EPA Assessment Refines Recommendations To Revise Air Standards for Carbon Monoxide

摘要

Environmental Protection Agency staff further refined recommendations for setting more protective air quality standards for carbon monoxide in a final policy assessment published Nov. 2 (75 Fed. Reg. 67,361).rnEPA's final Policy Assessment for the Review of the Carbon Monoxide National Ambient Air Quality Standards recommends that the agency consider revising one or both of the existing national ambient air quality standards (NAAQS) for carbon monoxide based on available research into the health effects of exposure to the pollutant. The policy assessment recommends setting an hourly standard for carbon monoxide in a range between 9 parts per million and 10 ppm to protect against short duration peak exposures to the pollutant. The policy assessment also recommends setting the eight-hour standard for carbon monoxide at 8 ppm or 9 ppm, retaining or slightly strengthening the existing standard. The policy assessment suggests EPA should give more consideration to setting a more protective hourly standard for carbon monoxide should it choose to revise only one of the standards.rnEPA set the air quality standards for carbon monoxide in 1971. They are 35 ppm averaged hourly and 9 ppm averaged over eight hours.