EPA Advisors Push Targeted SO2 NAAQS Review Focusing On Exposures

摘要

EPA advisors are suggesting the agency's just-launched review of its sulfur dioxide (SO2) national ambient air quality standard (NAAQS) focus on more research into short-term exposures to the pollutant, saying there is no need to also reassess health effects data as there is scant data to change existing findings on SO2's health threats. A focus on short-term exposure could potentially result in another shortening of the standard's averaging time, from one hour, that could provide further protection against short-lived spikes in pollution. Alternatively, EPA might opt to change how EPA calculates compliance with the existing NAAQS. The recommendations - made by clean air experts during a June 12-13 "kickoff" workshop to launch the Clean Air Act-mandated five-year review of the SO2 standard - could help EPA avoid developing a comprehensive new risk and exposure assessment (REA) for the review. For NAAQS reviews, the agency crafts an Integrated Science Assessment detailing new policy-relevant science, followed by an REA characterizing pollutant exposures and risks.