

[Federal Register: April 4, 2007 (Volume 72, Number 64)]
[Notices]               
[Page 16357-16359]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr04ap07-63]                         

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ENVIRONMENTAL PROTECTION AGENCY

[EPA-HQ-OPP-2007-0204; FRL-8120-9]

 
Potential Effects of Atrazine on Amphibian Gonadal Development

AGENCY: Environmental Protection Agency (EPA).

ACTION: Notice.

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SUMMARY:  In October 2007, EPA will make a presentation to the Federal 
Insecticide, Fungicide, and Rodenticide Act (FIFRA) Scientific Advisory 
Panel (SAP) concerning EPA's evaluation of the scientific research 
investigating whether exposure to the herbicide atrazine potentially 
affects amphibian gonadal development. The scientific research will 
include studies that were conducted by Syngenta Crop Protection, Inc. 
in 2005 and 2006 as well as published open literature studies. The 
notice identifies the open literature studies that EPA has reviewed and 
requests public comment to ensure that the list of publications is 
complete. The studies that have been reviewed focus on testing atrazine 
alone and only on atrazine's potential effects on amphibian gonadal 
development.

DATES: Comments must be received on or before May 4, 2007.

ADDRESSES:  Submit your comments, identified by docket identification 
(ID) number EPA-HQ-OPP-2007-0204, by one of the following methods:
     Federal eRulemaking Portal: http://www.regulations.gov. 

Follow the on-line instructions for submitting comments.
     Mail: Office of Pesticide Programs (OPP) Regulatory Public 
Docket (7502P), Environmental Protection Agency, 1200 Pennsylvania 
Ave., NW., Washington, DC 20460-0001.
     Delivery: OPP Regulatory Public Docket (7502P), 
Environmental Protection Agency, Rm. S-4400, One Potomac Yard (South 
Bldg.), 2777 S. Crystal Dr., Arlington, VA. Deliveries are only 
accepted during the Docket's normal hours of operation (8:30 a.m. to 4 
p.m., Monday through Friday, excluding legal holidays). Special 
arrangements should be made for deliveries of boxed information. The 
Docket telephone number is (703) 305-5805.
    Instructions: Direct your comments to docket ID number EPA-HQ-OPP-
2007-

[[Page 16358]]

0204. EPA's policy is that all comments received will be included in 
the docket without change and may be made available on-line at http://www.regulations.gov
, including any personal information provided, 

unless the comment includes information claimed to be Confidential 
Business Information (CBI) or other information whose disclosure is 
restricted by statute. Do not submit information that you consider to 
be CBI or otherwise protected through regulations.gov or e-mail. The 
Federal regulations.gov website is an ``anonymous access'' system, 
which means EPA will not know your identity or contact information 
unless you provide it in the body of your comment. If you send an e-
mail comment directly to EPA without going through regulations.gov, 
your e-mail address will be automatically captured and included as part 
of the comment that is placed in the docket and made available on the 
Internet. If you submit an electronic comment, EPA recommends that you 
include your name and other contact information in the body of your 
comment and with any disk or CD-ROM you submit. If EPA cannot read your 
comment due to technical difficulties and cannot contact you for 
clarification, EPA may not be able to consider your comment. Electronic 
files should avoid the use of special characters, any form of 
encryption, and be free of any defects or viruses.
    Docket: All documents in the docket are listed in the docket index 
available in regulations.gov. To access the electronic docket, go to 
http://www.regulations.gov, select ``Advanced Search,'' then ``Docket 

Search.'' Insert the docket ID number where indicated and select the 
``Submit'' button. Follow the instructions on the regulations.gov web 
site to view the docket index or access available documents. Although 
listed in the index, some information is not publicly available, e.g., 
CBI or other information whose disclosure is restricted by statute. 
Certain other material, such as copyrighted material, is not placed on 
the Internet and will be publicly available only in hard copy form. 
Publicly available docket materials are available either in the 
electronic docket at http://www.regulations.gov, or, if only available 

in hard copy, at the OPP Regulatory Public Docket in Rm. S-4400, One 
Potomac Yard (South Bldg.), 2777 S. Crystal Dr., Arlington, VA. The 
hours of operation of this Docket Facility are from 8:30 a.m. to 4 
p.m., Monday through Friday, excluding legal holidays. The Docket 
telephone number is (703) 305-5805.

FOR FURTHER INFORMATION CONTACT: Thomas Steeger, Environmental Fate and 
Effects Division, Office of Pesticide Programs, Environmental 
Protection Agency, 1200 Pennsylvania Ave., NW., Washington, DC 20460-
0001; telephone number: 703-305-5444; fax number: 703-305-7695; e-mail 
address: steeger.thomas@epa.gov.

SUPPLEMENTARY INFORMATION:

I. General Information

A. Does this Action Apply to Me?

    This action is directed to the public in general, and may be of 
particular interest to those persons who hold or seek registrations of 
pesticide products containing atrazine under FIFRA. This action may 
also be of particular interest to those who have published research 
regarding the potential effects of atrazine on amphibian gonadal 
development. Since other entities may also be interested, EPA has not 
attempted to describe all the specific entities that may be affected by 
this action. If you have any questions regarding the applicability of 
this action to a particular entity, consult the person listed under FOR 
FURTHER INFORMATION CONTACT.

B. What Should I Consider as I Prepare My Comments for EPA?

     When submitting comments identifying additional open literature 
studies that should be reviewed by EPA, commentors should provide a 
complete citation following the format of the studies listed in this 
notice. If possible, a copy of the open literature study should be 
submitted as well.

II. Background

A. What Action is the Agency Taking?

    In April 2002, EPA completed a revised science chapter that 
characterized the ecological effects of atrazine in support of an 
Interim Reregistration Eligibility Decision (IRED). At about the same 
time, scientific articles were published regarding the potential 
effects of atrazine on amphibian gonadal development, and concerns were 
raised that EPA had not sufficiently accounted for these data in its 
risk assessment. In response to an amended consent decree between EPA 
and the Natural Resources Defense Council (NRDC), EPA issued an 
atrazine IRED in January 31, 2003 which stipulated that EPA would issue 
a revised IRED by October 31, 2003. The revised IRED would incorporate 
recommendations and comments from a FIFRA Scientific Advisory Panel 
(SAP) regarding studies, submitted by February 28, 2003, on the 
potential effects of atrazine on amphibians. EPA also agreed to develop 
a paper, at least three months prior to signing this revised IRED, and 
submit it to the SAP for review and comment.
    In accordance with the consent decree, EPA conducted an extensive 
review of open literature and registrant-submitted studies concerning 
the potential effects of atrazine on amphibian gonadal development. 
After a thorough assessment of all of these studies, EPA concluded 
there was sufficient information to hypothesize that atrazine exposure 
can result in effects on amphibian gonadal development, but there was 
insufficient evidence to refute or confirm that hypothesis because the 
collective studies failed to show that atrazine produced consistent, 
reproducible effects across the range of exposure concentrations and 
amphibian species tested in the studies. EPA summarized the studies and 
its evaluation of the studies in a White Paper and presented its 
analysis, conclusions, and recommendations to the SAP during a meeting 
held on June 17 - 20, 2003.
    The SAP concurred with EPA's interpretation of the available data 
and with EPA's recommendations to seek additional data. Additionally, 
the SAP concurred with the study approach described in the White Paper 
for addressing uncertainties identified in the available studies. (For 
further information regarding this SAP meeting and to obtain a copy of 
the White Paper and the SAP's report, refer to http://www.epa.gov/scipoly/sap/meetings/2003/index.htm#061703.
)

    In response to the uncertainties identified in the White Paper and 
based on the recommendations made by the SAP, EPA issued a Data Call-in 
Notice (DCI) on November 12, 2004, to Syngenta Crop Protection, Inc. 
(Syngenta) and other atrazine registrants. The DCI required amphibian 
studies be conducted to determine if exposure to atrazine can affect 
amphibian gonadal development. Secondary objectives of these studies 
were to provide information on the repeatability of previous 
observations, to develop a sound dose-response relationship, and to 
determine the developmental sensitivity of the amphibian species that 
are being tested. Syngenta has initiated the studies according to EPA-
approved protocols and expects to submit the final study results to EPA 
in 2007.
    On October 9 -12, 2007, EPA will return to the SAP with a second 
White

[[Page 16359]]

Paper discussing the results of Syngenta's amphibian studies conducted 
in 2005 - 2006. In addition, EPA has continued to review the open 
literature studies investigating whether atrazine exposure affects 
amphibian gonadal development. For this second SAP meeting, EPA plans 
to include only those studies that tested atrazine alone and examined 
atrazine's potential effects on amphibian gonadal development. Studies 
on mixtures of pesticides that include atrazine as well as studies of 
the potential for atrazine to cause adverse effects other than or in 
addition to amphibian gonadal development are not being considered for 
the SAP meeting.
    In this Federal Register Notice, EPA is soliciting public comment 
on the completeness of its list of open literature studies on the 
potential effects of atrazine on amphibian gonadal development. If 
other publications relevant to these potential effects are available 
and have not been included in this list, EPA requests that citations be 
submitted during the comment period. If possible, a copy of the 
publication should be submitted as well.
    EPA has reviewed the following list of relevant open literature 
studies in preparation for the October SAP meeting:
    1. Coady K.K., Murphy M.B., Villeneuve D.L., Hecker M., Jones P.D., 
Carr J.A., Solomon K.R., Smith E.E., Van der Kraak G., Kendall R.J., 
and J.P. Giesy. 2004. Effects of Atrazine on Metamorphosis, Growth, 
Laryngeal and Gonadal Development, Aromatase Activity, and Plasma Sex 
Steroid Concentrations in Xenopus laevis. Ecotoxicology and 
Environmental Safety 62:160-173. MRID 458677-04.
    2. Coady K.K., Murphy M.B., Villeneuve D.L., Hecker M., Jones P.D., 
Carr J.A., Solomon K.R., Smith E.E., Van der Kraak G., Kendall R.J., 
and J.P. Giesy. 2004. Effects of Atrazine on Metamorphosis, Growth, and 
Gonadal Development in the Green Frog (Rana clamitans). Journal of 
Toxicology and Environmental Health, Part A, 67: 941-957. MRID 458677-
03.
    3. DuPreez L.H., Solomon K.R., Carr J.A., Giesy J.P., Gross C., R. 
J. Kendall et al. 2005. Population Structure Characterization of Clawed 
Frog (Xenopus laevis) in Corn-growing Versus Non-corn-growing Areas in 
South Africa. African Journal of Herpetology. 54: 61 - 68.
    4. Freeman, J.L. and A.L. Rayburn. 2005. Developmental Impact of 
Atrazine on Metamorphing Xenopus laevis as Revealed by Nuclear Analysis 
and Morphology. Environmental Toxicology and Chemistry 24(7): 1648 - 
1653.
    5. Forson, D. and A. Storfer. 2005. Effects of Atrazine and 
Iridovirus Infections on Survival and Life-history Traits of the Long-
toed Salamander (Ambystoma macrodactylum). Environmental Toxicology and 
Chemistry 25(1): 168 - 173.
    6. Hayes, T.B. 2004. There is No Denying This: Defusing the 
Confusion about Atrazine. Bioscience 54: 1138 - 1149.
    7. Hayes, T.B. 2005. Comment on ``Gonadal Development of Larval 
Male Xenopus laevis Exposed to Atrazine in Outdoor Microcosms.'' 
Environmental Science and Technology 39(19) 7757-7758.
    8. Hayes, T.B. 2005. Welcome to the Revolution: Integrative Biology 
and Assessing the Impact of Endocrine Disruptors on Environmental and 
Public Health. Journal of Integrative and Comparative Biology 45: 321-
329.
    9. Hayes T.B., Stuart A.A., Mendoza M., Collins A., Noriega N., 
Vonk A., Johnston W., Liu R., and D. Kpodzo. 2006. Characterization of 
Atrazine-Induced Gonadal Malformations in African Clawed Frogs (Xenopus 
laevis) and Comparisons with Effects of an Androgen Antagonist 
(Cyproterone Acetate) and Exogenous Estrogen (17-[beta]-estradiol): 
Support for the Demasculinization/Feminization Hypothesis. 
Environmental Health Perspectives 114: 134 - 141.
    10. Jooste A.M., Du Preez L.H., Carr J.A., Giesy J.P., Gross T.S., 
Kendall R.J., Smith E.E., Van Der Kraak G.J., and K.R. Solomon. 2004. 
Gonadal Development of Larval Male Xenopus laevis Exposed to Atrazine 
in Outdoor Microcosms. Environmental Science and Technology 39: 5255-
5261. MRID 458677.
    11. Murphy M.B., Hecker M., Coady K.K., Tompsett A.R., Jones,P.D., 
DuPreez L.H., Solomon K.R., Carr J.A., Smith, E.E., Kendall R.J., van 
der Kraak G., and J.P. Giesy. 2005. Sediment TCDD-Eq's and EROD and 
MROD Activities in Ranid Frogs from Agricultural and Non-agricultural 
Sites in Michigan (USA). Archives of Environmental Contamination and 
Toxicology 51(3): 467-477. MRID 458677-02.
    12. Murphy, M.B, Hecker M., Coady K.K., Tompsett A.R., DuPreez 
L.H., Everson G.J., Solomon K.R., Carr J.A., Smith E.E., Kendall R.J., 
van der Kraak G., and J.P. Giesy. 2005. Atrazine Concentrations, 
Gonadal Gross Morphology, and Histology in Ranid Frogs Collected in 
Michigan Agricultural Areas. Aquatic Toxicology 76: 230-245. MRID 
458677-02.
    13. Murphy, M. B., Hecker M., Coady K.K., Tompsett A.R., Higley 
E.B., Jones P.D., Du Preez L.H., Solomon K.R., Carr J.A., Smith E.E., 
Kendall R.J., Van Der Kraak G., and J. P. Giesy. 2006. Plasma Steroid 
Hormone Concentrations, Aromatase Activities and GSI in Ranid Frogs 
Collected from Agricultural and Non-Agricultural Sites in Michigan 
(USA). Aquatic Toxicology 77: 153 - 166.
    14. Orton, F., Carr J.A., and R. D. Handy. 2006. Effects of Nitrate 
and Atrazine on Larval Development and Sexual Differentiation in the 
Northern Leopard Frog Rana pipiens. Environmental Toxicology and 
Chemistry 25(1): 65 - 71.
    15. Smith E.E., Du Preez L.H., Gentles B.A., Solomon K.R., Tandler 
B., Carr J.A., Van Der Kraak G.J., Kendall R.J., Giesy J.P. and Gross 
T.S. 2005. Assessment of Laryngeal Muscle and Testicular Cell Types in 
Xenopus laevis (Anura Pipidae) Inhabiting Maize and Non-maize Growing 
Areas of South Africa. African Journal of Herpetology 54(1): 69-76. 
MRID 458677-10.
    16. Sullivan K. B, and K. M. Spence. 2003. Effects of Sublethal 
Concentrations of Atrazine and Nitrate on Metamorphosis of the African 
Clawed Frog. Environmental Toxicology and Chemistry 22(3): 627 - 635.

B. What is the Agency's Authority for Taking this Action?

    EPA is taking action under 7 U.S.C. 136b of the FIFRA.

List of Subjects

    Environmental protection, atrazine, amphibian gonadal development.

    Dated: March 29, 2007.
 Steve Bradbury,
Director, Environmental Fate and Effects Division
[FR Doc. E7-6253 Filed 4-3-07; 8:45 am]

BILLING CODE 6560-50-S
