Smoke from wildfires in Canada in July 2021 caused poor air quality and visibility in the Twin Cities. Credit: Jaida Grey Eagle | Sahan Journal

Haze hung over an empty beach at Bde Maka Ska in south Minneapolis the afternoon of July 21. The downtown skyline, typically a picturesque backdrop, almost disappeared behind a curtain of smoke. 

Wildfires in the Quetico Provincial Park, across the Canadian border from the Boundary Waters Canoe Area Wilderness, sent smoke billowing into Minnesota on July 19 and 20, causing days of poor air quality. These weather-driven events can be dangerous for the very young, the elderly, and those with respiratory conditions and other health problems. 

Winds blowing west across the Great Lakes through Wisconsin funnelled additional smoke into central Minnesota and the Twin Cities metropolitan area, which prompted state officials to issue poor air quality alerts and to urge residents to stay indoors as much as possible. 

The Environmental Protection Agency’s Air Quality Index, a tool used by researchers to measure the amount of ozone and hazardous particulate matter in the air, hit highs just over 150 in the metro on the evening of July 20.

By the next afternoon, those air quality levels had dropped into the mid 80s. And a small group of walkers, runners, and cyclists circled Bde Maka Ska seeking a midday break, despite the heavy air.  Among them was Abdulahi Osman and his father, Mohamed. Abdulahi likes to run around the lake in the evenings, but takes his elderly father out on walks during the day. 

“It’s a relief to walk around the lake,” Abdulahi said. “It’s a lot of fun.” 

The pair said they’d avoided the outdoors on July 20, when the Air Quality Index registered a level dangerous for just about anyone. But they appreciated the sparse crowd and the unusually cool late July weather on their walk the next day.  

With drought covering most of Minnesota and hot days in the forecast, the summer of 2021 has highlighted the reality of climate change for many Minnesotans. And it may be changing the way residents perceive this normally beloved season in the upper Midwest. Indeed, only the intense smoke cover obscuring the sun delayed the heatwave that hit July 23. 

“These smoke events are certainly upending our conceptual knowledge of where poor air quality occurs in the state,” said David Brown, an air quality forecaster and meteorologist with the Minnesota Pollution Control Agency. 

Dangerous smoke, disproportionate impact

On July 20, wildfire smoke caused record-setting levels of poor air quality in northern Minnesota, Brown said. Red Lake Nation measured an Air Quality Index reading of 397 on that Tuesday, and dangerously high levels persisted throughout the day. Those measurements were unprecedented, Brown said. 

Heavily polluted air presents health risks to the old, the young, and people with conditions such as asthma and chronic obstructive pulmonary disease (COPD), Brown said. But at Air Quality Index levels approaching 400 “anyone can be impacted.”

The Air Quality Index measures pollution levels between 0 and 500, using a color scale from green to maroon. Any number lower than 50 (green) is considered good. People sensitive to air quality can start feeling affected at moderate (yellow) levels, above 50. Most healthy people don’t feel the pollution until it reaches unhealthy (red) levels at 150. When the Air Quality Index is more than 300, it enters the hazardous (maroon) marker, meaning anybody exposed for extended times can begin to feel ill. 

Dr. Niladri Aichbhaumik of St. Paul Allergy and Asthma, a specialty health clinic, said poor air quality is a common trigger for the asthmatic population. He has patients who reported shortness of breath and chest tightness the week of July 21. But, luckily, no one needed to come in to treat acute symptoms. 

Everyone should avoid the outdoors as much as possible when air quality warnings are issued, Aichbhaumik said. The Air Quality Index is available on most smart phone weather apps. People can also search, a federal database that gives air quality readings in real time for the entire nation.  The Minnesota Pollution Control Agency provides updates on Air Quality Index online and via its Twitter account.

Those who must be outdoors should lean into lessons from COVID-19 and consider wearing masks that can help filter out particles in the air, such as the KN95 and N95 masks that have been used during the pandemic. 

With the smoky skies giving way to hot weather, the same sensitive groups need to keep their guard up. 

“The high heat and humidity can impact these same patients,” Aichbhaumik said. 

In Minnesota, asthmatic patients are disproportionately people of color. Black and Indigenous students are more likely to be diagnosed with asthma than their peers, according to the Minnesota Department of Health. African Americans have an asthma death rate four times higher than that of white Minnesotans. 

That disparity is evident across the United States to doctors who treat asthmatic patients, Aichbhaumik said. Many people of color also lack access to good and affordable care to manage asthma, he said. 

Smoke in the summer may leave people more vulnerable to flu in the winter 

The impacts of pollution from wildfires, transportation, and energy production are all socially patterned, according to Sheryl Magzamen, an epidemiologist who studies asthma and air pollution at Colorado State University. People with low incomes, communities of color, and recent immigrants often live closer to polluting industries, railways, highways, and the like.

“BIPOC communities are disproportionately exposed to all types of ambient air pollution,” she said.

Magzamen’s research includes wildfire pollution and the impacts for those living adjacent to the blazes, and farther away, too. Summer fires are the norm for people living in the Mountain West, and residents there are generally more aware of risks from fire and smoke, she said. But for people farther from the flames, there’s less knowledge about those health impacts. 

Large wildfires emit huge amounts of smoke, which can stay intact and travel long distances, causing issues for people thousands of miles away. That smoke can lead to changes in lung function, cardiovascular health, and blood pressure, she said. While the long-term effects are hard to measure, researchers believe impacts can linger. 

A recent study conducted in Montana found average lung function levels for healthy residents had not returned to normal a full year after exposure to wildfire smoke, Magzamen said. A separate study discovered that people exposed to wildfire smoke during the summer were more susceptible to flu the next season. 

‘Smoke will come and go’  

Sporadic rain events have not eased dry conditions in Minnesota this summer. About 72 percent of the state is experiencing severe drought and 18.5 percent is in extreme drought, according to the U.S. Drought Monitor. Those hot, dry conditions make fertile ground for wildfires. 

For now, northern-blowing winds have pushed the smoke back toward Canada, offering air quality relief for Minnesota. But with no sign of drought conditions improving and heat rising, the boreal forest will likely continue to burn. 

“We’re going to continue to experience these drought conditions and this heat for several more weeks, which means the fires will stick around for a while and the smoke will come and go throughout the summer,” Brown said.  

The seasonal pattern of heat, drought, and fire is “all tied to climate change,” Magzamen said. 

How to avoid the heat and foul air

Doctors and meteorologists recommend avoiding the outdoors during smoke events and excessive heat. In Minnesota, those without air conditioning, or who don’t want to rack up a large utility bill, can head to local public libraries. 

Seeking relief at libraries is “increasingly popular across the system,” according to Joshua Yetman, the spokesperson for Hennepin County libraries. The libraries are emerging from limited hours and are still building out the extended evening hours once common before the pandemic. People coming to spend time reading, surfing the web, or relaxing at libraries can also seek connections to other county services, Yetman said. 

High heat advisories are returning to central and southern Minnesota July 27 and 28, with highs well into the 90s. Elevated humidity levels that will push the heat index over 100 degrees, according to MPR meteorologists. The Twin Cities has recorded 90-degree temperatures on 20 days this year—already 9 days more than the annual average. 

Andrew Hazzard is a staff reporter with Sahan Journal who focuses on climate change and environmental justice issues. After starting his career in daily newspapers in Mississippi and North Dakota, Andrew...