Air Quality Increasingly Unhealthy Across US, Including in Connecticut

The American Lung Association’s “State of the Air” 2025 report finds that even after decades of successful efforts to reduce sources of air pollution, 46% of Americans—156.1 million people—are living in places that get failing grades for unhealthy levels of ozone or particle pollution. This is nearly 25 million more people breathing unhealthy air compared to last year’s report, and more than in any other “State of the Air” report in the last ten years.

Extreme heat, drought and wildfires are contributing to worsening levels of air pollution across much of the U.S., exposing a growing proportion of the population to ozone and particle pollution that put their health at risk.

“Families across the U.S. are dealing with the health impacts of air pollution every day, and extreme heat and wildfires are making it worse. Air pollution is causing kids to have asthma attacks, making people who work outdoors sick, and leading to low birth weight in babies. This year’s report shows the dramatic impact that air pollution has on a growing number of people,” said Harold Wimmer, President and CEO of the American Lung Association.

The “State of the Air” report looks at two of the most widespread and dangerous air pollutants, fine particles and ozone.

In Connecticut, the grades in the 2025 report tell the story.  In Particle Pollution category, 5 of Connecticut’s 8 counties provided sufficient data, and four of those (Fairfield, Hartford, Litchfield, New London) earned a D grade.  The fifth, New Haven county, received an F.  In the High Ozone Days category, all 8 counties provided sufficient data.  Windham received a C grade, Hartford, Litchfield and Tolland received a D, and the other four counties received an F grade.  More information about Connecticut and the overall report can be seen here.   

The air quality data used in the report are collected at official monitoring sites across the United States by federal, state, local and Tribal governments. The Lung Association calculates values reflecting the air pollution problem and assigns grades for daily and long-term measures of particle pollution and daily measures of ozone.

After several years of reporting that the worst of the nation’s air quality problems were increasingly concentrated in western states, “State of the Air” 2025 finds the geographic distribution of air pollution shifting to the East.

In addition, research has shown that communities of color are disproportionately exposed to unhealthy air and are also more likely to be living with one or more chronic conditions that make them more vulnerable to air pollution, including asthma, diabetes and heart disease. Although people of color make up 41.2% of the overall population of the U.S., they are 50.2% of the people living in a county with at least one failing grade. Notably, Hispanic individuals are nearly three times as likely as white individuals to live in a community with three failing grades.