Harvard Scientists Discover Link Between COVID-19 Deaths and Exposure to Wildfire Smoke
Researchers at Harvard University published a study in Science Advances on Friday revealing that smoke and particulate pollution from wildfires in the American West have led to an increase in COVID-19 fatalities.
“Wildfires produce high levels of fine particulate matter, which has been linked with a host of negative health outcomes, including premature death, asthma, chronic obstructive pulmonary diseases (COPD), and other respiratory illnesses,” the Harvard Gazette reported.
“We hypothesize that short-term exposure might increase the likelihood of (i) more severe infection so that an asymptomatic infection becomes symptomatic and is detected as a case and (ii) more severe infection that leads to death,” the team wrote.
“Our results have biological plausibility,” they added. “A recent review by Navarro et al. (28) described that the co-occurrence of SARS-CoV-2 infection and wildfire smoke inhalation may present an increased risk for COVID-19 illness. Woodby et al. (29) suggested that exposure to air pollution skews the adaptive immune response toward bacterial/allergic immune responses, as opposed to an antiviral response, which may affect COVID-19 severity and outcomes. Exposure to air pollutants could also predispose exposed populations toward developing COVID-19–associated immunopathology, enhancing virus-induced tissue inflammation and damage (28, 29).”
Notably, the study found that the correlation between inhalation of wildfire smoke and deadly coronavirus infections was statistically significant.
Senior author Francesca Dominici, the Clarence James Gamble Professor of Biostatistics, Population and Data Science at the Harvard TH Chan School of Public Health, explained that the first-of-its-kind report found a “daily increase of 10 µg/m3 in PM2.5 [‘fine particulate air pollution’] each day for 28 subsequent days was associated with an 11.7 percent increase in COVID-19 cases and an 8.4 percent increase in COVID-19 deaths. The biggest effects for cases were in the counties of Sonoma, California, and Whitman, Washington, with 65.3 percent and 71.6 percent increases, respectively. The biggest effects for deaths were in Calaveras, California, and San Bernardino, California, with 52.8 percent and 65.9 percent increases, respectively.”
Prolonged droughts and blisteringly hot temperatures attributed to man-made global warming have triggered hundreds of massive infernos across the United States. The California Dixie Fire – which has consumed more than 500,000 acres and incinerated entire towns – has become the largest blaze in the state’s history. So far, emergency crews have been unable to quench the flames.
Dominici explained that “the year 2020 brought unimaginable challenges in public health, with the convergence of the COVID-19 pandemic and wildfires across the western United States. In this study we are providing evidence that climate change — which increases the frequency and the intensity of wildfires — and the pandemic are a disastrous combination,” adding that “climate change will likely bring warmer and drier conditions to the west, providing more fuel for fires to consume and further enhancing fire activity. This study provides policymakers with key information regarding how the effects of one global crisis — climate change — can have cascading effects on concurrent global crises — in this case, the COVID-19 pandemic.”