Mar 25, 2024 - News

Air quality tanked across Midwest last year

Average air quality in major U.S. cities, 2023
Data: IQAir; Note: Among cities with at least 500k metro-area residents; Chart: Kavya Beheraj/Axios

Indianapolis and other Midwest cities saw some of the worst air quality in the country last year, with pollution levels two to three times higher than what the World Health Organization (WHO) recommends, according to a new report.

Why it matters: Air pollution is the world's leading environmental health threat, causing 6.7 million premature deaths every year, according to WHO estimates.

The big picture: After decades of progress, air quality in the U.S. is expected to steadily deteriorate over the coming decades as climate change causes more large wildfires, heat waves and drought, Axios' Jacob Knutson writes.

  • Most U.S. cities had levels one to two times higher than WHO guidelines, while pockets of the West met the guidelines, according to the report.

Flashback: Indianapolis experienced more days of dangerous air pollution last year than in more than a decade after smoke from massive Canadian wildfires blanketed the city.

How it works: The report is from IQAir. This Swiss air quality technology company maintains a global air quality system that continuously measures contaminants in thousands of cities worldwide.

  • The report examines the average level of fine particles less than 2.5 microns (PM2.5) in diameter — a particularly dangerous form of air pollution because the solid and liquid specks can penetrate deep into lung passageways.
  • Inhalation of PM2.5 can exacerbate pre-existing lung and heart conditions. Evidence suggests it can also have neurological effects.
  • Much of the fine particulate matter pollution in the U.S. and around the world is a byproduct of fossil fuel combustion and industrial activity, such as from car engines or concrete plants. Other drivers can include everything from dust storms to volcanoes, cigarettes and air fryers.

By the numbers: Columbus, Ohio had the worst air quality in the country last year for cities with at least 500,000 residents with a concentration of fine particulate pollution of 13.9 micrograms per cubic meter.

  • The Lancaster, Pennsylvania metro area was second worst (13.6), followed by Minneapolis (13.3), Chicago (13) and Detroit (12.9).
  • The pollution concentration in Indy's air averaged 12.6 micrograms, with a peak of 28 in June.

What we're watching: Before last year, Indianapolis had seen a marked improvement in air quality but now the question seems to be not if but how quickly the progress that had been made has been erased.


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