In a long-awaited decision, the Environmental Protection Agency (EPA) today set final air quality standards for soot that ignore the advice of outside scientists. The agency cut in half the allowable amount of fine particles, averaged over 24 hours, but didn't tighten the annual average for soot, as recommended by public health organizations and its own scientific advisory committee.
A substantial amount of evidence exists that breathing particles smaller than 2.5 microns can cause serious health problems, ranging from aggravated asthma to heart attacks. The agency is required to periodically review its standards for soot and other air pollutants. After the American Lung Association sued the agency for missing a deadline, EPA agreed in 2003 to revise them by 27 September 2006. In December 2005, the agency proposed to tighten the daily standard from 65 micrograms per cubic meter (µg/m³) to 35 µg/m³. Environmental groups and others criticized EPA, however, for ignoring another recommendation of its Clean Air Scientific Advisory Committee (CASAC): to lower the annual standard from 15 µg/m³ to 13 or 14 µg/m³ (ScienceNOW, 21 December 2005).
Administrator Stephen Johnson acknowledged today that the final rules depart from the CASAC recommendations. "This is complex science and reasonable people can disagree," he said in a teleconference. "Wherever the science gave us a clear picture, we took action. I'm confident that this is the right decision." EPA estimates that the new rules would prevent 2500 premature deaths each year as well as 5000 nonfatal heart attacks, 7300 cases of acute bronchitis, and 51,000 cases of aggravated asthma.
Environmental groups immediately criticized the new standards as inadequate. "EPA's action is truly breathtaking in ignoring the dangerous impact of particulate pollution on American's hearts and lungs," said John Balbus, who directs Environmental Defense's health program, in a statement today. "By ignoring medical science, EPA is fundamentally failing to protect Americans from the serious death and disease associated with particulate pollution."
Under the existing regulations, 109 counties currently violate one or both of the PM 2.5 standards; under the tighter daily standard, 32 additional counties are out of compliance. States have 14 months to tell EPA how they will abide by the new rules, which go into effect in 2015.