Mrs ERJ and I went to Mass today.
I am in the no-man's-land regarding masks. I think they help some...but are far from a magical talisman in stopping Covid-19.
The case for masks
Clearly, masks stop some virus-laden particles. The fact that they get damp suggests that some aerosoled saliva and mucus is captured by the weave of the cloth.
Comparisons between the size of the virus and the pore-size of the cloth are misleading. Our bodies rarely eject naked virus into the environment. Typically, the virus is embedded within droplets from clearing our throats, speaking or more typcially coughing or sneezing.
And if you ever removed a furnace filter, then you realize that the filter captures particles smaller than the spaces between the filaments of the filter element. The filaments pick up an electrostatic charge and the pollutant is attracted based on that charge.
The case against
A significant percentage of your breath you does not pass through the filter material. My glasses fogged. The breath that fogged my glasses did not pass through the mask. It passed between my mask and my face.
Just spit-balling here. If 30% of my exhalation does not pass through the filter (more when doing more than standing and praying), from an incremental risk standpoint, how is that any different than one-person-in-three choosing to not wear a mask?