LEXINGTON, Ky. — Louisville residents are struggling to breathe some of the most polluted air in Kentucky, according to a new report from the American Lung Association released this week that has prompted renewed concerns about health impacts across the region.

The 2026 "State of the Air" report shows the Louisville metropolitan area earned failing grades for both ozone smog and year-round particle pollution, placing it among the 25 most polluted cities in the nation. The area has received an F grade for years as it experiences nearly 11 unhealthy air days annually.

For Lindsay Thurman, a Louisville high school math teacher living with rare pulmonary arterial hypertension, the polluted air presents a daily battle. "It just seems as though my lungs were kind of built wrong, and the blood vessels in my lungs constrict and thicken, which makes it harder for my heart to push blood into my lungs to pick up oxygen," Thurman said in the report.

The findings reveal the scale of Kentucky's air quality challenge. According to the American Lung Association, 176,359 children in Kentucky breathe air with unhealthy levels of pollution. The report, now in its 27th year, grades cities and counties based on three measures of air quality using data from 2022, 2023 and 2024.

Engine exhaust, factory emissions and wildfire smoke drifting into the Ohio Valley contribute to Louisville's poor air quality. Shannon Baker, advocacy director for the American Lung Association in Kentucky, said the trends reflect broader patterns. "Louisville really sort of ranks the worst in the state by most measures, struggling continuously with ozone smog, which has this year and landed us among the dirtiest 25 cities in the U.S."

The health consequences are significant. Air pollution can trigger asthma, with about 12 percent of Kentucky adults and nearly 7 percent of children overall having the condition, according to the Cabinet for Health and Family Services. Dr. Scott G. Bickel, a pediatric pulmonologist with Norton Children's, noted asthma rates are higher in areas with worse air quality.

"Both ozone and particle pollution can cause premature death and other serious health effects such as asthma attacks, heart attacks and strokes," Baker said in a statement accompanying the report. According to the American Lung Association, nearly 46 percent of American children live in counties that received a failing grade for at least one measure of air pollution.

The report did offer some positive news for Kentucky. Eight counties in Eastern Kentucky — Bell, Boyd, Carter, Greenup, Morgan, Perry, Pike and Pulaski — earned A grades for low ozone levels, ranking among the cleanest in the nation.

Louisville's Air Pollution Control District implements federal and state air pollution laws and provides live air quality forecasts to help residents plan their activities around unhealthy air days. Ground-level ozone is a particular problem during afternoons and early evenings between June and September, when most of the pollutants come from vehicle exhaust and factory emissions.

As Jefferson County ranked worst in the state for ozone smog, the report underscores ongoing challenges in protecting public health in Kentucky's largest metropolitan area despite years of efforts to improve air quality.