As wildfire smoke clears, scientists warn air quality impacts aren’t over
“By the afternoon we couldn’t see the sun at all,” said Channell, who works as the events director for an aviation museum.
The rest of the week, Channell described feeling a sense of helplessness as smoke from Canadian wildfires enveloped the northeastern US, bringing hazardously high air pollution levels to millions of people.
New York City’s air quality index (AQI) reached a staggering 460 – the highest level of air pollution recorded in the city since measurements began in 1999 and more than an order of magnitude higher than the safe daily average of 35 set by the Environmental Protection Agency (EPA). Dangerous air pollution levels were also detected in Philadelphia and Washington, DC.
Channell mostly stayed indoors, making coffee and sending emails under an Armageddon orange sky, his air purifier running nonstop. When he tried to go for a walk, he quickly found it hard to breathe.
As the smoke blotted out the sun in Brooklyn, Jes Lyons, a publicist who suffers from asthma, decided to wear a mask even while in her apartment. She feared her drafty apartment windows would not provide sufficient protection from the toxins wafting through the air.
Lyons made it through the worst of the week without an asthma incident, but some New York City residents were less lucky – emergency room visits for asthma nearly doubled from Tuesday to Wednesday.
After a few hazardous days, the region’s air quality has improved. But meteorologists warn that smoke may return to northeastern skies this summer as Canadian wildfires rage on. While frequent and more intense wildfires bolstered by the warming climate have become a frightening new normal for the American West, scientists say smoke from burning forests will continue to have far-reaching air quality impacts.
Indeed, pollution from wildfires constitutes a growing source of poor air quality globally, a study published last July stated.
“The fire season is going to last longer and start earlier, and that’s going to impact everyone, not just the western US,” said Olivia Sablan, a graduate student at Colorado State University who researches pollution from smoke.
A worsening crisis
Eastern Canada is in the midst of a record-setting fire season, with 150 fires in Quebec alone. The western US has also been overcome by blazes in recent years, with extreme wildfire seasons between 2020 and 2022 shocking “many wildfire managers, as several huge blazes burned for months, others incinerated entire communities, and still others erupted during nighttime wind events…” according to the National Ocean and Atmospheric Administration (NOAA)’s website.
Human-caused climate change is the main driver behind the increase in US wildfires in recent decades, a 2021 study in the journal Proceedings of the National Academy of Sciences concluded. Smoke from these fires has erased decades of progress towards cleaner US air quality, exposing millions of Americans each year to dangerous pollutant levels, according to a 2022 study in Environmental Science & Technology.
More toxic than tailpipes?
Wildfire smoke contains particulate matter that measures 2.5 microns in diameter or smaller – a size at which the particles can embed themselves in the lungs and enter other parts of the body, affecting the heart, brain, and developing fetuses, said Kristie Ebi, a professor in the Center for Health and the Global Environment at the University of Washington.
While plenty of research exists on the health effects of urban air pollution, wildfire smoke particles are made of different chemicals. And unlike other air pollutants, people tend to encounter wildfire smoke in short bursts at high concentrations rather than through chronic exposure.
“Almost all of that research is about the kinds of air pollution one experiences in cities from pollution that comes out of tailpipes,” said Ebi. “There are some indications that wildfire smoke could be more toxic than what comes out of tailpipes.”
George Thurston, a researcher who studies the human health effect of air pollution at the New York University School of Medicine, is working to understand what the wildfire smoke particles that filled the city last week are made of and how their toxicity com
pares to the pollutants New Yorkers are normally exposed to.
“I’m a little bit of an air pollution detective,” he said. “We’ve been busy trying to get some samples so we can look at these particles and see what they’re like…[and how they] compare with particles we collect on a routine basis from diesel trucks, traffic, oil burning, and power plants. From what I know about these wood particles, they’re probably very different.”
So far, Thurston and his team are finding that the particles likely don’t contain a lot of black carbon soot, a chemical associated with fossil fuels.
“It’s plant matter, so along with the fine particles it’s probably biological matter,” he said, noting that particulate matter from plants can trigger allergic reactions.
Preparing for future wildfire smoke
With dangerous air quality fluctuations from wildfires expected to continue, experts say individuals and communities should be prepared.
“Hopefully you’re indoors when these kind of smoke events happen,” said Mark Hernandez, an environmental engineer and professor at the University of Colorado Boulder. “If you’re outside, you should have a mask on – a well-fitting N-95 mask. Medical grade mask won’t help.”
When sheltering inside with doors and windows closed, Hernandez recommends using a high efficiency particulate air (HEPA) filter, although he notes this may not be an option for members of low-income communities.
“Some people can’t afford that,” he said. “They have to choose between groceries and a HEPA filter, and that’s when things get tough.”
Hernandez suggests communities invest in higher performing buildings with better ventilation and filtration systems, noting that better equipped buildings work on both viruses such as SARS-CoV-2 and wildfire smoke.
Communities should also work to incorporate wildfire smoke warnings in the warning systems they already have for heat waves and other types of natural disasters, said Ebi. As these systems are being developed, representatives from particularly vulnerable groups should be included, she added, such as the unhoused, racial minorities, and people who provide services to elderly care facilities and schools.