One night in 2016, Laurie Crosbie woke up in her cabin off California’s Huntington Lake feeling like she was breathing underwater.
Located an hour and a half outside of Fresno, the cabin was in the cross-currents of local wildfires that raged during that drought-stricken summer. Smoke had filled the rooms and the fire alarm was going off.
“I felt like I was drowning,” Crosbie recalled.
Days later, she still couldn’t breathe properly and went to the doctor, who used a spirometer to measure how well she could inhale and exhale.
The result was shocking: Crosbie had lost 20 percent of her lung capacity, even though she was a non-smoker, physically active, and otherwise healthy. Simply inhaling and exhaling fire-tinged air had crippled her breathing.
The United States is now in the midst of its worst wildfire season ever, with record-breaking, deadly flames ripping across the West. The Carr and Mendocino Complex fires have burned swaths of northern California to ash. Parts of Oregon and Washington state have been ablaze, while the Cascades and British Columbia have active wildfires.
The fires pose a risk not just to lives and property in their path but to people much further away. That’s because wildfires shoot plumes of smoke into the atmosphere carried away by a combination of jet streams and eastward winds.
According to experts, people as far away as Montana and Idaho are inhaling particulates, or nearly invisible bits of liquids or solids—burnt debris from wildfires, for instance—that can have detrimental health effects.
Particulate matter is categorized by size. A PM 10, for example, means the particulate is 10 microns in diameter, or ten millionths of a meter. That’s one-fifth the width of a human hair.
The smaller the particulate, the more dangerous. And the wildfires are producing really small matter.
“The smallest we’ve tracked is PM 2.5, or less than 2.5 microns in diameter,” said Tracey Holloway, a professor in the Department of Atmospheric and Oceanic Sciences at the University of Wisconsin-Madison, where she also leads NASA‘s Health and Air Quality Applied Sciences Team, or HAQAST.
“They are super small and can penetrate deeper into lungs and cause more damage,” Holloway said. “The bigger particles can settle out from gravity but the 2.5s can stay for days and get transported”—all the way up your nose or mouth into the crevices of your lungs.
And that can be bad for your health. Jia Coco Liu, an environmental epidemiologist at Johns Hopkins University who studies how air pollution affects health, said her research shows that wildfire days can bring levels of PM 2.5 that are 10 times the concentration of non-wildfire days, with “high proportions of organic carbon, elemental carbon, [and] ... small proportions of metals.”
These are pushed forward by what she calls “smoke waves,” or “intense wildfire smoke pollution episodes,” which have high levels of PM 2.5 and last at least two days.
The particulates stick around longer because of climate change. The hot, dry conditions that set the stage for wildfires also mean less chance of rain, “so the particulates in the air wouldn’t be washed away by rain, which makes the smoke episodes last longer,” Liu said.
Holloway said there’s “no question the elevated levels of particles in the air lead to negative health outcomes” including asthma and lung disease. “You can see in [public] records that more people check into the ER and more people die during high smoke events and the days following these events.”
What’s not clear, Holloway said, is whether the impact on health is greater in a wildfire season like the one underway now.
“Does it keep getting worse and worse and worse, or do the health impacts flatten out?” she asked. “How are different types of particles affecting people’s health? Is there a difference in the smoke from a forest fires and the smoke from a diesel engine?”
HAQAST, she said, is working on a project forecasting the number of additional fatalities and asthma cases from fires, but there are hurdles.
Smoke episodes are trackable via satellite, but rural areas don’t have as many satellites and monitors to measure air quality. The NASA satellite system currently only takes images once a day over large swaths of land; when a fire is moving quickly and rapidly disseminating particulate, once a day simply isn’t enough.
Another complication: Particulate matter varies from location to location based on geographical characteristics, according to Holloway. Fire-affected areas might see more organic carbon, “the same stuff you would see come off from wood in a bonfire,” Holloway said. Meanwhile, a city like Los Angeles is famous for the visible blanket of smog composed of nitrate and nitrogen oxide from car emissions.
Zach Wettstein is an emergency physician in training at the University of Washington and lead author of a study published in April in the Journal of the American Heart Association based on data from 2015, “a bad wildfire year… though not as bad as this year,” he said.
Wettstein’s team were looking for cardiovascular effects from wildfires, something that was understudied. Respiratory effects were clear—asthma, difficulty breathing—but was the cardiac system at risk, too?
He says it was. Five months of data and over a million ER visits showed clear associations between a five-day exposure to wildfires and heart attacks, particularly for those over the age of 65.
That may sound elementary, but Wettstein said it’s far from simple.
“It’s a complex physiological process by which someone has a heart attack or stroke,” he said. “There has to be plaque in the heart, and there has to be an increase in blood pressure and inflammation that could cause this plaque to rupture. Smoke itself is accelerating the timeline. Exposure to high levels of smoke at a particular time might make these events happen, or happen sooner.”
Liu’s research found that females are more likely to fall sick after being affected by smoke waves than males are, and that children are potentially more vulnerable than adults. “A possible reason for these results is that women have smaller lung volumes and maximal expiratory flow rates compared to men,” she said, explaining that would make females more likely to be affected by PM 2.5s.
Because heart attacks are fairly rare under the age of 18, children were left out of the study design, though Wettstein said there is no reason to think that wildfires don’t affect kids’ cardiovascular health, as well. Kids also don‘t visit the ER as much as adults do, but that doesn’t mean they are not experiencing symptoms that deserve medical treatment.
Lung cancer is something that the researchers want to look at more, especially given how smoke inhalation and air pollution have been linked to the disease. Wettstein said the population at risk of wildfire-induced lung cancer could stretch all the way across the country.
The solution? For now, Wettstein said, straightforward preventative measures: Wear a mask. Make sure air conditioners have proper air filters. Stay indoors. Clean indoor air. Don’t go outside.
“But that’s a tough message during the summer,” he acknowledged.
And in a future where wildfires will be even more common, simply wearing masks and staying inside might not cut it.
Ana Rappold, a statistician with the Environmental Protection Agency, is leading a citizen science project called Smoke Sense to create an app that gauges public health effects on smoke days. The premise is simple: People download the app and upload data about the surrounding area, including smoke quality, wildfires nearby, and breathing ability.
“Really, there’s very little data as to what people do and what works,” Rappold told The Daily Beast. It helps that the response has been “overwhelming,” Rappold said. “We had over 5,000 users [last year] with 50,000 sessions and a 93 percent return rate.”
Most users join because they are worried about their health, and Rappold has found they often have pre-existing health conditions. Intriguingly, the users are more likely to be younger women, mostly educated, and overwhelmingly white. That could be because young women dominate some of the areas wildfires have been striking, or it could that women are more attuned to health than men are, she said.
At the moment, the data collected is biased towards a small group of people who know about it and feel the urge to use it. Rappold said she hopes it will one day be something akin to your weather app on your phone. “You can plan your day around it, like the weather. You don’t go running off into a thunderstorm if it’s 6 and there’s one coming at 7. We can plan our days similarly around smoke,” she said.
Crosbie knows this all too well.
In the two years since 2016, Crosbie’s lungs have improved. While they haven’t healed completely, gone is the sensation of being underwater every time she sucked in air—thanks to regular visits to her doctor, planning her days around whether there was smoke in the air, and wearing masks when smoke levels were higher.
But earlier this summer, Crosbie got a glimpse of things to come. “In Fresno, the sun was orange,” she said. “We had 100-degree weather for 30 days. Fresno is like a valley so when there’s smoke it’s like a bowl and you put a plate over it.”
The concentration of smoke meant Crosbie could feel her lungs deteriorate again. The feeling of “drowning” returned.
“You can’t exercise. You’re not conscious of it but you breathe shallowly, you’re trying to protect yourself, your chest feels tight all the time,” she said.
On one drive, she was forced to pull to the side of the road. “I couldn’t breathe, I was just coughing and coughing,” she said. “It’s just ghastly.”
The feeling of being smothered and unable to breathe also mental health implications. Crosbie is a practicing psychotherapist and she’s noticed the pervasive feeling of being trapped.
After all, weeks went by where she hadn’t spotted the sky, hadn’t seen the sun save for an odd orange glow, hadn‘t gazed at the stars. Then one day, in the midst of the pale smokiness of the air, she caught a glimpse of blue sky.
“It was joyful,” she said.
She’s not sure how many more summers she’ll have where she can see that sky. For now, she and her husband are staying put, but there’s a chance that with her breathing problems and the frequency of wildfires in the area, she might not be in fire country much longer.
In the meantime, the threat of the wildfires is never far from her mind.
“I know exactly what paintings to grab and what rugs to roll,” she said. “You learn that life is not as much in your control as you think.”