Smoke from Canadian wildfires that turned skies along the East Coast a sickly yellow also brought air quality alerts to much of the Midwest this week. State health departments cautioned people with heart and lung conditions to reduce outdoor exposure.
It’s likely more days of bad air will come — not only are fires burning in the west in Alberta and Saskatchewan, and in the east in Quebec, but new blazes have erupted in Ontario, directly north of Minnesota, according to Minnesota Pollution Control Agency air quality meteorologist David Brown. The next plume could arrive Friday.
“We’re kind of surrounded at this point. Any wind direction is likely going to bring some smoke now,” Brown said.
In mid-May, sustained winds blew wildfire smoke in from the West, then a few slow-moving weather systems brought stagnant air that triggered ozone advisories.
“It’s been a very unique spring,” said Craig Czarnecki, outreach coordinator for the Wisconsin Department of Natural Resource’s air management program.
Climate experts say that as the planet continues to warm, this kind of spring will become less and less of an anomaly. In the process, air quality will continue to worsen, as will its impact on human health.
The largest fires have historically been concentrated in the West, and though there are examples of damaging fires elsewhere, wildfire scientists assumed the eastern part of the continent was immune from the worst effects, said Erica Smithwick, director of the Earth and Environmental Systems Institute at Penn State.
Higher temperatures, periods of drought and more volatile winds are yielding wildfires that burn faster and stronger than before, Smithwick said. Wildfire season is also getting longer, as rivers in the West dry out sooner and the East sees stronger storms mixed with drought. Some scientists question whether the whole idea of a wildfire season still applies.
“I’ve studied wildfires for decades, and I’m quite alarmed by the changes that we’re seeing to the wildfire systems,” Smithwick said.
The severity of the fires is even affecting how far their smoke can travel. Smithwick said the stronger the blaze, the higher into the atmosphere the smoke can waft, being picked up by winds that travel long distances and ultimately push it into places it wouldn’t normally go.
Poorer air quality means more respiratory, heart problems
Fine particulate matter, also known as PM2.5, is one of the main pollutants released from wildfire smoke, which are so tiny they “penetrate pretty deep into our lungs and get into our bloodstream,” according to Katelyn O’Dell, a researcher at George Washington University.
Hotter summers are also making stagnant air days more frequent, according to an analysis from Climate Central, a nonprofit news organization that analyzes and reports on climate science. During those stagnation events, pollutants like ozone get trapped and make breathing more difficult.
Both fine particles from wildfire smoke and ozone can cause respiratory issues like coughing, difficulty breathing and aggravated asthma. People doing physical activity outdoors, particularly those who already suffer from respiratory problems, will usually find it harder to do.
On top of that, PM2.5 can have more dramatic effects because the particles are small enough to get deep into the lungs and even the bloodstream.
“Particulate matter is one of the most well-studied types of air pollution, and it is incredibly dangerous to the body,” said Dr. Neelu Tummala, a clinical assistant professor of surgery and co-director of the Climate and Health Institute at George Washington University.
While short-term exposure typically results in respiratory concerns, chronic exposure brings worsening impacts like increased risk of heart disease, high blood pressure and stroke, Tummala said.
For Black, brown and low-income communities, which already bear a higher burden of air pollution, the recent short-term exposures could further elevate their risk.
Both fine particle and ozone exposure can also result in pregnancy complications like preterm births and babies with low birth weights, Tummala said.
And a 2021 study in the journal Pediatrics found that the particles in that smoke are 10 times more harmful to children’s respiratory health than other types of air pollution. Smithwick, who is also a representative of the Science Moms campaign, said kids are vulnerable because they are more active, play outside more and are still growing.
“We’re definitely going to be seeing this play out in our health systems for many years to come,” she said.
How to protect yourself
Pay attention to air quality. The Air Quality Index, or AQI, measures risk from dirty air on a scale of 0 to 500. The AQI doesn’t measure the amount of a specific pollutant but generally reflects health impact.
The Environmental Protection Agency’s AirNow site offers real-time readings of AQI and also shows where fires are burning and where smoke is wafting. Purple Air, a company that makes air sensors, also has a network of AQI sensor readings at map.purpleair.com.
People should start paying attention at the orange category of AQI — readings between 101 and 150. That’s when sensitive groups like children, the elderly and those with breathing or heart conditions can encounter problems, said Brown.
He added that relatively healthy people might start to feel headaches or chest tightness at the higher end of orange readings.
In the red category from 151 to 200 AQI, all people, regardless of health, may start to feel effects; the purple category from 201 to 300 is considered very unhealthy; and maroon readings of 301 or higher are hazardous.
Avoid time outdoors when the air is bad. Jesse Berman, assistant professor at the University of Minnesota’s School of Public Health, said it’s safest to stay inside with windows closed and air conditioning on. In a car, run the air conditioner set to re-circulate in the interior of the vehicle, he said.
Put those N95 masks back on. For those who have to be outside for work or commuting, try to relocate tasks or reschedule them, reduce strenuous activity, take breaks in a place free of smoke, and wear a well-fitting mask designed to filter out small particles, like an N95.
The Centers for Disease Control 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. In the home, air purifiers with high-quality HEPA filters can help remove pollution that sneaks inside, Berman said.
It may also be worth switching out the filter on a home HVAC system. Airflow filters with a higher MERV rating, an industry measurement of how effective the screen is in capturing small particles, can also help. The Environmental Protection Agency recommends MERV 13 or higher.
Berman warned, though, that tighter filters can clog more quickly and may need to be changed more often.
For a cheaper option, O’Dell recommended creating one at home with some filters taped to the four edges 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. Sign up to republish stories like this one for free.
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