United States
Environmental Protection
Agency
Office of the Administrator
Science Advisory Board
Washington, DC 20460
SAB-CASAC-S&021
May 1986
Report of the
Clean Air Scientific
Advisory Committee
Review
U.S.
Health Effects
Assessment
on Nitrogen
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UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
WASHINGTON, D.C. 20460
May 9, 1986
OFFICE
THE AD
Honorable Carol Dawson
Acting Chairman
U.S. Consumer Product Safety Conrnission
Washington, DC 20207
Dear Ms. Dawscm
The Clean Mr Scientific Advisory Cormittfie (C^SAC) of the U.S.
Environmental Protection Agency has completed its review of the health
effects and exposure assessment documents on nitrogen dioxide provided by
the U.S. Consumer Product Safety Commission* This review was conducted
at the Commission's request in order to obtain independent outside scienti-
fic advios on the potential health hazards associated with exposure to
0.1 to 1,0 ppm nitrogen dioxide generated by undented indoor combustion
sources, IXte are pleased to transmit to you the enclosed report which
represents the Committee's analysis and reccsmendations concerning the
documents and the specific' questions that you raised.
The Committee has concluded that: 1) repeated peak exposures at concen-
trations of 0.3 ppm of nitrogen dioxide may cause health effects in some
individuals and there is a possibility that such effects may occur at
concentrations as low as 0.1 ppm. We note, howaver, that both the epide-
roiolcgical and chamber studies at or near this range of concentrations
have produced inconsistent evidence regarding the health effects of such
exposures? 2) the population groups that appear most sensitive to nitrogen
dioxide exposure include children, chronic bronchitics, asthmatics, and
individuals with emphysema; and 3) the most direct evidence regarding lung
damage associated with nitrogen dioxide is obtained frcm animal studies -
such studies conclude that a number of effects occur in a variety of
animal species, many of which can be considered serious and irreversible.
Bae relevance of these studies to human exposure at concentrations found
indoors is uncertain.
The Committee also addressed the adequacy of the CPSC documents as
a basis for assessing the risks of exposure to nitrogen dioxide emissions,
and provided guidance regarding further efforts to assess the risks
associated with indoor use of appliances producing nitrogen dioxide
emissions. We found that the CPSC documents addressed the appropriate
issues, but that they were repetitive and not well integrated. Perhaps
this was reflective of their being prepared by various authors at different
times for different purposes. We recommend that the CPSC utilize more
fully the EPA Criteria Document and Staff Paper on Nitrogen Dioxide as
primary resources in developing an assessment of the health risks of
indoor combustion sources.
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-2-
The Committee appreciates this unictue opportunity to interact with the
Commission and to provide scientific advice on an issue of current interest
and great importance to us all*
Sincerely,
\Ware, Chairman
Inel on Nitrogen Dioxide
'Advisory
Morton Lippann/Chairman
Clean Air Scientific Advisory Conmittee
Science Advisory;Board .
cc: Lee Thomas
A. James Barnes
Don Ehreth
Craig Potter
Peter Preuss
Terry Yosie
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A 1EVIEW OP THE CONSUMER PRODUCT SAFETY
COMMISSION'S HEALTH EFFECTS AND EXPOSURE
ASSESSMENT DOCUMENTS ON NITFDGM DIOXIDE
A. Report by the Clean Air Scientific
Advisory Committee of the U.S.
Environmental Protection Agency
Science Advisory Board
U.S. Environmental Protection Agency
Washingtonr I3C
May 1986
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NOTICE
This report has been written as part of the activities of the
Environmental Protection Agency's Gongressionally established Science
Advisory Board, a public group providing advice on scientific issues.
The Board is structured to provide a balanced, independent, expert
assessment of the scientific issues it reviews. "Che contents of this
report do not necessarily represent the views and policies of the U.S.
Environmental Protection Agency, the U.S. Consumer product Safety
Conmission nor of other agencies in the Executive Branch of the Federal
government.
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U.S. finvirontnental Protection Agency
Science Advisory Board
Clean Air Scientific Advisory Conmittee
Panel for the Review of Nitrogen Dioxide Health
EffectsandExposure Assessment Documents for the
Consumer Product Safety Ccmniss ion.
Chairman
Dr. James Ware, Department of Bios tat is tics, Harvard School of Public
Health, Boston, Massachusetts
Panel Members
Dr. Ekjjward Crandall, Division of Pulmonary Medicine, Cornell Medical
College, New York, New York
Dr. Robert Prank., Department of Environmental and Health Sciences,
School of Hygiene and Public Health, Johns Hopkins University,
Baltimore, Maryland
Dr. Jack Hackney, Environmental Health Laboratories, Saneho Los Ainigos
Hospital, University of Southern California, Downey, California
Dr. Ian T»T, Higgins, American Health Foundation, Mew York, New York
Dr. Timothy Larson, Department of Civil Engineering, University of
Washington, Seattle, Washington
Dr., Brian Leaderer, Pierce Laboratory, Yale University, New Haven,
Connecticut
Dr. Mark Utell, Pulmonary and Critical Care Unit, University of Rochester
Medical Center, Rochester, New York
Dr. James whittenberger. Southern Occupational Health Center, University
of California, Irvine, California
Executive Secretary
Mr. A, Robert Flaak, Science Advisory Board, U,S. Environmental Protection
Agency, Washington, DC
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U.S. Environmental Protection Agency
Science Advisory Board
CleanAir Scientific
Chaipnan
Dr. Morton Lippmann, Professor, Department of Environmental Medicine,
New York University Medical Center, Tuxedo, New York
Members
Dr. Robert Frank, Professor of Environmental Health Sciences, Johns
Hopkins School of Hygiene and Public Health, Baltimore, Maryland
Dr. Warren B, Johnson, Director, Atmospheric Science Center, SRI
International, Menlo Park, California
Dr. Paul Kotin, Adjunct Professor of Pathology, University of Colorado
Medical School, Denver, Colorado
Dr. James H. Ware, Associate Professor, Department of Biostatistics,
Harvard School of Public Health, Boston, Massachusetts
Dr. Jerry Wesolowski, Chief, Air and Industrial Hygiene Lab, California
Department of Health, Berkeley, California
Executive Secretary
Mr. A, Robert Flaak, Environmental Scientist, Science Advisory Board,
U.S. Environmental Protection Agency, Washington, DC
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TABLE OF CONTENTS
1. EXECUTIVE SUMMARY . , 1
2. INTRODUCTION 2
A. Background * ...'.... 2
B. Report Format »»,»......».... 2
3. COMMENTS ON THE GOALS OP THE REVIEW ........ 3
4. MAJOR CONCLUSIONS MID RECOMffiNDMTONS ON ISSUES
POSED BY CPSC ................ 4
5. ADDITIONAL ISSUES 7
6. APPENDICES
A. Document Review - More Detailed Comments ..... A-l
B. Nitrogen Dioxide Closure Letter of the Clean Air
Scientific Advisory Committee - October 18, 1984 . . . B-l
C. Letter from CPSC Commissioner Scanlon
March 29, 1985 .............. C-l
D. Letter from EPA Administrator Lee Thomas
May 1, 1985 D-l
E. Literature Cited E-l
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1. EXECUTIVE JgUMMftRY
This Is the report of the U.S. Environmental Protection Agency's (EPA)
Congressionally established Clean Air Scientific Advisory Committee (C&SAC)
concerning its review of the Nitrogen Dioxide {N02) Health Effects and
Exposure Assessment Documents of the U.S* Consumer Product Safety Commission
(CPSC), Under the provisions of an interageney agreement between the two
agencies, the CASAC reviewed the CPSC documents at a public meeting on
September 26-27, 1985, in Bethesda, Maryland.
Following its ire view of the documents prepared by the CPSC, the CAS&C
reached the following major conclusions:
* Preliminary evidence from epidemiologic and related indoor air
pollution monitoring studies suggest that repeated peak exposures
at concentrations of 0*3 ppni of NOj may cause health effects in
some individuals and raises the possibility that such effects
may occur at concentrations as low as 0*1 pptu However, the
epideraiologic and controlled human exposure studies provide
somewhat inconsistent evidence which makes it difficult to be
more definitive.
• Population groups that appear to be most sensitive to N02 exposures
include children, chronic bronchitics, asthmatics, and individuals
with emphysema.
• Human epidemiologic studies suggest that exposure to N02 may lead
to increased respiratory illness rates among children. However,
the most direct evidence regarding lung damage associated with
t«2 is obtained from animal studies. Such studies conclude that
a number of effects occur in a variety of animal species, many
of which can be considered serious and irreversible*
* The work undertaken by the CPSC to quantify the indoor NO2 concentra-
tions produced by kerosene space heaters is innovative and important
and provides information 'that is essential to assess human health
risks from these and other appliances producing N02 emissions.
* The EPA Air Quality Criteria Document and Staff Paper for N02
provide peer reviewed information and assessments directly relevant
to questions facing the CPSC. The CASAC recommends that CPSC use
these documents more fully as a primary resource in developing an
assessment of the health risks of indoor combustion sources*
* The documents submitted by CPSC for CASAC's review were prepared
at different times by various authors, for different CPSC purposesj
therefore, they were sometimes repetitive and not well integrated.
Although the documents generally identified the appropriate issues,
they were not sufficiently developed to provide a primary resource
for risk assessment without further revision. However, in light
of the availability of the EPA Nitrogen Dioxide Criteria Document
and Staff Paper, such revision may not be needed.
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2. INT5QDOCTION
• ^* Background
The Consumer Product Safety Commission (CPSC) has been concerned
about exposure to nitrogen dioxide associated with the use of gas cooking
stoves and a variety of home combustion heaters. Various studies, including
several conducted for the CPSC, have shown that the levels of nitrogen
dioxide exposure associated with the use of these appliances significantly
exceed the national ambient air quality standard (NAAQS) as well as the
short-term standard for nitrogen dioxide recommended by staff of the o.S*
Environmental Protection Agency (EPA).
On March 29, 1985, Coronission Chairman Terrence Scanlon requested the
assistance of the EPA's Congressionally established Clean Air Scientific
Advisory Comnittee (CASAC) in conducting the CPSC's review of the potential
health hazards associated-with exposure to 0.1 to 1,0 plus parts per million
(ppm) nitrogen dioxide generated by the unvented combustion sources used
in the home (see Appendix C). In this request, the CPSC requested guidance
on issues such ass
* the levels of nitrogen dioxide for which there are data
indicating adverse health effects*
• the identity of subsets of the population more sensitive
to nitrogen dioxide than others? and
» whether exposure to nitrogen dioxide leads to irreversible
lung damage.
On May 1, 1985, SPA Administrator Lee M. Thomas agreed to this
request, noting that the CASAC, which has reviewed the scientific basis
of EPA's NAAQS for nitrogen dioxide, is well qualified to address the issues
raised by the CPSC (see Appendix D), 'Staff of both agencies then developed
an interagency agreement which was signed in August 1985.
Under the provisions of this interagency agreement, the C&SAC reviewed
the CPSC documents at a public meeting on-September 26** 27, 1985, in Bethesda,
Maryland. At this meet ing, the Committee'heard presentations from CPSC
staff on exposure assessment, controlled human exposure, animal toxicology
and epidemiology relating to nitrogen dioxide, as well as conroents from
the interested public. The focus of this review was the September 1985
report of the Commission entitled Review oj_J^LbrQ^nJ3ioxide;_ Health
Effects..and_ jSxBpsure. f_r^m^Consumer jfiroducts, a six-part document discussing
health effects of nitrogen dioxide and presenting information on kerosene
heaters and unvented gas space heaters.
B. Report Format
This report has been divided into an Executive Sutonary, Introduction,
three major Sections and an Appendix. Of the three major sections, Section
3 discusses the similarities between the assessment needs of the EPA and
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the CPSC as well as the CASAC's view of its role in the CPSC review,
in particular, the Comnittee's views regarding use of information generated
by the EPA to simplify CPSC's assessment process. Section 4 contains the
conclusions and recommendations of the Committee concerning Chairman
Scanlon's three questions. Section 5 addresses additional issues that
go beyond the information requested by Chairman Scanlon. Appendix A
addresses in wore detailed fashion some of the CASAC's comments on the
documents supplied by the CPSC. Appendix B is a copy of the October 18,
1985 CASAC report to EPA detailing its findings and recommendations
concerning EPA's National Ambient Air Quality Standard for nitrogen
dioxide. Appendix C contains Chairman Scanlon's March 29 , 1985 letter
requesting the review. Appendix D presents Administrator Thomas1 May 1,
1985 response to the request. Appendix E contains full citations to the
literature referenced in this report.
3. CCmEOTS.pN THE GOALS OF THE REVIEW
During the course of its meetings on September 26-27 , the CASAC
sought to clarify the goals of the review. The Committee concluded that
it had three tasks;
• To conroent on the three questions posed by Chairman Scanlon
regarding the healtih effects of
• To assess the adequacy of the documents prepared by CPSC
staff as a basis for assessing the risks of exposure to
emissions.
» To provide guidance to CPSC regarding further efforts to assess
the risks associated with indoor use of space heaters and other
appliances producing NO2 emissions.
The questions posed by Chairman Scanlon in his letter to the SPA are
both difficult and highly relevant to CPSC concerns about the potential
health effects of kerosene space heaters. Fortunately, the EPA Criteria
Document and Staff Paper on NC>2 provide peer-reviewed information directly
relevant to these questions. We encourage CPSC staff to use these documents
as a primary resource in future efforts to assess the health risks of indoor
combustion sources.
The second and third tasks are similar to those that the CASAC ordi-
narily performs in advising EPA on the adequacy of air quality criteria
documents and staff papers. Given the availability of these EPA documents,
we believe that further CPSC efforts should focus on quantification of
the peak and average NC-2 concentrations produced in residences by unvented
combustJjDn sources and on systematic revaluation of the evidence summarized
in the EPA Criteria Document and Staff Paper with a focus on the higher
indoor NC>2 concentrations produced by unvented combustion sources relative
to the tjpical ambient concentrations of N02 implicitly addressed in the
EPA documents.
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4. MAJOR CONCLUSIONS MD RfiOCMMENDATlONS ON ISSUES POSED BY CPSC
In its evaluation of the materials provided by the CPSC, the CASAC
drew a distinction between the material on exposure assessment and the
documents reviewing the health effects literature. The Committee noted
that CPSC staff and contractors have undertaken important and innovative
work to quantify the indoor KfC>2 concentrations produced by different,
but typical uses o£ kerosene space heaters. The documents summarizing
this work provide new and important information directly relevant to
CPSC concerns. This information is central to assessing the health risk
of indoor use of these and other applicances producing N02 emissions.
Moreover, this material is unlikely to be assembled by other government
or private groups. Thus, the CASAC urges the CPSC to continue this work
and to further investigate the implications of these data for the impact
of space heaters and other indoor sources on the population distribution
of exposures to WC>2« Specifically, further efforts by CPSC staff to
assess, .t^_,h^jj±_ri^s_asspciatedrwith, indoor use of kerosene space
heaters and other sources of nitrogen dioxide emissions should focus on
efforts to quantify the nitrogen dioxide concentrations produced by
.these,.sources. We urge the CPSC to avoid duplication of EPA's effort to
develop a comprehensive review of the literature on health effects of NC>2.
The following paragraphs respond to the questions posed by CPSC
Chairman Scanlon.
* For what levels of nitrogen dioxide are there data indicating
adverse health effects?
The CASAC has concurred with EPA's reconmendation to retain the
current Annual Primary National Ambient Air Quality Standard of 0.053
ppm (Appendix B). Evidence suggests that this average annual concentra-
tion should provide adequate protection against the adverse health effects
associated with long-term exposure and protect to a lesser degree against
short-term effects related to peaking of outdoor concentrations. Among
the adverse effects related to chronic exposure in animals are a reduction
in resistance to respiratory infection, accelerated aging of the lung
manifested as a loss of elastic recoil^ f ibrotic and eKphyseiroatous-like
structural changes in the lung, and impairment of function.
The lowest concentrations) associated with acute adverse health
effects can be expressed in a range of estimates. Preliminary epideraiologic
findings and related indoor air pollution monitoring studies assessing the
variation of NQ2 levels in gas stove homes suggest that repeated peaks in
the range of 0.15 to 0.30 ppm may be of concern for children (USEPA, 1982).
The limited number of controlled laboratory studies on human subjects,
both healthy and with underlying lung disease, have produced conflicting
results. For example, increased bronchial reactivity to a provocative
aerosol has been reported after exposure to 0.1 ppm NC>2 in asthmatics
{Orehek et al,f 1976). This finding was not confirmed in a second study
at the same concentration involving asthmatics and healthy subjects
(Bazucha et al., 1983), while a third study found a "...variable
effect..." on bronchial reactivity (Ahmed et al., 1982). The effect
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of 0.2 ppm NC>2 on bronchial reactivity in asthmatics has been equivocal
{Kleinman et al*, 1983). Although both bronchoconstriction (Bauer et al.,
1984; Rogers et al., 1985) and increased airway reactivity (Bauer et al,f
1984) were found in response to 0,3 ppti NQ2, another study could find
little or no effects at 4.0 ppm (Linn et al., in press). Therefore, the
data base remains too sparse and the between-studies variance too great to
project definitive dose-response relationships and complicates the task of
identifying "safe levels" for the general population. Moreover, the
mechanisms underlying these effects, and consequently their potential for
contributing to chronic lung damage, are unknown. Such information may
be vital in judging which effects are adverse, but much of this latest
generation of studies has not yet appeared in the peer reviewed literature.
Nonetheless, this preliminary evidence suggests that repeated peak exposures
at concentrations of 0.3 ppm of N02 may cause health effects in sews indi-
viduals and raises the possibility that such effects may occur at concentra-
tions as low as 0,1 ppm, encouraging a cautionary approach in matters of
pol icy.
As discussed in Appendix A, both the epidemic-logic studies of children
exposed to gas stove emissions and the controlled exposure studies of
adults exposed to NOj have reported inconsistent findings regarding the
health effects of these exposures. Such large uncertainties in clinical
and epidemiological data are troubling to policy makers but are a reality
in interpreting the currently available evidence on the health effects
of NQ2-
* Which subsets of ,_j^e_j»gul_atipnTi_are TOS^^^nsitiye^to^Aitycgen
dioxide?
The EPA Staff Paper on NC»2 states that:
».,the groups that appear to be most sensitive to exposures
to NC>2 include children, chronic bronchitics, asthmatics,
and individuals with emphysema....Health effects data from
epideraiological studies in gas stove homes suggest that young
children are at increased risk of respiratory symptoms and
infection from exposures to elevated concentrations of
NOj Other groups at risk to NOj exposures are asthmatics
and bronchitics. Human clinical study data have provided
evidence that sane of these individuals suffer mild sympto-
matic effects {nasal discharge, headaches, dizziness, and
labored breathing) after light to moderate exercise during
an exposure to 0.5 ppm NO2 for two hours.1
CASAC concurs with this statement.
Review of the National Ambient Air Quality Standards for Nitrogen Oxides:
Assessment of the Scientific and Technical Information. U.S. EPA, Office
of Air Quality Planning and Standards, Research Triangle Park, NC,
EPA 450/5-82-002, Page 41, August 1982.
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• Does exposure to nitrogen dioxide lead to irreversible lung damage?
As noted in Appendix A, controlled exposure studies provide little
information about this question. Human epidemiologic studies suggest
that exposure to_nitrogen dioxide may lead to^j^reas^ respiratory
illness rates among children. Although a history of respiratory illness
in childhood may be predictive of respiratory disorders in adult life,
relatively little is knewn about this relationship at the present time.
Thus, the irost direct evidence regarding lung damage resulting from
exposure to nitrogen dioxide is obtained from animal studies. These
studies are reviewed in EPA's Criteria Document and Staff Paper. The
Staff Paper provides the following summary of this complex and extensive
data base:
In critically assessing animal studies involving short-term
exposure to N02, it is obvious that numerous effects have
been observed for a variety of animal species (dogs, rabbits,
guinea pigs, monkeys, rats, and mice.). There is presently
no reliable way to relate human and animal dose-response
data. Many of the effects associated with short-term ex-
posures appear to result not from a single exposure, but
from multiple exposures in the range of 0.2 ppm to 0.5 ppm
for several hours. Of particular interest is that exposure
of animals to concentrations slightly above those currently
being experienced in the ambient air appears to cause a
decrease in resistance to bacterial infection,... this
same type of effect has also been reported to occur in
huraans, ,
,.. effects which have been associated with animals exposed
to NC>2 over relatively long periods (1 day to several years)
... includet (1) significantly increased susceptibility
to infection resulting in increased mortality for continuous
and intermittent exposure to > 0.5 ppm NQ2; (2) decreased
immunologieal response resulting in increased respiratory
infection for exposures of 0.5^1.0 ppm NOj, continuous and
intermittent? (3) increased lung protein content suggesting
edema and cell death for 3-6 week exposures to 0.5 or 1*0
ppm NOj in Vitamin C deficient animals; (4) hematological
disturbances (e.g. increased cholinesterase lysozyme levels)
suggestive of liver and heart damage at 0,5 ppm N02 f°r 1
week; (5) increased EBC 2,3-diphosphoglycerate, indicating
tissue deoxygenation after 1 week exposure to 0.36 ppm
N02; (6) eraphysematous alterations resulting from a six
month exposure to 0,1 ppm M32 with daily spikes of 1.0 ppm
N02 or 68 months exposure to 0.64 ppm NQ2 an<3 °*25 PP* NO
followed by a 2 year period in clean air.
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A critical assessment of the available animal toxioo-
logical data for long-term exposure to NC>2 reveals that
many of the above effects occur in a variety of animal
species, and that many of the effects can be considered
serious and irreversible. For exanple, the eraphysematous
alterations in dogs associated with long-term exposure to
Nt>2 are of major concern since the occurrence of this
type of effect in humans would clearly be adverse.
While most of the chronic studies were conducted at
exposures considerably higher than those encountered in
the atnbient air, it should be noted that one study did
observe epphysematous alterations in mice when exposed to
N02 levels about twice the current annual standard. However,
in this study, the chronic exposure was supplemented with
daily spikes of 1.0 ppn and it is not possible to determine
if the cause of the effect was chronic exposurer short-term
spikes or a combination of these two.
Currently there is no means available to extrapolate
the results of the animal studies (either short-term or
chronic) directly to humans. Nevertheless, the animal
toxicology studies do indicate that N02 exposure causes
serious biological damage to a number of animals. These
studies clearly raise a "warning flag" for potential
effects in humans.^
Thus, whilethe animal studies do provide evidence that both short-
term and long~term exposureto nitrogen dioxide can lead to irreversible
health effects in a variety of animal speciesf it is difficult at the
present tame to determine whether these effects are of concern at con-
centrations associated with use of kerosene heaters/ gas stoves, or other
indoor sources of N02-
5. ADDITIONAL ISSUES
The documents summarizing the evidence regarding the health effects
of NC>2 exposure correctly identify many of the inportant issues and
studies, but the Comnittee believes that the materials have some important
deficiencies. In particular, we note that the various documents have not
been integrated, and we also have numerous questions about the studies
chosen for emphasis and about the interpretation of some of the evidence.
An informal compilation of CftSAC's comments regarding the CPSC's review
of the health effects literature is included as Appendix A*
2 Keview of the National Ambient Air Quality Standards for Nitrogen Oxides:
Assessment of the Scientific and Technical Information. U.S. EPA, 'Office
of Air Quality Planning and Standards, Research Triangle Park, Nt,
EPA 450/5-82-002, Pages 10-11, August 1982.
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The EPA's experience in. preparing Criteria Documents and Staff Papers
for the periodic assessment of criteria pollutants has shown that prepara-
tion of such reviews is enormously difficult and time consuming. Moreover,.
SPA staff routinely submit several revisions of each of these documents
to CASAC in their efforts to develop a consensus on the relevant literature
and its triplications. In our view, the CP9C materials are conparable to
the first draft of such integrated documents. From that perspective, the
documents could provide a basis for developing an integrated review of the
relevant literature. Given the effort involved in developing an integrated
risk assessment, however, the Conmlttee uzxjes CPSC not to duplicate the
resource-consuming effort required of the EPA in its periodic assessment
o€ the health effects of NQ2« ttether> CPSC should make extensive use
of the EPA Criteria Document and^ Staff Paper on Nitrogen Dioxide in its
assessment of the health risks associated with indoor sources of nitrogen
dioxide* In particular, the CPSC sj^ld^tjljgeJpPV.s_Staff_ Paper to the
extent practicable. Every effort should be made to avoid duplication of
reviews of the health effects literature carried out by EPA and reviewed
by CASAC under the requirements of the Clean Air Act.
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WPENDIX A
Document Review - More Detailed Coraraents
*
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*
DQCtWENT JREVIljW
The CPSC provided the following six documents to the Committee as
background for the review:
* Update on Health Effects Associated with N02
* Health Effects of Nitrogen Dioxide
* Status Report on Kerosene Heaters (includes updates Health
Effects of N02? Nitrogen Dioxide Health Assessment 1984}
* Status Report: Pollutants Generated by Unvested Gas
Space Heaters
* Kerosene Heater Emissions: Estimation of Exposure
* Indoor Air Quality Kerosene Heater Testing Documentation
A. Overall Comments
Because these documents were prepared at different tiroes by various
authors for different CPSC purposes, they were sometimes repetitive and
not well integrated, An introduction for the documents presented by CPSC
delineating the purpose of the review would have been helpful. In addition,
the CASAC's decision not to recouraend a short term standard for ambient
NOj concentrations in its review for EPA should not be interpreted as
implying that no adverse effects are associated with the higher concen-
trations produced by indoor sources. Thus, an introduction discussing
the potentially high M02 concentrations caused;by space heaters and other
sources and the need to re-evaluate the health effects literature with
these concentrations in mind would have provided a sharper focus for the
assessment.
The CPSC should consider organizing the material according to major
topics and issues. This has already - and conroendably -* been done in part,
i.e., Biochemistry, Pulmonary Functional Effects, and Extra Pulmonary
Effects. In dealing with any category of effects, emphasis should be
given to what is known about the mechanisms of the effect - this being a
particularly valuable contribution of animal and in vitro toxicology - and
whether similar mechanisms have been demonstrated or are plausible in humans*
An faportant way of organizing and classifying effects is by duration, i.e.,
acute and chronic. Virtually the only e;xplieit information available on
the chronic effects of NC>2 (short of industrial accidents affecting indi-
vidual workers) results from animal studies.
The CPSC should atteirpt to define the actual exposure levels of the
indoor environment and to focus the discussion of health effects on those
levels, insofar as possible. This effort should include any information
on the frequency of occurance of such levels as well as the relationship
between pollutant level and averaging time. Such an approach would help
distinguish this document from the EPA documents which were concerned
with outdoor effects.
There is a tendancy in the CPSC documents to overstate findings
which may actually be more attributable to chance and which are not really
statistically significant. Normal variation is a reasonable expectation,
A-l
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but 'wore caution is needed in interpreting statistical significance* The
Committee was advised by the CPSC that their normal practice Is to state
when a finding is not statistically significant and may have been attrib-
utable bo change and that caveats have been added when necessary.
For animal toxicology studies, the GASAC recognizes that one of the
major problems, beyond the issue of whether or not the animal's health is
adversely affected, is how to extrapolate animal data to humans. Relative
dosing is one of the major issues in these extrapolations* This document .
need not exhaustively review dosimetry, but giving some perspective
relative to the problems with animal studies would be helpful.
B, Exposure
Nitrogen dioxide is produced by a variety of combustion sources
within the home, including space heaters and gas stoves. Although the
CPSC document carefully describes a limited number of studies concerning
emissions from certain space heater devices, additional discussion is
needed of the relative N02 contribution of these devices compared to gas
stoves.
The current protocols used by the CP9C to characterize emissions from
space heaters are carefully conceived and well executed. Their approach
focuses on the contributions to steady state levels represented by a 4 to
6-hour average concentration* The extrapolation of this information on
steady state levels in confined spaces to actual homes is obviously wore
difficult. To the extent that additional information on the potential
for shorter term (one-hour) peaks and their spatial distribution within
the home can be generated from current data, this information would be
very useful.
The chamber studies ;and modeling work carried out by CP3C and its
contractors have been informative. In particular, these studies have
identified a range of steady state concentrations associated with contin-
uous operation of space heaters in chambers, and have characterized the
•relative emission rates of white and blue flame heaters, as well as the
reductions in emissions achieved by catalytic converters and dual chamber
designs. Such modeling activities are insufficient, however, to charac-
terize distribution and temporal pattern of concentrations experienced
by persons using.space heaters in their homes. Factors that could affect
the distribution of exposure include model preferences, age of heating
units, mode of operation, and hero characteristics. Given the potential
health and regulatory significance of issues concerning kerosene space
heaters, additional direct resasurements of indoor'concentrations are
urgently needed. Such data should ideally be gathered in the context of
a well designed sampling'frame, with attention to temporal and home-to-home
variability and to such covariates as wind speed and indoor and outdoor
temperature. Given the paucity of direct measurement data available, a
well-defined set of measurements in 50 to 100 homes, for example, would
be of great value. If the CPSC is unable to undertake such a study,
A-2
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interested scientific and industry groups should be encouraged to collect
NOj measurements in homes, using kerosene heaters. To the extent that
long-tern exposures of NC>2 are relevant to health, the present passive
collector technology can be directly applied to this large home to home
survey. If short-term (less than 6-hour) peak concentrations are more
relevant, then the passive sanpler technology must be supplemented with
continuous M>2 analyzers.
C. Animal Studies
The section on .in vitro and animal toxicology is concise, and, for
the most part, clearly stated. However, at times it is too selective
and superficial in its atbenpt to reduce some complex problems to siaple
judgments.
If the CPSC chooses to rewrite the document, it should consider
organizing the material more effectively. Effects might be organized
under Pulmonary (biochemical, functional, innwnological, resistance to
infection, morphological), and Extra-pulmonary. Wherever possible, the
document should distinguish between acute, subacute and chronic effects.
Virtually the only eitpirical information available on the subacute and
chronic effects of N02 (short of occupational accidents) comes from
animal studies and, thus, this information is particularly important,
A topic not treated anywhere in the document is the uptake of NC>2
within the respiratory system, an issue which has implications for regional
dose and for identifying target tissues. N02 uptake has been measured in
some animal species; it has also been modeled in a preliminary way for
the human lung. A critical issue in any atbenpt to extrapolate from
animals to humans is the extent to which, for a specified ambient concen-
tration, both total dose (corrected for differences in size) and regional
dose are comparable across species.
An important issue that warrants separate, integrated treatment is
a discussion of factors influencing susceptibility. These might include
age, sex, nutritional status, and any anitnal models of underlying lung
disease or extrapulmonary disease that nay have been tested. This is
another area of research in which animal toxicology can contribute signif-
icantly to insight into human risk. Whatever information is available
on mechanisms of effect should also be added.
Summary tables for all three sections (animal, clinical, epidentiol-
ogical) providing details on selected critical studies are useful and
could tae organized to show effects as functions of increasing concentrations
(separate tables for acute and 'chronic exposures). Such tables could also
include whatever information is available on the reversibility of effects.
The animal toxicology discussion includes a variety of biochemical
changes that occur in response to single or repeated exposures to NC>2» In
general, these changes are reversible; even dead epithelial cells may be
replaced through regenerative processes. However, some of the changes may
A-3
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become part of a process that culminates in irreversible tissue damage
and deformity. This process may be sustained if the exposure to NC>2 is
sufficiently protracted or severe, if other forms of environmental stress
are also present, or if the defensive and reparative responses of the body
are conproroised. The studies of Gillespie and co-workers suggest that
the evolution of changes that are "emphysema tous-1 Ike'1 in character may
continue even after cessation of exposure to NOj; howeverf this work has
defects in esqaeriroental design and should be redesigned. Hew reversible
the effect of N02 may be following protracted exposure must be determined
empirically by allowing the animals to survive after ending the exposure,
data of this sort are presently scarce.
D» Controlled Human Exposure
This section of the CPSC Report gives a useful review of the key
scientific literature. The Committee identified no substantial errors or
omissions in this material. Nevertheless, a reader wishing to conpare
and contrast the various studies needs a tabular summary similar to Tables
2 and 6 in the EPA Staff Paper on Nitrogen Dioxide (USEPA, 1982).
Committee members offered many suggestions for changes in content,
enphasis, or language. The specific comments below highlight some issues
about responsiveness of population sub-groups, .'interpretation of pulmonary
function meas«rem0ntst and interpretation of conflicting results from
different controlled human exposure studies. '.
Specific Suggestions?
Coiments in the CPSC document that inply definitive knowledge about
the relative N02 responsiveness of population sub-groups who have lung
disease should be revised (see pages 19 and 20)3. Because, available
results are conflicting, they should be cautiously interpreted and
statements about them referenced whenever possible.
The discussion of confounding issues that arise in the interpretation
of pulmonary function measurements (see page 20)3 should be changed to
indicate! 1) that intra-subject variability in clinical studies is mitigated
by using repeated measures with subjects serving as their own control,
2) that with due care, subjects with decreased lung function reserve from
respiratory disease can and are being studied to collect evidence about
how their responsiveness to N02 exposure varies with disease severity, and
3) that the use of the term "significance" has statistical support? if not,
another word should be used.
As pointed out in the CPSC document (see page 21) ,3 results of the
presently available studies on N02 effects are inconsistent. The CPSC
should expand its discussion of the reasons for Such inconsistency to include
3 Page references are to the CPSC Report Update on Health Effects Associated
with Nitrogen Dioxide, 1985 by Lori Saltzman
A-4
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other factors that are also likely (if not wore likely) for this
development - such as differences in exposure methods as well as differ-
ences in subject populations* For example, the "positive" studies
have probably involved more sensitive asthmatics than the "negative"
studies, but judging this will be very difficult until detailed results
have been released and critically reviewed-
Prom short-term (1-hour) controlled studies of adults, one could es-
timate the lowest-observable-effect level to be below 0.2 ppm at one
extreme, or above 4.0 ppm at the other extreme depending on the response
being tested. This large discrepancy between different findings is trou-
bling to scientists as well as to policymakers* With ozone ancl sulfur
dioxide, the discrepancies between different studies and different
laboratories are much smaller. However, two recent reports (Bauer et al.,
1984; Rogers et al., 1985) have observed changes in lung function in
exercising asthmatics exposed to 0.3 ppm N02* Despite the failure of
other studies to demonstrate such changes, these levels may provoke
responses in some asthmatic individuals. There is no good explanation
for the widely divergent results on NQ2- •:
The controlled human studies which have suggested unfavorable effects
at lew concentrations (0,2 - 0,3 ppm or even Icwer) all have employed
adult asthmatics. Asthmatics thus are the best candidates for the "more
sensitive" designation. However, other studies have concluded that many
mild asthmatics experience a detectable effect at concentrations an order
of magnitude higher. This has led to the suggestion (not explicitly
tested as yet) that N02 sensitivity is correlated with an index of severity
of asthma, perhaps the degree of airway obstruction or baseline airway
hjperreactivity.
The demonstration of unfavorable short-term reversible effects is
sometimes thought to imply a possible risk of long-term irreversible
effects, but any direct relationship between short-and long-term effects
remains unclear* As indicated above, even short-term effects have not
been demonstrabed unequivocally for WQ2*
E. Epidemiology
The most relevant studies for the CPSC's needs are the British and
U.S. studies of the health status of children and adults living in
homes where gas is used for cooking or heating. The CPSC review document
is an accurate evaluation of these studies. The Staff Paper (USEPA, 1982)
represents a more extensive evaluation of all N02-related epidemic logic
studies, with conclusions that are consistent with the CPSC evaluation.
In brief, the extensive information available is suggestive but not
conclusive that unvented :gas combustion devices in heroes are associated
with slight excesses of respiratory illnesses, especially in children.
The inconsistent findings among investigators and among different studies
by the same investigators, seme of which are eonparisons of cross-sectional
A-5
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and longitudinal observations, suggest that the many confounding factors
which inevitably occur have not been adequately accounted for (andr in
some instances possibly "over-corrected").
It is evident that use of gas for cooking or heating is not a risk
factor of great magnitude In conparison with a factor such as cigarette
smoking. It is also not certain that N02 is the causal factor for whatever
risk may be associated with gas stoves or heaters. Unfortunately the
majority of epidemiologic studies include no information on NO2» and
among those that do have actual measurements, the number of homes and
characterization of concentrations are very limited* This suggests that
better
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APPENDIX B
--^- Closure
.. .
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NEW YORK UNIVERSITY MEDICAL CENTER
A private university in the public service
Institute of Environmental Medicine
550 FIRST AVINUl, NEW YORK, N.Y, 1001$
AREA 212 J«-?300» EM, 8*5-
ANTHONY j. LANZA RESEARCH LABORATORIES AT UNIVERSITY VALLEY
iONC MEADOW ftOAD, STERUNC FOREST, TUX£00, N.Y, 10§87
MAIL AND TiLfiPHONi ADDRESS: 550 F1S5T AVINUE, NEW YORK, N.Y. 10015
October IS, 1984
Honorable William RacJcelshaus
Administrator
U.S. Environmental Protection Agency
401 M Street, S*W*
Washington, DC 2Q46Q
Dear Mr* Ruckelshaus:
On July 19-20, 19S4, the Clean Mr scientific advisory Committee
(caSAC) met to consider the Agency's proposal regarding revisions to
the National Mdbient Mr Quality Standards (NAAQS) for Nitrogen Dioxide.
Included in this proposal-is the reaffirmation'of the existing annual
average standards for nitrogen dioxide at 0*053 ppm (100 ttg/m ), and
solicitation of public comments on both the need to set a separate
short«term standard and -the need to use an alternative form of the
standard (statistical instead of deterministic)* The Committee has
prepared this closure letter to advise you of its major conclusions
and recommendations concerning the scientific and technical aspects of
these and other issues associated with 'the Agency's proposal for the
revision of the NM.QS for'nitrogen dioxide. :
previous' -closure letters dated June 19, 1981 and July 6;
1982, respectively, the CASAC advised, that the 'revised Air Quality
Criteria Document for Nitrogen Oxides was scientifically adequate for
standard setting and that the office of Air Quality Planning and
Standards (QAQPS) Staff Paper represented a balanced and thorough
interpretation of the scientific evidence contained in the criteria
document* The Committee has reviewed relevant research which has been.
published since those docuicents were prepared , and concludes that the
scientific conclusions reached in those doeKaents are still satisfactory.
The CASAC has concluded that the existing1 annual average primary
standard for nitrogen dioxide adequately protects against adverse health
effects associated with long-term exposure and. provides some neasure of
protection against short-term health effects* Therefore, the Committee:
concurs with the Agency's- recommendation to retain the cijrrent annual
average primary standard of 0*053 ppm. The Committee farther concludes
that, while short-tern effects frcpt nitrogen dioxide are documented in
the scientific literature, the available information was insufficient
.SESQUl'* : &~1
•CENTEN:
'MfliSi;;
OLE:
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to provide an adequate scientific basis for establishing any specific
short-term standard, or for determining an acceptable number of
exceedances, a concentration limit, and an averaging time for such a
standard. Indeed, the scientific basis for set-ting a separate short-term
standard appears to be less firm than it was ait the time of the Committee's
previous review. We recommend that the Agency vigorously pursue a research
program designed to address and resolve the issues related to short-tera
effects of nitrogen, dioxide.
The Committee reaffirms its conclusion from two years ago that a
secondary standard set at a level equivalent to the annual primary standard
would -offer sufficient protraction against the identified welfare effects of
nitrogen dioxide. ' '.
Members of the Cemmittee who held 4 view on the issue of the form of
the standard favored retaining the present deterministic form, rather than
adopting a statistical form for the annual standard.
R. more extended analysis of the factors leading to the Cosmittee's
recommendations is contained in the enclosed report. Thank you for the
opportunity to present the Committee1s views on this important public
health issue*
Sincerely,
Morton Lippiaaxm, Ph.D.
Chairmant Clean Air scientific
Advisory Conmitfcee > •
Enclosure
cc: Mr. Alvin Aim
Mr. Joseph Cannon
Dr» Bernard Goldstein
Dr. Terry
B-2
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Findings and Recommendations oa the Scientific Basis for
a Revised NM.QS for Nitrogen Dioxide
by the
Agency 'staff presented for CASAC review and comment three options
the Agency could pursue in concluding its current review of the
for nitrogen dioxide. These are as follows:
1* Reaffirm the an.iiu.al standard at the current level and propose
a ghort-term standard , or
2» leaf firm the annual standard at the current level and conclude
that a short-term standard is not needed r or
3* Reaffirm the annual standard at the current level, defer a
decision on a short-term standard , and perform high priority
research on short-term effects 'of nitrogen dioxide*
Based OH the Committee's review of the scientific issues associated
with the reaffirmation of the annual standard and the possible short-term
standard as discussed below, the Committee believes t 1) that there is an
Insufficient scientific basis for action on option 1; and, 2} that options
£ and 3 are functionally equivalent, i.e. a vigorous program of research
j,nto the short-term effects, of nitrogen dioxide is needed and can be
accflaplished " under either option.
5cientifi.c_Is_sues^_in .Revising the Standards
In C&SAC's closure letter of July 6, 1982, the Coaxnittee discussed-
review of the nitrogen oxides staff paper, noting that no single
provided the scientific basis for a decision on revising the -primary
ptjanciard for nitrogen dioxide* Kather, it could be based on a "-weight;
of .evidence™ approach, using animal studies, controlled human exposure
and epidemiology studies to provide both quantitative (i.e.
t:) and qualitative (mechanistic ) support for such a decision.
gince that time new studies have been completed and, along with previously
'discussed studies, form the basis for the Committee's conclusions and
recommendations concerning the critical issues associated with reaffirming
the annual standard and evaluating a short-term standard for nitrogen
dioxide.
1. Animal Toxicology Studies.
The results from recent animal studies provide further substantiation
' of the effects of nitrogen dioxide exposure on immune functions and increased
susceptibility to infection. Seme of these studies also examine patterns
of exposure to nitrogen dioxide that are closer simulations of what may be
•actually occurring in, for example, gas stove homes* An example of this
B-3
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-2*
is superimposing repeated short-term higher levels of exposure to nitrogen
dioxide (e-f* 0.4 to 5.0 ppn, or more) on relatively low background levels
of nitrogen dioxi<3e, such as found in gas stove homes •
2* Controlled Human Exposure Studies-
The more recent controlled human exposure studies (mostly unpublished)
present rather mixed and often contradictory results concerning respiratory
effects in asthmatic and normal subjects exposed -to concentrations in the
range of 0.1 to 4.0 ppta nitrogen dioxide. Kagawa and $suru {1979} reported
results possibly suggestive of short-term nitrogen dioxide effects on
pulmonary function in normal subjects without combined provocative challenge
by other agents {Such as carbmchol) * Although they reported no significant
differences for mean pulmonary function changes for a group of six subjects
exposed to 0*15 ppm nitrogen dioxidet there were small significant decreases
in airway conductance in three of the six subjects* However, the smallness
of these decrements and questions regarding the statistical analyses used
suggest caution in accepting the reported findings as demonstrating
nitrogen dioxide effects on pulmonary function1at Q.1S ppm. More recently,
Bauer et al, (1384 - abstract) exposed asthmatics to 0,3 ppm nitrogen
dioxide and observed effects on both pulmonary function after exercise
and airway reactivity following cold air challenge.
3* Epidsiiologieal Studies*
The most recent epidemiclogical studies indicate less conclusive
findi-gs of an association between,nitrogen dioxide and respiratory
effects than previously•reported. The first report of the Harvard six
cities Study* published several years ago/ noted one positive result —
an association between both lung function changes and respiratory ill-
nesses in children under age two and exposure to gas stoves — among a
number of associated variables* More recent analyses, published in
Ferris et al, (1983) and Ware et al, (1984) made adjustment for the
socio-economic status of the children under age two and reported that
the association between their living in homes with gas stoves and their
incidence of respiratory illness is no longer statistically significant*
Prom these results, as well as those reported by other investigators
studying people living in hopes with gas stoves, CAS&C concludes that
the scientific evidence supporting an association between living in
homes with gas stoves and increases in respiratory illnesses and symptoms
is insufficient to support specific limits for: either short-term or
long-term standards for nitrogen dioxide.
Annual Standards
1« Primary Standard.
•She C&SAC reviewed the results of animal, controlled human exposure,
and epideaiological studies to determine if such evidence provided a scien-
tific basis for retention of the annual standard and scientific support
B-4
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-3-
for establishment of a short-term standard. The most serious effects
associated with nitrogen dioxide exposures that are reported in the
scientific literature result from animal studies conducted at concentra-
tions well above those permitted by the current annual standard. Although
there are large uncertainties in extrapolating these results directly to ,
humans, the seriousness of these effects coupled with the biological
similarities between animals and humans suggests that there is risk to
human health from long-term exposure to nitrogen dioxide. This set of
factors, widely accepted within the scientific community, leads the
Committee to conclude that there is a continuing need for a long-term
nitrogen dioxide standard.
The results from recent studies showing some evidence of detectable
health effects due to short-term nitrogen dioxide exposures do not provide
sufficient evidence to develop a concentration level, an averaging time, or
a number of exceedences for a'short-term standard* For example, the gas
stove studies were originally used in support of the rationale for a short-
term standard; however, recent reassessments by the authors of these studies
led them to reduce the level of statistical significance of their reported
results. Moreover, the results of the recent clinical studies have been
inconsistent. As a result, the overall scientific support for a short-term
standard Is more equivocal than previously thought.' If the CASAC were to
make a recommendation favoring a short-term standard, the Committee would
also have to take Into account the need to determine the number of allowable
exceedances, the establishment of a concentration level, and the identifi-
cation of an averaging time. At the present time, the Committee is unable
to nake such recommendations due to the absence of a sufficient body of
Information on such factors.
2. Secondary Standard.
i
The CASAC has not identified any further information to change its
conclusion from two years ago that a.secondary standard set equivalent to
the annual primary standard would offer sufficient protection against the
identified welfare effects of- exposures to nitrogen, dioxide. Although the
Issue of visibility impairment was raised, several members noted that,
given the present state of knowledge, It is difficult to identify the
degree to which nitrogen dioxide concentrations may contribute to this
phenomenon. The Agency Indicated that further work on this complex, multi-
pollutant issue has been assigned a high priority in relation to the task
force on visibility and that the issue will be addressed further at subsequent
CASAC meetings. The Committee Is looking forward to reviewing the results of
the Agency's progress on this important issue*
Form_of the Standard
The Committee did not reach a consensus on" the desirability of
changing the form of the standard from the present deterministic form
to a statistical form which uses the available arithmetic averages from
B-5
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.4-
the last three—years to determine ccaplianee* Although jnostt members of
the Cofflftittee took no position, one member suggested that there Is a
stronger argument for a statistical approach to1short-term standards than
for annual standards. Two others favored the retention of the current
deterministic form for the' annual standard•
ResearchT Efforts
The C&.S&C ws encouraged to learn that the Agency is currently
pursuing research which addresses some of the issues raised in our December
30, 1983 report to you on Besearch Needed to Support the Development of
NAAQS. We look forward to, continued reports from the Agency on the pro-
gress of this important research. The Committee feels compelled to
reiterate that witheat an adequately funded research jsrograia aimed at
assessing the significance" of the health effects associated with short-term
nitrogsn dioxide exposures, the Agency cannot make scientifically informed
decisions concerning the need for a short-term standard, its coneen.trat.ioa
level, averaging tine or an acceptable nuafcer of exceedances*
S-omnary of C&.S&C Recoimendatioias
For the reasons stated* the Committee recommends that you. reaffirm
the annual standard at the current level, and that you defer a decision
on the short-term standard' while p«rS"«i»g an aggressive research program
on short-term effects of nitrogen dioxide*
B-6
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APPENDIX C
Letter £rcm CPSC Coiroiss loner Scanlon
: March 2.9, 1985
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UNITED STATES
CONSUMER PRODUCT SAFETY COMMISSION
WASHINGTON, D.C, 20207
*
The Chairman
March 29, 1985
Honorable Les M. Thomis
Administrator
U.S. Environmental Protection Agency
401 H Street S.W.
Washington, DC E046Q
Dear Mr. Thomas:
I am requesting the assistance of the Environmental Protection
Agency's Clean Air Science Advisory Committee (CASAC) in our review of
the potential health hazards associated with exposure to 0.1 to 1.0 plus
ppm nitrogen dioxide generated by the unvtnted combustion sources used
in the home.
The Commission has been conctrned about consumer exposure to
nitrogen dioxide associated with the use of gas cooking stoves and a
variety of combustion home heaters. Various studies, including several
conducted for the CPSC, have shown that the levels of nitrogen dioxide
exposure associattd, with the use of these appliances significantly
exceed the ambient air standard as will as the short term standard
previously recommended by the EPA staff.
Various gas stove and combustion heater industry representatives
have indicated a willingness to modify their product in order to reduce
consumer exposure to nitrogen dioxide but there remains some
disagreement as to what the target level should be. In an effort to
expedite this process, 1 believe that the. CASAC, since it has recently
reviewed the dati on NQ_f could- give the Conmisslon guidance on
questions such as:
-the levels of nitrogen dioxide for which there are data indicating
adverse health effects;
-the identity of subsets of the population more sensitive to
nitrogen dioxide than others; and
-whether exposure to nitrogen dioxide leads to irreversible lung
"damage.
c-i
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Please advise me es to the feasibility of obtaining such
assistance, and, if it is feasible, the process for obtaining CASAC
review. Thank you for your assistance in this matter.
Sincerely yours,
•f
Terrenes Scan Ion
Chairman
C I
D^^^
C-2
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APPENDIX D
LgtterJErqm EPA Administrator Lee Thomas
May 1, 1985
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UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
\^~^f WASHINGTON. D-C. 20460
MftY 11385
TH£ ADMINISTRATOR
Honorable Terrence Scanlon
Chairman
U. S. Consumer Product Safety
Commission
Washington, D. C. 20207
Dear Mr. Scanlon:
Thank you for your March 29 letter in which you request the
assistance of EPA's Cleafc. Air Scientific Advisory Committee (CASAC) in
evaluating consumer exposures to nitrogen dioxide associated with the
use of gas cooking stoves and a variety of combustion hone heaters.
The Committee, which has reviewed the scientific basis of EPA*s National
Ambient Air Quality Standard for Iltrogen Dioxide, Is well qualified to
address the Issues identified in your letter, and I support your request
to solicit its scientific advice. I know that the CASAC Chairman,
Dr. Morton Llppmann of New York University, would also be willing to
assemble his "panel to undertake this review,
I suggest that your staff coordinate the preparation for the CASAC
sseetlng with Dr. Terry F. Yosie, Director of EPA*s Science Advisory Board,
(382-4126) and Mr, Bruce Jordan of IPA's Office of Air Quality Planning
and Standards (919) 541-5655. Two specific requests that I have of the
Commission staff Is to work closely with Dr« Yosie and Mr« Jordan in
preparing the scientific tuaterlals to submit to CASAC, and to provide
budgetary support to defray the cost of the meeting* I estimate that
the costs of the review will approximate $15,000 - $20,000.
Thank you for your Interest in working with the Agency on this
important public health Issue.
^Sincerely,
Lee M. Thomas
Administrator
D-l
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APPENDIX E
Literature Cited
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LITERATURE CITED
Ahmed, T., B. Marehette, I. Danta, S. Birch, R.L. Dougherty, R. Schreck
and M.A. Sackner. 1982. Effect of 0.1 ppm NQ2 °n bronchial reactivity
in norrnals and subjects with bronchial asthma. Am. Rev. Respir. Dis.r
125:A152 (abstract).
Bauer, M.A., M.J. Utell, P.E. Morrow, D.M, Speers and F.R. Gibb. 1984.
0.30 ppm nitrogen dioxide inhalation potentiates exercise-induced
bronchospasm in asthmatics. Am. Rev* Respir. Dis., 129;A151
(abstract),
Hazucha, M.J., J»F. Ginsberg, W.F. McDonnell* E.D. Haak, R.L. Pjimiel,
S.A. Salaam, O.E, House and P.A. Broraberg. 1983. Effects of 0.1 ppm
nitrogen dioxide on airway of normal and asthmatic subjects. J* Appl.
Physlol., 54s730-739:,
Kleinroan, M.T., R.M. Bailey, W,S. Linn, K.R. Anderson, J.D. Whynot, D.A.
Shamoo, and J.D. Hackney, 1983. Effects of 0.2 ppm nitrogen dioxide
on pulmonary function and response to bronchoprovocation in asthmatics.
J, Tox. Env. Health, 12;815-826.
Linn, W.S., J.C. Solomon, S.C. Trim, C.E. Spierf D.A. Shamoo, T.G. Venet,
E.L. Aroi and J.D. Hackney. 1986. Effects of Exposure to 4 ppm nitrogen
dioxide in healthy and asthmatic volunteers. Arch. Environ. Health.
(In press).
Orehek, J-f J.P. Massari, P. Gayrard, C. Griroaud and J. Charpin, 1976.
Effect of short-term low^level nitrogen dioxide exposure on bronchial
sensitivity of asthmatic patients, J. Clin, Invest., 57s301-307.
Rogers, L.J., D.H. Horstman, W.F, McDonnel, H. Kherl, E. Seal, R.S. Chapman,
and E.J. Massaro. 1985. Pulmonary effects in asthmatics exposed to
0.3 ppti nitrogen dioxide during repeated exercise. Toxicologist, _5:70
(abstract).
TJSEPA, 1982. Review of ;the National Ambient Air Quality Standards for
Nitrogen Oxides? Assessment of Scientific and Technical Information*
U.S. EPA, Office of Air Quality Planning and Standards (QAQPS),
Research Triangle Park, NC, EPA-450/5-82-002, August 1982.
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