San Francisco Chronicle - (Sunday)
After smoke is gone, health impacts can linger long
“Now you have the combination of flu season and COVID and the wildfires. How are all these things going to interact come late fall or winter?”
Chris Migliaccio, immunologist
have found that people’s lung capacity declined in the first two years after the smoke cleared. Chris Migliaccio, an immunologist with the University of Montana, and his team found the percentage of residents whose lung function sank below normal thresholds more than doubled in the first year after the fire and remained low a year after that.
“There’s something wrong there,” Migliaccio said.
While it’s long been known that smoke can be dangerous when in the thick of it — triggering asthma attacks, cardiac arrests, hospitalizations and more — the Seeley Lake research confirmed what public health experts feared: Wildfire haze can have consequences long after it’s gone.
That doesn’t bode well for the 78 million people in the western United States now confronting historic wildfires.
Toxic air from fires has blanketed California and the Pacific Northwest for weeks now, causing some of the world’s worst air quality. California fires have burned roughly 2.3 million acres so far this year, and the wildfire season isn’t over yet. Oregon estimates 500,000 people in the state have been under a notice to either prepare to evacuate or leave. Smoke from the West Coast blazes has drifted as far away as Europe.
Extreme wildfires are predicted to become a regular occurrence due to climate change. And, as more people increasingly settle in fireprone places, the risks increase. That’s shifted wildfires from being a perennial reality for rural mountain towns to becoming an annual threat for areas across the West.
Dr. Perry Hystad, an associate professor in the College of Health and Human Sciences at Oregon State University, said the Seeley Lake research offers unique insights into wildfire smoke’s impact, which until recently had largely been unexplored. He said similar studies are likely to follow because of this fire season.
“This is the question that everybody is asking,” Hystad said. “‘I’ve been sitting in smoke for two weeks, how concerned should I be?’ ”
Migliaccio wants to know whether the lung damage he saw in Seeley Lake is reversible — or even treatable. (Think of an inhaler for asthma or other medication that prevents swollen airways.)
But those discoveries will have to wait. The team hasn’t been able to return to Seeley Lake this year because of the coronavirus pandemic.
Migliaccio said more research is needed on whether wildfire smoke damages organs besides the lungs, and whether routine exposure makes people more susceptible to diseases.
The combination of the fire season and the pandemic has spurred other questions as well, like whether heavy smoke exposure could lead to more COVID19 deaths. A recent study showed a spike in influenza cases following major fire seasons. “Now you have the combination of flu season and COVID and the wildfires,” Migliaccio said. “How are all these things going to interact come late fall or winter?” One of the known dangers of smoke is particulate matter. Smaller than the width of a human hair, it can bypass a body’s defenses, lodging deep into lungs. Lu Hu, an atmospheric chemist with the University of Montana, said air quality reports are based on how much of that pollution is in the air.
“It’s like lead; there’s no safe level, but still we have a safety measure for what’s allowable,” Hu said. “Some things kill you fast and some things kill you slowly.”
While air quality measurements can gauge the overall amount of pollution, they can’t assess which specific toxins people are inhaling. Hu is collaborating with other scientists to better predict how smoke travels and what pollutants people actually breathe.
He said smoke’s chemistry changes based on how far it travels and what’s burning, among other factors.
Over the past few years, teams of researchers drove trucks along fire lines to collect smoke samples. Other scientists boarded cargo planes and flew into smoke plumes to take samples right from a fire’s source.
Still others stationed at a mountain lookout captured smoke drifting in from nearby fires. And groundlevel machines at a Missoula site logged data over two summers.
Bob Yokelson, a longtime smoke researcher with the University of Montana, said scientists are getting closer to understanding its contents. And, he said, “it’s not all bad news.” Temperature and sunlight can change some pollutants over time. Some dangerous particles seem to disappear. But others, such as ozone, can increase as smoke ages.
Yokelson said scientists are still a long way from determining a safe level of exposure to the 100odd pollutants in smoke.
“We can complete the circle by measuring not only what’s in smoke, but measuring what’s happening to the people who breathe it,” Yokelson said. “That’s where the future of health research on smoke is going to go.”
Katheryn Houghton writes for Kaiser Health News, an editorially independent program of the Kaiser Family Foundation. Email: katherynhoughton @gmail.com Twitter: @K_Hought