Indianapolis Metro Area Ozone Pollution Worsens

Indianapolis’ ozone pollution (smog) has worsened and the metro area is now ranked the 54th most polluted city in the nation, according to the 2018 “State of the Air” report released by the American Lung Association in Indiana today. This is a significant increase, as the city was ranked the 93rd most polluted city for ozone in last year’s report. The metro area also ranked 13th most polluted for year-round particle pollution and 21st most polluted for short-term particle pollution.

“The 2018 ‘State of the Air’ report finds that unhealthful levels of ozone and particle pollution in Indiana put Hoosiers at risk for premature death and other serious health effects such as asthma attacks and greater difficulty breathing for those living with a lung disease like COPD,” said Angela Tin, Vice President of Clean Air for the American Lung Association, Upper Midwest Region. “Across the nation, the report found improvement in air quality, but still, more than four in 10 Americans – 133.9 million – live in counties that have unhealthful levels of either ozone or particle pollution, where their health is at risk.”

Each year the “State of the Air” provides a report card on the two most widespread outdoor air pollutants, ozone pollution, also known as smog, and particle pollution, also called soot. The report analyzes particle pollution in two ways: through average annual particle pollution levels and short-term spikes in particle pollution. Both ozone and particle pollution are dangerous to public health and can increase the risk of premature death and other serious health effects such as lung cancer, asthma attacks, cardiovascular damage, and developmental and reproductive harm.

Ozone Pollution in the Indianapolis Metro Area
Compared to the 2017 report, Indianapolis experienced significantly more unhealthy days of high ozone in this year’s report. Marion County had 10 days that were classified as unhealthy in this year’s report compared to four days in last year’s report.

“Ozone especially harms children, older adults and those with asthma and other lung diseases,” said Tin. “When older adults or children with asthma breathe ozone-polluted air, too often they end up in the doctor’s office, the hospital or the emergency room. Ozone can even shorten life itself.”

This report documents how warmer temperatures brought by climate change make ozone more likely to form and harder to clean up. This year’s report showed that ozone levels increased in most cities nationwide, in large part due to warmer temperatures in 2016, the second hottest year on record in the U.S. Over the past decades, ozone pollution has decreased nationwide because the nation has cleaned up major sources of the emissions that create ozone, especially coal-fired power plants and vehicles.

Particle Pollution in the Indianapolis Metro Area
The 2018 report also found year-round particle pollution levels slightly lower than last year, although the area keeps the same ranking as the 2017 report – 13th most polluted. This is the lowest year ever for year-round particle pollution in Indianapolis. Nationwide, the best progress in this year’s report came in reducing year-round levels of particle pollution.

“Particle pollution is made of soot or tiny particles that come from coal-fired power plants, diesel emissions, wildfires and wood-burning devices. These particles are so small that they can lodge deep in the lungs and trigger asthma attacks, heart attacks and strokes, and can even be lethal,” said Tin. “Year-round particle pollution levels have dropped thanks to the cleanup of coal-fired power plants and the retirement of old, dirty diesel engines.”

“State of the Air” 2018 also tracked short-term spikes in particle pollution, as these can be extremely dangerous and even lethal. The report found that Indianapolis has the same amount of days when short-term particle pollution has reached unhealthy levels in 2014-2016.

The trends reported in this year’s report, which covers data collected by states, cities, counties, tribes and federal agencies in 2014-2016, reflect the ongoing challenges to reduce each pollutant in the changing political and outdoor climate.

“We can and should do more to save lives,” Tin said. “The Lung Association calls on our members of Congress to defend the Clean Air Act, currently under threat from those who want to weaken this effective public health law. We also call on the U.S. Environmental Protection Agency to implement and enforce the law instead of trying to roll back major safeguards like the Clean Power Plan and cleaner cars, both steps that help us fight climate change and reduce air pollution.” 

While the report examined data from 2014-2016, this 19th annual report provides online information on air pollution trends back to the first report covering 1996-1998. Learn more about Indianapolis rankings, as well as air quality across Indiana and the nation, in the 2018 “State of the Air” report at For media interested in speaking with an expert about lung health and healthy air, and threats to air quality, contact Jill Thompson at 312-940-7001 or at [email protected]

For more information, contact:

James A. Martinez
(312) 445-2501
[email protected]

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