Danish study finds face masks provide limited protection to wearer

I am going to disagree with the study based upon (1) the study didn't perform a proper experiment and are misinterpreting their results... and (2) basic particle/aerosol science. Finally I give a "close to home" ancedotal story.

(1) It only takes one non-masked, close-contact exposure to coronavirus to become infected... that it, mostly. how it is spreading. The study does not control for the exposure risk profile of the sample populations so... there you go. This study is next to worthless...

(2) There have already been numerous studies, recently, that cloth masks are effective at filtering out particles, even down to 1-5 microns in some cases. Most cloth face masks are very effective and filtering larger particles (50-250 microns). Particle mass/volume scale with the particle diameter to the third power (i.e. V=1.33PIR^3 or 0.166PID^3). So a 100 micron particle contains 1000 times more mass/volume or viral load than an 10 micron particle and a million times more than a 1 micron particle. Thus is most important to filter the big particles in reducing viral load expelled by infected individual and breathed in by others. Cloth face masks, and surgical masks are pretty good at doing this. N95 and KN95 are already well tested in this area. So while masks can't filter out all virus... they are pretty good a significantly reducing the viral load which is important.

(3) I know people at work who became infected at a party and came to work for days while they were unknowingly infected. But thus far, there have been no "at work" coronavirus transmission cases because we wear good masks. Thus far this is true at our other sites as well. I know a local state epidemiologist who remarked to me that the overall rate of transmission in the workplace, for places with good mask protocols, is remarkably low.

This might make you even more surprised about my existence, but I'm not entirely unsympathetic to the "ideological" types.

Let me put it another way: why weren't you wearing a mask during flu season every year? Or, given that Covid will probably exist in some form for many years to come (even with a vaccine), when will you stop wearing one?

Because you could make a case for mandatory mask wearing at all times, forever, using the same logic that's currently being employed: "it's only a minor inconvenience and if it saves even one life, it's worth it".

Presumably you won't wear a mask forever: you'll make a personal decision, based on data or gut feeling, that the "effect size" of mask wearing is no longer worth the inconvenience. You were already making that calculation, implicitly, when you chose not to wear a mask during flu season last year.

That calculation will be different for every individual. Which is why I don't think any of us is really in a position to judge another person when the parameters of the calculation are different for them. Ultimately, the differing parameters of that calculation are what we call "ideology".

To return to my original point, it's also why we vitally need an open discussion on the "effect size" of wearing a mask. If it's large (I suspect it is not), then it gives more weight to the idea that all the Karens should just shut up and wear one. If it's small, there's a lot more room for personal choice.

0.3% better chance for wearing a piece of cloth over a face - for a mild inconvenience. I'll take it anytime still.

I've seen accounts of maraton runners not able to run a 1K months after recovering.

I'll take 0.3% over nothing, thanks.

Also noteworthy, that is 10% less of a chance of getting infected. If you were to get infected.

The study is fine, but the way it's using the word "asymptomatic" is not consistent with the conclusion you drew from it, and the 6% shows why. A case which is "asymptomatic" in the study has no noticeable symptoms through the whole course of infection. If you know in advance that you're that kind of case, then you're less likely to spread the disease. But 94% of cases are not that kind of case, and no test except waiting a couple of weeks can distinguish asymptomatic from pre-symptomatic. Information that's not available until 14 days from now can't be used to determine who should wear a mask today.

https://www.who.int/news-room/q-a-detail/coronavirus-disease...

"What is the difference between people who are asymptomatic or pre-symptomatic? Don’t they both mean someone without symptoms?"

"Both terms refer to people who do not have symptoms. The difference is that ‘asymptomatic’ refers to people who are infected but never develop any symptoms, while ‘pre-symptomatic’ refers to infected people who have not yet developed symptoms but go on to develop symptoms later."

I would have no problem with mask to be adopted as a thing that people do.

Try changing this argument from 'wearing masks' to 'washing hands' or wearing seatbelt.