Washington, D.C. — Total emissions of the six principal pollutants identified in the Clean Air Act dropped again in 2003, signaling that America's air is the cleanest ever in three decades, the U.S. Environmental Protection Agency (EPA) reported in September.

Annual emissions statistics for the six pollutants are considered major indicators of the quality of the nation's air because of their importance for human health and the existence of their long-standing national standards.

Emissions have continued to decrease even as our economy has increased more than 150 percent. Since 1970 (change numbers to reflect 1970 baseline), the aggregate total emissions for the six pollutants [carbon monoxide (CO), nitrogen oxides (NOx), sulfur dioxide (SO2), particulate matter (PM), volatile organic compounds

(VOCs) and lead (Pb)] have been cut from 301.5 million tons per year to 147.8 million tons per year, a decrease of 51 percent. Total 2003 emissions were down 12 million tons since 2000, a 7.8 percent reduction. (See summary table at http://www.

epa.gov/airtrends/econ-emissions.html.)

“Thanks to this progress, today's air is the cleanest most Americans have ever breathed,” said Administrator Mike Leavitt. “Now, EPA is taking up the challenge to accelerate the pace of that progress into the future.”

The agency recently issued regulations that will cut diesel pollution by 90 percent, and later this year will finalize regulations cutting power plant pollution by approximately 70 percent.

A major reason for the nation's progress is the innovative, market-based acid rain cap-and-trade program enacted in 1990. The Acid Rain Progress Report, also released in September, shows annual SO2 and NOx emissions have declined 5.1 million tons (32 percent) and 2.5 million tons (37 percent), respectively, since 1990. The Bush Administration's Clean Air Interstate Rule (CAIR) will use the same proven cap-and-trade approach as the Acid Rain program, creating financial incentives for electricity generators to look for new and low-cost ways to reduce emissions early.

CAIR will use cap-and-trade to address power plant emissions in 29 eastern states plus the District of Columbia. The program would cut SO2 by more than 40 percent from today's levels by 2010, and 70 percent when fully implemented. NOx emissions would be cut by 50 percent from today's levels by 2010, and 60 percent when fully implemented. The administration plans to finalize CAIR this fall.

“The Acid Rain Program is a national success story because we achieved early reductions, cost-effectively and with near-perfect compliance,” said Leavitt. “CAIR will provide similar benefits, ensuring that our nation's air continues to get cleaner well into the next decade.”