https://threadreaderapp.com/thread/1515074816801398791.html
Hospitalizations doubled in MA and current CDC risk level is “medium” with proposed measures being talk to your doctor about wearing a mask if you’re immunocompromised
Nobody could have foreseen this
So, the reason that masks don't really have a negative effect on respiration is because the diffusion is primarily driven by the propensity of gases to mix and fill the container or room they are in, and the existing movement of air in the room you're in. You breathing doesn't really contribute very much to that.
There is no appreciable difference in CO2 concentration you're breathing with a mask, especially since what masks do is block small particles of water, snot, and spittle from getting blasted at people, rather than blocking the air.
deleted by creator