npub1xr8gd35szene0r2yvfafr29tjwdedgwd89lnfpmh3pylnygnvd4qmf3q0g (npub1xr8…3q0g)
This tested the masks' ability to block covid that was exhaled by the wearer. This is proper use of masks.
Everybody thinks that N95 masks protect the wearer from covid in the air. I would like to know about the degree that this is true.