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

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Report Information

EPA has released the Integrated Science Assessment of Ozone and Related Photochemical Oxidants (Second External Review Draft) 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.

James S. Brown

by phone at: 919-541-0765
by email at: brown.james@epa.gov

Background

EPA released the Second 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 second 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 respiratory morbidity and mortality. 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 respiratory morbidity and mortality are associated with O₃ long-term exposure.

History/Chronology

Feb 2006	EPA released the final report of the Air Quality Criteria Document for Ozone (EPA/600/R-05/004). [Federal Register Feb 28, 2006]
Sep 2008	EPA announced notice of workshop and call for Information on Integrated Science Assessment. [Federal Register Sep 29, 2008]
Sep 2009	EPA released an Integrated Review Plan for the Ozone National Ambient Air Quality Standards (PDF, 78pp, 486Kb) (EPA 452/D-09-001).
Jul 2010	EPA 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 2011	EPA's Science Advisory Board's CASAC announced a meeting of the Ozone Review Panel for the Reconsideration of the 2008 National Ambient Air Quality Standard. [Federal Register Feb 28, 2011] Also, EPA released the first external review draft for public review and comments. [Federal Register Feb 28, 2011]
Mar 2011	EPA 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 2011	EPA's Science Advisory Board's CASAC announced 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]
Sep 2011	EPA released the second external review draft for public review and comments. [Federal Register Sep 30, 2011]
Nov 2011	EPA announced an extension of the public comment period until December 30, 2011. [Federal Register Notice Nov 28, 2011]
Dec 2011	EPA's Science Advisory Board's CASAC announced a public peer review meeting for the second review draft of the Ozone ISA for Jan 9-10, 2012 in Durham, NC. [Federal Register Notice Dec 8, 2011]
Feb 2012	EPA's Science Advisory Board's CASAC announced a follow-up teleconference call to discuss the review of the second review draft of the Ozone ISA on March 9, 2012. [Federal Register Notice Feb 10, 2012]

Next Steps

This draft document addresses 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 (Second External Review Draft). U.S. Environmental Protection Agency, Washington, DC, EPA/600/R-10/076B, 2011.

Downloads

This download(s) is distributed solely for the purpose of pre-dissemination peer review under applicable information quality guidelines. It has not been formally disseminated by EPA. It does not represent and should not be construed to represent any Agency determination or policy.