A MARTINEZ, HOST:
Skies are hazy across much of the U.S. because wildfires are burning from California to Minnesota. The smoky air is the worst in Western states, and it's forcing people indoors in places where vaccination rates are low. Montana Public Radio's Aaron Bolton reports on what's being called a recipe for new infections.
AARON BOLTON, BYLINE: In western Montana, Missoula just opened a brand-new public library. And people, including Grant Noblitt, Charlie Booher and Dave Juran, are flocking to it.
GRANT NOBLITT: One of the things is getting out of the smoky air.
CHARLIE BOOHER: We're definitely trying to stay out of the smoke.
DAVE JURAN: It's smoky and it's hot, and so, yeah, come to the library for a little bit.
BOLTON: About a quarter of the people here are wearing masks, and Missoula has the state's highest vaccination rate at 60%. But it's an outlier compared to the rest of Montana and most other Rocky Mountain states. The infection rate is pretty low here right now, but a couple hours' drive north...
JOE RUSSELL: We've seen a pretty significant uptick in cases, what I feel is a, you know, at least a 50% increase in cases.
BOLTON: Joe Russell is the health officer in Flathead County, Mont., where the vaccination rate is about half of Missoula's. Wildfire smoke has been bad here, too. Russell can't specifically say how much that's pushed people indoors, but he says unvaccinated people attending events are driving up cases.
RUSSELL: These are activities that are happening specific to events or settings, and they are indoors.
BOLTON: Like many other deeply conservative counties in Western states, most people aren't wearing masks indoors in Flathead County. The science is clear that unmasked people gathering indoors drives infection rates up. But it's very early to say exactly what wildfire smoke means in terms of COVID risk. Daniel Kiser with the Desert Research Institute analyzed COVID test results in Reno, Nev., last summer when a lot of smoke drifted into the area.
DANIEL KISER: And what we found was that there was about a 18% increase in the rate of positive tests during the period that was most affected by wildfire smoke.
BOLTON: That's only an association between smoke and a spike in positive COVID tests. Kiser's research doesn't provide a causal link. But the Centers for Disease Control and Prevention says the very tiny particles in wildfire smoke can lodge in the lungs, making people more susceptible to respiratory infections like COVID-19, especially as particles build up over time. John Felton is the health officer in Montana's most populous county.
JOHN FELTON: In Yellowstone County, we're under 50% of the eligible folks are vaccinated. So any time we start moving more people indoors, in this case, you know, to try and stay out of the smoke, it's certainly going to increase the risk of people getting ill with COVID-19.
BOLTON: Back at the new library in Missoula, Whitney Kors and her daughter, who is too young to get vaccinated, are taking precautions.
WHITNEY KORS: My daughter and I are still masked because she's not vaccinated.
BOLTON: That just makes sense, says Sarah Coefield with the Missoula County Health Department.
SARAH COEFIELD: So we know that wildfire smoke messes with your immune system, we know that it increases your susceptibility to infectious disease, and we know it leads to worse health outcomes if you have a disease.
BOLTON: What's also known is that Western states are dealing with a drought of historic proportions. Two-point-five million acres have already burned in the U.S. this year, and what's traditionally the worst weeks for fires in the Northern Rockies are just getting underway.
For NPR News, I'm Aaron Bolton in Columbia Falls, Mont. Transcript provided by NPR, Copyright NPR.
