Ozone Staff Paper Recommends Assessessment of Tighter Standards
EPA staff scientists have recommended analysis of the risks assocated with 8-hour ozone standards ranging from the current standard of 0.08 ppm down to a much tighter level 0.06 ppm. The recommendations are contained in the first draff ozone Staff Paper released for public and peer review on November 15, 2005.
EPA has published for public comment its first draft Staff Paper on the review of the NAAQS for ozone, as well as a first draft exposure assessment and risk assessment. The draft will be reviewed at the December 6-8, 2005 meeting of the Clean Air Scientific Advisory Committee in Research Triangle Park, NC. Written comments are due by December 30 2005.
An EPA fact sheet on the action is available online.
The full staff is available online.
The additional technical documents and supporting data including the draft risk assessment and exposure assessment are also published by EPA [www.epa.gov/ttn/naaqs/standards/ozone]online.
The Staff Paper does not contain policy recommendations regarding revisions to the air quality standards but does provide a preview where staff may be headed by recommending that the next draft risk assessment analyze health risks occurring in a range from 0.06 ppm to 0.08 ppm, 8-hour average. The current standard is 0.08 ppm. During the last review in 1997, the policy range under consideration was 0.07 to 0.09 ppm.
The staff recommended that the analysis also consider alternate forms of the standard that measure nonattainment based on the 3rd to 5th highest exceedances over a 3-year period.
The draft staff paper said that meeting the current ozone 0.08 ppm standard “would likely result in substantial reductions in exposures of concern and associated risks of serious health effects,” but that initial analyses “also suggest that there is risk of moderate or greater lung function decrements in children, hospital admissions, and mortality from [ozone] resulting from exposures across the range of levels allowed by the current standard.”
The Staff Paper adds “small but significant effects estimates have been reported” from exposures as low as 0.06 ppm.”
The next draft Staff Paper due to be released in Spring 2006 will contain recommendations about whether to retain or revise the existing ozone standard.
