Which pollutants are primarily regulated by the NAAQS?

The primary pollutants regulated by the National Ambient Air Quality Standards (NAAQS) are known as criteria air pollutants. These are specific pollutants that have been identified by the Environmental Protection Agency (EPA) as harmful to public health and the environment, and they have established standards to protect air quality.

Criteria air pollutants include substances such as particulate matter, sulfur dioxide, carbon monoxide, nitrogen dioxide, ozone, and lead. These pollutants have established health and environmental effects, and NAAQS aims to ensure that air quality remains within safe limits to protect the health of the public and the environment.

Other pollutants mentioned, like volatile organic compounds, heavy metals, and greenhouse gases, may be regulated under different frameworks or guidelines, but they are not classified as criteria pollutants under the NAAQS. Thus, the focus on criteria air pollutants aligns with the standards developed by the EPA to monitor and improve air quality.