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Ex Parte Meeting Summary:  Ozone NAAQS

Date:  December 21, 2007, 10:00 – 11:00 am. 

Attendees: 

Visitors: 

In Person:

John Balbus, MD, Environmental Defense

Gary Ewart, American Thoracic Society (also representing ALA)

Tee Guidotti, MD, MPH, American Thoracic Society

Janice E. Nolen, American Lung Association

Deborah Shprentz, American Lung Association

By Phone:

Jonathan Levy, ScD (Professor at Harvard School of Public Health, but
representing own views)

William F. McDonnell, MD (requested by ALA, but views are own)

Jerome Paulson, MD, American Academy of Pediatrics

EPA attendees: 

George Gray, ORD

Pamela Williams, ORD

Bob Fegley, ORD

John Vandenberg, ORD

Ila Cote, ORD

Debra Walsh, ORD

Mary Ross, ORD

Susan Stone, OAQPS

David McKee, OAQPS

Summary of discussion:  

Janice Nolen provided an introduction on behalf of the American Lung
Association (ALA) , in which she stated that it is their belief that
there is powerful and conclusive evidence that the current standard is
not protective of public health and should be much tighter (along the
lines of what CASAC recommended).  Specifically, she indicated that ALA
supports 0.06 ppm as the appropriate standard.

John Balbus, representing the Environmental Defense, next provided a
general overview of several issues.  First, he indicated that ozone is a
simpler chemical than particulate matter and there is less uncertainty
regarding the nature of exposure to ozone.  Second, he stated that there
is strong evidence from multiple studies (e.g., controlled studies of
healthy adults and EPI studies that include sensitive populations) that
show health effects from exposure to ozone at the current standard or
lower levels.  Third, he indicated that he wanted to ensure that the
uncertainty regarding the health effects of ozone were appropriately
characterized and not overinflated.  Finally, he stated that both CASAC
and the Children’s Health Advisory had called on EPA to lower the
standard to 0.06 ppm.

Tee Guidotti, representing the American Thoracic Society, also stated
that there was a large body of evidence that indicated the current ozone
standard was not protective of human health.  He indicated that there is
a tight exposure-response relationship on both an individual and
population-level basis, and that based on what is known about its
mechanism, there is no threshold for ozone.  He stated that because of
this, ideally the standard should be set as low as possible.  However,
he believes that 0.06 ppm is an acceptable comprise, given the natural
background levels of ozone.  He also indicated that the prevalence of
asthma has increased in the US, and although the reasons for this are
unknown and there is no known causal association with ozone, there is no
question that ozone is a strong trigger for asthma.  

Jonathan Levy, a Professor at the Harvard School of Public Health (but
representing his own views), highlighted some of the more salient
aspects of some of the ozone epidemiology studies.  He stated that the
findings in the more recent literature are extremely consistent and
demonstrate health effects at or below the current standard (with
greater effects in the summer than winter and synergistic relationships
with some factors such as temperature and humidity).  In particular, he
stated that the three meta-analyses (of which he is the lead author of
one) had good comparability and showed that the variability in studies
was due to lag time (e.g., effects greater on same day than after 1 or
more days) and prevalence of air conditioning.  He indicated that the
Bell et al. NMAPs study also found significant effects associated with
ozone, although the estimates were lower than those from the EPI studies
(he believes that this is due primarily to methodological differences). 
 He also indicated that a later Bell et al. study showed linearity down
to 20 ppb (as did other studies), and there is an extremely consistent
body of evidence about ozone’s exposure-response relationship.  He
stated that exposure assessments are tricky for ozone, due to its
reactivity and lower indoor/outdoor ratio, but studies have shown that
there are cross-correlations between ambient and personal exposures
(i.e., when ozone levels increase so do personal exposures based on
longitudinal data, especially for people who spend a lot of time
outdoors).  He also stated that the Staff paper and the CASAC present
studies that together show effects of ozone less than the current
standard.

William McDonnell, whose presentation was at the request of ALA,
indicated that he is not advocating any particular level for ozone, but
is a scientist who has been involved in some of the clinical studies on
ozone (which are currently under consideration).  He indicated that the
1997 standard was based on two EPA studies, which showed effects in
health adults at 0.08 ppm, but there was too much uncertainty about
whether the standard should be lowered based on such few data points. 
Since then, he stated that several studies by Adams et al. have shown
the same results.  He also indicated that we know individuals vary
considerably in their response to ozone and that combined, and we now
know with certainty that some percentage of the population will
experience effects at the current standard (e.g., >10% change in FEV1 or
>20% change in FEV1, the latter of which is clearly adverse).  He
indicated that although effects less than 0.08 ppm are less certain, it
is unlikely that they would drop to zero immediately below this level. 
He also indicated that the Adams (2006) study has been widely
misinterpreted.  He stated that because this study was interested in the
temporal pattern of response, it required multiple comparison tests
(e.g., the purpose was not to assess the effects at 0.06  ppm versus
filtered air, which would have entailed a different study design and
methodology).  Because of its design, he stated that the failure of this
study to find significant differences may have been due to a Type II
error, and that this study can only be considered to be
“inconclusive” in regards to effects at 0.06 ppm.  He also stated
that it is unlikely that the differences observed between 0.06 and 0.08
ppm are due to chance alone, and that these effects are not just driven
by one or two responses (and the results were found to be symmetrical
around the mean).  He also mentioned that he had recently published a
2007 paper in Inhalation Toxicology regarding an exposure-response model
for ozone.   

Jerome Paulson, representing the American Academy of Pediatrics, stated
that he sees more children wheezing when ozone levels are up.  He
indicated that these children are extremely uncomfortable and often miss
school or playing with friends.  He also stated that these events can be
frightening to parents and siblings and that acute treatment takes hours
to days and requires many days of medication.  He stated that he also
sees non-asthmatics with sore throats and irritated eyes when ozone
levels are increased.   He indicated that he is worried about the
long-term consequences of ozone exposures on children who may have
decreased lung function later in life.  He is advocating a strong ozone
standard that will be protective of children.

Janice Nolen concluded by stating that because effects are observed in
health adults at the current standard and we know children are more
susceptible, that we cannot keep the current standard.  John Balbus also
questioned what sort of evidence would be compelling to say that CASAC
was wrong.

Two written materials were provided during the meeting: (1) list of
medical societies and public health organizations supporting a primary
8-hr ozone NAAQS of 0.060 ppm and (2) recent epidemiological studies
reporting respiratory effects and low concentrations (see attached). 

