Review of Ozone Standard in Full Swing, 3-22-06
EPA published the final ozone Air Quality Criteria Document laying out the latest scientific evidence of the adverse health effects of ozone on March 21, 2006.
The document forms the scientifc basis for EPA’s ongoing review of the National Ambient Air Quality Standards (NAAQS) 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.
The Criteria Document 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.
The document reports evidence that ozone reduces lung function, causes respiratory symptoms such as cough and pain on inspiration, increases respiratory symptoms in asthmatic children, causes inflammation and narrowing of the airways, and is associated with increased hospital admissions and emergency department visits for respiratory problems. In addition, the document concludes that the “overall body of evidence is highly suggestive that ozone directly or indirectly contributes to non-accidental and cardiopulmonary-related mortality, but additional research is needed to more fully establish underlying mechanisms by which such effects occur.”
As a result of the 1997 review, EPA set an eight-hour ozone standard, which is 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.
The next step in the process is for EPA to issue a second draft Staff Paper and Risk Assessment in late April for review by the public and by CASAC. The risk assessment is evaluating the public health implications of alternative standards ranging from .06 to .08 ppm.
The draft Criteria Document and Staff Paper were reviewed by the Clean Air Scientific Advisory Committee (CASAC).
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 Ozone AQCD is available [www.epa.gov/ncea] online. For print copies, call 1-800-490-9198 and ask for report number EPA 600/R-05/004aF–cF.
The CASAC review letters on the Criteria Document and on the first draft Staff Paper and Risk Assessment are available [www.epa.gov/sab] online.
