Study authors from Harvard University in Boston and the Environmental Systems Research Institute in Redlands, California, discovered that daily changes in levels of fine particulate air pollution (PM2.5) corresponded to significant percentage increases in SARS-CoV-2 infections and fatalities in counties battling wildfires in the western United States. SARS-CoV-2 is the virus that causes COVID-19. “We found that 52 of 92 counties had strong evidence of a positive association between exposure to PM2.5 and increased risk of COVID-19 cases four weeks later,” concluded the scientists, stressing that a high level of particulate matter was “a key factor in exacerbating the severity of the COVID-19 pandemic in affected counties across three states.” Particulate pollution is measured in micrograms per cubic meter of air (mcg/m3), and Mary Prunicki, MD, PhD, the director of air pollution and health research at Stanford University in California, notes that it doesn’t take much of a rise to ignite health problems. “With just a 10-unit increase in PM2.5, you’ll see an uptick in emergency room visits and hospital admissions for heart attacks, strokes, arrhythmias, and severe breathing problems related to asthma, COPD, or bronchitis,” she says. Investigators for this study observed that a daily uptick of 10 mcg/m3 in particulate matter for 28 subsequent days was associated with an 11.7 percent increase in COVID-19 cases and an 8.4 percent climb in COVID-19 deaths. “We know that air pollution causes your immune system to become kind of dysfunctional, and that’s going to make you more susceptible to any type of virus, including COVID-19,” Dr. Prunicki says. The Centers for Disease Control and Prevention (CDC) also recognizes that wildfire smoke can irritate your lungs, cause inflammation, affect your immune system, and make you more prone to lung infections, including the novel coronavirus that causes COVID-19. “The best way to protect against the potentially harmful effects of wildfire smoke is to reduce your exposure to wildfire smoke, for example, by seeking cleaner air shelters and cleaner air spaces,” says the CDC. The federal health agency adds that cloth masks provide little protection against smoke, but N95 and KN95 respirators can help while simultaneously preventing the spread of the coronavirus. Because N95 respirators should be reserved for healthcare workers, the CDC suggests looking for KN95 masks that meet federal standards.