Montana Public Radio

Wildfire Smoke Could Intensify Spread, Deadliness Of COVID-19, Researchers Say

Jul 14, 2020

As the number of coronavirus cases in Montana rise, public health officials and researchers say smoke from the upcoming wildfire season could make people more susceptible to catching the virus, and make patient outcomes much more deadly.

With wildfire seasons becoming more intense, researchers have been looking into the public-health impacts of wildfire smoke. Now they’re focusing in on how harmful particles in smoke could make COVID-19 infections worse.

Dr. John Balmes is a California-based medical researcher at the University of California San Francisco and UC Berkeley School of Public Health. His work focuses on air pollution and public health outcomes.

“There is already fairly good evidence from China, Italy and one important study in the U.S. to suggest that people that are infected with the virus who are exposed to fine particulate pollution, have increased risk of severe COVID-19 and death,” he said.

Fine particulate pollution, known as PM 2.5, can bypass the body’s natural defenses and is known to cause a myriad of health issues.

Balmes pointed to preliminary Harvard research suggesting an increase of average PM levels by just one microgram in a particular county is associated with an 8% increase in COVID-19 deaths.

“We had bad air quality in the San Francisco Bay Area in the midst of November 2018," he said. "Our levels were, for several days, as high as 200 micrograms per meter cubed."

During Montana’s historic 2017 wildfire season, more than one million acres burned. According to one study, particulate readings in Seeley Lake that summer exceeded 1,000 micrograms at times. These intense, short-term smoke events can increase the average PM exposure well beyond the one-microgram increase used in the Harvard study.

A plane flies over the Rice Ridge Fire near Seeley Lake, MT, August 8, 2017.
Credit Inciweb

And forecasts show Montana could face an above normal fire season this year.

Researchers say more study is needed to fully understand the issue, but large amounts of wildfire smoke in the air could make COVID-19 patient outcomes more deadly, both in the near and long-term.

There is also concern about smoke exposure making people more susceptible to catching the disease this winter, when a second wave is expected. Erin Landguth at the University of Montana recently published a study showing influenza case numbers spiked three to five times during winters following intense fire seasons.

“And so 50 out of the 51 counties, essentially, that we looked at came back positively associated with this effect,” she said.

Landguth is adapting her study to examine that same correlation with COVID-19. She said a similar effect is likely, given the strong results from her study on influenza.

While ongoing research on COVID-19 and air pollution is painting an ominous picture, there are efforts to mitigate the impact.

“So, this is a basic fan, right?” Amy Cilimburg asked. “Just got this from the local hardware store. Cost $17, not too much money.”

Cilimburg is with the environmental nonprofit Climate Smart Missoula. She recently filmed a demonstration in her backyard, showing viewers how to make a portable air cleaner for under $45.

“And you can also, at the hardware store, buy a filter, and you can put it together,” she said.

A filter with a high enough rating can be attached to the back of the fan with tape or a bungee cord, Cilimburg said, and placed in the middle of a closed-off room to filter out PM 2.5 particles.

In the past, Climate Smart and the Missoula City-County Health Department have worked to buy portable, high-efficiency air or HEPA filters to borrow or hand out to residents with underlying health conditions who can’t afford them. The machines run anywhere from $100 to $1,000.

Amy Cilimburg, the director of Climate Smart Missoula, helped Seeley Lake residents Joy and Don Dunagan get a HEPA air filter through a partnership with the Missoula City-County Health Department, January, 2018.
Credit Nora Saks

Missoula City-County Health Department Air Specialist Sarah Coefield explained that finding cheap, effective ways to clean air indoors is especially important for people with underlying health conditions. Those conditions make that population sensitive to smoke and at risk of a severe case of COVID-19.

“The reality is the sensitive-groups category is usually about 30% of a population,” Coefield said. “So if we’re sitting here in Missoula County, and we have over 100,000 people, that’s more than 30,000 people who are what we consider sensitive to wildfire smoke, and who's health is at greater risk than someone else.”

Coefield and Cilimburg built a website with all the necessary information to create a clean air space. Their biggest piece of advice? COVID-19 isn’t going anywhere soon, so plan out how to create that space before the smoke arrives, too.

Get the latest Montana wildfire, fire management and air quality news on your radio, via podcast, or in your inbox.