New federal pollution controls have improved the summer air breathed by 100 million Americans, according to a study released yesterday by the Environmental Protection Agency.
Under rules that took effect last year, 21 eastern states and the District of Columbia must reduce regional nitrogen oxide emissions by 1 million tons between May 1 and Sept. 30. On hot, sunny days nitrogen oxides combine with pollutants called volatile organic compounds and form ozone smog, which has been linked to asthma and premature death.
Last year, nitrogen oxide emissions from power plants and other sources dropped by half compared with 2000, according to the EPA, and ozone concentrations fell 10 percent during that same period. Other sources of nitrogen oxide emissions include oil refineries, pulp and paper mills, and cement kilns.
"This report is a pretty big deal," Jeffrey Holmstead, the agency's assistant administrator for air and radiation, said yesterday. "This summer I, along with other parents, can play baseball outside with my kids knowing the air is cleaner."
Holmstead added that the administration is demanding greater pollution cuts under a Clean Air Interstate Rule (CAIR) it adopted this spring. It will permanently limit power plant emissions of nitrogen oxide and sulfur dioxide, another air pollutant, in 28 eastern states and the District of Columbia.
Environmentalists also hailed the findings, saying they show that industry can operate more cleanly once the government demands it. Under the new program, known as "state implementation plan call," states have to meet an overall pollution cap but individual plants can trade emissions, so a cleaner facility can sell its "credits" to a dirtier one.
"This is command and control that also employs market mechanisms, which is what everyone favors," said John Stanton, a senior attorney for the advocacy group Clear the Air.
Stanton added that unlike CAIR, which allows up to a decade to achieve some pollution cuts, the nitrogen oxide rule gave states a three-year deadline to comply with the stricter standards.
"By requiring nitrogen oxide reductions for the 2004 summer season, we saw immediate health benefits," Stanton said.
EPA officials said it is too early to say whether 2005 will have fewer unhealthy air days than past hot summers, but preliminary findings indicate this summer has had less smog than 2002, which had a similar number of hot, dry days.