Every year, wildfire season results in massive areas of burnt land, displaced residents, poor air quality, and deaths.  But, this year’s record-breaking wildfire season comes with an additional concern: the dangerous mix of wildfire smoke and the coronavirus pandemic.

How dangerous is wildfire smoke?

Wildfire smoke contains a toxic mix of gases and microscopic particles from vegetation, metals, and other building materials that have been burnt. The smallest particles, known as PM 2.5, are able to travel the farthest (even across continents) and are also the most dangerous. That’s because the human body is not equipped to handle such small particles. PM 2.5 are able to bypass the body’s defenses and disturb the air sacs where oxygen crosses over into the blood.

Fortunately, the body does have some protection against PM 2.5. Macrophages are specialized immune cells in the air sacs which are supposed to seek out and destroy foreign material. But, studies have shown that repeated exposure to wood smoke can suppress macrophages and lead to lung inflammation.

Can being around wildfire smoke make you more susceptible to COVID-19?

Unfortunately, the answer seems to be yes. Scientists at Harvard University’s T.H. Chan School of Public Health found that even a small increase in the amount of PM2.5 from one U.S. county to the next is associated with a large increase in the death rate from COVID-19. This is consistent with previous studies showing that air pollutants can increase the viral load in the lungs and make it harder for macrophages to destroy viral invaders.

The elderly and people with compromised immune systems are particularly at risk of complications from COVID and should take extra precautions to minimize their exposure to wildfire smoke.

Does wearing a mask help reduce exposure to PM2.5 particles from wildfire smoke?

While cloth masks are useful in slowing the spread of COVID-19, they won’t protect you from wildfire smoke.  Cloth masks are able to filter out larger respiratory droplets, but they are useless in blocking PM2.5 particles.

N95 masks do offer protection from wildfire smoke, but they may be in limited supply due to the pandemic.

How are symptoms from wildfire smoke exposure different from symptoms of COVID-19?

Because both smoke and COVID-19 can affect the lungs, the symptoms can be similar.  The CDC recommends using their Self-Checker if you are experiencing symptoms unrelated to smoke exposure such as fever or chills, muscle or body aches, diarrhea.

How can you lower your risk of COVID-19 if you’re near wildfires?

The best way to lower your risk of contracting the coronavirus is to continue following the CDC’s guidelines on social distancing, along with minimizing your exposure to wildfire smoke. Since wildfire smoke can enter your home, it’s also important to keep your indoor air clean to avoid the dangerous effect of PM2.5 particles. The CDC recommends using an air purifier with a True HEPA filter for both reducing wildfire smoke and lowering COVID transmission.