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EPA Continues Efforts to Understand Effects of Ozone on Human Health and the Environment - Ozone Air Quality Criteria Document Released

Release Date: 03/22/2006
Contact Information: Suzanne Ackerman, (202) 564-4355 /

(Washington, D.C. - March 22, 2006) EPA will review the current air quality standard for ozone to determine if it needs to be revised. The "Air Quality Criteria for Ozone and Related Photochemical Oxidants," document provides scientific bases for EPA's periodic review of the current air quality standards for ozone. The Clean Air Act requires EPA to periodically review the scientific basis for National Ambient Air Quality Standards (NAAQS) for six major pollutants, including ozone, to determine whether the standards sufficiently protect public health and the environment.

This final Ozone Air Quality Criteria Document (AQCD) is a revision of the EPA Ozone AQCD published in 1996. The document released today evaluates the scientific peer-reviewed literature that has been generated since the current ozone NAAQS was set in 1997, and integrates the new findings with previously available studies. The publication of important new research is one part of the public process to review air quality standards.

As a result of the 1997 review, EPA took strong action to improve air quality by implementing an eight-hour ozone standard, which is significantly more protective of human health than the previous one-hour standard. By monitoring over an eight-hour period and tightening the standard from .12 to .08 parts-per-million (ppm), citizens are protected against health effects from longer exposure periods.

EPA is scheduled to propose whether to retain or revise the current national ozone standards in March 2007, and to issue a final decision by December 2007.

The reduction of smog is a critical element of the Bush Administration's comprehensive national clean air strategy. This strategy includes EPA's Clean Air Nonroad Diesel Program, the Clean Air Interstate Rule, the BART rules and the Administration's Clear Skies legislation. These programs are important components of EPA's efforts to help states and localities meet the more protective fine-particle and 8-hour ozone national air quality standards. In combination with other federal and state controls already in place, these programs will bring most of the country into attainment with these new standards.

The Ozone AQCD:

For print copies, call 1-800-490-9198 and ask for report number EPA 600/R-05/004aF–cF.