For months, the Centers for Disease Control and Prevention (CDC) has said that the novel coronavirus mainly spreads when someone comes into close contact with another person who has the virus. In October, the CDC acknowledged another way that COVID-19 spreads: Through airborne transmission.
To lower your risk of getting infected by this newly recognized method of transmission, you may need to adopt some new habits.
“Mask-wearing, hand-washing and practicing social distancing are still among the most important ways to stop the spread of COVID-19, but there are additional steps that you can take to help protect yourself from airborne spread of the virus,” says Nazar Raoof, M.D., division director of infectious disease at Raritan Bay Medical Center. “However, the most common way to get COVID-19 is still through close contact with others, not airborne transmission.”
The role of respiratory droplets in COVID-19 transmission
For both forms of COVID-19 disease transmission – close contact and airborne – it’s respiratory droplets containing the virus that spread illness.
Everyone produces respiratory droplets, which are tiny, moist particles that are expelled from the nose or mouth when you cough, sneeze, talk, shout, sing or exhale deeply. Respiratory droplets typically travel a few feet through the air before they fall to the ground. They may carry bacteria or viruses if you’re sick.
When people are very close together, these small, largely invisible, droplets may travel from one person to another without either person realizing it, spreading disease. This is why social-distancing guidelines recommend that people stay six feet apart; larger respiratory droplets have trouble traveling that far before gravity pulls them to the ground. Masks also help prevent droplets from spreading between people.
Why airborne transmission is different
Some respiratory droplets are so small, they may hang in the air for minutes or hours, rather than falling to the ground. These droplets, which are sometimes called aerosols, are typically found in indoor spaces with poor ventilation. When outdoors, fresh air and breezes help dissipate these particles.
Aerosols may move through the air within an enclosed space, infecting people who are farther away than six feet. They may also hang in the air after someone with COVID-19 has moved on, infecting others who breathe the tiny particles in.
The more time that you spend in a poorly ventilated indoor space and the more crowded it is, the greater your risk is of contracting COVID-19. For these reasons, experts recommend against spending extended periods in indoor spaces with other people, especially if you aren’t wearing a mask.
Opening windows in indoor spaces can allow for better air circulation and may lower the risk of airborne transmission.
How to protect yourself from airborne COVID-19
To lower your risk of COVID-19, continue to follow the habits that health experts have recommended, and add some new practices to your repertoire:
- stay six feet away from people outside of your household
- wear a mask in public
- wash your hands often
- don’t touch your face unless you have clean hands
- avoid indoor spaces with poor air circulation, especially crowded spots
- plan to meet people in outdoor settings, rather than indoor locations
If you must visit a poorly ventilated indoor space:
- keep your mask over your nose and mouth at all times
- try to stay at least six feet away from others
- open a window to increase air circulation, if possible
- spend as little time as possible there, then leave