Tim Duggan

November 8, 2006

On September 21, 2006, the Environmental Protection Agency (EPA) issued new standards pertaining to airborne soot, otherwise known as fine particulate matter or PM-2.5. The new regulations lower the 24-hour standard for PM-2.5 from 65 micrograms per cubic meter to 35 micrograms per cubic meter. The new regulations, however, retain the annual standard for PM-2.5, despite the urging of the Clean Air Scientific Advisory Council (CASAC) to lower the standard. That standard remains at 15 micrograms per cubic meter. As expected, environmental groups criticized the new standards as too lax and unprotective of the public health and welfare, while industry trade groups criticized the standards as too onerous on business and unsupported by scientific evidence.

Under the Clean Air Act, the EPA must review its primary and secondary National Ambient Air Quality Standards (NAAQS) every five years for each of six listed (criteria) pollutants. Fine particulate matter (PM-2.5) is one such pollutant. The Act requires EPA to set primary standards to protect the public health within an "adequate margin of safety," and it prohibits the EPA from considering costs in setting those standards. The Act also authorizes CASAC to provide scientific advice to the EPA before the agency sets revised NAAQS. Since the 1970s, the EPA has consistently accepted CASAC's advice in making final NAAQS determinations. Thus, the recent PM-2.5 NAAQS represents an abrupt, though not altogether unexpected, break from tradition.

In a recent letter to EPA Administrator Stephen L. Johnson, CASAC objected to EPA's refusal to amend the annual PM-2.5 standard. CASAC had urged EPA to lower the annual standard—currently set at 15 micrograms per cubic meter—to either 13 or 14 micrograms per cubic meter. According to CASAC and the EPA itself, a reduction in the annual PM-2.5 NAAQS could prevent as many as 30,000 premature deaths per year.

"It is the CASAC's consensus scientific opinion that the decision to retain without change the annual PM-2.5 standard does not provide an Ôadequate margin of safety . . . requisite to protect the public health' (as required by the Clean Air Act), leaving parts of the population of this country at significant risk of adverse health effects from exposure to fine PM." CASAC noted that its advice was consistent with the advice of every major medical and public health organization, including the American Medical Association, American Lung Association, and the American Heart Association. The letter went on to question whether the EPA gave full consideration to CASAC's advice. EPA's decision to retain the annual standard has been criticized as the latest instance in which the Bush Administration has ignored scientific recommendations when those recommendations interfere with its political agenda.

The standards are set to go into effect in a few years; however, they will likely be confronted by a legal challenge from the environmental community.

For more information, see:

EPA Air Advisory Panel Criticizes Agency's Soot Rule, Oct. 3, 2006, available at http://www.ens-newswire.com/ens/oct2006/2006-10-03-09.asp

Envtl. Prot. Agency, Fact Sheet: Proposal to Revise the National Ambient Air Quality Standards for Particulate Matter, available at http://epa.gov/pm/fs20051220pm.html (last updated Sept. 27, 2006).

Letter from Clean Air Scientific Advisory Council to EPA Administrator Stephen L. Johnson (Sept. 29, 2006), available at http://www.epa.gov/sab/pdf/casac-ltr-06-003.pdf.

Janet Wilson, Epa Criticized for Not Toughening Soot Law, L.A. Times, Oct. 7, 2006, available at http://www.latimes.com/features/health/medicine/la-me-soot7oct07,1,7511715.story?coll=la-health-medicine.

Juliet Eilperin, EPA Cuts Soot Level Allowable Daily in Air, Wash. Post, Sept. 22, 2006, available at http://www.washingtonpost.com/wp-dyn/content/article/2006/09/21/AR2006092101616.html.

Editorial, Science Ignored, Again, N.Y. Times, Oct. 14, 2006, available at http://www.nytimes.com/2006/10/14/opinion/14sat1.html.