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Two million Americans face heightened cancer risks from air pollution, EPA says

June 24, 2009

Robin Bravender

Two million Americans face increased cancer risks of greater than 100 in a million from exposure to toxic air pollution, according to a U.S. EPA report released today. EPA estimates that all 285 million U.S. residents have an increased cancer risk of greater than 10 in a million from exposure to air toxics. The average cancer risk, based on 2002 pollution levels, is 36 in a million. The agency has asserted that levels above a 100-in-a-million risk level are generally unacceptable.

The data comes from a county-by-county analysis of toxic air pollution released today in a survey known as the National Air Toxics Assessment (NATA). The report covers 181 air toxics and diesel particulate matter and estimates risks from exposure to emissions from industrial sources and mobile sources such as cars and trucks. "The implication for me is we still have a long way to go to reduce toxic air pollution to protect the public," said John Walke, a senior attorney at the Natural Resources Defense Council. "It still shows an unacceptable number of Americans being exposed to cancer risk solely attributed to air pollution on top of all the other risks from smoking and indoor air pollution and other risks." Mobile emissions account for about 30 percent of the overall cancer risk, the study found. The majority of that risk comes from benzene, a carcinogen that is released into the air by burning coal and oil. Gasoline service stations and motor vehicle exhaust also release benzene.

Other contributors to cancer risks include local industry emissions, which make up about 25 percent of the average overall risk, and "background" pollutants with no known emission sources. Those "background" toxics, including carbon tetrachloride, account for the remaining 45 percent of overall cancer risk. The study is based on 2002 data and is the first such document released by EPA since 2006, when the agency analyzed 1999 data. The new report does not account for changes in air quality since 2002. The agency has already begun work on the next such analysis that will focus on 2005 emissions inventory data.

EPA study site