The Covid-19 virus can be in the air. Airborne transmission is considered by the CDC, NIH, and all other experts of note as the primary means of person-to-person transmission.

Masks clearly can be helpful in reducing by more than zero the risk of inhaling or coming into contact with the virus.

The true reason that the wearing of masks is not recommended for the general asymptomatic public is the fact that there are no good masks generally available and the fear is that if the CDC comes out with a recommendation that everyone should wear a mask, the supply to those in greater need of masks would be greatly compromised.

Here is decent general article about the mask issue: https://www.npr.org/sections/health...blic-health-experts-revisit-the-question

The best advice is that if you have a mask - use it when you are grocery shopping or otherwise out in public. As Dr. Fauci has said - it will not hurt you to wear one.