In a July 2 article about U.S. air quality standards, Frank O'Donnell was erroneously identified as the head of the advocacy group Clean Air Trust. O'Donnell is the president of Clean Air Watch. (Published 7/7/2005)

Environmental Protection Agency staff members proposed tightening the nation's air pollution standards yesterday, a move that environmentalists said could save the lives of thousands of Americans.

Aides to EPA Administrator Stephen L. Johnson outlined two scenarios in their report on what should be the acceptable nationwide level for "fine particulate matter," the soot that invades people's lungs and causes respiratory ailments. Both scenarios would slash the amount of small particles in the air, although one proposal would go significantly further than the other.

Under standards set in 1997, soot levels should not exceed 15 micrograms per cubic meter of air on an annual basis, or 65 micrograms during a single 24-hour period. EPA aides said yesterday that the agency could either maintain the annual soot standard but reduce the daily level to between 25 and 35 micrograms, or reduce the annual limit to as low as 12 to 15 micrograms per cubic meter of air and cap the 24-hour level at between 25 and 40 micrograms.

Public health advocates, who back the more stringent proposal, hailed the EPA for moving to curb harmful air pollution. According to the EPA, fine particulate matter, which is one-thirtieth the width of a human hair, accounts for 5,000 premature deaths each year in nine cities: Boston, Detroit, Los Angeles, Philadelphia, Phoenix, Pittsburgh, St. Louis, San Jose and Seattle.

"These standards could provide the Bush administration with a historic opportunity to protect public health," said Frank O'Donnell, who heads the advocacy group Clean Air Trust.

Cities and communities across the country have to meet the air standards or risk facing a series of penalties, including lost federal highway funds. The federal government also tailors new rules, such as the recently unveiled Clean Air Interstate Rule, to conform with national soot standards.

Some industry groups, however, oppose tightening the standards on the grounds that they can hamper economic growth.

Bryan Brendle, director of air quality issues at the National Association of Manufacturers, said state and local officials tend to target manufacturers in an effort to comply with stricter standards, which "imposes compliance costs on industry." He added: "At NAM, we try to balance environmental quality with increased economic growth."

Many communities are still struggling to meet the nation's 1997 guidelines. According to a recent EPA report, about 88 million Americans are breathing air that fails to meet federal standards.

George Thurston, an associate professor at New York University Medical Center, said researchers have learned enough over the past decade to insist that federal officials need to adopt stricter air pollution standards.

"While it sounds like an academic debate, it provides protection for all of us across the country," Thurston said.

In a statement issued yesterday, the agency did not say which approach Johnson, who is required to make a decision on the final air quality proposal by Dec. 20, would adopt. It did say, "The reduction of fine particle pollution is a critical element of the administration's comprehensive national clean air strategy."

The new standards are supposed to take effect by Sept. 27, 2006.