at it.
                  DR. DANIEL SCHLENK:  Okay.  Well, thanks for the comments.  You initiated four hands coming up straight away.  So, we'll go down the line.  Dr. Chaisson, you are next.
                  DR. CHRISTINE CHAISSON:  Thanks for that commentary, Dr. Kissel.  I think it's particularly important for in the discussion we're going to have in the next question, 4d, but I also wanted to point out that John's examples that he gave here, I think should be a matter of record, and also ones that he has given on previous days of the conversation because it is relevant to the very definition of what is fenceline community.  
                  And, once again, going back to this idea about proximity, groundwater contamination is a direct consequence, as Dr. Kissel has pointed out in these examples and previous ones that he talked about, where the concentration and the consequence of that contamination could be far distant from the source.
                  And especially if it's redundant, and it accumulates someplace else, or the people who are suffering directly from that contamination might not be defined within an X amount of proximity to the source of the exposure.  So, I really would urge EPA to completely rethink the definition of fenceline so that it accurately encompasses, or let me say, that it thoroughly encompasses all of the points of damage, let's call it, that are consequential to the point of the emission.  
                  So, thanks again for that, Dr. Kissel.
                  DR. DANIEL SCHLENK:  Dr. Heiger-Bernays.
                  DR. WENDY HEIGER-BERNAYS:  Yes, thank you.  Dr. Wendy Heiger-Bernays.  I have two points.  One is to support the discussion that has just been made and the data sources that are available that Dr. Kissel points out.  And also, to bring to the attention the 2016 Vapor Intrusions Screening Level calculator that EPA has made available.  There are great efforts that are going on right now on vapor intrusion that are tied directly to those releases that have been in discussion.  So, another source.
                  I also, for the record, stand corrected.  Maybe it's not enough caffeine, it was not CCR; it's CCL, which is why Dr. Davies probably had no idea.  It is the Contaminant Criteria List.  It was specifically CCL3, in which the data sources and information with regard to contaminants in drinking water could be accessed, and I'll provide that.  But I wanted to correct the record.  Thank you.
                  DR. DANIEL SCHLENK:  Yeah, I actually should've caught that myself.  The CCL3 through Office of Water, actually.  Yeah.  Dr. Blystone?
                  DR. SHERI BLYSTONE:  Yeah, as usual I want to correct the record at least a little bit that spills and excursions and related are required to be reported.  I can't answer for any facility that may be doing that illegally, but there are regulations in place.  We track everything on the site that I am currently working on for every time something escapes a piece of equipment, and if it's a reporting requirement, they get reported.
                  I also want to recognize that industry in general, and I'm sure it isn't static in time.  Things change over time, and things that maybe were common 30 years ago, may not be any longer and that should be recognized as well. 
                  DR. DANIEL SCHLENK:  Thanks.  Look forward to reading the question.  
                  DR. HOLLY DAVIES:  I have a quick question.
                  DR. DANIEL SCHLENK:  Hold on, please.  Actually, can we please just go on just a bit?  Yeah.  Just raise your hand.  That'd be great.  Thanks.  Yeah, I'll look forward to the -- obviously, there's some discussion both ways on this point.  So, yeah, if we can get that into the written record that would be very, very helpful.  Yeah.  Dr. Davies?
                  DR. HOLLY DAVIES:  Oh, thank you.  I just wanted to ask Dr. Blystone where those reports go to.  I think the earlier comment that I was taking notes on was about reports to the TRI and if those spill reports were to the TRI or to a different place?  Thank you for letting me ask that clarifying question.  
                  DR. DANIEL SCHLENK:  Thanks.  
                  DR. SHERI BLYSTONE:  You know, that's not my particular responsibility.  I believe it goes to an office in EPA.  I will clarify that and send it to you.  
                  DR. DANIEL SCHLENK:  Okay, Dr. Ferry.
                  DR. JOHN FERRY:  Just sort of an interesting point to further justify adding groundwater in case we need further justification for that is two of our future targets for this process, tetrachloroethylene and carbon tetrachloride both in groundwater, undergo partial hydrogenation to make another one of the future products, trichloroethylene, and one of the one's we're talking about today, methylene chloride.  And I will send you, Dr. Davies, some references for that.  But just pointing out those can't be untangled.  
                  DR. DANIEL SCHLENK:  Great, thank you.  Dr. Gribble?
                  DR. MATTHEW GRIBBLE:  Thank you.  This is a comment -- sorry, this is Matthew Gribble, temporary member of the SACC.  This is partially in response to 4b and also in response to 4c.  But coming to the issue of environmental justice and community awareness of the problems, for drinking water contaminants that can be odorless, tasteless, and colorless, communities may have no way of knowing there's a problem until kids start getting sick.  
                  And I think that it's really important that we not treat humans as the canary in the coal mine for there being a pollution problem.  So, for contaminants that would have potential for harm and a limited plausibility of people being aware before they start getting sick, I think that might be something EPA, if they're considering a tiered approach, might consider kind of the visibility or lack thereof of the chemical as a consideration.  
                  If it's a chemical that people would not easily be able to report to EPA that they were having an odor problem, for example, then that's something that EPA should be very attentive to when they're doing the screening assessment.  
                  DR. DANIEL SCHLENK:  Thank you.  Dr. Reiss.
                  DR. RICK REISS:  Yeah, just dissent on the idea of including spills in this.  I think that's covered by a lot of other EPA programs.  And you talk about what's out in the groundwater, I mean, a lot of those originate from things that have been 50 years ago.  I mean, we still deal with litigation for contaminated sites with the spills.  Some serious spills have happened many, many years ago, and I just worry about this whole thing getting bogged down.
                  Considering a spill is different because with the air emissions you have an emissions number; there's uncertainty for sure about those numbers.  But for spills, you're going to have to make some supposition about what might happen, scenarios about accidental releases.  I just think it's ultimately EPA's policy call here, but I just don't think that that should be the focus of this.
                  DR. DANIEL SCHLENK:  Great.  Thanks for getting that on the record.  Dr. Unseld.
                  DR. MONICA UNSELD:  Yes.  I wanted to, I guess, support or thank Dr. Gribble for bringing up the point about not being able to taste or smell.  I have a question, and maybe this is just for the Agency.  I'm not sure.  And if we're looking for recommendations, should we already have something prepared to say this is a way to account for chemicals that are not visible, or is it okay that we flag that?  Because I do think that's a very important issue.  I am just not currently aware of a specific recommendation to give to the Agency.  
                  DR. DANIEL SCHLENK:  Yeah.  This is Dan Schlenk.  I think as long as you -- I think they would appreciate as much information as you can provide in terms of if you have a recommendation to follow it up with information.  But we can go to them at the end, and they can make that comment themselves.  But it's been my approach, at least through the 30 some odd Panel meetings I've been on, that they would appreciate the recommendations as well as some information that would help them with that recommendation.  But I'll let them get there when we get to that point.  
                  Dr. Reiss.  Your hand's still up.  Did you --
                  DR. RICK REISS:  Sorry, I'll take my hand down.  
                  DR. DANIEL SCHLENK:  Oh, no worries.  Okay.  Anybody else want to weigh in on this one?  Okay, Dr. Davies -- oh, Dr. Kissel, you're back.  Go ahead.
                  DR. JOHN KISSEL:  Yeah, I just want to respond to the spills are the old days, and everyone can be trusted and nothing bad happens now argument, which is simply not true.  I taught hazardous waste management for 35 years and recently stopped.  This is the first year in 35 that I haven't taught a hazardous waste management course.  But there are the historical cases like Russell Bliss in Missouri spreading dioxin and oil all over the countryside to make a small profit for himself and make a huge problem for the larger society.  And I use that example in class.  
                  But as recent as 2010 -- and it takes a little while for these cases to get through the judicial process, so we don't find out about them immediately.  So, if somebody is doing something illicit today, it's not going to show up in the newspapers for a little while.  So, I don't have absolutely current numbers, but when I last taught, I brought up a case of a waste hauler in Ohio, who at night, he was getting fracking waste.
                  There was a fracking boom, which meant his business was going up leaps and bounds.  And he found that the waste disposal wells were overscheduled, and so he was having a mass balance problem.  That stuff was coming in his front gate faster than he was able to dispose of it through legal wells.  And so, he just ran a line from his -- one of his storage tanks to the Mahoning River and dumped into the river at night when no one was paying attention.  And that was in the 2010s that that occurred.
                  So, the notion that everybody's above board now and we've learned our lesson and everything is swell is a nice fairy tale, but it isn't true.  
                  DR. DANIEL SCHLENK:  Okay, thanks.  Dr. Reiss.
                  DR. RICK REISS:  Hi, so my comment certainly didn't mean to imply that everything is above board now.  I just think that from the standpoint of TSCA and fenceline monitoring or fenceline exposures, we've been in a situation where not a lot has gotten done for a long time.  And there's a frustration about getting more done with TSCA, getting more of these issues addressed.  
                  It's just a reality in life that you have to focus on something, and I think focusing on the air exposures is a good thing.  Focusing on water exposure from direct discharges is a good thing.  I just think dealing with spills under this program is not the right way.  Again, you talk about these dumping scenarios.  I mean, you'd have to make some sort of scenario for intentional dumping to address that and I just think that's going to bog this whole process down.  I'd like to see it move forward.
                  DR. DANIEL SCHLENK:  Okie doke.  Dr. Davies.
                  DR. HOLLY DAVIES:  On the spills topic, in my experience, some chemicals and uses do have regular spills, whether they're called historical spills or not.  And I know in talking to all the people in Washington state that have PCB-containing electrical equipment, all of them, the first thing they said was, "It's an enclosed system."  And the second thing they said was, "We clean up all spills promptly." 
                  So, I think there are sometimes, some chemicals where spills is an important pathway, and so I would argue for including it at least for consideration in the first tier.
                  DR. DANIEL SCHLENK:  Okay, so obviously have some lack of consensus on this issue.  So, look forward to seeing -- oh, Dr. Kissel, you have another comment.
                  DR. JOHN KISSEL:  Yeah, so I mentioned the RCRA Corrective Action Plans.  Among the things that the RCRA Corrective Action Plan requires is a groundwater survey.  So, you have to monitor your groundwater to continue to operate as a hazardous waste facility.  It seems to me that that is a strategy that, as a matter of doing business, if you have to report what's going out in your air and you have to report what you're discharging to a sewer, why don't you have to report what's leaving your facility through groundwater underneath your plant regardless of whether it's a current-day spill or an old spill?
                  This notion that we protect these communities that ultimately -- we're trying to do a screening tool here to protect people that live close to these facilities because there is a history of people who live close to facilities being victimized by higher levels of pollution than people that live further away. 
                  And there's screening for one of the questions that I'm still kind of unclear on.  Maybe somebody addressed it, and I wasn't paying attention.  But so what does it mean to have screened these facilities for fenceline exposures if groundwater is excluded?  Have we checked the box?  If one of these chemicals passes this test today, which is based upon TRI releases, and we say they don't have a problem so this industry is clean, is there any requirement that at some point in the future -- Version 2 or whatever is coming up -- that groundwater is assessed?  
                  Or are those industries that are cleared in this initial -- if we do the first or the second in ten chemicals or if it's the first 10 or first 20 or whatever it is, if they pass this muster or they pass this screen, are they then grandfathered in?  Or are they still subject to further evaluation, investigation at some future date?  And it's not clear to me what the follow-up here is.  I think it's misleading to say we found a screening and you've passed, and so you get a little star on your forehead and things are good.  I don't think the world works that way.
                  And Sheri mentioned spills.  Spills, you have to report spills of certain quantities if you are transporting material by truck or rail, and one of your railcars or your trucks overturns and there's a spill.  The kind of spill that I talked about at Woburn, which was the paint shop farm and walking out back and tossing a quart of solvent onto the ground, that doesn't have to be reported.  
                  Fugitive emissions have to be estimated and reported, but I don't think liquid spills fall into the fugitive emissions world.  And so, I think there's lots of loopholes that are not adequately reported, and I'm concerned that we created a false sense of security if we say we screen for air emissions and the air emissions are okay. 
                  The air is much better mixed than groundwater is, and so you get dilution much faster.  The epidemiology usually turns out to be kind of equivocal because epidemiology's such a weak took anyway.  Basically, it has extraordinarily high limits of detection.  And epidemiological studies around specific facilities are often a boon to the polluter because they tend to involve 200 people, and with 200 people you don't have power to find anything anyway.  And so, the epi study then announces that everything is swell when, in fact, everything is not swell.
                  And groundwater tends to be less well dispersed, and so people can get bigger doses.  The system just is protective of the lower threat and unprotective of the greater threat, and that's kind of failing the mission of TSCA.  Thanks.
                  DR. DANIEL SCHLENK:  Sure.  I'd like to wrap this up if we can.  Dr. Blystone, if you could -- again, there's obviously some lack of consensus here in terms of spills.  And I would say also that, Dr. Kissel, if you could provide the Agency -- I mean, it's pretty clear that groundwater should be evaluated.  If you could, again, provide the Agency with some concrete mechanisms to evaluate those smaller spills, I think that would be very useful to them as well.  
                  But, Sheri, did you want to comment?  I saw you put your hand down.
                  DR. SHERI BLYSTONE:  Yeah, I'll just be very quick just to clarify.  Certainly, at facilities that I have worked at, there is a great deal of effort to contain spills.  That's why there's diking and all this stuff.  And, absolutely, if something makes it to the ground, that's a whole level of response different than what happens when it's in a dike.  So, spills to the ground, absolutely, are reviewed.  Things happen as a result of those types of spills. 
                  Again, I can't answer for commercial operations, that sort of thing.  But absolutely, at the chemical manufacture side, spills to the ground are important.
                  DR. DANIEL SCHLENK:  Okay, so we've talked a lot about -- obviously, spills are important, and again, we definitely need to make that point known.  It's just a matter now of how the EPA actually deals with those spills, I think, is kind of what they're interested in.  In fact, I just got a message from Dr. Choudhary that he is interested in that.  Dr. Li?
                  DR. LI LI:  So, this is Li Li speaking.  So, I'm not making a comment, but I have a question.  So, does EPA have tools or models ready to perform like a site-specific evaluation for groundwater at this moment?  I mean, site-specific evaluation just like what they did for air and water exposure because they do the evaluation based on site-specific environmental data.  So, I'm not sure whether we have a model or tools that support such refining evaluation for each individual facilities or sites.
                  DR. DANIEL SCHLENK:  Okay, I guess we can ask Dr. Choudhary that question.
                  DR. REHAN CHOUDHARY:  Yes, good morning, everybody.  Rehan Choudhary from EPA.  So, your question is a pointed one and a relevant one.  We had methodologies for the air pathway and the water pathway to start things off.  And this is why, also, the project has been scoped the way it has as a starting point, Version 1.0.  There are other pathways for which we do not have established methods and approaches, and that is why we came to the SACC asking how we might address those data gaps.
                  So, I think that addresses your question.  We don't have readily available approaches for all these other pathways, but we would not be in a good position if we had readily available approaches and still did not include them in Version 1.0.  So, we have air.  We have the water that we presented to you.  We have gaps on the other pathways we're identifying.
                  DR. LI LI:  Okay, so that means, if you must do some evaluation for groundwater, you must rely on some generic approach instead of site-specific evaluations.  Right?
                  DR. REHAN CHOUDHARY:  Again, I think that depends on the recommendations the SACC Committee provides us.  If, in your written comments and even if you're in your verbal dialog, you're able to prescribe certain things the Agency can focus on, that would give us some focus to go evaluate, whether it's monitoring database, whether it's site-specific models, whether it's generic models.
                  DR. LI LI:  Okay.  Thanks.  
                  DR. DANIEL SCHLENK:  Dr. Johnson.
                  DR. MARK JOHNSON:  Yeah, when we think about spills, I guess spills, to me, are accidents by definition, right?  And I think it's really important that we provide EPA with comments that'll be actionable.  It'll be usable for them to make a decision because that's why you do a risk assessment, to help you make a decision.  And so, I don't know what we're actually asking the EPA to do when we say consider spills. 
                  Unless we have some empirical understanding of the frequency of spills and the volume and the nature to quantitate something, I don't know how you do it.  I really don't.  I think we need to provide them something more concrete if we're going to say, okay, we've got to look at spills.  I know states do.  I know our state does.  And then maybe handle different jurisdictions when those sorts of things happen.
                  But to be able to make the sort of decision I think that the EPA is trying to make in this case, I don't know how helpful it is to say, okay, we've got to consider spills, without some kind of empirical understanding of the frequency and the volume.  
                  DR. DANIEL SCHLENK:  Okay.  Dr. Kissel.
                  DR. JOHN KISSEL:  Yeah.  As I pointed out, there is a method in the regional screening levels calculator.  I don't know the merits of it, but it exists for evaluating the soil to groundwater pathway.  So, it's not true that EPA has no method and has nothing to do there.  And also, within the air pathway, this current screening tool doesn't have the vapor to skin, and the consumer exposure model that EPA has already published has got that method in it.  And so, that method is available to EPA, and they could've used it, but they just chose not to.
                  With respect to prediction of spills, again there's some industrial/commercial specificity here.  The historical use of dry-cleaning solvents is that most dry-cleaning sites ultimately have a groundwater problem.  So, this is not some weird thing that, oh, gee, it only happens -- it's only been recorded in Oklahoma in 1953, and so we don't really need to worry about it. 
                  It's basically if you have a dry-cleaning facility with underground storage tanks, those solvents are going to wind up in the ground, and that property is going to become contaminated commercial property and maybe a brownfield.  And its contamination may spread well beyond the surface limits of the actual property from which the activity's occurring.  And it's occurred with such frequency, in fact, it's routine for dry-cleaning establishments to leak.  So the notion that we couldn't possibly predict what might happen is, again, kind of a convenient excuse but just not in touch with reality. 
                  I talked earlier about truck spills.  Insurance companies have a pretty good idea how often -- if you're running 500 trucks from your facility a day, an insurance company can tell you with a reasonable probability how many of those trucks are going to be in accidents.  And so, you can get a handle on that sort of stuff.  
                  And for some types of spill releases, they occur with such frequency that, in fact, they can be quantified.  We could estimate.  We could require simply mass balances as part of the TRI reporting, which is, okay, we know how much is going out in the sewer, and we know how much is going out in the air.  How much was poured into the facility in the first place, and how much went out as commercial product.  And what's the difference?  What's the unaccounted-for portion?  And that would be a logical way to behave?  But humans are not good at logical behavior.  So, I don't know if we'll ever get there.  
                  But there is missing mass all over the place, and that should be taken into account.  Sorry, but I taught this for 35 years and didn't see nearly as much progress in 35 years as I would like to see in 35 years, so I get all worked up.
                  DR. DANIEL SCHLENK:  Understandable.  I'll say it again.  If you can please make specific recommendations on, perhaps, mass balance calculations or those types of endpoints, which I think you've done in past SACCs.  But if you could provide that information again for the Agency specifically addressing the charge question of other sources, I think that would be very useful to them.  Dr. Heiger-Bernays.
                  DR. WENDY HEIGER-BERNAYS:  Yes.  So, I was going to wait until Question 4d, but I think that it's right to make this comment and then revisit specifics in 4d based on the discussion that we're having now.  Thinking about the discussion yesterday and specifically about Dr. Li's statements yesterday and for today about the need for a tool or a method that's capable of answering the important questions and yet is not so specific or site specific and so unwieldy that decisions can't be made, and in my brain, I'm thinking about really two categories of chemicals.  
                  First, the ones we're dealing with here, the three even extended to the TSCA 20.  Those chemicals that are listed and well documented in lists that have been made available in the docket yesterday and today on hazardous waste, toxics dockets, releases to air and groundwater.  And the second is those chemicals for which there is less environmental release data or better yet those perhaps in the future that have not been omitted from the stacks yet. 
                  So listening, or better yet, hearing fenceline communities is imperative, but I'm thinking specifically about two communities with whom my group works.  These folks live and work within what would be the AERMOD predicted zone described, yet their air, their groundwater, their surface water is contaminated by a single facility: one is in manufacturing, the other is a hazardous waste transfer facility.  And these facilities are not required to report all the stuff that's in their emissions.
                  And that gets me to the fact that the first category, those chemicals, those 20 for example, those solvents for which Dr. Kissel is referring that we've got data for the past 25 years if not 30, those real bad actors that we know about where the data are good, the emissions haven't continued to result in unacceptable health outcomes.  I don't mean even in a pejorative sense, but to workers themselves, let alone the fenceline communities.  
                  So, for this category of chemicals, I think what we've been asked to think about is what's needed by us for EPA to move forward to risk management for these really bad actors.  And so, I wonder if -- I'll make the recommendation that maybe we have two sets of recommendations:  what's needed now to take action on these known bad actors and what's needed to develop or make the screening more comprehensive for those chemicals for which that first tier -- I'll say tier -- isn't met.  And thank you.
                  DR. DANIEL SCHLENK:  Thanks.  Again, specific comments on how would be much appreciated, I think.  
                  DR. WENDY HEIGER-BERNAYS:  4d.
                  DR. DANIEL SCHLENK:  Okay, well we'll get to that one, I guess.  Dr. Cobb.
                  DR. GEORGE COBB:  Just briefly I'd like to echo what Dr. Kissel said, and that mass balance.  If you look back at our early review of these first ten chemicals, I made these same comments.  The masses that are unaccounted for are quite large in most cases and are the majority of the chemical under consideration in some cases.  So, I really think that's an essential aspect of trying to get a handle on this, and that's all I'll have to say.
                  DR. DANIEL SCHLENK:  Thanks, George.  Now we've made that comment several times if I recall.  
                  Okay, at this point, let's take a break, actually.  It's been a very intense discussion.  Before I go back to the Agency to ask for questions of clarification, I think it'd be wise to take about a ten-minute break.  So, let's reconvene after -- say, 20 minutes after the hour if that'll be okay with everybody.  And we'll come back, and then I'll go to the Agency to ask for their questions or clarification.  Thanks.
                  
                                    [BREAK]

                  DR. DANIEL SCHLENK:  Okay, at this point in time -- okay.  Dr. Gribble, did you have a last comment before we go to the Agency?  I saw your hand up.  Nope.  Okay.
                  DR. MATTHEW GRIBBLE:  This is just a logistical question, but will we be getting a copy of the closed caption provided to us at the end of this meeting?
                  DR. DANIEL SCHLENK:  It's accessible.  I think you just need to contact Alaa to get it.
                  DR. MATTHEW GRIBBLE:  Okay.  Cool.
                  DR. ALAA KAMEL:  Sure, if you go on the YouTube site also, you will have the recording of all this session, and it has closed captions.  But if you want a transcript of the closed captions, I guess, there is a way to get that. 
                  DR. MATTHEW GRIBBLE:  Yeah, it automatically makes it.  I just wasn't sure who had it.  
                  DR. DANIEL SCHLENK:  Yeah.
                  DR. CHRISTINE CHAISSON:  Alaa, could you send us the link just to make sure we can get that?
                  DR. ALAA KAMEL:  Sure.
                  DR. CHRISTINE CHAISSON:  Thank you for that.  
                  DR. DANIEL SCHLENK:  Okay, so let's go ahead and get started.  Reconvene.  Unless anyone has any more comments, we'll go to the Agency.  We've had a bit of time to deliberate in terms of questions or clarification for the Committee.  You've heard quite a bit of discussion about certain new pathways.  Do you have any particular specific questions or clarification?
                  DR. REHAN CHOUDHARY:  Yes, good morning.  This is Rehan Choudhary from the EPA.  I believe during the deliberations, someone has posed a question that they wanted to ask us.  And I think, Dr. Schlenk, you had suggested what your understanding was, would the Agency appreciate specific prescriptions on how to proceed?  And in that line, we've listened to the deliberations.  
                  We noticed in the last 20 minutes that there was more of a focus on how.  To the extent the Committee members can prescribe generic nationwide kind of approaches that our program can implement because our focus is nationwide and not very site specific, that would be helpful to us.
                  And when identifying very program or site-specific methodologies or models in your prescriptions and how you're highlighting them in the written record, it will be helpful to us to understand how that program-specific or site-specific could be extended and integrated into the Version 1.0 we've communicated to you.  
                  So, I think that's the big takeaway; that we have a Version 1.0 framework.  What pathways we can include is one aspect of it.  Then how to incorporate them into that Version 1.0 is another aspect to help us operationalize it.
                  DR. DANIEL SCHLENK:  Great.  Dr. Davies, well, everybody, I guess all the leads for Question 4, it seems this is kind of a consistent theme for all subcomponents of Question 4.  If we can, again, use that as our focusing component in the minutes, that, I think, would be very useful.  
                  Okay.  Let's go ahead and move forward with our last question.  If we can get that up on the screen, and, Dr. Choudhary, if you could read that into the record, that'd be great.
                  
CHARGE QUESTION 4D
                  
                  DR. REHAN CHOUDHARY:  Yes, good afternoon.  Rehan Choudhary from the EPA.  Charge Question 4, subpart d to the SACC Committee:  "Please propose and describe approaches that EPA can take into consideration for the purposes of expanding the capacity of the proposed screening methodology, Version 1.0, presented in this work.  Some possible examples may include, but are not limited to, subpart d, how the proposed screening level approach may be expanded to evaluate exposures relevant to tribes, indigenous populations, subsistent lifestyles, cultural practices, and other unique circumstances."
                  DR. DANIEL SCHLENK:  Great.  The lead discussant on this is Dr. Chaisson.
                  DR. CHRISTINE CHAISSON:  Thank you.  I'm going to read this summation, and many of the parts of this refer back to previous discussions.  If I've missed any, please make sure to chime in.  
                  First of all, "EPA is to be commended for its policy and actions focused to protection of millions of Americans in all 50 states, D.C., and all U.S. territories whose lifestyles and living conditions create unique opportunities for exposure to toxic chemicals.
                  "Dr. Freedhoff pointedly acknowledged this goal in her address, Tuesday, to this Committee.  It's remarkable and appreciated that EPA architects of the fenceline screening tool have invited guidance, as articulated in Question 4d, so they can make Dr. Freedhoff's aspirational goals a reality, at least, for this EPA tool. 
                  "Question 4d is well fashioned, recognizing that tribal communities are iconic to the challenge at hand, but not alone in needing attention for constructing appropriate exposure and risk paradigms.  The issue extends to a broad swath of living conditions and lifestyles such as ethnically defined communities, other indigenous communities, border communities, non-tribal communities relying on subsistence practices, et cetera, which place them or their foods, their air, their water, at the fenceline.
                  "Assuring the screening process and tool embraces the realities of this will require some additional features," which we'll talk about.  "It is more important than ever to assure that these exposure and risk paradigms are as inclusive as possible.  Over the past two days, there have been repeated discussions for the need for a broader scope of exposure sources in this model.  Perhaps that's the issue of greatest consensus so far, and it is the critical issue for inclusion of people living in unique communities.  
                  "This is summarized in the letter from the National Tribal Toxics Councils with examples and illustrations of exposure factor values representative of tribal communities but significantly differing from those assumed for the general U.S. population.  
                  "I will note there are much more data available, some of which developed with EPA funding, to inform the fenceline screen algorithms and are available presently from NTTC; some from even NRDC, and several other sources.
                  "Many of those have been provided to EPA during comments on individual chemical assessments, and some are available from other sources.  Surely, those can be accrued, and we can briefly illustrate the issues about exposure opportunities relevant to the fenceline community.  I'd like to show four slides to summarize this."  Great.  
                  This is just sort of an overview of the kinds of things that happen at fenceline communities, or the kinds of communities that we've talked about, including tribal.  For most of these communities, the diet is both commercial and traditional.  The blending of those two, however, infer very different possibilities of the sources of the things that are eaten, which is the point here for this kind of thing.
                  Even where commercial diets are, quote, the thing that all of us buy in the store, frequently their sources for some of these commercial items are far more restricted than one would assume, meaning that if there is a contamination anywhere in that process or in the waters that are used to also make the finished product before eating it, that can be contaminated.  And it's a durable contamination because frequently we have the source be the same time after time.  
                  That also includes traditional diets, which we'll talk about more in a moment.  And even thinking about this in a broader sense, this includes home gardens, community gardens, et cetera, that may be in contaminated soil or irrigated with contaminated water.  In addition, many of these communities, whether they're tribal per se or ethnically defined, have traditional therapies which are taken from the environment.
                  Their occupational and family role are frequently blended.  Children participate in the occupations.  Some of the classic examples of this are the skill sets and the use of environmental sources where the whole family can be gathering and learning how to do these kinds of things.  So, it's not the idea of you go off to an office when you're 21 years old, et cetera.  These occupational exposures start right at very, very young ages.
                  Arts and crafts, the same thing, and frequently, this is home-based.  This is becoming more integrated into our quote general population thinking as our much, much more of our day-to-day activities begin to be home centered.  And so, I think that some of the lessons learned here will become more and more applicable to quote general population thinking, and this screening tool is a good place to start that.  
                  Can we go to the next slide?  The same could be said, by the way, about homeschooling.  
                  This is just an illustration that I've frequently used in classes I've taught to just illustrate many of the component parts which make the potential for contaminant to reach the consumer in the quote general population as it is virtually hard-wired into the dietary exposure software that's used not only by EPA but FDA and most globally, which starts with farm gate or port.  
                  The odds that, for example, if you buy grapes today or citrus today and then you return to your store a month later to buy think of the same thing, the source of that, it may be coming from a completely different country or whatever.  Nonetheless, that is all taken into account in considering the probability of contamination as well as the potential levels for those.  
                  What it means to you as a consumer is that in the commercial world, there's far less possibility that your exposure is durable time, after time, after time, because your source is not durable.  That's not true on the right-hand side.  If you're in a community which is harvesting its food, storing it, and your seasonal source for that food is the same moose or the same whale or the same fish or whatever that you harvested at a certain point, if that's contaminated, you're going to be seeing a repetition of exposure day after day.  
                  Obviously, the kinds of foods that are going to be eaten are very different, and I'll show you more detail about things like that.  
                  Processing industries.  The processing factors are well known and utilized so that as you go from an orange to orange juice or as you go from wheat to Cheerios, we know what the effect of that processing is on the contaminants that might be in there.  
                  That is not well applied to indigenous foods or community foods or, for that matter, the foods coming in from your home gardens, community gardens, or other environmental sources of foods.  Seasonality is a very big deal with subsistence living, not so much you.  You expect to get oranges 12 months a year.  The foods that are eaten here, the dietary profiles of people change dramatically with seasonality and the economics of supplementing their subsistence foods with the commercial foods.
                  So, you have very different profile of exposure, a significant profile of exposure for these kinds of communities which more and more include non-tribal communities, as I said, that really need to be -- or it's critical because many of these people, because of the economics that's implied in fenceline communities, will be at the front, if you will.  
                  Next slide.  This is just a screenshot of the kinds of foods.  It is no more appropriate to say, to represent the diet of a tribal community by saying, let's look at fish than it would be for the commercial regular general population to say, well, we'll just look at beef.  The diets that could contain particularly water-borne or airborne contaminants are dramatic, and it has something to do also with not just where the people are, but where their foods went.  
                  So, for example, these are just a listing from the sub-arctic data set, a very extensive data set about the kinds of foods that are eaten and the amounts eaten at different ages.  And these are foods that are eaten as part of a normal diet in the sub-arctic freshwater communities.  They are beaver, deer, moose, muskrat.  Now maybe you and I don't eat all this stuff, but I assure you they do.  Sea mammals are broken down, and there are different parts of these animals are preferentially served to different age groups within the community in keeping with, not just their traditions, but their nutritional needs.
                  And it's also true for those things that are highlighted in the darker blue.  Those are expanded just like sea mammals are or game mammals in this illustration.  These kinds of data in great detail -- and by the way, peer reviewed by outstanding groups of professionals and community members, including the people who distribute these kinds of foods -- have been developed with EPA funding and are freely available and being used certainly in those communities and in research groups.
                  The data sets, as well as the tools that read the data sets, can be supplied to this group at EPA.  And just like using other kinds of assessment tools that they have already depended on, I suggest that they take a look at this and be able to at least use these data.  Next slide.  
                  This is also true for activity profiles that are non-dietary.  This is just a picture of what's called sweat lodges.  This is very much like the steam baths that we go to in the city at the clubs.  There's water poured over hot -- in this case -- stones to create a very humid and hot condition inside.  Well water's being used.  Surface water is being used here.  You've got incredible conditions for whole-body exposures, increased uptake.  Obviously, inhalation and oral exposure.  They're drinking the water as well as pouring it over.  
                  There aren't many swimming pools in these communities, but there are a lot of these.  And if we can publicly talk about exposure sources, I think it would be necessary to include realistic exposure sources such as these, where literally thousands of people across the country have this kind.  And it's directly, I think, applicable to the same issue in the general population.  So, thank you for that help.  Let's go back.  
                  I'm done with the slides.  "A brief listing of the issues raised by our Committee, our discussant group actually, will be expanded and organized after the discussion today.  Our discussants joined the previous frequent Committee opinions including concern that diet must be included along with cultural work in other sources.  
                  "Routes of exposure.  Routes, not just sources of exposure, consequential to the sources of contaminants should include important routes such as below for which much information has already been supplied to EPA by NTDC, individual tribes, and others.  And these can likely be collected again to assist this development team.
                  "One, hand to mouth exposures, which are age dependent and culturally dependent."  It has something to do with cultural practices of, do you put your kids on the floor?  We have incorporated work like this in looking at the risks to fire retardants in carpeting, where children are obviously going to get exposed because they're crawling around on it a lot less than the adults that are walking across it, especially with shoes on. 
                  "It should include, number two, dermal, and oral, and inhalation exposure consequential to deposition from air to dust."  This may be particularly important for vast areas of the U.S. in the southwest and the west because these contaminations are taken into the household.  
                  "Whole body exposures by recreation and work in surface waters and use of water in bathing and steam baths such as in the pictures I've already shown."  This is not just a cultural practice; this is hygienic practices frequently in these communities.  
                  "Regarding aggregate, also there's been consensus on the need for aggregate and cumulative exposure opportunities at least in acknowledging these exist, especially considering people who live and work in the affected area, or who take their food from the affected areas.  
                  "There's been concern raised in our committee, in our discussant group, including over the last two days in the definition of the zone to be considered.  This is particularly important for rural areas where the contaminant source may be distant from areas suffering from the accrued contamination or where food services near the fenceline are harvested distant from there."  The deer don't stay put; they certainly migrate, and they may be captured after they've been contaminated.  
                  "The definition of fenceline; perhaps the concept should include communities with higher than national averages that expressed health problems and are subject to exposure sources suspected to originate from pollution sources of interest for this screen.
                  "There's also been quite a bit of discussion and apparent consensus is where there are inadequate understandings of the exposure opportunity in terms of how it affects these unique communities where special data on key factors in the exposure calculation, a safety factor could be considered until such time that the information is available and formally recalculated using it.
                  "The use of the safety factors where the understanding of exposure or missing data are evident."  For example, I picked up Dr. Gribble's comments in Question 3 regarding chemicals hard to note by the public, "Odorless, tasteless, and colorless in groundwater and potentially very dangerous to vulnerable populations or the application to the population of wide safety factors where evidence of community health problems, which could be related to chemical exposures and the non-chemical underlying health disparity issues."
                  "Next, the screening procedure should include processes whereby" -- now, this is not speaking to the mechanics of the screening.  Here I'm talking about pairing use of the screen with the required process.  "EPA could explicitly reach out to unique communities, especially those who have already made their interest known such as the NNTC, other tribal/indigenous groups, for information and assurance that its information will be applied.  
                  "Establishing a pre-calculation" or before the screening tool is taken out of its case, "problem formulation step and practice -- a required practice -- required to accrue needed information and definition of the exposure opportunity scenarios to be considered.
                  "Number three, establish policies for acceptable use of information for a screen as different from the formalized risk assessments on which regulatory decisions are made require that tribal and other community profiles are included." 
                  Next, "Consideration of accidental and/or durable emissions now not considered in the screen and presentation of the events include representation of emission spikes and repeated events."  Dr. Kissel might be able to help me define that a tad better than that.  It's a little clumsy.  "For unique communities, it's especially important to include pathways such as land disposal and groundwater contamination."  This comment was similar and supported by discussions on Question 4c.  Likewise, dust and water contamination from the air should be included."  
                  It's unclear to me if there's consensus, but there were several discussions previously and have been raised again in this discussion.  "Number one, consideration of non-chemical stressors for the screen and how specifically would that work.  
                  Number two, "If Version 1.0 is indeed utilized now, without the expansions and where no problem comes out the answer, how would these amendments that would be included in the future be revisited on those decisions?"  Once you get a clean bill of health as an industry, you just walk away and put that in your pocket from a limited version, Version 1?  And along with that, what would be the message?  Utilizing Version 1, what message would you be sending to these tribal communities as to the worthiness, if you will, of their perspective in any screen that is used for EPA for this?
                  Deciding there is, quote, no issue or no risk is, in fact, a regulatory decision because revisiting that after such an edict is made by EPA will be legally complicated.  Some Committee members also have added the additional items I'm going to list here, which may be points for further discussion now, and I invite the people who have brought these up to elaborate after I'm done, the effect of climate change.  
                  Number two, "To include the products database, CPDat, into this process, into the screen.  To consider the disposal of personal care products that may contaminate groundwater and land.  While these chemicals may not fall under TSCA, they may have an impact as they mix with chemicals that do fall under TSCA, including this would route all methodology to a daily reality of fenceline communities."  I'll invite the person who sent that in to elaborate and explain.  
                  Next, "The need for a way to handle chemicals for which there are little data about emissions and contamination is evident but hard to link to the emission source."  This point was initiated in 4c by Dr. Heiger-Bernays.  "The need for practical ways to use information and practical ways for communities and community advisors to participate."  This also was a common theme on other charge questions.
                  And, finally, "The need for quick action now for the bad actors."  This was brought up as a discussion initiated in 4c by Dr. Li and Dr. Heiger-Bernays, and I would welcome their comments and extension on those thoughts.  If I've missed any points from the discussions or for others interested in this, please add to the record.  I'm going to try to keep a list of people participating in the discussion to follow and make sure that, when I write this summary up, that I'll try to send it to you.  Thank you.
                  DR. DANIEL SCHLENK:  Thank you, Dr. Chaisson.  Okay, next on the list are our associate discussants.  And that will be Dr. Calder.
                  DR. RYAN CALDER:  Hi, thank you, Christine, for summarizing.  My apologies for not sending you this comment for you to aggregate in the global discussion, but I'll just read it into the record now.  "I just wanted to suggest that to the extent that the EPA's engagement with indigenous populations communicates risk associated with traditional activities and especially traditional diets, that could be either explicitly in terms of the output from risks screening model or even implicitly in terms of targeted data collection."
                  EPA should be mindful about the possibility for reduced intake of traditional foods or other loss of traditional lifestyles to lead to net health harms even if you're avoiding contaminate exposure.  Given the food insecurity in indigenous populations, the loss of nutritional sufficiency can have serious adverse effects and that needs to be considered much, in my opinion, quite strongly alongside the benefits of reduced chemical intake, which given the uncertainties in this model might be quite speculative.  So that's just qualitative consideration to keep in mind.  Thank you.
                  DR. CHRISTINE CHAISSON:  Just for clarification, Dr. Calder, are you concerned that inclusion of the consideration or announcement that you are including that would deter consumption of those foods.  Is that what you're saying?
                  DR. DANIEL SCHLENK:  That was Dr. Chaisson.
                  DR. RYAN CALDER:  Right, yeah.  Ryan Calder, again.  Yeah, I'm concerned about risk perception among indigenous populations leading to reduced intake of traditional foods.  And then the alternatives to those traditional foods can be much worse for overall health given the alternatives in indigenous populations.  
                  DR. DANIEL SCHLENK:  Please state your name, Chris, please each time when you do that.
                  DR. CHRISTINE CHAISSON:  Oh, I'm sorry.  I apologize.  That's hard for me to remember.  This is Christine Chaisson.  I'm not sure.  I mean, I understand you're talking about caution, but could you expand that to give guidance here on -- I'm not sure what you're advising them -- not to reveal it, or how would that be?
                  DR. RYAN CALDER:  Well, when, for instance, information is related to indigenous populations about risks of exposure to chemical contaminants, so that should be paired with guidance, for instance, on how best to respond.  We can't say, don't eat this fish, or don't eat this or that because that might lead to -- depending on the level of risk from chemical exposures, that might not be health-protective advice.
                  And so, I would say that risk communication should be paired with advice that is likely to lead to positive health outcomes.  Like from the indigenous diet -- their traditional diet -- should they eat instead.  Positive messaging around how to maintain nutritional sufficiency without -- while also minimizing exposure to contaminants. 
                  DR. CHRISTINE CHAISSON:  This is Dr. Chaisson, again.  Dr. Calder, would you mind writing that up in the context of how it should be applied to the screen?
                  DR. RYAN CALDER:  Yep.
                  DR. CHRISTINE CHAISSON:  Okay, so that I'll include your comments, but I want to make sure that they're articulated correctly.
                  DR. RYAN CALDER:  Okay.  I'll send you an email.
                  DR. CHRISTINE CHAISSON:  Thank you.
                  DR. RYAN CALDER:  Okay, thank you.  
                  DR. DANIEL SCHLENK:  Okay, thanks.  Next on the list is Dr. Unseld.
                  DR. MONICA UNSELD:  Yes, this is Monica Unseld.  Thank you for that summary.  I was the one who made the comment about the disposal of personal care products, and that was really in relation to the fact that the screening, at least in the methodology presented, was used to determine that a chemical was not a reasonable risk -- or an unreasonable risk, sorry. 
                  We know in a lot of these communities that are disproportionately impacted, they have a lot of dollar stores, and there's research that shows that these products in the dollar stores tend to have higher levels of toxic chemical contamination than what you may find in a Target or Walmart, which already has personal care products that have chemicals of concern.  And I'm just worried that, if they mix with a chemical under TSCA and we've used the methodology to say it's not a risk, what if there's a synergistic effect that's going to knock this into the potential risk category?
                  And also for Dr. Calder, maybe an asset framework may help you get your ideas together.  So any time, like, I call them doomsday talks where I'm just telling people all the toxic chemicals that they're exposed to, I always try to lead them with something they can do about it.  And sometimes that something can be as simple as, share this on social media or that the EPA needs to provide more education on how -- other recipes or something.  But an asset-framing concept may help you gather your thoughts.  And that's all. 
                  DR. DANIEL SCHLENK:  Great.  Okay, our next associate is Dr. Gribble.  
                  DR. MATTHEW GRIBBLE:  Great.  So, first I'd like to respond to some of the previous discussion between Dr. Calder and then Dr. Chaisson, and then I'd like to read into the record my prepared comment.  
                  So, I fully appreciate Dr. Calder's point that communicating risks and benefits and affirming traditional lifeways can be challenging in environmental health.  And that the EPA, as an authority, entering into dialog with communities about the risk of fugitive emissions and the potential harm to their local seafood, for example, might be a stimulus for anxiety in the community. 
                  But I think there's a difference between the question of what advice you give an individual consumer about which fish or which parts of the seal are safer to harvest, versus conversation with the polluter about, this is an acceptable threshold or not for you to be discharging into the environment.  
                  And so, I think individual behavioral decisions might be outside the scope of what the screening tool is seeking to do, and I think that, as long as the communication with the local community were managed in a way that it was clear that this is not providing individual dietary guidance, it might be less of an issue.  But, Dr. Calder, later please elaborate on your thoughts.
                  What I wanted to note in my comment was that I thought that seafood was a very notable omission.  Seafood is a class of subsistence diet, and I include in that also shellfish, different contaminants of different bioaccumulation/biomagnification properties.  Different game species may have different migration patterns.  
                  So, for example, Pacific Northwest and Southeast Alaska communities relying on subsistent shellfish harvest might have different contaminants that are of greater concern than communities that are relying on migratory hunted species, for example.  And like Dr. Chaisson was saying, I think we need a place-based approach to what is the emissions profile from the site and then what are the things happening with people around the site.
                  I think having a blanket approach will be challenging and that having an approach that allows for site-specific considerations will be very valuable for EPA.  And I think that those considerations should include social norms of what people's practices are in a local setting.  And the other thing which came up briefly in 4b, is this idea that whether or not a community is engaged in the water body should be viewed in a holistic, potentially counterfactual way of would they engage if they had greater trust that the water body weren't polluted?
                  I really don't think we should be excluding communities who have chosen to rely on a bottled water supply or on something like that because they're worried about their surface or groundwater being contaminated as a drinking water source.  To me, those are fenceline communities for the pollution entering that water body that they are not partaking of because of their concerns.  
                  So, I think some consideration of but/for causation -- for thinking about would they be involved with the water body but for the pollution -- might be something EPA could take into consideration as they consider locally tailored guidance on what a safe level or not of discharge might be for a local community.  I'll stop.  
                  DR. DANIEL SCHLENK:  Okay.  Thank you, Dr. Gribble.  Dr. Blystone, your hand is up.
                  DR. SHERI BLYSTONE:  Yeah, I just wanted to react to something that Dr. Unseld said about synergistic effects.  I am, by no means, up to date on the science of that but I know that's a really complex issue, and I would be interested if there are specifics that Dr. Unseld has that could be practically applied in the screening approach.  It's aggregate and accumulative exposures are already very complex and now synergistic.  I don't even know that we're close to have something that would be practical to apply. 
                  DR. DANIEL SCHLENK:  Yeah, thanks.  Dr. Unseld?
                  DR. MONICA UNSELD:  Monica Unseld.  To answer your question, I do not have specifics because I am not aware of any methodology that's currently available, but it doesn't mean it's not there.  I just don't know of it.  But my concern was that, if we're going to prematurely, perhaps, classify a chemical as not a risk, that that could be potentially hazardous to public health.
                  And then, lastly, I just wanted to state for the record, if we are going to engage environmental justice communities, disproportionately impacted communities, the Agency really needs to take a look at the language.  Referring to people as receptors is not very welcoming.  And also, I know reality is there will be risk, but we must realize that when we're engaging with these communities if we talk about reasonable risk, that's someone's loved one.  
                  So, I just want to get on the record that the EPA should consider this as they look for ways to further engage with these communities.  
                  DR. DANIEL SCHLENK:  Dr. Heiger-Bernays.
                  DR. WENDY HEIGER-BERNAYS:  Yes, Dr. Heiger-Bernays.  I want to respond to some of the comments that have suggested that under this screening program -- or a screening program -- that EPA would or might make recommendations to modify people's behaviors.  It's my understanding that what we've been asked to look at is what should we be considering or recommend for considering in a screening assessment?  
                  And so, these are all really great points, but I think the objective here is to identify what's bad and not to necessarily go that additional step.  The other thing I believe is that this is a national assessment.  Right, and so the challenges to make sure that the data, the inputs, in the screen reflect national considerations.  
                  And we know that there are plenty of fenceline communities across this country.  They have different characteristics and what's the best way to reflect those characteristics and to provide that kind of specific information to the Agency.  Thank you.
                  DR. DANIEL SCHLENK:  Thanks.  Dr. Johnson.
                  DR. MARK JOHNSON:  Just a couple suggestions.  I know one was to mention food/wet transfer and, as I mentioned before in some of the guidance of the Clean Air Act folks have for incinerator permitting, what they do is they use a log Kow of 3.5 as sort of a cutoff to begin to look at free web transfers by magnification, by accumulation for organics.  So that's just one suggestion.  It doesn't work so well for metals, but it does work fairly well with organics.  
                  They also consider persistence, of course as well, so any housing inorganic would be potentially treated differently but also would conform to that log Kow 3.5 rule.  
                  Regarding synergies of potentiation, it doesn't happen all that often, but it does happen.  And it happens on a kinetic basis, happens on a dynamic basis.  And sometimes some new approach methods such as adverse outcome pathways may help inform that.
                  And the only other suggestion I have is for safety factors.  I'm not opposed to using safety factors.  I think it's a good idea.  I just think they should have some sort of empirical basis.  I am sensitive to the comment of compounding conservatism.  I understand this is a screen, but we need to be able to support them scientifically.  And that's all I have, thanks. 
                  DR. CHRISTINE CHAISSON:  This is Chris Chaisson.  Dr. Johnson, would you mind sending me a paragraph to include about your cutoff limits.  I wasn't able to capture those all in my notes.  
                  DR. MARK JOHNSON:  Sure, will do.
                  DR. CHRISTINE CHAISSON:  Thank you.  
                  DR. DANIEL SCHLENK:  Okay.  Any other comments from the Committee?  Dr. Apte?
                  DR. UDAYAN APTE:  Yeah, I just wanted to bring up the issue of double exposure that I think I brought up a little and was mentioned a couple of times later in the discussion as well, where a lot of the fenceline communities, the people will work in the same factory or facility where they might get an occupational exposure and they will have a second dose -- so to speak -- at their homes or park or whatever they are doing later.  
                  And so, I know that in this 1.0 version that has not been addressed, and EPA commented on that.  But we should strongly encourage to look at that as they go forward modifying this as something they could put it on their to-do list for the future, which would probably improve the risk assessment a lot. 
                  DR. DANIEL SCHLENK:  Thank you.  Any other comments?  Okay.  Just to summarize it, it appears that, yeah, there's a fine line between a screening conceptual model and a risk assessment.  Conceptual model in trying to put those two together, yeah, might be a bit difficult.  Dr. Gribble, yes.
                  DR. MATTHEW GRIBBLE:  This is Dr. Gribble, temporary member of the SAAC.  I also just wanted to briefly raise the question of whether the Clean Water Act section 303D was of impaired water bodies versus unimpaired water bodies.  Total maximum daily loads allowed to be discharged into a water body would be pertinent for the screening level approach as we're trying to figure out cumulative impacts on communities that are fenceline.
                  Some of these impaired water bodies may already be flagged, and so adding to an already impaired water body or one that is kind of on the border might be important for the cumulative exposure the community faces potentially to chemicals of a similar mode of action.  
                  DR. DANIEL SCHLENK:  Thanks. 
                  DR. CHRISTINE CHAISSON:  Dr. Gribble, this is Chris Chaisson, again.  Would you please send me that reference, so I include it correctly?
                  DR. MATTHEW GRIBBLE:  It's in the paragraph I sent you before. 
                  DR. CHRISTINE CHAISSON:  Oh, the same one.  Thank you. 
                  DR. DANIEL SCHLENK:  Again, I'll just reiterate anything specific databases that can be provided to the Agency in terms of how to assess communities would be very, very useful, I think.  Any other -- Dr. Li?
                  DR. LI LI:  This is Li Li speaking.  So, in terms of the culture for bioaccumulation of food chain bio-transfer, so I can also provide some database for you.  So, I can send you the literature.  
                  DR. DANIEL SCHLENK:  Okay.  I just got a comment from one of our EPA staff.  Just to comment at comments on other statutory authorities and what they may or may not authorize to do, you need to be careful with those comments.  Primarily just reference other potential relevant statues and avoid interpretation in your minutes.  Okay, Bill.  Dr. Doucette.
                  DR. WILLIAM DOUCETTE:  This is Bill Doucette.  Just to follow up on Dr. Johnson's comment about the optional water partition coefficient cutoff log 3.5 for bioaccumulative things, I think that using physical-chemical properties to try to better understand potential routes of exposure and what chemicals are likely to be important through food pathways and things are important.
                  But we need to be a little bit careful.  For example, all the perfluorinated compounds we didn't think were going to bioaccumulate, they have log Kows lower than the cutoff and yet they show up.  So, they can be used to guide initial decisions, but we have to be aware of the numerous exceptions that are out there.  
                  DR. DANIEL SCHLENK:  Yeah, good point, Bill.  The PFAS ones are definitely out there on their own, for sure.  Dr. Davies.
                  DR. HOLLY DAVIES:  Yeah, just jumping on that, there's a lot of different lists of possible PBT chemicals: Health Canada's list versus Environment Canada versus EPA's list.  And there's a lot of different cut-offs.  I think this is where EPA would be looking at the chemicals specifically and what we know about its characteristics in fate and transport.  
                  DR. DANIEL SCHLENK:  Okay.  Any other comments for 4d?  Dr. Li.
                  DR. LI LI:  I have one more comment.  The use of cutoff, I don't think cutoff can prioritize the exposure pathway.  For example, it won't tell you which one is important because we have many, many exceptions.  But it can use to deprioritize.  For example, it can tell you which one is not likely to be important.  So maybe I think this way is more appropriately used of the cutoffs in chemical-like screening.  That's it.  
                  DR. DANIEL SCHLENK:  Okay, it will be interesting to see how that's written up, but thanks for the comments.  
                  DR. CHRISTINE CHAISSON:  This is Dr. Chaisson.  Once again any of the comments about the cutoffs, I would appreciate a brief email so that I don't misrepresent your points in the summary.  
                  DR. DANIEL SCHLENK:  Okay.  Any other comments?  Okay, at this point I guess this concludes sort of our comments to the questions.  I guess, as we've alluded to throughout -- well, first, let's go to the Agency to see if they have any questions or clarification on 4d.  
                  DR. CHRISTINE CHAISSON:  Dr. Schlenk, before we go to that, I had one more comment.  If you don't mind, I'd like to put it in the record.
                  DR. DANIEL SCHLENK:  Sure.
                  DR. CHRISTINE CHAISSON:  This is a comment about the discussion that was raised previously by EPA and then I think also by Dr. Heiger-Bernays.  I wanted some clarification on this.  The issue is about including factors or considerations -- let me broaden that -- to considerations which apply to a national assessment.  EPA in its work with tribal communities has already acknowledged -- as well as states like Alaska even -- that particularly for diet and people's activities, their diet and activities obviously put them in direct relationships with their environment which creates the opportunities for exposure.
                  But that these are going to be regional, and that is why the dietary profiles for the southeast U.S. don't look anything like the ones I showed you in the screen capture for one section of Alaska.  In fact, the dieticians in the Department of Health in Alaska as well as the entire communities of indigenous populations there have recognized Alaska to fall into five distinctly different subgroups as it has to do with both their diet, their sources of food, and their activity patterns.
                  So, I think these need to be acknowledged, and that doesn't mean that isn't nationally represented.  But it's simply creating different population subgroups who have distinctly different opportunities for exposure.  We do exactly the same thing when we utilize the huge databases about nutrition and dietary sources or consumption of different forms, even, of the foods that are being consumed.  
                  The national databases are divided up, if you will, to their applicability to different regional parts of the country or of the territories, and they are applied separately.  So, I don't really see any difference between that normal assessment practice that is very traditional within EPA and FDA and every other regulatory authority I know of that considers people's activities and diets.  The data and the underlying profiles that are to be considered would also be regionalized.
                  So, we don't have to assume that anybody in the northeast consumes beluga or whale meat or anything like that, but we must consider that to be representative of Alaska that they're eating this.  So, it's got to be not just statistically correct and have a good pedigree or whatever, it, once again, needs to be, I believe, relevant to the issue.  This is particularly, acutely necessary when you're looking at the kinds of communities that are likely to be at the fenceline, however we define it. 
                  DR. DANIEL SCHLENK:  Okay.  Dr. Heiger-Bernays.
                  DR. WENDY HEIGER-BERNAYS:  Yes.  Wendy Heiger-Bernays.  Thank you.  And to Dr. Chaisson, for the record, I was not in any way making this statement that these should not be considered.  I made the statement in light of the charge questions that have been posed.  So, absolutely.  And for a screening assessment, one might say that in this region this is the driver, right?
                  DR. CHRISTINE CHAISSON:  Right.
                  DR. WENDY HEIGER-BERNAYS:  So for the record, again, not stating that it should not be considered, that it should not be included.  Those data are imperative, but how those data get used need to be.  
                  We need, I think, to provide some recommendation.
                  DR. CHRISTINE CHAISSON:  Right.  This is Chris Chaisson, again.  Dr. Heiger-Bernays, I know that's what you meant because I know your work.  But I wanted to make sure it wasn't misunderstood by anybody hearing your comment. 
                  DR. WENDY HEIGER-BERNAYS:  Thank you.  
                  DR. DANIEL SCHLENK:  Yeah.  This is Dan Schlenk.  I think, again, it goes to the point where you need to decide a generic component for the screening or more of a site-specific component for the screening because, obviously, there's different components in that conceptual model for exposure.  So, recommendations, I think, need to be made for those components qualitatively initially.  And then, again, I think as much quantitative information that you can provide.  
                  Dr. Chaisson, you mentioned those five subgroupings.  I think it would be really good to get the source of those demarcations if you can as a reference to the Agency, for sure. You certainly can.
                  DR. CHRISTINE CHAISSON:  This is Chris Chaisson, again.  Dr. Schlenk, we have extensive -- I'll provide to you the entire datasets, the background on these, the peer review, and the tools that read them, basically, in multiple formats.
                  DR. DANIEL SCHLENK:  Sure.
                  DR. CHRISTINE CHAISSON:  So, I will package that up and make sure that that is available to EPA as well as the record.
                  DR. DANIEL SCHLENK:  Sure.  I think if those tools can be utilized for other communities, I think that would be very, very useful.  As you mentioned, there's so much difference.  So however they came to that decision of demarcating those five zones, if that same toolset can be utilized in some other parts of the country, that would be fantastic.  
                  DR. CHRISTINE CHAISSON:  This is Dr. Chaisson again.  As part of that, we have the same kind of information for tribal communities in the southwest, ethnically defined communities along the border, et cetera.  I will make sure that all of this is transported to this team as well as this Committee.
                  DR. DANIEL SCHLENK:  Yeah, the more tools, the better, I think in that regard.
                  DR. CHRISTINE CHAISSON:  This is Dr. Chaisson, again.  Just as a matter for the record, all of this information and the tools are freely and openly available to anyone who requests it, period.
                  DR. DANIEL SCHLENK:  Great.  Any other comments before we conclude this question?  Dr. Gribble?
                  DR. MATTHEW GRIBBLE:  This is a little out of date but just something I noticed that I wanted to make sure was on the record.  This actually comes back to Question 1.  Sorry, it's a little out of order.  
                  I noticed there was a typo on the definition of fenceline communities, "Specific distance measured form a receiving water body."  It should be, "From a receiving water body."  You might be totally changing it in the EPA text, but I thought the EPA should be aware there's a repeated typo of what the definition is of the water source.  Yeah, just FYI.
                  DR. DANIEL SCHLENK:  Okay, thank you very much.  Any other comments?  I apologize if you're hearing the demolition going across the street from my house here.  It's a little bit annoying.  Okay, if we're good with 4d, at this point let's go to Dr. Choudhary to see if he has any questions or clarification.
                  DR. REHAN CHOUDHARY:  Good afternoon.  Rehan Choudhary from the EPA.  No, there are no further clarifications on 4d from our side.  
                  DR. DANIEL SCHLENK:  Okay, great.  At this point, a couple members of the Committee mentioned a couple additional comments that don't necessarily fit the questions provided.  And at this point, we can discuss those.  I think, Bill, you had mentioned something either yesterday or the day before.  I forget which day it was, but is there something you would -- a question that should've been asked, so to speak, and want to provide some comments there?
                  DR. WILLIAM DOUCETTE:  Dan, I think this is the appropriate spot since we're pretty much out of time.  I guess it was back to the more fundamental question and how this whole process is organized around the charge questions and the redundancy that results from the way the charge questions are worded.  And it's getting difficult because in Question 1 we talked about uncertainty, sensitivity analysis and that kept getting brought up throughout all the questions.
                  And I'm wondering if somehow if it just should be a more fundamental question; is the proposed screening level approach truly useful given the limitations and release estimates and the lack of corroborating monitoring data?  And that would be a very general sort of thing that all our comments could be focused on instead of trying to pigeonhole them into a specific charge question.  It's a frustration for me.  It's been this way for the last ten SACC meetings with the charge questions.  
                  It's, again, almost like a leading question, and I think somehow -- and the way people review you can see this because of the redundancy.  People don't necessarily look at the charge question or try to look at the charge question, but really it overlaps the whole document.  And it's just a frustration for me, and I don't know if anybody else feels that way.  But I'd just like to throw that out there for future meetings since we're going to be doing this again.
                  DR. DANIEL SCHLENK:  Sure.  Again, if you could write up your comments and put them out there, it gives the Committee a chance to agree or to not respond at least at that point.
                  DR. WILLIAM DOUCETTE:  Dan, where would that go?
                  DR. DANIEL SCHLENK:  At the end.  
                  DR. WILLIAM DOUCETTE:  At the end?
                  DR. DANIEL SCHLENK:  Yeah.  But send it as a separate to Alaa --
                  DR. WILLIAM DOUCETTE:  Who would be the lead on that?
                  DR. DANIEL SCHLENK:  You would.
                  DR. WILLIAM DOUCETTE:  Pardon me?
                  DR. DANIEL SCHLENK:  You would.  Send your written comments --
                  DR. WILLIAM DOUCETTE:  I would send that directly --
                  DR. DANIEL SCHLENK:  To Alaa, yes, as if you were a lead discussant.  Right. 
                  DR. WILLIAM DOUCETTE:  Okay.  All right.  Thank you.  
                  DR. DANIEL SCHLENK:  Yeah, sure.  Dr. Unseld.
                  DR. MONICA UNSELD:  Yes.  I just wanted to support Bill's comment and to add that as someone who's doing this for the first time, it's a bit surprising to hear from, not only more experienced SACC members, but the public that suggestions and recommendations have not been implemented, even on the process of the charge questions.
                  And so, I would lift that up to say, like, what is the utility of this entire process?  What's the best use of all of the brainpower that has gathered here?  What's the best use of the community's time?  Because I'm also not convinced that we gave the Agency what it needed because the charge questions were not very precise or concise in what they were looking for.  So, I can type that up and send that in.
                  DR. DANIEL SCHLENK:  Great.  Dr. Chaisson.
                  DR. CHRISTINE CHAISSON:  This is Dr. Chaisson.  Dr. Schlenk, is there a process by which, after the charge questions are specifically summarized and written up, that somehow we could reconvene to form sort of an overall listing of where there's great commonality or issues that just came up over and over again so that the importance of that could be emphasized and also, to make it maybe easier for the public to understand what we're trying to say?
                  DR. DANIEL SCHLENK:  We'll discuss that at the conclusion of this meeting, so stay on the line.
                  DR. CHRISTINE CHAISSON:  Okay.  Thank you.
                  DR. DANIEL SCHLENK:  The logistics of the report writing will be discussed at that point.
                  DR. CHRISTINE CHAISSON:  Thank you.
                  DR. DANIEL SCHLENK:  Yeah.  Dr. Johnson.
                  DR. MARK JOHNSON:  Yeah, I just want to agree with Monica and Bill.  And I seem to remember at one SACC meeting, we had an opportunity to review the charge questions before they went final, and maybe that's a good solution.  Maybe we can get a shot of actually corresponding and asking exactly what you want because what we want to do is be helpful.  At least, I do.  And so, maybe if we had an opportunity to review the charge questions beforehand and provide the input back to the EPA, they can consider our comments and adjust them accordingly.  
                  DR. DANIEL SCHLENK:  Okay.  You do receive the charge questions before the meeting, though.  So, if you're asking for a more formal process, I guess, in terms of responding to them, that's something, I guess, we could put forward.
                  DR. MARK JOHNSON:  Yeah, we got the questions, but we weren't asked to provide any input back on them.  So I didn't, but I could've.  I could've said I could see a storm coming and if you adjust this way or something like that.
                  DR. DANIEL SCHLENK:  Sure.
                  DR. MARK JOHNSON:  It's a process question, really, or suggestion.
                  DR. DANIEL SCHLENK:  Yeah, I understand.  Yeah.  Bill, back to you.
                  DR. WILLIAM DOUCETTE:  Yeah, I didn't mean to imply that, for those that weren't involved in previous SACC meetings, the EPA doesn't listen to our comments or doesn't respond.  I didn't mean that at all.  We've always had an opportunity to respond or ask clarification for the charge questions.  My suggestion was eliminating the charge questions to a single more general review question rather than having us try to focus in specific areas because we obviously are trained.
                  Most reviewers just go through from the top of the document to the bottom of the document and make our comments, and we tend to focus on the areas that we're familiar with.  That's why we have such a wonderfully diverse background in the Panel.  So I didn't mean to imply that EPA is not responsive at all; I just meant that I think there might be a better way to deal with this in terms of that question.
                  DR. DANIEL SCHLENK:  Sure.  I think making that recommendation is totally appropriate at that point.  Sheela?
                  DR. SHEELA SATHYANARAYANA:  Yeah, I just wanted to agree with Dr. Doucette, Dr. Unseld, and Dr. Johnson about the charge questions.  We have, in the past, met as a group to discuss the charge questions, and they were modified after the discussion to reflect the conversation.  And so, it would be great if we could do that in the future.  
                  The only thing I wanted to add is that there is a lot of richness in terms of meeting in person.  And many times in the past meetings, the side conversations that we've had have really improved our responses and our ability to provide EPA with the information that they need and to help them.  And in this setting, it's really hard to do, and it's also hard to be virtual and attentive for like eight hours in a row.  So, I just wanted to make the plug for that.
                  I know that these are extenuating circumstances and there's a pandemic, but in the future, it would be great if we could meet in person.
                  DR. DANIEL SCHLENK:  Okay, thanks.  Dr. Cobb.
                  DR. GEORGE COBB:  Just very briefly.  I'd kind of like to come to the Agency's defense a little bit here.  This entire meeting that we're having is directly in response to comments of the SACC to the Agency as we were reviewing the first ten.  So, they are doing their best to be responsive and I appreciate that, and I'll be quiet.
                  DR. DANIEL SCHLENK:  Thanks, George.  Dr. Li.
                  DR. LI LI:  So, this is Li Li speaking.  So, we just had some email communication with Dr. Heiger-Bernays.  So, we realized that we need to take the last few minutes to emphasize the importance of the tiered screen approach used for this.  So, I can have some thoughts, and Dr. Heiger-Bernays can add if you want.  So, because we really find it important to hammer this home, so basically, we may take the tiered approach.
                  So, the first approach is to identify what exposure pathway or what exposure sources are most important.  We can do this by either screening the chemical properties or by considering the routes of exposure to a specific population, to a specific group of people.  And if we identify the most important exposure pathway or exposure source, then we can perform more refined assessments, specifically to these exposure routes.
                  And we can go back.  For example, we can go back to the air/water pathway, and we can also consider the groundwater.  Or we can also consider some exposure pathway specific to some indigenous people, to some tribes, to some specific groups of people.  So maybe this is something we can pursue.  Yeah.
                  DR. DANIEL SCHLENK:  Dr. Heiger-Bernays.
                  DR. WENDY HEIGER-BERNAYS:  Yes, thank you, Dr. Li.  I know that this is in the context of -- I'll say it like this, that we've got three compound chemicals that have been examined now.  They're really bad actors.  Their data are very good.  The current screen that was proposed to us shows, with all of its challenges that members have raised, that these chemicals --and, again, I'll repeat -- even in the occupational setting alone, are ripe for regulatory decision. 
                  And I would propose that a tiered approach could be taken such that the -- I'll call it the -- more robust, or maybe that's the wrong -- more sophisticated inclusionary screening tool that would include multiple additional pathways could be in the sort of the second round or the second step if there is evidence that the risk is truly unacceptable -- and I'll put this in air quotes -- decisions are made that these chemicals need to be dealt with.  They meet some regulatory threshold and enough study of those has been done and then we can move onto those chemicals or those chemicals for which there is a question as to whether that screening was actually sufficient.
                  DR. DANIEL SCHLENK:  Okay.  Yeah, just reading through the charge questions, I think both of those comments would probably fit into one or three of the charge questions, the way that the charge questions written.  So, if you want to propose a tiered approach, I think you can recommend that and write that up in those particular charge questions if you like.  I think those would be appropriate.  Dr. Chaisson.
                  DR. CHRISTINE CHAISSON:  Yeah.  This is Dr. Chaisson.  Dr. Heiger-Bernays, I would urge you to write out what you just put out so that it's formally introduced in those terms.  
                  The issue sort of generically about how tiered approaches really work across the Agency or any other group doing it is my understanding of it may be a little different than you presented, Dr. Li.  So maybe you could clarify this.
                  When tiered approaches that I work with are employed, the first cut is usually all-encompassing, and you can't, as you tier down, you don't add to it.  So, you don't bring in 15 more routes of exposure in Tier 2 or Tier 3; you're just refining the screen that you included in Tier 1.  
                  The application, however, as Dr. Heiger-Bernays is pointing out, is almost like a triage.  It's not really a tiered approach.  It's sort of a triaging.  Let's take the critically important ones off the top of the pile and deal with it, which is a slightly different way of using what could be considered an incomplete tool but certainly has the capacity to triage for those critical and obvious situations.  
                  So, I would caution against accepting as applicable a tool that's not encompassing hoping that, oh, you'll catch the stuff later on downstream because it won't happen.  
                  And there will be legal challenges to that kind of thing.  I can just see that whole issue coming up that, well, we weren't caught in the screen; don't throw us in now.  
                  There's a third consideration to this, specifically for the charge question that I was responsible for.  These underserved communities have been ignored repeatedly throughout the history of all regulatory communities be it they federal, state, international, or whatever.  To do that again now and set this thing out there in clear -- if you will -- non-inclusion, I think sends a really terrible message to the entire regulatory community and challenges the very charge that the assistant administrator made perfectly clear in her opening remarks.
                  Personally, I think that at this stage of the game, particularly for this moment in time with this administration, this is where it's going to happen.  It's not going to happen possibly later on.  It certainly didn't happen ever before, and once again, I think that there's a moral obligation to make explicitly the inclusion of unique communities that are most likely to be the ones affected for the purpose of this screening tool explicit and included before it's ever used.  And that's just my personal, obviously very strong, opinion about a mistake that I'd like to see EPA avoid making here. 
                  DR. DANIEL SCHLENK:  That's for the comments.  Let me just remind the Committee that we're not here to make regulatory decisions at all.  
                  DR. CHRISTINE CHAISSON:  Right.
                  DR. DANIEL SCHLENK:  So, an interpretation of regulatory statutes as well.  I'll just say that again.  We need to stick to the science, obviously, and make those recommendations based upon that.  Dr. Cobb.
                  DR. GEORGE COBB:  Really quick, just to the point of a tiered approach.  Actually, just overnight or maybe this morning, Charge Question 1, there was some language starting to emerge around that topic.  We can try to incorporate that, or I can try to incorporate that into Q1.  Having said that, Dan, I'll just fess up.  I am probably the least qualified person to be smoothing and combining and merging other people's comments into something coherent.  
                  I'm certainly happy for that to be in Charge Question 3 or in a separate question.  But if you want it in Q1, we can certainly do it.  And there's starting to be a little bit of momentum in that direction for Q1.  
                  DR. DANIEL SCHLENK:  Yeah, that's where I see it fitting the best, George.  And if you already have material there, Dr. Li and Heiger-Bernays, if you want to focus in on that, I think that would be appropriate for Question 1, if that's okay.
                  DR. GEORGE COBB:  Thank you, Dan.  This is George Cobb, again.  I think Bill Doucette had sent some comments that were -- it wasn't necessarily speaking of a tiered approach, however, it was leaning along those lines.  And I think Dr. Reiss had also sent something.  Perhaps even some of the comments that Dr. Johnson had sent in were kind of touching on the tiered approach kind of concepts. 
                  DR. DANIEL SCHLENK:  Sure, yeah.  I think it's very appropriate for one.  Fantastic.  Dr. Heiger-Bernays.
                  DR. WENDY HEIGER-BERNAYS:  Yeah.  Thank you, Dr. Chaisson.  I absolutely agree.  This is a triage as opposed to a tier.  And I absolutely agree this is the opportunity.  The time is now to encompass for the screen -- as we call it a screen -- to cast the wide net to include the information and data from and about fenceline communities.  No questions asked.  I really do like the triage approach, and I will work with Dr. Cobb in a -- I guess, provide some specific comment with that regard.  Thank you.
                  DR. DANIEL SCHLENK:  Thank you.  Thanks a lot.  Dr. Unseld, do you want to go ahead make the comments about your community engagement link?  That would be great.
                  DR. MONICA UNSELD:  Yeah.  I wasn't sure if this fit under the charge questions, but I do have resources because this is part of my job on how to have effective community engagements and building trust and that sort of thing.  So, I just wasn't sure if I should send those in or who they go to.
                  DR. DANIEL SCHLENK:  4b.  I would put it under 4b under your -- now that you have it on the record, I think we're good.  Dr. Doucette.
                  DR. WILLIAM DOUCETTE:  Dan, just clarification based on your last comment.  The general comment that I made about potentially restructuring or at least considering restructuring the way the charge questions, I'm still not a hundred percent sure where that should go.
                  DR. DANIEL SCHLENK:  At the end.
                  DR. WILLIAM DOUCETTE:  At the end of -- so it doesn't go into a specific charge question?
                  DR. DANIEL SCHLENK:  No.  It will go into -- I mean, this is the way I see it is this will go at the end because it's not a formal charge question that was addressed.  
                  DR. WILLIAM DOUCETTE:  Okay.  Right.
                  DR. DANIEL SCHLENK:  So, this will be a recommendation that normally we put at the end of the document to say we'll make a recommendation for a more generalized approach if overlap -- I mean, I'm interpreting your comment here so if I'm wrong.  But if the Agency thinks overlap is going to be consistent with specific components, that maybe a more generalized open-ended question might be more appropriate.  
                  But that would go after the charge questions because we obviously haven't been asked that, so that's a recommendation.
                  DR. WILLIAM DOUCETTE:  Okay.  Also, there would be, not necessarily, consensus on that, right?
                  DR. DANIEL SCHLENK:  No, it's going to go out to the Committee, and we'll begin it with one Committee member thought dot, dot, dot.
                  DR. WILLIAM DOUCETTE:  Okay, we'll see what happens.
                  DR. DANIEL SCHLENK:  Exactly.
                  DR. WILLIAM DOUCETTE:  Okay.  All right, thank you.  
                  DR. DANIEL SCHLENK:  Yeah.  George, are you still -- do you have something else?  Your hand's still up.  No.  You're mute.
                  DR. GEORGE COBB:  I do not.  I'm trying to send an email.  Sorry.
                  DR. DANIEL SCHLENK:  No worries.  Okay, great.  All right.  Any other comments or concerns?  Okay, let me just remind the Committee that we need to stay on after the meeting is adjourned to discuss the logistics of the report and Alaa will fill us in on that.  And I think we're ready to close.  Dr. Choudhary, do you have any final comments from the Agency?
                  DR. REHAN CHOUDHARY:  Yes, good afternoon, everybody.  Rehan Choudhary from the EPA.  We appreciate all the deliberations that the Committee members have gone through, and we look forward to receiving your written recommendations.  As we emphasized before, the more prescriptive and specific you can be, I believe the more actionable this team can be to try and be responsive.  Thank you very much.  
                  DR. DANIEL SCHLENK:  Thank you. Thanks to you, and to your team, for the presentations that you made.  They were very clear.  And thank you for the questions and answering the questions or clarification that came from the Committee as well.  
                  And at this point, I'd like to thank the EPA staff for putting this together and the back and forths that we've had trying to do a Zoom meeting here for, I believe, the first time for us anyway outside of the teams' concepts.
                  It's actually, I know, Sheela, you had mentioned we would much rather be in person, but this is way better than the teams was where we couldn't even see each other's face.  So, I guess we're moving in the right direction, at least, in terms of interactions.  But hopefully, at some point, we'll be able to interact in person.  So again, thanks to the Committee, thanks to the public commenters, and thanks to the EPA staff and Alaa for putting all this together.
                  With that, I'll turn it over to Alaa.
                  DR. ALAA KAMEL:  Well, thank you, Dan.  In closing, I want to thank everyone who contributed to this meeting.  I would first like to thank the peer review and ethics branch in EPA for preparing for this meeting.  And it includes the executive secretary, Steve Knott; and the designated federal officials that are also involved, Dr. Sharlene Matten and Dr. Todd Peterson; and also, the administrative staff who participated in preparing for this meeting.  I'd also like to thank the contractor EnDyna for their help in the Zoom meeting preparations and in the YouTube webcasting.  
                  Dr. Schlenk, you really did a great job in organizing this meeting and leading all the discussions, going through all the agenda items following the FACA requirements.  Thank you very much.  
                  Thank you, also, to all the SACC members who participated in this meeting and for the ad hoc reviewers for their input and participation. 
                  I would also importantly like to thank the EPA's assistant administrator, Dr. Michal Freedhoff, and the Deputy Office Director of the Office of Pollution Prevention and Toxics, Mark Hartman, for their welcome and introductory remarks.  
                  Thanks are also due to the OPPT team, Office of Pollution Prevention and Toxics.  Sorry.  For all the team for presenting the draft methodology and for responding to the Committee questions. 
                  Thank you, Rehan.  Thank you, Kevin.  Thank you for all the team.  
                  And then, thank you to the public commenters who sent written comments and presented oral comments.  
                  And then, in the end, we will be meeting after this meeting, and Committee members will stay in the meeting and everyone else can leave, including EPA staff.  And the meeting is now adjourned. 

                              [MEETING ADJOURNED]
                                       
