[tomxor]

There was a paper posted on HN ages ago now, studying the mechanism by which masks were effective against covid... they argued it was essentially due to maintaining a higher temperature and humidity in the nose and throat. It's well known that rhinovirus for instance, reproduces more efficiently in cooler environments, so this seems plausible.

It's also possible there is more than one mechanism, and that an n95 or equivalent mask with fine enough particulate filter can additionally reduce exposure significantly (initial exposure level also being accepted as having some effect for viruses in general).

So you can look down on people with those fabric masks, but possibly not be completely correct. Honestly though... the whole mask wearing thing is more about trends of what is "socially acceptable" than science. I'm not saying there is no value, but that the forces dictating when most people do or do not wear a mask have very little to do with how well informed they are or on the current accepted understanding having changed, and far more to do with what is considered socially acceptable at the present time... so it's hardly surprising no one particularly cares about the type of mask.

[simondotau]

> So you can look down on people with those fabric masks, but possibly not be completely correct.

And strapping yourself to your car seat with a knitted scarf might reduce injury risk/severity relative to a person with no seatbelt. That doesn’t mean we should expand the seatbelt mandate to include scarves.

[tomxor]

Your comparison suggests a quantitative difference, because seatbelts are effective through only one mechanism; whereas I've highlighted two qualitatively different mechanisms through which masks reduce probability of becoming infected, exploiting completely different properties of the mask. It's not even clear if filtering has more or less of an impact than change in temperature and humidity.

[simondotau]

Your response remains starkly oblique to my point. My point is that people in elevated risk groups (elderly, immunocompromised, etc) should be encouraged to wear an effective mask. We know that N95+ masks have strong supporting evidence of their efficacy. We know that similar evidence is distinctly lacking when it comes to most cloth and surgical masks. The continued social acceptance of sub-standard masks sends (IMHO) a dangerously misleading message which places these people at risk.