FACILITIES EMITTING CRITERIA AIR POLLUTANTS
Criteria air pollutants are the six most common air pollutants in the U.S. The poor air quality that many Americans know as smog and soot is actually due to criteria pollutants like ozone and particulate matter. Exposure to criteria pollutants can cause breathing difficulties, aggravate heart and lung disease, and result in premature mortality. Over 100 million people still live in counties with unhealthy air. This pollution comes from mobile, area and point sources.
For environmental justice analyses, Scorecard uses a measure of the number of facilities emitting criteria air pollutants per square mile.
NOTE: Facilities per square mile is a relatively weak indicator of the potential for unhealthy exposures to criteria air pollutants, because it does not capture the amount of chemicals released by a facility, or the importance of other major sources like cars. For more, see Scorecard's overview of smog and particulates.
IMPORTANT NOTE - TEMPORARY DISCREPANCY: Scorecard's environmental justice reports are in the process of being updated to 2000 census data and more current environmental data. The data underlying environmental justice reports will differ from other sections of Scorecard until this update is complete. For example: cancer risks from hazardous air pollutants in environmental justice reports are based on 1990 EPA exposure estimates and 1990 census data, while Hazardous Air Pollutant reports have been updated to 1996 EPA exposure estimates and 2000 census data. Toxic chemical release indicators are based on 1998 TRI data, while Toxic Chemical Release reports have been updated to 2001 data.