Forest fires in western North America could provoke an increase in the incidence and mortality from COVID-19 in several U.S. states. A dangerous connection between smoke and the condition of patients with coronavirus was revealed by scientists at Harvard University, who published an article in the journal Science Advances.
According to the authors of the article, the spread of ultrafine PM2.5 particles (diameter 2.5 micrometers or less) probably caused a surge in cases of COVID-19 and related deaths. Previous studies have demonstrated an association between high concentrations of particles in the air and the number of people with complicated coronavirus infection, asthma, exacerbations of chronic obstructive pulmonary disease, and other respiratory viral infections. The most at risk are the elderly, young children, and people with heart and lung diseases.
The researchers analyzed 92 counties in California, Washington, and Oregon to assess the contribution of various factors to the surge in the incidence of coronavirus infection, including fires in local forests, weather, seasonal changes, and mobility population size. It turned out that in 2020, the natural disaster had the greatest impact on the incidence of COVID-19 in Butte (California) and Whitman (Washington) counties and on mortality — in the California counties of Butte and Calaveras. Short-term exposure to smoke increased the level of coronavirus infection by almost 20 percent in some districts. At the same time, in some places, environmental pollution due to fires was associated with half of all deaths from infection.