WHITMAN COUNTY, Wash. — Wildfire smoke is linked to a rise of COVID-19 cases in Washington state during 2020, particularly in Whitman County, according to the findings of a study done by Harvard University.
Researchers looked at data from 92 counties in Washington, California and Oregon with active fires between March and December of 2020. They looked at the connection between data on fine particulate matter concentrations and the number of COVID-19 cases and deaths across the three states.
The study found a connection between exposure to wildfire smoke and high levels of fine particulate matter, otherwise known as PM2.5, and a rise in symptomatic cases of COVID-19.
"It's possible that one has contracted COVID and is asymptomatic and being exposed to this wildfire smoke, becomes symptomatic," said Francesca Dominici, a professor of biostatistics at Harvard and one of the co-authors of the study.
Washington saw one of the most severe wildfire seasons in state history in 2020. Over 800,000 acres burned statewide. The Babb-Malden fire in Whitman County burned over 15,000 acres and destroyed over 80% of the buildings in Malden and Pine City.
Whitman County had one of the highest percentages of COVID-19 cases attributable to high levels of wildfire smoke exposure at 18.2%. Butte, California came in second, with 17.3% of cases attributable to high levels of PM2.5, according to the study's findings.
Overall, researchers estimated wildfire smoke contributed to 20 thousand more cases of COVID-19 and 750 additional deaths on the west coast.
Exposure to PM2.5 induces inflammation in lung cells and can make a person more susceptible to contracting respiratory infections, like COVID-19, according to the CDC.