NRC STUDY MAY AID PUSH FOR AIR ACT FIX FOR 'NO THRESHOLD' POLLUTANTS

摘要

A new study by a National Research Council (NRC) panel confirms that ozone exposure causes premature death, a finding that backs widespread criticism that EPA's recently unveiled ozone national ambient air quality standard (NAAQS) is not sufficiently protective of human health. At the same time, however, the panel report may also bolster legislative efforts by EPA and others to allow for consideration of costs when setting standards for pollutants that have no threshold or safe level of exposure, sources say, because it underscores the difficulty the agency faces in setting standards that protect human health with an "ample margin of safety,"as the law currently requires. State and industry sources say that the NRC panel's backing of recent studies showing mortality impacts of ozone at low levels have increased the difficulty in setting the NAAQS because the Clean Air Act requires the agency to set the standard at a level that protects the most sensitive subpopulations without any consideration of cost of meeting the standard. "Ozone is the poster child" for the problem of setting a standard for a pollutant that is not safe at any level yet must by law have an ample margin of safety, a state source says, but adds that there are others, including fine paniculate matter (PM2.5).