New ‘State of the Air’ Report Finds Hoosiers Are Breathing Some of the Most Polluted Air in the Country

The air quality in Greater Indianapolis has worsened according to the American Lung Association’s 2025 “State of the Air” report, released today. Residents are being exposed to more unhealthy ozone smog and particle pollution the report finds. In fact, the Indianapolis metro area ranks as the 54th worst in the nation for ozone pollution with 5 unhealthy days per year and ranks as the 21st worst in the nation for particle pollution with 9.8 unhealthy days per year.

The report also found that nearly half of the U.S. population, 156 million people, live in areas with unhealthy levels of air pollution. Researchers add extreme heat and wildfires contributed to the worsening air quality across much of the country.

The Lung Association’s 26th annual “State of the Air” report grades exposure to unhealthy levels of ozone air pollution and particle pollution over a three-year period (2021-2023). The report looks at the latest quality-assured air quality data from 2021-2023. Findings for the Indianapolis Metro Area:

• Ground-level Ozone Pollution in the Indianapolis-Carmel-Muncie, IN metro area:
  • National Ranking: 54th worst out of 228 (60th worst in 2024 report)
  • Number of Unhealthy Days Per Year: 5 days per year (2 days per year in 2024 report)
  • Grade: F, Marion County worst in metro area (C in 2024 report)
• Particle Pollution in the Indianapolis-Carmel-Muncie, IN metro area:
  • National Ranking: 21st worst out of 223 (32nd worst in 2024 report)
  • Number of Unhealthy Days Per Year: 9.8 days per year (5.8 days per year in 2024 report)
  • Grade: F, Marion County worst in metro-area (F in 2024 report)
• Year-Round Average Level of Particle Pollution in the Indianapolis-Carmel-Muncie, IN metro area:  
  • National Ranking: 11th worst in the nation (11th worst in 2024 report)
  • Grade: Failing grade, pollution levels above the federal standard

Ozone smog and particle pollution are widespread and can impact anyone’s health. Both pollutants can cause premature death and other serious health effects such as asthma attacks, heart attacks and strokes, preterm births and impaired cognitive functioning later in life. Particle pollution can also cause lung cancer.

“Unfortunately, too many Hoosiers in Greater Indianapolis are living with unhealthy levels of ozone and particle pollution. This air pollution is a threat to human health at every stage of life – from increasing the risk of premature birth and low birth weight babies to causing or worsening lung disease,” said Tiffany Nichols, Advocacy Director for the American Lung Association.

“We urge Indiana’s Federal policymakers to take action to improve our air quality, including voting for strong policies that address indoor air pollution and climate change, and we are calling on everyone to support the incredibly important work of the U.S. Environmental Protection Agency (EPA).”

Air quality in most other areas of the state also worsened since last year’s report. Highlights include: The South Bend metro area ranked 42nd worst for ozone pollution and 48th worst for year-round particle pollution; and the Terre Haute metro area ranked 45th worst for year-round particle pollution and its grade for ozone pollution fell from a B to a D.

On a national level, the “State of the Air” report found that 156 million people in the U.S. (46%) live in an area that received a failing grade for at least one measure of air pollution. 42.5 million people live in areas with failing grades for all three measures. The report also found that a person of color in the U.S. is more than twice as likely as a white individual to live in a community with a failing grade on all three pollution measures. Notably, Hispanic individuals are nearly three times as likely as white individuals to live in a community with three failing grades.

The Lung Association is calling on everyone to support the U.S. Environmental Protection Agency. The EPA is essential to protecting people’s health from ozone and particle pollution. Join the American Lung Association in advocating to protect EPA’s expert staff and lifesaving programs. See the full report results and take action at Lung.org/sota.

The “State of the Air” report relies on data from air quality monitors managed by state, local and Tribal air pollution control authorities in counties across the U.S. The rankings are based on the worst county in the area’s average number of unhealthy days.

Get involved and help the mission of American Lung Association. The Indiana Gala is Saturday, April 26, 2025.

Media Resources

• B-roll: Media | American Lung Association
• American Lung Association Logos: American Lung Association Digital Logos | Powered by Box