NASA Study: Wildfire Smoke Erases Midwest Ozone Gains

Wildfire smoke is undoing years of hard-won progress on air quality right here in the Midwest. A new NASA-funded study reveals that wildfires have worsened ground-level ozone pollution across the country, effectively wiping out nearly four years of regulatory gains nationally. For the Midwest, the setback is even steeper.

Researchers found that without wildfire pollution, ground-level ozone in the Midwest would have kept declining. Instead, smoke from distant fires erased about 5.3 years of ozone-control progress since 2015. It is a stark reminder that heavy local regulations cannot stop pollution that drifts across state and international borders.

Midwest Hit Hard by Distant Fires

The study, published June 4 in the journal Science, highlights a reality that many Iowans might not expect. When we think of wildfire smoke, we usually picture the soot and ash that makes the sky look hazy. But smoke also carries invisible gases like carbon monoxide. When sunlight hits those gases and mixes them with other pollutants, it creates surface ozone.