Can you catch COVID-19 through cigarette smoke?

While there is no evidence directly linking secondhand cigarette smoke and the spread of COVID-19, experts believe that it is possible for infected smokers to spread the virus through droplets when they exhale (via Health). COVID-19 is primarily spread through respiratory droplets that enter the mucous membranes of the nose and mouth. These same droplets are also released when someone exhales cigarette smoke.

"Since the novel coronavirus is spread via direct person-to-person contact, activities that include being in close contact (less than 6 feet) without a mask on should be avoided, which includes secondhand smoke," Dr. Julie Lyou, a pulmonologist at St. Jude Medical Center in Fullerton, California, told Health. Since it is impossible to smoke with a face mask on, smoking increases the risk of transmission for anyone nearby.

COVID-19 can also be spread through aerosolization. Secondhand smoke can stay in the air for up to several hours, making it possible for the virus to linger in a cloud of smoke, which can lead to infection.

How far secondhand smoke and COVID-19 can travel

If you're close enough to smell someone else's secondhand smoke, you're at an increased risk of being exposed to their respiratory droplets. If a smoker has COVID-19, however, staying 6 feet away may not be far enough. Secondhand smoke can travel up to 20 feet, causing infected respiratory particles to potentially travel farther than they normally would if someone with the virus had simply breathed or coughed (via Healthline).

Smokers also tend to exhale secondhand smoke more forcefully, causing droplets and particles to travel an even greater distance. Smokers themselves are already at a higher risk of contracting COVID-19 and developing serious symptoms and complications. This only increases the risk of transmission through secondhand smoke.

Vaping can also spread COVID-19. Since vaping is often seen as less harmful than smoking, many people who vape are not shy about doing so indoors, where the virus is most likely to spread. Quitting smoking or vaping can reduce the overall chances that you or someone around you will contract COVID-19.