A case study
Seeley Lake has long known smoke. It sits in a narrow valley between vast stretches of thick forests.
On a recent September day, Boyd Gossard stood on his back porch and pointed toward the mountains that were ablaze in 2017.
Mr. Gossard, 80, expects to have some summer days veiled in haze. But that year, he said, he could hardly see his neighbor’s house a few hundred feet away.
“I’ve seen a lot of smoke in my career,” said Mr. Gossard, who worked in timber management and served as a wildland firefighter. “But having to just live in it like this was very different. It got to you after a while.”
When Missoula County health officials urged people to leave town and flee the hazardous smoke, many residents stayed close to home. Some said their jobs wouldn’t let them leave. Others didn’t have a place to go – or the money to get there.
Health officials warned those who stayed to avoid exercising and breathing too hard, to remain inside, and to follow steps to make their homes as smoke free as possible. The health department also worked to get air filters to those who needed them most.
But when flames got too close, some people had to sleep outside in campsites on the other side of town.
Understanding the science of smoke
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, PhD, 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,” Dr. 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. Dr. 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 ground-level machines at a Missoula site logged data over 2 summers.
Bob Yokelson, PhD, 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.
Dr. Yokelson said scientists are still a long way from determining a safe level of exposure to the hundred-odd 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,” Dr. Yokelson said. “That’s where the future of health research on smoke is going to go.”
Coping with nowhere to flee
In the meantime, those studying wildland smoke hope what they’ve learned so far can better prepare people to live in the haze when evacuation isn’t an option.
Joan Wollan, 82, was one of the Seeley Lake study participants. She stayed put during the 2017 fire because her house at the time sat on a border of the evacuation zone. The air made her eyes burn and her husband cough. She ordered air filters to create cleaner air inside her home, which helped.
On a recent day, the air in Mrs. Wollan’s new neighborhood in Missoula turned that familiar gray-orange as traces of fires from elsewhere appeared. Local health officials warned that western Montana could get hit by some of the worst air quality the state had seen since those 2017 fires.
If it got bad enough, Mrs. Wollan said, she’d get the filters out of storage or look for a way to get to cleaner air – “if there is someplace in Montana that isn’t smoky.”
KHN (Kaiser Health News) is a nonprofit news service covering health issues. It is an editorially independent program of KFF (Kaiser Family Foundation), which is not affiliated with Kaiser Permanente.