Originally Posted by celandina

Here is the simple math and what are you missing logic !

Double layered cloth mask is about 60 % effective while exhaling and about 40% effective while inhaling.

Now look at a viral load of a factor 100 in a person next to you who has a mask:

His viral load while exhaling in your direction is reduced to 40.

Now if you are wearing a mask you may inhale only 40% of the load from a factor 40 which is factor 16 of the initial load.

So simple stated, if both are wearing a mask, the risk of transmission is reduced 5x or more.