Smoke from wildfires may increase risk of COVID-19: study

CARSON CITY, Nevada (AP) – Scientists from Nevada say in a new study that smoke from wildfires may increase the risk of contracting the coronavirus.

A study published last week by scientists at the Desert Research Institute found that coronavirus infection rates rose disproportionately during the wildfire season of 2020, when smoke from fires in neighboring states blanketed a much of northern Nevada.

In an article in the Journal of Exposure Science & Environmental Epidemiology, Desert Research Institute assistant scientist Daniel Kiser and four co-authors note that the test positivity rate in Washoe County increased significantly during times when monitors have measured high levels of particles in the air from wildfire smoke.

For every 10 micrograms per cubic meter of small particles known as PM2.5 in the air, the positivity rate increased by about 6.3% two to six days later, according to the study.

Kiser said the study was observational and noted that the rise could be attributed to other factors, such as last year’s second wave, students returning to school, or changes in local restrictions. But he said momentary increases during times of high pollution suggested a link between the smoke and the spread of the virus.

“This temporary association amid a surge in the number of cases overall is what convinced us that something was happening,” he told The Associated Press.

The authors argued that the association between smoke from wildfires and the coronavirus likely suggests that pollution makes people more prone to viruses more generally.

“Our results also strengthen the arguments that PM2.5 from other sources such as automobile traffic or industry increases susceptibility to” coronavirus, they wrote.

Kiser said wildfires and other weather events linked to climate change were likely to feature more widely in the study of viruses in the future.

Smoke from the Tamarack and Beckwourth compound fire envelops parts of northern Nevada, causing pollution in Reno, Carson City and Gardnerville.

Sam Metz is a member of the Associated Press / Report for America Statehouse News Initiative corps. Report for America is a national, nonprofit service program that places reporters in local newsrooms to cover undercover issues.