COVID-19 and PM2.5

A recent analysis of COVID-19 and the 2020 wildfires in California, Oregon, and Washington estimated increases in COVID cases and mortality of about 20% associated with increased levels of fine particulate matter (PM2.5) based on satellite smoke observations. The study caught my eye for several reasons: PM2.5 is not “smoke,” the COVID-19 increases were not statistically significant, and a much simpler and transparent analysis of their data yielded different results. Here’s what I found.
COVID-19 remains a seasonal respiratory virus, and the pandemic has waxed and waned with our summers and winters. A new study tries to quantify the impact of three climate variables: temperature, humidity, and ultraviolet light. The study also updates our understanding of PM 2.5.