[BalinKing]

Isn't the recommendations by many countries to wear even cloth masks (e.g. the recent reversal by the CDC) _because_ there's a good chance COVID-19 can spread via large (i.e. non-aerosolized) respiratory droplets? (Not that it doesn't also spread in other ways, but removing even one vector would be better in this case than not doing so.)

[mbreese]

I'm not sure why there is a recommendation to wear cloth masks in other countries (not discounting it, I just haven't looked). However, I believe that the primary rationale for the CDC switching their recommendation that everyone should wear masks has to do with the great numbers of asymptomatic carriers. In this scenario, wearing a mask is not designed to protect the wearer from others. Wearing an ill-fitting mask is not protective to the individual. Instead, wearing a mask is designed to protect others from the wearer. Because people are carriers before they exhibit symptoms (if they ever have symptoms), you can't know if you are infected or not. If you are wearing a mask, you are limiting the potential spread of virus from you. This way, you are keeping any potential virus closer to you so that others are more protected. This goes hand in hand with social distancing. If you use a mask and don't distance yourself, you aren't helping at all. I'm looking for a CDC reference, but this was also the rationale presented in local media reports.

If you're really curious, Ars Technica has a really good writeup of all of the relevant studies.

https://arstechnica.com/science/2020/04/should-you-wear-a-fa...

Most of the research above assumed either surgical or N95-style masks. There was one study that looked at use of cloth (non-medical, non N95) masks, and this was the key finding (from Ars, not the paper):

Wearing cloth masks resulted in significantly higher rates of infection, the authors found. They also noted that in their test, the cloth masks were only 3 percent effective at blocking particles.

Regarding everyone wearing (surgical) masks to protect others:

In a study published April 3, 2020 in Nature Medicine, researchers found that surgical masks reduced the detection of respiratory viruses in aerosols generated by infected people breathing or coughing in a breath-collecting machine.

[Dylan16807]

> Wearing cloth masks resulted in significantly higher rates of infection, the authors found. They also noted that in their test, the cloth masks were only 3 percent effective at blocking particles.

Hoo boy that's misleading by itself. The control group was "use what you normally use", and had the following numbers:

> In the control arm, 170/458 (37%) used medical masks, 38/458 (8%) used cloth masks, and 245/458 (53%) used a combination of both medical and cloth masks during the study period.

Given those numbers, it's basically impossible to use this data to tell us anything about the efficacy of cloth mask vs. no mask. The control group did wear their masks less often, but it's still very unhelpful data.

[pmachinery]

>https://arstechnica.com/science/2020/04/should-you-wear-a-fa...

> This may lead some members of the public to be lax about ... washing their hands frequently and thoroughly. Moreover, donning [a] mask may lead some people to touch their faces more, some argued.

> simply touching their mask could contaminate their hands if there are viral particles caught on the outside ... a mask wearer could then transfer virus particles from their mask to their face

"May". "May". "Some argued". "Could". "If". "Could".

> negating any benefit of having the mask.

So even with all the above steps that have to occur, it's still no worse than getting a face-full of Covid directly.

Almost every stupid, pointless, dangerous argument against masks boils down to:

People may not wear a mask properly. People may not wash their hands properly.

The first one is used as an argument against masks, so why is the second not only not used as an argument against hand washing, but also used in arguments against masks?

People don't always practice social distancing. So why don't people argue against that? Oh, because that too is reserved for arguments against masks.

It's fucking ridiculous. Why do some people continue to spend so much time and effort trying to discourage use of potentially life-saving items?

[virgilp]

> I'm not sure why there is a recommendation to wear cloth masks in other countries

You're spreading actively dangerous advice, that has already been proven wrong. DO look up why there is that recommendation.

[Dylan16807]

A cloth mask can capture some sizes of droplet, but a flat wall that the all the air goes around is not really going to do anything.