Updated to hopefully fix the link in the cite to the first study.
While the literal idiots who run the federal government, and there can’t be more than ten people in the country who don’t really think they are idiots at this point, are extending the transportation mask mandate and forcing children to be masked in school, with no science or data to support those policies; evidence on how well masks really work is piling up.
This study takes an unusually open-minded approach in these ideological times. The authors say in the paper’s background section that “pandemic mitigation requires evidence-based strategies”. What a novel idea. They then attempt to ascertain whether mask mandates or their absence was associated with case growth. (Medrxiv Paper) I know the answer from looking at epidemic curves. (My usual caution as well that I prefer studies that look at actual mask wearing behavior versus just a mandate.) They compare various jurisdictions with mandates and those without. Mask mandates were, dare I say it, not associated with lower case growth or lower maximum growth rates. There might have been a very slight association with lower minimum growth rates. And looking by wave, there was no association at all in last spring and fall’s wave, the biggest so far. Remember my caution above, well these authors did go on to also look at mask use. Shockingly, just shockingly, there was no association between actual mask-wearing behavior and cases or case growth, even though mask mandates were associated with greater mask use.
Next up, another study on virus in aerosols and mask effectiveness. (Medrxiv Paper) Another good study because the researchers used actively infected patients, all asymptomatic or mild, and tested what spewed forth while wearing and not wearing a mask. They found that viral RNA (so not necessarily actual viable virus) was present in 45% of fine aerosols, 31% of coarse aerosols and 65% of fomite samples. As a refresher, fomites are particles that fall onto a surface. A lot of virus is in fine aerosols. A mask blocked only 48% of fine aerosols and 77% of coarse ones. Alpha variant virus apparently had an 18 times greater presence in fine aerosols. There was no significant difference in performance between cloth and surgical masks. Uhh, this is interesting, none of the fine aerosol samples collected while people weren’t wearing masks had virus that cultured. Two of the samples of fine aerosols collected while wearing masks did have culturable virus. Strangely, the authors said their results indicated that many aerosols have viable virus that can be passed to another person. That is not what their culture results would indicate. So let me translate the main finding for you. Masks don’t work. A lot of virus in is fine aerosols and half the time masks aren’t going to block those. But these authors subscribe to the mask religion; their solution is everyone should wear more and stronger masks.