May 10, 2023 - Business

Des Moines' air quality improves while Iowa fight looms

A photo of MidAmerican's George Neal Center South plant near Sioux City.

MidAmerican Energy plans to phase out its five remaining coal plants by 2049. But groups like the Iowa Environmental Council are pushing the utility to shutter ones like this plant near Sioux City sooner. Photo courtesy of MidAmerican Energy

Air quality in the metro, as measured by fine particle pollution, has improved since 2000.

Why it matters: There's a national effort to set stricter universal air pollution limits, putting some Iowa industry and environmental advocates at odds.

State of play: Fine particles generated from fossil fuel-burning and other sources can enter our bodies when we breathe, making their way to the lungs or bloodstream and causing a myriad of health problems.

  • They are linked to nearly 11,000 excess deaths across the U.S. annually, by one estimate.
  • Known as PM2.5 due to their tiny size of 2.5 micrometers, they are the most hazardous form of particulate matter.

Zoom in: Non-white and low-income Americans have a higher risk of death from exposure to fine particle pollution compared to other groups, per a 2022 study published in Nature.

By the numbers: The three-year rolling annual average concentration of fine particle pollution across the DSM area was 8.8 micrograms per cubic meter as of 2021 (the latest year for which data is available). That's compared to 14.3 in 2000 — a 38% decrease.

  • Concentrations below 12 micrograms per cubic meter are considered healthy, the EPA says — though it is seeking to tighten that standard.
Air quality in the <b style='text-decoration: underline; text-underline-position: under; color: #6533ff;'>Des Moines</b> metro area and <b style='text-decoration: underline; text-underline-position: under; color: #13c278;'>U.S.</b>
Data: EPA; Note: A concentration below 12 micrograms per cubic meter is considered healthy; Chart: Axios Visuals

Driving the news: The EPA in January proposed reducing its fine particle pollution standard to "a level between 9 and 10" micrograms per cubic meter.

  • Changing the standard would prevent up to 4,200 premature deaths and 270,000 lost workdays per year, the agency says.
  • The EPA is taking other steps to improve air quality, including newly proposed vehicle emissions standards.

Yes, but: Public health advocacy groups like the American Lung Association say the fine particulate standard should be even lower than the EPA's proposed range.

  • Iowans who live near major polluters like coal plants commonly suffer from chronic asthma and die at younger ages, Karen Stein, the state coordinator for Moms Clean Air Force, wrote in testimony submitted last month to the EPA.

Meanwhile, industry groups like the Iowa Association of Business and Industry (ABI) argue that lowering the standard would be overly burdensome.

  • Setting "more onerous standards" and additional permitting is the wrong way to go, Nicole Crain, ABI's vice president, wrote to the EPA in March.

The bottom line: As the fight over lowering the fine particle standard heats up, the EPA once again finds itself at the heart of the climate change and public health debate.


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