Interesting data dive into masking mandates vs COVID outcomes in the United States (technical):
And did masking potentially lead to worse outcomes?
Yes, I know this is an influenza study, but it has important implications for SARS-CoV-2 (also an enveloped virus, similar size, that is primarily transmitted via aerosols).
There is an interesting study (sorry I cannot find it) that demonstrates that masks can shear droplets into aerosols - think of throwing a water balloon against a chain link fence. Aerosols (1-3 microns) can obviously travel deeper into the lungs than droplets (which often cannot travel beyond the nasal passages). Another study looked at droplet vs aerosol infection in mice. The mice infected with droplets had very mild symptoms, whereas mice infected with aerosol had much worse symptoms. This is not surprising, of course. Additionally, aerosols can remain suspended in a climate controlled environment (i.e. the home) for several hours.
And did masking potentially lead to worse outcomes?
Yes, I know this is an influenza study, but it has important implications for SARS-CoV-2 (also an enveloped virus, similar size, that is primarily transmitted via aerosols).
There is an interesting study (sorry I cannot find it) that demonstrates that masks can shear droplets into aerosols - think of throwing a water balloon against a chain link fence. Aerosols (1-3 microns) can obviously travel deeper into the lungs than droplets (which often cannot travel beyond the nasal passages). Another study looked at droplet vs aerosol infection in mice. The mice infected with droplets had very mild symptoms, whereas mice infected with aerosol had much worse symptoms. This is not surprising, of course. Additionally, aerosols can remain suspended in a climate controlled environment (i.e. the home) for several hours.