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Integrated Science Assessment of Ozone and Related Photochemical Oxidants (First External Review Draft)

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Report Information

EPA announced that the First External Review Draft of the Integrated Science Assessment for Ozone and Related Photochemical Oxidants has been made available for independent peer review and public review. This draft document represents a concise synthesis and evaluation of the most policy-relevant science and will ultimately provide the scientific bases for EPA’s decision regarding the adequacy of the current national ambient air quality standards for ozone to protect human health, public welfare, and the environment.

Background

EPA released the First External Review Draft of the Integrated Science Assessment for Ozone and Related Photochemical Oxidants for peer review and public comment. Ozone (O3) is one of six principal (or criteria) pollutants for which EPA has established national ambient air quality standards (NAAQS). The Clean Air Act requires EPA to periodically review the scientific basis for these standards by preparing an Integrated Science Assessment (ISA), formerly called an Air Quality Criteria Document (AQCD). These reviews play a significant role in EPA’s commitment to ensuring a clean and healthy environment for the public. The first draft ISA is part of the Agency’s periodic review of the primary and secondary NAAQS for O3. New material has been included in this draft, but many of the overall conclusions remain generally the same as the last NAAQS review which was completed in 2008. For example, in relation to short-term exposures, new evidence for O3-induced health effects strengthens the body of evidence for associations with premature mortality and respiratory morbidity. Also, the current ambient O3 concentrations in many areas of the US are sufficient to impair growth of numerous plant species. Within an ecosystem, O3 can alter timber production, water availability in watersheds and carbon sequestration; and, it can affect ecosystem biodiversity. In addition, as was concluded in the last NAAQS review, O3 can affect the climate by acting as a climate-forcing greenhouse gas. In contrast to the last review, there is now evidence suggesting that premature mortality and respiratory morbidity are associated with O3 long-term exposure.

History/Chronology

Feb 2006EPA released the final report of the Air Quality Criteria Document for Ozone (EPA/600/R-05/004). [Federal Register Feb 28, 2006]
Sep 2008EPA announced notice of workshop and call for Information on Integrated Science Assessment. [Federal Register Sep 29, 2008]
Sep 2009EPA released an Integrated Review Plan for the Ozone National Ambient Air Quality Standards (PDF, 78pp, 486Kb) (EPA 452/D-09-001).
Jul 2010EPA announced an Aug 2010 public workshop to evaluate initial draft materials for the health effects sections of the upcoming Ozone Integrated Science Assessment. [Federal Register Jul 20, 2010]
Feb 2011EPA's Science Advisory Board's CASAC announces a meeting of the Ozone Review Panel for the Reconsideration of the 2008 National Ambient Air Quality Standard. [Federal Register Feb 28, 2011]
Feb 2011EPA released the first external review draft for public review and comments. [Federal Register Feb 28, 2011]
Mar 2011EPA announced an extension of the public comment period for the draft document , First External Review Draft Integrated Science Assessment for Ozone and Related Photochemical Oxidants. [Federal Register Mar 28, 2011]
Jun 2011EPA's Science Advisory Board's CASAC announces a meeting of the Ozone Review Panel for the review of the EPA's Integrated Science Assessment for Ozone and Related Photochemical Oxidants (March 2011 Draft). [Federal Register Jun 3, 2011]

Next Steps

The first draft ISA will be reviewed by the Clean Air Scientific Advisory Committee (CASAC) at a public meeting in May 2011. A second draft ISA will be released later in September 2011, which will address CASAC and public comments received on the first draft ISA. Once final, the complete ISA will be posted on the EPA Web site to provide the scientific bases for EPA’s periodic review and possible revision of the primary NAAQS for ozone and Related Photochemical Oxidants.

Additional Information

Comments on this draft report may be submitted and reviewed using the e-Government Regulations.gov Web site. From the site, select “Environmental Protection Agency” and the keyword “EPA-HQ-ORD-2011-0050" (for the docket ID) to comment on this report.

Citation

U.S. EPA. Integrated Science Assessment of Ozone and Related Photochemical Oxidants (First External Review Draft). U.S. Environmental Protection Agency, Washington, DC, EPA/600/R-10/076A, 2011.

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