A new research study from Harvard University revealed that 2020’s intense wildfire season in the West Coast led to higher COVID-19 cases and deaths. California, Oregon, and Washington all experienced tragic wildfire damage, with smoke and ash clouding over the majority of cities. The increase in fine particulate air pollution (PM2.5) from wildfire smoke increased lung infections, including COVID-19.
Between March and December 2020, many counties in the Western United States experienced increased exposure to PM2.5. The Harvard study found that 52 of the 92 counties that wildfires threatened had an increased risk of COVID-19 one month later. The positive association of PM2.5 seems to be a key factor in why COVID-19 cases and deaths drastically increased in those areas.
What Is In Wildfire Smoke?
As mentioned previously, wildfire smoke contains particulate matter, including PM2.5. For reference, PM2.5 is about one-fiftieth of the width of a human hair, meaning that it can easily enter the lungs and deep tissues in the lungs. When this happens, it’s common to experience inflammation of lung cells, which sparks sore throat, nose irritation, coughing, and sore chest. For people with asthma or heart disease, prolonged exposure to PM2.5 can be fatal. For example, a 10-unit increase in PM2.5 can lead to an increase in emergency room visits for heart attacks, strokes, arrhythmias, and respiratory issues. Additionally, the damage that PM2.5 does to the lungs can make people more susceptible to viruses, including SARS-CoV-2, which causes COVID-19.
When the body encounters particulate matter, the immune system addresses the issue to keep you safe. Because of the immune system’s focus on fighting PM2.5, it doesn’t put as much energy toward fighting COVID-19. Essentially, inhaling particulate matter from wildfire smoke compromised the body’s ability to battle COVID-19.
What Does The Data Say?
The Harvard study compared satellite Environmental Protection Agency (EPA) air quality assessments with publicly available health data. The data indicated that wildfire smoke was associated with and average 11% more COVID-19 cases and 8% more deaths. Some counties with higher PM2.5 exposure saw more dramatic percentages. For example, counties in Washington and California saw a 20% increase in COVID-19 cases during the 2020 wildfire season. The entire wildfire season in California, Washington, and Oregon contributed to 19,742 COVID-19 cases and 748 deaths. The reality is that 2020 was a record-setting wildfire season for the West, with California’s fires releasing over 100 million tons of greenhouse gases. Washington experienced more individual fires in 2020 than any year on record.
Wildfires And COVID-19
From August 15th to October 15th, 2020, fire activity was at an all-time high. Daily levels of PM2.5 were much higher during wildfire days than non-wildfire days. The Harvard study observed an average of 31.2 micrograms per cubic meter of air on wildfire days. In comparison, non-wildfire days saw an average of 6.4 micrograms per cubic meter of air. These hazardous levels were nothing compared to some counties, which experienced PM2.5 levels higher than 500 micrograms per cubic meter of air.
The lung irritation from wildfire smoke leaves the body susceptible to any type of virus. By irritating the lungs and causing inflammation, the body can easily contract respiratory or lung infections like COVID-19. Even wearing a cloth mask in areas affected by wildfires may still not be enough. KN95 and N95 respirators do a better job at preventing particulate matter from entering the lungs, but it’s still possible for them to pass through the mask.
The bottom line is that wildfire smoke and COVID-19 is a dangerous combination. As COVID-19 variants develop and the wildfires continue to occur, keep yourself safe and avoid smoke as much as possible.Â
