The hazy sun hangs behind the smoke of the Canadian wildfire above an oak tree in southern Wisconsin on June 4. (Photo by Tom Purdy via Twitter)
Smoke from Canada's wildfires that turned skies along the East Coast a sickly yellow also brought air quality warnings across much of the Midwest last week. State health agencies warned people with heart and lung conditions to reduce outdoor exposure.
More bad air days are likely to come — not only are fires burning to the west in Alberta and Saskatchewan and to the east in Quebec, but new fires have broken out in Ontario, just north of Minnesota, according to the Minnesota Air Pollution Control Agency's qualitative meteorologist David Brown. The next plume could arrive on Friday.
“We're kind of surrounded at this point. Any wind direction is likely to bring in some smoke now,” Brown said.
In mid-May, steady winds brought smoke from the west, and then a few slow-moving weather systems brought stagnant air that prompted ozone warnings.
“It's been a very unique spring,” said Craig Czarnecki, outreach coordinator for the Wisconsin Department of Natural Resources' air management program.
Climate experts say that as the planet continues to warm, this type of spring will become less of an anomaly. Along the way, air quality will continue to deteriorate, as will its impact on human health.
The largest fires have historically been concentrated in the West, and although there are examples of devastating fires elsewhere, wildfire scientists assumed the eastern part of the continent was immune to the worst effects, said Erica Smithwick, director of the Earth and Environmental Systems Institute at Penn State.
Warmer temperatures, dry spells and more erratic winds are causing fires to burn faster and harder than before, Smithwick said. The fire season is also getting longer as rivers in the West dry up earlier and the East sees stronger storms mixed with drought. Some scientists question whether the whole fire season idea is still valid.
“I've studied wildfires for decades, and I'm quite alarmed by the changes we're seeing in fire regimes,” Smithwick said.
The severity of fires even affects how far their smoke can travel. Smithwick said the stronger the blaze, the higher into the atmosphere the smoke can be blown, picked up by winds that travel long distances and eventually push it to places it wouldn't normally go.
Poor air quality means more respiratory, heart problems
Fine particles, also known as PM2.5, are one of the main pollutants released by forest fire smokewhich are so tiny that they “penetrate deep enough into our lungs and into our bloodstream,” according to Katelyn O'Dell, a researcher at George Washington University.
Hotter summers also make stagnant days more frequent, according to an analysis by Climate Central, a nonprofit news organization that analyzes and reports on climate science. During these stagnation events, pollutants such as ozone become trapped and make breathing more difficult.
Smoke from Canada's wildfires casts a golden glow across the sky as the sun sinks behind South St. High School. Paul in Minnesota on June 6. (Photo by Mark J. Westpfahl via Twitter)
Both fine particles from wildfire smoke and ozone can cause respiratory problems such as coughing, difficulty breathing and worsening asthma. People who do physical activity outdoors, especially those who already suffer from respiratory problems, will usually find it difficult to do so.
In addition, PM2.5 can have more dramatic effects because the particles are small enough to get deep into the lungs and even into the bloodstream.
“Particulate matter is one of the most well-studied types of air pollution and is incredibly dangerous to the body,” said Dr. Neelu Tummala, clinical assistant professor of surgery and co-director of the Institute for Climate and Health at George Washington University.
While short-term exposure usually leads to respiratory problems, chronic exposure brings about worsening effects such as an increased risk of heart disease, high blood pressure and stroke, Tummala said.
For black, brown and low-income communities, which already bear a greater burden of air pollutionrecent short exposures could further increase their risk.
Both exposure to fine particles and exposure to ozone can also lead to pregnancy complications, such as premature births and low birth weight babies, Tummala said.
And one 2021 study in the journal Pediatrics found that the particles in this smoke are 10 times more harmful to children's respiratory health than other types of air pollution. Smithwick, who is also its representative Science Moms Campaignshe said children are vulnerable because they are more active, play outside more and are still growing.
“We will certainly see this playing out in our health systems for many years to come,” he said.
How to protect yourself
Attention to air quality. The air quality index, or AQI, measures the risk from dirty air on a scale of 0 to 500. AQI does not measure the amount of a specific pollutant, but generally reflects the impact on health.
of the Environmental Protection Agency AirNow website it offers real-time AQI readings and also shows where fires are burning and where smoke is rising. Purple Air, a company that manufactures air sensors, also has a network of AQI sensor measurements at map.purpleair.com.
People should start paying attention to the AQI's orange category — readings between 101 and 150. That's when sensitive groups like children, the elderly and those with respiratory or heart conditions may run into trouble, Brown said.
He added that relatively healthy people may start to feel headaches or chest tightness at the higher end of orange readings.
In the red category of 151 to 200 AQI, all people, regardless of health, may begin to feel effects. the purple category from 201 to 300 is considered very unhealthy. and coffee counts of 301 or higher are dangerous.
The sun rises through a light fog in Bayside, Wis. on May 23. Due to the wildfires in Canada, smoke has drifted into the region affecting weather and air quality. (Mike De Sisti/The Milwaukee Journal Sentinel)
Avoid time outside when the air is bad. Jesse Berman, an assistant professor at the University of Minnesota School of Public Health, said it's safer to stay inside with the windows closed and the air conditioning on. In a car, run the air conditioner set to recirculate inside the vehicle, he said.
Put those N95 masks back on. For those who must be outside for work or commuting, try to move or reschedule tasks, reduce vigorous activity, take breaks in a smoke-free area, and wear an appropriate mask designed to filter small particles, such as an N95 .
The Centers for Disease Control and PRevention warns, however, that N95 masks are not made to fit children and will not work effectively to protect them from smoke.
Filter your indoor air. At home, air purifiers with high-quality HEPA filters can help remove pollution that's lurking inside, Berman said.
It may also be worth disabling the filter in a home HVAC system. Airflow filters with a higher MERV rating, an industry measurement of how effective a screen is at capturing small particles, can also help. The Environmental Protection Agency recommends MERV 13 or higher.
Berman cautioned, however, that tighter filters can clog more quickly and may need to be changed more often.
For a cheaper option, O'Dell recommended building one at home with a few filters taped to the four ends of a box fan—a do-it-yourself method known as a Corsi-Rosenthal box.
This story is a product of the Mississippi River Basin Ag & Water Desk, an independent reporting network based at the University of Missouri in partnership with Report for America, funded by the Walton Family Foundation.
