United States Of flea of th* Administrator EPA-SAB-CASAC-89-0 19 Environmental prediction 5cl«nc« Advisory Board May 1983 Agency ' Washington, DC 204SO Report of the Clean Air Scientific Advisory Committee (CASAC) Review of the NAAQS for Ozone: Closure on the OAQPS Staff Paper (1988) and the Criteria Document Supplement (1988) ------- ABSTRACT This Is tha report of the EPA'a Clean Air Scientific Advisory Committee (CASAC) on its review of Agency's draft "Air Quality Criteria Document Supplement (1988)" and the "Review of National Ambient Air Quality Standards for Ozone: Assessment of Scientific Technical Information (198S)11. documents were reviewed in public session on 14-15, 1988, with the Committee reaching the conclusion that the provide an adequate scientific and technical basis for EPA to retain or revise primary secondary national ambient air quality standards for ozone. ------- NOTICE This report has been written as part of the activities of the Science Advisory Board, a public advisory group providing extramural scientific information and advice to the Administrator and other officials of Environmental Protection Agency. The Board is structured to provide a balanced expert assessment of scientific matters related to problems facing the Agency. This report has not, been reviewed for approval by the Agency? and, nance, the contents of this report do not: necessarily represent the views and policies of the Environmental Protection Agency or other agencies in the Federal Government. Mention of trade or commercial products does not constitute a raeonmendation for use. ------- U.S. ENVIRONMENTAL PROTECTION AGENCY SCIENCE ADVISORY AIR SCIENTIFIC Chairman Dr. Roger o. McClellan, President, Chemical Industry Institute of Toxicology, Research Triangle Park, North Carolina Members Dr. Timothy Larson, Environmental Engineering Science Program, Department of Civil Engineering, University of Washington, Seattle, Washington Dr. Gilbert s. Omenn, Professor and Dean, School of Public Health and Community Medicine, University of Washington, Seattle, Washington Dr. Marc B. Schenker, Director, Occupational and Environmental Health Unit, University of California, Davis, California Dr, Mark J, Utell, Professor of Medicine Toxicology, Co-Director, Pulmonary Disease Unit, University of Rochester School of Medicine, Rochester, New „ork Dr. Jerome J. Wesolowski, Chief, Air and Industrial Hygiene Laboratory, California Department of Health, Berkeley, California Dr. George T. Wolff, Principal Scientist, General Motors Research Labs, Environmental Science Department, Warren, Michigan Executive Secretary Mr. A. Robert Flaak, Environmental Scientist, Science Advisory (A-101F), U.S. Environmental Protection Agency, 401 M Straat, SW, Washington, D.C. 20460 ------- U, s. Environmental Protection Agency Science Advisory Board Clean Air Scientific Advisory Committee chairma Dr» Roger 0, McClellan, President, Chealeal Industry Institute of Toxicology, Research Triangle Park? North Carolina IJembers Dr. Eileen G. Brennan, Professor Emerita, Plant Pathology Department, Cook College, lutgera University, New Brunswick, New Jersey Dr. Edward D. Crandall, Chief, Division of Pulmonary and Critical Care Medicine, Cornell University Medical College, New „ork» New York Dr. James D. Crapo, Duke University Medical Center, Department of Medicine, Division of Allergy, Critical Care and Respiratory Medicine, Durham, North. Carolina Dr. Robert Prank, Professor of Environmental Health Sciences, The Johns Hopkins School of Hygiene and Public Health, Baltimore, Maryland Dr. A. Myrick Freeman III, Resources for the Future, Washington, District of Clombia Dr. Jay S. Jacobson, Plant Physiologist, Boyca Thompson Institute, Ithaca, New York Dr. Jane Q« Koenig, Research Associate Professor, Department of Environmental Health, University of Washington, Seattle, Washington Dr. Timothy Larson, Environmental Engineering and Science Program, of civil Engineering, University of Washington, Seattle, Washington Dr. Morton Lippmann, Professor, Institute of Environmental Medicine, New „ork University Medical Canter, Tuxedo, New York Dr. M. Morgan, Head, Department of Engineering and Public Policy, Carnegie-Mellon University, Pittsburgh, Pennsylvania Dr. D. North, Principal, Inc., Lo« Altos, California ------- Dr. Gilbert S. Onienn, Professor of Medicine and of Environmental Health, Dean, School of Public Health and Community Medicine, University of Washington, Seattle, Washington Dr. Robert D, Rowe, Senior Vice President, RCG/Hagler, Bailly, Inc., Boulder, Colorado Dr. Marc B. Schenker, Director, Occupational and Environmental Health Unit, University of California, Davis, California Dr» George E. Taylor, Jr., Group Leader, Physiological Ecology, Environmental Sciences Division, Oak Ridge national Laboratory, Oak Ridge, Tennessee Dr. Mark 3, Utell, Professor of Medicine and Toxicology, Co-Director, Pulmonary Disease Unit, University of Rochester School of Medicine, Rochester, New „ork Dr. Jerome j. Wesolowski, Chief, Air Industrial Hygiene Lab, California of Health, Berkeley, California Dr. George T. Wolff, Principal Scientist, General Motors Research Laboratories, Environmental Science Department, Warren, Michigan Executive Secretary. Mr. A. Robert Plaak, Environmental Scientist, Science Advisory Board (A-101F), U.S. Environmental Protection Agency, 401 M Street, SW, Washington, DC 20460 ------- UNITED STATES ENVIRONMENTAL PROTECTION AGENCY WASHINGTON, D C. 20460 May 1. 1989 The Honorable William K. Reilty Administrator U. S. Environmental Protection Agency 401 M Street, SW Washington, DC Dear Mr. Reilly: I am pleased to transmit via this the advice of the Clear Air Scientific Advisory Committee (CASAC) concerning the National Ambient Air Quality Standards for Ozone. CASAC has reviewed and offered comments directly to EPA staff on the EPA criteria document "Air Quality Criteria for Ozone and Other Photochemical Oxidants (1986)," the "Criteria Supplement (1988)." and the Office of Air Quality Planning and Standards staff position paper "Review of the Air Quality Standards for Ozone Assessment of Scientific and Technical Information (1988)" and related support documents. CASAC previously closure on the 1986 Criteria Document. At a meeting held on December 14-15, 1§88» CASAC came to closure on the "Criteria (1988)" and the 1988 Staff Position Paper and concluded that they provide an adequate scientific basis for EPA to or primary and secondary standards for ozone. While reaching closure at this time, the Committee did an on the effects resulting from 6-pius hours of ozone exposure, providing evidence of the possible need for a standard with a §-8 hour averaging time. However, it was the Committee's view that It would be time enough of information would be published In journals to receive full review and, thus, be suitable for in a CASAC concluded such information can better be considered In the next review of the ozone standards. CASAC did not a on of the staff position papef recommendation that "the range of 1-hour average ozone levels of concern for standard setting purposes is 0.08-0.12 ppm for a primary standard," The opinion of the CASAC Ozone Review Committee with regard to the upper range of the standard with eight individuals favoring a range with an of 0.12 ppm, an in the range of 0,10-0,12 ppm, four individuals favored an upper bound natun no higher than ------- -2- 0.10 ppm, and one Individual abstained from offering an opinion. Several Individuals an of 0,12 ppm as well as all of the other individuals who favored a lower value for the upper end of the range expressed the view that at 0.12 little or no margin of safety. As you are aware, the margin of safety Is intended to provide protection against adverse effects which have not yet uncovered by research and effects whose medical significance is a matter of disagreement. Finally, several members of the subcommittee favored development of a standard with a more statistically robust upper bound on the annual distribution of ozone concentrations rather than reliance on the current expected exceedance form of the standard. While the Committee offers no further advice on what form the Agency should consider, we would caution you against any form which alters the degree of health protection afforded by the current standard, CASAC substantial discussion of the of what are or are not adverse health effects. This discussion by the presentation of this issue in the staff position paper. Within CASAC there diversity of opinion; some members felt that healthy Individuals experience adverse effects when ozone exposure induced any of the as moderate (i.e., >10% decrement in FEV or mild to moderate respiratory symptoms) in the staff position paper, while a^few members believed that adverse effects would not be experienced until ozone induced more severe effects (i.e., >20% decrement In FEV and moderate to severe respiratory symptoms). The view of some Individuals %n this matter was influenced by recognition that resolution of the adverse health issue represents a blending of scientific and policy judgments and, thus, we feel it appropriate to inform you of the range of our views on this matter. Of particular concern to CASAC Is the potential for arising from exposures to ozone with daily concentrations at or near 0.12 ppm for periods of §-8 hours co-exposure to other pollutants. This concern Is due to air quality analyses which have shown that even in which do not repeatedly the standard, remain to 0.12 ppm for several hours per day for extended periods of time in summer. There was concern based on recent controlled hyman exposure, epidemiology and toxicology studies. that such prolonged exposures could result In increased respiratory impairment. Further, for exposed to these ozone concentrations over a lifetime, the possibility that chronic Irreversible effects mav result Is of concern, although such changes hav« not been demonstrated. The Committee noted that the Criteria Document Supplement failed to cite and discuss a group of "ecological" epidemiologies! of the of on various measures of human health such as for respiratory or of problems. Although studies have obvious limitations in establishing cause and relationships, they have ------- -3- certain strengths which can aid In regulatory decision-making. Studies of this type should be discussed and evaluated In future criteria documents as a complementary source of information. While reaching closure on the staff paper recommending a i-hour standard, CAS AC that the increased support for research that will prove an Improved scientific basis for evaluating the need for standards with multi-hour or times. Clearly, the obvious, research on this critical environmental health issue must be supported now In order for results to be for consideration In the next 5-year review cycle. CAS AC has enumerated these research needs In some detail in a September 1987 submission to the Agency. The Committee feels these research recommendations are still valid and should be incorporated as expeditiousiy as Into the Agency research program. CASAC did not reach a consensus opinion on endorsement of the staff position recommendation of "a 1-hour averaging time In the range of 0.06-0.12 ppm" for a secondary standard. The CASAC Ozone Welfare Effects matter a divided opinion; two favored a range with an upper value of 0,12 ppm, three favored an upper value of less than 0.12 ppm, five favored an upper value of 0.10 ppm. The Committee noted that the form of the standard was of critical importance In protecting against ozone effects on vegetation. The Committee was of the opinion that a cumulative seasonal standard would be more appropriate than a 1-hour standard and felt that such a standard could be developed. CASAC favored issuance of a cumulative seasonal standard form assuming its development would not further the standard setting process. If this form of standard cannot be developed in time for the current 'eview, the Committee is of the opinion you should give serious consideration to setting a 1-hour secondary standard with a maximum concentration of 0.10 ppm. The Committee took of the lack of information on the of on ecosystems and urged support for research to In closing, I would like to briefly comment on CASAC's failure to reach a consensus as to the appropriate range for setting the ozone standards. This lack of consensus Is reflective of major deficiencies In our knowledge regarding health and welfare of long-term exposure (beyond a few hours) to ozone. The data bas« is very targe and adequate for knowledgeable individuals to reach agreement on the effects of exposure to In the for setting a i-hour standard. However, there Is not an on the of or to as whether such may produce chronic health effects. This is especially troubling long-term to occur in many parts of the United and involve many millions of people and thousands of of crop and lands. As a result, continues to be concern for the public health ------- and welfare threat which may be posed by chronic exposure to ozone. It is critical that the data base on health and welfare effects to multiple hour. seasonal and lifetime exposures of ozone be increased through an accelerated and expanded research effort. This must be done so that future considerations of ozone standards will derive from a stronger scientific base. CAS AC that your statutory responsibility to set standards requires public health policy judgments In addition to determinations of a strictly scientific nature. While the Committee is willing to further advise you on the ozone standards, we see no need, in view of the already extensive provided, to review the proposed ozone standards prior to their publication in the Federal Register. In this Instance, the public comment period will provide sufficient opportunity for the Committee to provide any or that may be necessary. CASAC would appreciate being kept informed of progress on establishing revised or new ozone standards and plans for research on ozone effects. Please do not to contact me if CASAC be of further assistance on this matter. Sincerely, O. McCWIan, D.V.M. Chairman, Clean Air Scientific Advisory Committee ROMrewb ------- |