Heavy wildfire smoke linked to increased COVID-19 risk, researchers say

A study published in the Nature science journal found that heavy wildfire smoke could be linked to an increase in COVID-19 cases.

Researchers looked at Washoe County in northern Nevada, which saw a simultaneous increase in COVID-19 cases while also being exposed to wildfire smoke last year.

“We had a unique situation here in Reno last year where we were exposed to wildfire smoke more often than many other areas, including the Bay Area,” Gai Elhanan, co-lead author of the study, told the Reno Gazette Journal.

“We are located in an intermountain valley that restricts the dispersion of pollutants and possibly increases the magnitude of exposure, which makes it even more important for us to understand smoke impacts on human health,” he added.

The study was conducted from May 15, 2020, to Oct 20, 2020.

“We found a large increase in the SARS-CoV-2 test positivity rate at Renown during periods of elevated PM2.5 from wildfires. These results, although based on observational data with their inherent limitations, lend credence to earlier predictions that wildfire smoke would exacerbate the COVID-19 pandemic,” the researchers wrote.

The researchers observed cases at the Renown Health system, the largest health system in the county.

They also pointed to how their findings bolstered the findings of similar studies also conducted in the U.S., Italy and England that found an association between heightened air pollution levels and the “increased infectivity and severity of COVID-19.”

“Hotter temperatures, climate change, wildfires, air pollution, all seem to have some association with a greater risk of COVID-19 cases,” Kent Pinkerton, an air pollution expert from the University of California, Davis told the Journal.

“If you’re susceptible to air pollution, such as particulate matter, it could be that you just have a situation where you’ll be also much more susceptible to viral particles that might be in the air that you’re breathing,” Pinkerton said. “It’s not that the air pollution makes the COVID-19 cases more likely to happen, but it may simply be a reflection of just the fact that, where areas of high pollution are, … the risk for COVID-19 cases may be greater.”

The highest rate of positivity was found in the younger demographic of patients aged 18-29, with a rate of 11.3 percent. Wildfire smoke affected the air quality of the region for 59 days of the study, with dust storms also contributing to the air quality in the same period.