Minnesota's bad air days set records for poor air quality

DULUTH – The smoky haze that clouded Minnesota skies for long stretches of July and August set several state records for poor air quality.

Smoke from massive Canadian wildfires and later the Greenwood fire in Minnesota's Superior National Forest, filled the air with enough particulate matter to cause serious health problems.

Twenty air quality alerts have been issued across the state this year, according to the Minnesota Pollution Control Agency (MPCA), which tracks air quality and issues alerts when air is deemed unhealthy. That tops the record of six alerts in 2018.

Air quality has reached "very unhealthy" levels a record six times this year. Such levels can cause problems for those with underlying health issues as well as otherwise healthy people.

"That's unprecedented," said Daniel Dix, who supervises the Risk Evaluation and Air Modeling Unit for the MPCA. "We did touch the hazardous category for one or two hours, which is as bad as it is in some of these California wildfires."

While 2021 has seen exceptionally bad air quality readings, researchers and health scientist say these alerts may become more common because of widespread drought and climate change across the country.

"We've seen more severe fires in recent years. We have larger fires burning hotter and covering more area," said Jesse Berman, an air pollution expert and environmental health sciences professor at the University of Minnesota. "So it wouldn't be surprising if this becomes more of a common occurrence for us in Minnesota."

Smoke-filled air can lead to coughing or itchy eyes and can cause or worsen lung disease, even with short-term exposure, doctors say. Poor air quality often leads to an increase in emergency heart attacks.

"We tend to see it on bad air days in cities all over the world." Dr. Rory Farnan, an interventional cardiologist at Essentia Health, said this summer.

The fine particles in wildfire smoke — about one-thirtieth the thickness of human hair — get trapped deep in lungs, damage sensitive cells and can even cross into the bloodstream.

"Air quality warnings are very important," Berman said. "It affects everyone."

The particles are just part of the problem, however.

"When you have wood fire smoke travel a long distance, a lot of chemical reactions take place," Dix said. "It's much nastier than your campfire. It has more of a plastic smell due to all the other pollutants embedded in that."

An MPCA study found that 2,000 to 4,000 Minnesota deaths in 2013 resulted in part to "exposure to fine particles in the air or ground-level ozone," another common pollutant. That year saw several "moderate" air quality readings, especially in the Twin Cities metro area, but air reached "unhealthy for sensitive groups" levels just five times, according to the study released in 2019.

This year, parts of northeastern Minnesota have had air quality alerts for a combined 704 hours (nearly 30 days) as of Thursday. A record was set for parts of Lake and Cook counties around the Greenwood fire for the longest continuous air quality alert: 11 days, 13 hours. And this year marked the first time the entire state was under an air quality alert for more than one day.

As the Greenwood fire continues to burn, smoke may again reach those far from the forest. But the near-term forecast is promising.

"Smoke production has been minimal with the recent reduction in fire activity," the U.S. Interagency Wildland Fire Air Quality Response Program said. "Generally good air quality is expected across northern Minnesota."

Smoke from fires in the West may drift across the Midwest in coming days, according to FireSmoke Canada, which provides wildfire information and forecasts. "The season isn't over yet," Dix said.

If the air again reaches unhealthy levels, officials recommend limiting time and especially exertion outdoors, closing windows at home and in cars and paying attention to worsening cardiovascular symptoms.

"Very small and simple behavioral changes can often lead to keeping yourself and your family members safe," Berman said.

Brooks Johnson • 218-491-6496