Iowa's air pollutants nosedive in last 20 years

Iowa's air pollutant levels have fallen by more than 40% in the last two decades and overall air quality has improved, according to data from the state Department of Natural Resources (DNR).

• Emissions of sulfur dioxide and nitrogen oxide — gasses that can be toxic — are down more than 70% since 2002.

Why it matters: Clean air is linked to better health and a higher quality of life.

The big picture: Emissions reductions, driven by the federal Clean Air Act (CAA) of 1970, have led to a dramatic improvement in air quality across the U.S. over the last 50 years, according to the EPA.

• The combined emissions of the six most-tracked pollutants dropped by 78% between 1970 and 2020, according to EPA data.

Legislators also amended the CAA's air quality standards in 1990 to expand its reach and help fight acid rain, urban smog, toxic pollution and ozone destruction.

• New vehicles are now roughly 99% cleaner for common pollutants as compared to 1970 models, per the EPA.
• Pollution control technology is also required in new industrial facilities.

Yes, but: Despite progress, about 40% of Americans still live in places with failing grades for unhealthy levels of particle pollution or ozone, according to the American Lung Association's 2022 State of the Air report.

Zoom in: The largest contributor of Iowa air pollution tracked by the DNR is electricity generation, which has significantly fallen in recent years, according to a January report.

• Total emissions from the 39 electricity facilities that are tracked in Iowa decreased by 40,000 tons a year — almost 50% — between 2018 and 2020, DNR data shows.

What to watch: Iowa environmental groups are lobbying MidAmerican Energy to expedite the retirement of all of the utility's coal power generation plants in the state.

• They're also urging Des Moines to use an upcoming utility franchise agreement as a way to help achieve that goal quicker.
• Des Moines and MidAmerican are expected to approve an agreement next month to work together on eliminating fossil fuel electricity for its residents by 2035.