EPA: Emissions of Six Key Pollutants Has Decreased

An early look at air quality and emissions data for 2006 shows continued improvement in the nation's air quality over the long term, EPA reported on April 30. Emissions of six key pollutants have dropped by more than half since 1970, and the national average concentration for each criteria pollutant is below the level of its air quality standard.

"The data is in and the trends are good -- our nation's air continues to improve because of the Bush administration's innovative clean air policies," said EPA Administrator Stephen L. Johnson. "By tackling tailpipes and smokestacks, EPA is clearing the air, and all Americans are breathing easier."

Total emissions of the six key pollutants dropped 54 percent between 1970 and 2006, the agency stated. During the same time period, the U.S. gross domestic product increased 203 percent, vehicle miles traveled increased 177 percent, energy consumption increased 49 percent, and U.S. population grew by 46 percent. In addition, emissions of air toxics in 2002 were 35 percent lower than 1990 levels, the agency stated.

Under the Clean Air Act, EPA sets national air quality standards for six key pollutants: nitrogen dioxide (NO2), ozone (O3), sulfur dioxide (SO2), particulate matter (PM), carbon monoxide (CO) and lead (Pb). Each year, EPA examines the levels of these pollutants in the air and the emissions from various sources to see how both have changed over time and to summarize the current status of air quality. While national average concentrations of the six key pollutants are below national standards, results vary by site. Annual pollution levels at some monitoring sites do remain above one or more of the national air quality standards, with ozone and particulate matter remaining as the most persistent problems.

The day after EPA's announcement, the American Lung Association (ALA) issued its annual air quality report card, finding that Americans in the eastern United States are breathing more soot, while stricter local and state controls have dropped air pollution in West.

"The increased (particulate matter) pollution in the East is a particularly troubling trend, because exposure to particle pollution can not only take years off your life, it can threaten your life immediately," said Terri E. Weaver, PhD, RN, ALA chairperson. "Even in many areas EPA currently considers safe, the science clearly shows that the air is too often dangerous to breathe, particularly for those with lung disease. Protecting Americans from potentially deadly air pollution means we need more protective federal standards, so that every community in the United States can have truly clean air."

Higher soot levels in the East are linked to an increase in electricity generated by heavy polluting power plants, according to ALA. In the West, by contrast, soot levels continue to drop even in areas that rank historically high in particle pollution. California showed the most improvement with 32 counties dropping their year-round particulate matter pollution levels.

This article originally appeared in the 05/01/2007 issue of Environmental Protection.

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