A growing body of evidence suggests that SARS-CoV-2, the coronavirus that causes COVID-19, may be airborne — meaning tiny bits of virus exhaled into the air by an infected person could remain viable for long enough to infect someone else who inhales them.
These tiny particles can linger in enclosed spaces for hours. So, what should you do to avoid them – and COVID-19? And how can you lower your risk of catching the coronavirus that way?
We spoke with our infectious diseases and infection control specialist Roy Chemaly, M.D., for details.
Is this coronavirus airborne?
Yes, but it is only very rarely transmitted that way. It depends on what people are doing. It’s much more likely during certain medical procedures involving the lungs, but here at MD Anderson, we test patients for COVID-19 before such procedures and take precautions to protect our patients and employees.
The coronavirus can also be airborne if someone is expelling air forcefully, such as by shouting or singing. But that is not the most common situation. The main route of transmission remains droplet, followed by contact and then, much less frequently, by aerosol.
What does “airborne” mean?
Airborne means a virus can be transmitted from person to person by the tiny particles of moisture released from the mouth or nose when speaking, breathing or singing. These droplets are suspended in the air over long periods of time.
How does an “aerosol” differ from a “droplet?”
Aerosols are much smaller in size, so they tend to stay in the air for a longer period of time. They can also travel further over long distances. Droplets are much heavier, so they don’t stay in the air for very long or travel very far. Droplets are generated by coughing or sneezing and are heavy enough that they drop right down onto a nearby surface.
How does this change what people should be doing to protect themselves from COVID-19?
It doesn’t, except in a health care setting. When procedures that generate aerosols are done, a special mask called an N95 needs to be worn. In most other situations, wearing a cloth or a medical-grade mask is still the best way to reduce both aerosol and droplet transmission. But people still need to be practicing social distancing and good hand hygiene, too.
Are there additional precautions people need to be taking to prevent airborne or droplet spread of the coronavirus?
No. Wearing masks is still No. 1, followed by social distancing.
Does airborne or droplet transmission mean I need to be wear a mask inside all the time to prevent COVID-19, even if I’m not around other people?
No. It only applies if you’re going to be around other people. If you’re just sitting in your office alone, you don’t have to. Or, if you’re going for a run by yourself, you’re fine. You don’t need one.
But if you’re going to be out in public around other people — whether it’s at the grocery store or a local business — put on a mask before you step inside. You should also still wear one at outdoor gatherings, where social distancing is more difficult to maintain.
Does this change what and how often I need to be disinfecting?