EPA has released the latest version of a state-of-the-science tool that estimates health risks from breathing air toxics in the United States. The National Air Toxics Assessment (NATA), based on 2002 air emissions data, helps federal, state, local and tribal governments identify areas and specific pollutants for further evaluation to better understand risks they may pose.
Air toxics are of concern because they are known to or are suspected of causing cancer and other serious health problems, including birth defects. The report assessed 180 air toxics plus diesel particulate matter from stationary sources of all sizes and from mobile sources such as cars, trucks, buses and construction equipment.
The 2002 NATA estimates that most people in the United States have an average cancer risk of 36 in 1 million if exposed to 2002 emissions levels over the course of their lifetime. In addition, 2 million peopleâ€”less than one percent of the total U.S. populationâ€”have an increased cancer risk of greater than 100 in 1 million. Benzene was the largest contributor to the increased cancer risks.
NATA provides broad estimates of risk over geographic areas of the country and not definitive risks to specific individuals. The results are best used to prioritize pollutants and areas for further study, not as the sole basis for regulation or risk reduction activities.
Since the 1990 Clean Air Act Amendments, air toxic emissions have decreased by 40 percent from all sources. NATA can be used to help all levels of government target further reductions in air toxics emissions.