Do wildfires exacerbate COVID-19 infections and deaths in vulnerable communities? Evidence from California

The potential impact of wildfire smoke on COVID-19 cumulative deaths in the San Diego-Tijuana border region

“…Similarly, previously published work by coauthors of this work found variability in the effect of wildfire smoke on COVID-19 case fatality ratios in the San Francisco Bay Area with some counties showing a precise association and others counties showing no effect [13]. Yu and Hsueh found the effect of wildfire smoke on COVID-19 mortality in California to be moderated by the availability of hospital and public housing resources at the county level and disproportionally affects counties with higher social vulnerability [20]. Our results in the context of the existing literature further reinforce the heterogeneity of the role of wildfire smoke on COVID-19 severity.…”

“…As wildfire smoke and COVID-19 affect the same biological systems and organs, wildfire-specific particulate matter has been hypothesized and shown to increase the risk of severe infection due to its widespread effect on the respiratory and cardiovascular system [9]. There is strong evidence of the adverse health effects of wildfire smoke [10][11][12] and emerging evidence of its effects on COVID-19 transmission and severity [5,[13][14][15][16][17][18][19][20]. However, the majority of epidemiological studies on wildfire smoke have been conducted in the US, Canada, and Australia, with little evidence from other contexts [10].…”

Spatiotemporal heterogeneity of the association between short-term exposure to carbon monoxide and COVID-19 incidence: A multistage time-series study in the continental United States

“…The relationship between CO exposure and COVID-19 incidence may demonstrate considerable spatiotemporal heterogeneity, influenced largely by these diverse factors. Despite a significant reduction in CO concentrations over the past few decades, with levels stabilizing at a relatively low average (∼200 ppb) in recent years, certain local regions, such as California (CA), continue to face high CO concentrations due to frequent wildfires [ 21 , 22 ]. A previous study has uncovered that the health burden attributable to CO in relation to COVID-19 remains substantial in the U.S., surpassing the impacts of other air pollutants [ 15 ].…”