This site provides information for air quality data analysts inside and outside EPA. Much of the information is in the form of documented analyses that support EPA's NAAQS Review Process. The site also contains other documented analyses of special interest.
NAAQS Reviews - Air Quality Analyses and Data Sets
The Clean Air Act requires EPA to set national air quality standards for particulate matter and five other pollutants considered harmful to public health and the environment (the other pollutants are ozone, nitrogen oxides, carbon monoxide, sulfur dioxide and lead). The law also requires EPA to periodically review the standards to ensure that they provide adequate health and environmental protection, and to update those standards as necessary. Learn more about this process
Analyses supporting the NAAQS Review Process are ongoing. As analyses are completed, they will be posted along with source data at the links below.
This site links to documents concerning the review and handling of Exceptional Events. These events are unusual or naturally occurring events that can affect air quality but are not reasonably controllable using techniques that tribal, state or local air agencies may implement in order to attain and maintain the National Ambient Air Quality Standards.
This site links to Special Studies that describe policy-relevant information. Topics include analysis of Particulate Matter (PM) concentrations that will help policy makers understand sources of PM and its precursors, trends of carbon monoxide, ozone exceedances, and characterization of national spatial variation.