EPA Updates Air Toxics' Assessment with 2005 Data

The assessment shows that between 1990 and 2005, air toxic emissions were reduced by about 42 percent from industrial and mobile sources.

The U.S. Environmental Protection Agency has released the fourth update of a computer tool that helps federal, state, local governments, and other stakeholders better understand the potential health risks from exposure to air toxics.

The National Air Toxics Assessment (NATA) contains 2005 emissions data submitted primarily from the states for 178 pollutants. Models are used to make broad estimates of health risks for areas of the country. The tool is not designed to determine actual health risks to individuals living in these areas.

Because the data submitted varies from state to state, it is also not possible to use the data to compare risks between different areas of the country.

The assessment shows that EPA, the states, and industry are continuing to make progress to reduce air toxic emissions. Between 1990 and 2005, air toxic emissions were reduced by about 42 percent from industrial and mobile sources.

NATA is used to identify which geographic areas, pollutants, and types of emission sources might need closer investigation to more fully characterize potential risks and determine if actions may need to be taken to protect public health. EPA can also use the assessment to work with communities to design their own local assessment, improve the agency’s emissions inventories, and identify priorities for expanding the air toxics monitoring network. Once risks are fully characterized, state air agencies can decide if steps should be taken to reduce air toxics emissions.

In its summary (pdf), EPA identified the following compounds and their risks:

National cancer risk driver:
Formaldehyde, "likely carcinogenic to humans."

Regional cancer risk drivers:
Benzene: "carcinogenic to humans," polyaromatic hydrocarbons: "likely carcinogenic to humans," and naphthalene: "suggestive evidence of carcinogenicity."

National cancer risk contributors:
1,3-butadiene, arsenic compounds, chromium compounds, coke oven emissions: all “carcinogenic to humans.”
Acetaldehyde, acrylonitrile, carbon tetrachloride; ethylene oxide, tetrachloroethylene: all “likely carcinogenic to humans.”
1,4-dichlorobenzene: “suggestive evidence of carcinogenicity.”

Regional cancer risk contributors:
Nickel compounds: "carcinogenic to humans."
1,3-dichloropropene; methylene chloride: both "likely carcinogenic to humans.

National noncancer hazard drivers:

Regional noncancer hazard drivers:
2,4-toluene diisocyanate, chlorine, diesel PM, hexamethylene diisocyanate, hydrochloric acid, and manganese compounds.

Source: U.S. EPA