Air Quality Summaries and Trends

Graphs of air quality trends can be used to compare historical air quality to modern air quality and to determine if control and abatement strategies have been effective. The six pollutants listed are considered "criteria" pollutants and have National Ambient Air Quality Standards (NAAQS) set by the EPA Office of Air Quality Planning and Standards (OAQPS).

The below air quality plots show the relative trends through the latest year available. Click the graph thumbnails below to view larger versions and additional information.

Ozone (O3)Thumbnail of a graph showing ozone trends in CT  Particulate Matter (PM) Thumbnail of a graph showing pm2.5 trends in CT   
Learn More About Ozone Pollution
Annual Summaries of Ozone Exceedance Days
Learn More About Particulate Matter Pollution
Carbon Monoxide (CO) Thumbnail of graph showing CO trends in CT  Nitrogen Dioxide (NO2) Thumbnail of graph showing NO2 trends in CT 
 Learn More About Carbon Monoxide Pollution
Learn More About Nitrogen Dioxide Pollution
Sulfur Dioxide (SO2) Thumbnail of graph showing SO2 trends in CT  Lead (Pb) Thumbnail of graph showing Pb trends in CT 
Learn More About Sulfur Dioxide Pollution Learn More About Lead Pollution


Additionally, the EPA annual air quality summary reports can be found in the following link: Annual Air Quality Summary


Content last updated on May 22nd, 2023