An official website of the United States government.

This is not the current EPA website. To navigate to the current EPA website, please go to www.epa.gov. This website is historical material reflecting the EPA website as it existed on January 19, 2021. This website is no longer updated and links to external websites and some internal pages may not work. More information »

National Air Quality: Status and Trends of Key Air Pollutants

EPA tracks trends in six key pollutants called criteria air pollutants.

Explore air quality trends interactively - Our Nation's Air: Status and Trends Through 2019
(link will open in a new tab or window)

National Air Quality: Status and Trends of Key Air Pollutants