Exposure to air pollution concentrations above NAAQS in the U.S. 2022, by pollutant
In 2022, roughly 78 million people in the United States lived in counties that were exposed to ozone concentrations above the levels determined by the National Ambient Air Quality Standards (NAAQS).
The NAAQS were established as part of the Clean Air Act and serve as limits on pollutant concentrations for outdoor air. The pollutants covered by the NAAQS include ozone, particulate matter, lead, carbon monoxide, sulfur oxides, and nitrogen oxides.