Second National Assessment Of Toxic Air Pollutants Released

EPA announced on Feb. 22 it has released a tool to guide further local, state and federal steps to cut toxic air pollution and build upon emissions reductions achieved since 1990. The second National-Scale Air Toxics Assessment (NATA) is a screening tool that estimates cancer and other health risks from exposure to air toxics.

"Since 1990, we've significantly cut toxic emissions and risks in the United States," said Acting EPA Assistant Administrator for Air and Radiation Bill Wehrum. "This tool will help EPA and states refine our understanding and approaches to further reduce air toxics. With strong industrial standards already in place, our efforts to cut risks from toxic pollution will rely on more advanced technology, more sophisticated analysis and enhanced cooperation among federal, state and local agencies."

Since the Clean Air Act was amended in 1990, EPA has issued 96 standards for 174 different types of industrial sources of air toxics, including chemical plants, oil refineries, aerospace manufacturers and steel mills. The agency also has issued regulations for 15 categories of smaller sources, such as dry cleaners, commercial sterilizers, secondary lead smelters and chromium electroplating facilities. Together, these standards are projected to reduce annual emissions of air toxics by about 1.7 million tons from 1990 levels when fully implemented, officials said. These reductions are not fully reflected in this assessment, however, because a number of these regulations took effect after 1999.

NATA is not designed to be used as the sole basis for regulatory action. The results of the assessment, however, will help EPA and state and local air quality regulators identify pollutants and sources of greatest concern and set priorities for addressing that pollution. NATA also will help identify areas where EPA needs to collect additional information to improve the understanding of risks from air toxics exposure.

NATA covers 177 of the Clean Air Act's list of 187 air toxics plus diesel particulate matter. For 133 of these air toxics (those with health data based on chronic exposure) the assessment includes estimates of cancer or non-cancer health effects including non-cancer health effects for diesel particulate matter.

The second NATA expands on EPA's first national-scale assessment with a more complete emissions inventory and the latest health effects information. The first assessment, based on 1996 data, was release in 2002.

EPA plans to develop new national-scale assessments as inventory data from subsequent years become available. The next such analysis will focus on exposure and risks from 2002 emissions.

For more information about the National-Scale Air Toxics Assessment, visit

This article originally appeared in the 02/01/2006 issue of Environmental Protection.

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