3 ms·

You asked why you got downvotes. I offered my perspective. You seem to be overreaching with your conclusions. You accuse me of the same, but I didn't say anythi

You asked why you got downvotes. I offered my perspective. You seem to be overreaching with your conclusions. You accuse me of the same, but I didn't say anything was conclusive, I pointed out contradictory evidence, that the issue of whether cloth masks are effective looks unsettled. You are saying that I was selective with the studies I looked at. But it sure seems like you are doing the same. Or worse by saying that this is conclusive when it sure doesn't look it. Not just the studies, which vary in quality, but wave after wave of covid in states and countries with mask mandates.

vannevar 5y ago
I can only tell you that there are many more studies indicating masks work than studies showing their effectiveness is inconclusive. And again, even if masks are 100% effective, there are so many people not wearing them even in jurisdictions that have mandates that there is a limit to their overall impact. Whether masks work is one thing, whether mask mandates work is an entirely different question.
- mikem170 5y ago
  Unless you have a better study to point to than the hairdressers and the navy ship studies that I looked at (both pretty sloppy in their own way), I'd say that you don't have proof. I'm not saying that you are provably incorrect. You pointed out that the studies I referenced were for personal protection, not to deter spread. However seeing how poorly cloth masks performed in those studies doesn't impart much confidence for their ability to stop spread, either.
  - vannevar 5y ago
    Note that the studies you have unspecified qualms about are only 2 of 11 cited in that first survey reference. I meant to include the link to the other survey study I quoted above: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7883189/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7883189/. I'm satisfied by these and many other studies that masks do work. You are of course free to rely on your intuition regarding which studies are valid and which are not, but I stand by my statement.
    - mikem170 5y ago
      Wow, that's quite collection of studies within that link! Ideally I'd find something in there with details that pass my sniff test, including the methodology and resulting numbers. That's why I only looked at a couple from your link before, it takes time. But you've sent a lot of information my way. An overwhelming amount, to be honest! I'm not sure how long I'd need to look to find some good specifics. I'm poking around now... Looking for a critique first, I stumbled found this article listing a bunch of pro-mask studies [2], with summaries. I took a quick peek at #3, which mentioned using laser light to examine droplets being exhaled. Sounded like a neat way to quantify things. As I got into it I wondered about the sizes of viruses in relation to the particles they were measuring. But I read some more and it appears they used a slightly damp washcloth, not a mask. That's the kind of thing that I find discouraging - the article quotes this as one of many studies supporting masks, but it was a damp washcloth! I don't consider that to be valid, and it doesn't help the credibility of the headline in my mind. Have you got that far into details on any of this? The titles of these studies aren't enough to convince me, especially when I've clicked on several definitively titled studies and they are anything but. Maybe I have bad luck choosing which studies to read. I went back to your link in the comment above. Under the Exhalation section I looked at this [1] 2020 study, it was the newest. It places a couple hundred people with the flu in cars and bedrooms, with and without masks, and used a device to measure particles in size from 20-1000nm, and found that masks had a significant effect. I then looked to see what size particles spread covid-19 and found this study [2] that mentions 80-90% of particles from human expiratory activities were aerosols with the diameter being smaller than 1μm. I confirmed that 1μm equals 1000nm [3]. They did something else with an aerosol generator and a dryer and a neutralizer, which is kind of confusing, but I think they were just doing some bench measurements. The worst I can say about this study is that the results in Table 2 include a pretty wide variations, and I'm not sure why. For example, in round numbers bedroom background particles were 51K +/- 16k, no mask was 93k +/- 63k, medical mask was 53k +/- 18k. What does it mean that background ranged from 35-67k and no mask from 30-156k? They mentioned these were "in group comparisons", maybe that has something to do with these numbers. I have to assume those aren't error ranges? I didn't see a link to their raw data to know for sure. So that last study is interesting! It certainly passes my initial sniff tests. I'd save this link if I were you, it's the best I've looked into. At this point I'm curious to keep an eye out for a best conflicting study. Until then I've shifted my opinion, I'm not as sceptical as I was. I'm still not a fan of mask mandates, based on other reasons, but I respect hard data and wouldn't want to argue from an inaccurate position. [0] https://www.kxan.com/news/coronavirus/do-face-masks-work-here-are-49-scientific-studies-that-explain-why-they-do/ https://www.kxan.com/news/coronavirus/do-face-masks-work-her... [1] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7883189/#mds310163-bib-0042 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7883189/#mds310... [2] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7293495/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7293495/ [3] https://www.traditionaloven.com/tutorials/distance/convert-micro-meter-to-nanometer-nm.html https://www.traditionaloven.com/tutorials/distance/convert-m...

vannevar 5y ago

I can only tell you that there are many more studies indicating masks work than studies showing their effectiveness is inconclusive. And again, even if masks are 100% effective, there are so many people not wearing them even in jurisdictions that have mandates that there is a limit to their overall impact. Whether masks work is one thing, whether mask mandates work is an entirely different question.

mikem170 5y ago
Unless you have a better study to point to than the hairdressers and the navy ship studies that I looked at (both pretty sloppy in their own way), I'd say that you don't have proof. I'm not saying that you are provably incorrect. You pointed out that the studies I referenced were for personal protection, not to deter spread. However seeing how poorly cloth masks performed in those studies doesn't impart much confidence for their ability to stop spread, either.
- vannevar 5y ago
  Note that the studies you have unspecified qualms about are only 2 of 11 cited in that first survey reference. I meant to include the link to the other survey study I quoted above: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7883189/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7883189/. I'm satisfied by these and many other studies that masks do work. You are of course free to rely on your intuition regarding which studies are valid and which are not, but I stand by my statement.
  - mikem170 5y ago
    Wow, that's quite collection of studies within that link! Ideally I'd find something in there with details that pass my sniff test, including the methodology and resulting numbers. That's why I only looked at a couple from your link before, it takes time. But you've sent a lot of information my way. An overwhelming amount, to be honest! I'm not sure how long I'd need to look to find some good specifics. I'm poking around now... Looking for a critique first, I stumbled found this article listing a bunch of pro-mask studies [2], with summaries. I took a quick peek at #3, which mentioned using laser light to examine droplets being exhaled. Sounded like a neat way to quantify things. As I got into it I wondered about the sizes of viruses in relation to the particles they were measuring. But I read some more and it appears they used a slightly damp washcloth, not a mask. That's the kind of thing that I find discouraging - the article quotes this as one of many studies supporting masks, but it was a damp washcloth! I don't consider that to be valid, and it doesn't help the credibility of the headline in my mind. Have you got that far into details on any of this? The titles of these studies aren't enough to convince me, especially when I've clicked on several definitively titled studies and they are anything but. Maybe I have bad luck choosing which studies to read. I went back to your link in the comment above. Under the Exhalation section I looked at this [1] 2020 study, it was the newest. It places a couple hundred people with the flu in cars and bedrooms, with and without masks, and used a device to measure particles in size from 20-1000nm, and found that masks had a significant effect. I then looked to see what size particles spread covid-19 and found this study [2] that mentions 80-90% of particles from human expiratory activities were aerosols with the diameter being smaller than 1μm. I confirmed that 1μm equals 1000nm [3]. They did something else with an aerosol generator and a dryer and a neutralizer, which is kind of confusing, but I think they were just doing some bench measurements. The worst I can say about this study is that the results in Table 2 include a pretty wide variations, and I'm not sure why. For example, in round numbers bedroom background particles were 51K +/- 16k, no mask was 93k +/- 63k, medical mask was 53k +/- 18k. What does it mean that background ranged from 35-67k and no mask from 30-156k? They mentioned these were "in group comparisons", maybe that has something to do with these numbers. I have to assume those aren't error ranges? I didn't see a link to their raw data to know for sure. So that last study is interesting! It certainly passes my initial sniff tests. I'd save this link if I were you, it's the best I've looked into. At this point I'm curious to keep an eye out for a best conflicting study. Until then I've shifted my opinion, I'm not as sceptical as I was. I'm still not a fan of mask mandates, based on other reasons, but I respect hard data and wouldn't want to argue from an inaccurate position. [0] https://www.kxan.com/news/coronavirus/do-face-masks-work-here-are-49-scientific-studies-that-explain-why-they-do/ https://www.kxan.com/news/coronavirus/do-face-masks-work-her... [1] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7883189/#mds310163-bib-0042 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7883189/#mds310... [2] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7293495/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7293495/ [3] https://www.traditionaloven.com/tutorials/distance/convert-micro-meter-to-nanometer-nm.html https://www.traditionaloven.com/tutorials/distance/convert-m...