4 ms·

I don't get angry at people wearing masks. I comply with the local mask mandates where I live. Having said that, I have a question. Why does anybody think that

I don't get angry at people wearing masks. I comply with the local mask mandates where I live. Having said that, I have a question. Why does anybody think that masks actually help? I've basically been under the impression that masks are health theater that allows people to go on with life without being scared, though it doesn't actually do much of anything. Apparently I'm in the minority in thinking that. But I put on a surgical mask, twist the side ear loop so that air comes out the side instead of the top (right at my eyes), and I ask myself what in the world it is supposed to be accomplishing. It's not like people are wearing properly fitted N95 masks, and even then, the way people are talking about micro droplets seems like they might get through just fine.

webkike 6y ago
There are studies pointing to their efficacy https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7191274/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7191274/
- jtbayly 6y ago
  I've read a fair bit now, and I'm left with... questions. I haven't read it all yet, but nothing I've seen so far indicates that masks actually accomplish anything directly. From the summary of results: "Medical masks were not effective, and cloth masks even less effective." I'm assuming that is referring to in hospital settings, but still... somehow they magically they work "in the community." Has anybody proposed or tested a reason for why they would work in one setting but not the other? I saw no mention of controlling for how much time the participants (college students) spent with other people. Can we truly assume that wearing a mask had no other effect on the behavior of young people who are incredibly image-conscious and facing intense peer pressure to fit in? If I had to guess, the only thing they proved is that college students asked to wear masks will stay alone in their rooms more often than those not asked to wear masks. Of course, indirect benefits are still benefits. It is possible that something like this could happen when masks are mandated in public today. Meaning, mask mandates lead to people staying home more, which is obviously going to be effective. However, see next paragraph. Another problem I saw immediately is that they were required to wear masks for long periods when in their dwelling, but not required outside of their dwelling. This, of course, is the opposite of what we are doing. What is the result of inverting the study practices? They were studies on the flu. Can we assume the same effect on Coronaviruses? From one study... "Generalizability limited to similar settings and age groups." Ok... so we're ignoring the paper's warnings about what we can learn from it? In one study they were able to measure a decrease in flu-like-illnesses(ILI) with mask use, but it wasn't statistically significant, and it was only in the second half of the study (weeks 4-6). The summary ends with: "Neither face mask use and hand hygiene nor face mask use alone was associated with a significant reduction in the rate of ILI cumulatively." It then proceeds in the next sentence (the conclusion summary), to say, "These findings suggest that face masks and hand hygiene may reduce respiratory illnesses in shared living settings and mitigate the impact of the influenza A(H1N1) pandemic." Isn't this an example of a study what normally would be lampooned on this site? How exactly does the conclusion follow from the data? Another study saw statistically significant reductions in ILI, but again, only in the second half of the study, and did not find statistically significant reduction in actual positive flu tests. It is summarized by: "Face masks and hand hygiene combined may reduce the rate of ILI and confirmed influenza in community settings. These non-pharmaceutical measures should be recommended in crowded settings at the start of an influenza pandemic." However, there was no control group that was just hand washing. Doesn't it seem much more reasonable to assume that the benefits are from hand-washing, rather than hand-washing and masks combined, since the mask-only group saw little to no benefit? And if so, why are we using this paper to prove that masks work?
  - Tagbert 6y ago
    Flu transmission and Covid transmission are not identical. Covid seems to be mainly transmitted by relatively large respiratory droplets. The expiration and transmission of those droplets is greatly reduced by a mask, even if some leakage occurs around the edges. Perhaps because the drops are more likely to just drop as a result. Most of the studies have been done in high risk, high exposure situations. The high concentration and repeated exposure over extended periods of time greatly increase the chance of infection. This does not reflect the lower concentrations and shorter duration of most civilian exposures. It generally takes more than a single virus to actually result in infection. Since there are indications that wearing masks does give you some protection and does give significant protection to those around you, why not accept the minor inconvenience and wear one?
    - jtbayly 6y ago
      "Since there are indications that wearing masks does give you some protection and does give significant protection to those around you..." This is precisely what I'm trying to find evidence of. So far, I've clicked through to one summary of the research, followed by three papers linked in there, which supposedly support the claim, and found that there is almost no support for those claims. And as I already said above, I do wear one. Edited to add: Also, I've been reading more and more articles questioning the claim that Coronavirus is mostly limited to the larger droplets.
      - jakeogh 6y ago
        "There is no benefit and there may even be negative impact." https://www.dailymail.co.uk/news/article-8583925/The-land-no-face-masks-Hollands-scientists-say-theres-no-solid-evidence-coverings-work.html https://www.dailymail.co.uk/news/article-8583925/The-land-no... Not remotely surprising. The fake masks are basically dirty sponges stuck in the most important air stream. https://news.ycombinator.com/item?id=24045096 https://news.ycombinator.com/item?id=24045096
      - roel_v 6y ago
        You're right, from an evidence-based medicine perspective there is little to no proof that masks work, and some indication that they are counter-productive. There are plenty of people posting links with dozens of papers claiming to prove that they do work, but very few if any of those people seem to have actually read anything on those lists, as none of them claim what the people posting the links claim they claim. (note that I'm not claiming here people should or should not wear them, this is a position-neutral meta observation). That said, at this point wearing/'believing in' face masks is a political issue, not an evidence based rational choice. It's tribal signaling. Noboby really knows a or b, but choosing to believe a or b has become (yet another) aspect of identity politics. Which is what worries me the most, because now that position has become entrenched, regardless of whether we reach any conclusive findings at some point in the future.
ahelwer 6y ago
Take a look at this story, where covid-positive hairdressers interacted with over a hundred clients (all involved wearing masks) without infecting any of them: https://www.cdc.gov/mmwr/volumes/69/wr/mm6928e2.htm https://www.cdc.gov/mmwr/volumes/69/wr/mm6928e2.htm Masks are tremendously effective. They protect you from others a small amount, but protect others from you a huge amount. They are absolutely not theatrical. When it comes to stopping transmission, we don't have to get 100% effectiveness. We just need to get the r-value below 1 and the disease will die out. It's a game if probabilities, not absolutes. Masks have a very low cost for the tremendous benefit they confer.
CharlesW 6y ago
> Why does anybody think that masks actually help? If you know of scientific studies that show that masks don't make a significant difference, please share them. Here's a list of 70 scientific papers (including reviews/meta-analysis and individual studies) on the efficacy of masks: https://threader.app/thread/1279144399897866248 https://threader.app/thread/1279144399897866248
mdorazio 6y ago
I understand why you would think that given the really poor recommendations and information handling at the beginning of the pandemic. However, take a look at [1], then refer to your choice of studies on this topic via Google Scholar, perhaps [2]. Cheap masks will of course not prevent you from inhaling microparticles, but they drastically cut down on how many particles are pushed into the air and how far they travel. You should think of them as spread limiters rather than infection preventers. [1] https://twitter.com/vaccinologist/status/1247510457323343874?lang=en https://twitter.com/vaccinologist/status/1247510457323343874... [2] https://www.sciencedirect.com/science/article/pii/S0163445320302358 https://www.sciencedirect.com/science/article/pii/S016344532...
ExThermoGuy 6y ago
You shouldn't get down-voted for an honest question. Especially since the messaging from our (US) experts was, in my opinion, criminally confused. There is a lot of theater going on but: 1. masks do help in aggregate 2. theater can also help (I won't address that). For the record I am a physicist, not a physician or a biologist. Everything I'm writing below are conclusions I arrived at from an understanding of physics, not biology. But it turned out that my conclusions were largely correct. Let's assume this is, primarily, a respiratory disease. Therefore, the virus is present in the respiratory tract -> let's assume that it will exploit that power of exhalation (to jump out) and inhalation (to establish) to spread itself. I think my assumptions are fair. As you point out, there are two types of masks: N95 vs. surgical masks. In fact, there is an important subtype of mask, the N95 with valve. These last ones are great for individuals, but are very dangerous overall. The cheap surgical masks with wide openings on the sides doesn't protect you very much. It's not meant to. It's meant to protect others from you. It does this by destroying the kinetic energy of the droplets so that they mostly come into contact with you (and you're already sick, so who cares?). Also if the virus needs droplets to survive, the mask will dry them out. The N95 with a valve only protects you, not others. The N95 mask seals your face and forces all inhaled air through a filter that the virus cannot penetrate. But the valve forces the unfiltered air in am accelerated jet aimed at whoever you are facing. The N95 mask without a filter protects others and yourself. Now, there is mounting evidence that the COVID virus is aerosolized, meaning that it doesn't need a droplet. Still, the face coverings are important because the exhaled air is slower and therefore limited in its spread. I arrived at these conclusions in late January, and was able to buy a few N95 masks in time. I didn't buy many because I didn't want to be an asshole (and I couldn't find them already). I planned to re-use them and I have. In five months my wife and I have lost two to due wear, so at this rate we have enough to last about a year, year and half. I never believed the admonition that you cant re-use masks. You can, if done right, and Dr.s have been forced to do so at work.

webkike 6y ago

There are studies pointing to their efficacy https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7191274/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7191274/

jtbayly 6y ago
I've read a fair bit now, and I'm left with... questions. I haven't read it all yet, but nothing I've seen so far indicates that masks actually accomplish anything directly. From the summary of results: "Medical masks were not effective, and cloth masks even less effective." I'm assuming that is referring to in hospital settings, but still... somehow they magically they work "in the community." Has anybody proposed or tested a reason for why they would work in one setting but not the other? I saw no mention of controlling for how much time the participants (college students) spent with other people. Can we truly assume that wearing a mask had no other effect on the behavior of young people who are incredibly image-conscious and facing intense peer pressure to fit in? If I had to guess, the only thing they proved is that college students asked to wear masks will stay alone in their rooms more often than those not asked to wear masks. Of course, indirect benefits are still benefits. It is possible that something like this could happen when masks are mandated in public today. Meaning, mask mandates lead to people staying home more, which is obviously going to be effective. However, see next paragraph. Another problem I saw immediately is that they were required to wear masks for long periods when in their dwelling, but not required outside of their dwelling. This, of course, is the opposite of what we are doing. What is the result of inverting the study practices? They were studies on the flu. Can we assume the same effect on Coronaviruses? From one study... "Generalizability limited to similar settings and age groups." Ok... so we're ignoring the paper's warnings about what we can learn from it? In one study they were able to measure a decrease in flu-like-illnesses(ILI) with mask use, but it wasn't statistically significant, and it was only in the second half of the study (weeks 4-6). The summary ends with: "Neither face mask use and hand hygiene nor face mask use alone was associated with a significant reduction in the rate of ILI cumulatively." It then proceeds in the next sentence (the conclusion summary), to say, "These findings suggest that face masks and hand hygiene may reduce respiratory illnesses in shared living settings and mitigate the impact of the influenza A(H1N1) pandemic." Isn't this an example of a study what normally would be lampooned on this site? How exactly does the conclusion follow from the data? Another study saw statistically significant reductions in ILI, but again, only in the second half of the study, and did not find statistically significant reduction in actual positive flu tests. It is summarized by: "Face masks and hand hygiene combined may reduce the rate of ILI and confirmed influenza in community settings. These non-pharmaceutical measures should be recommended in crowded settings at the start of an influenza pandemic." However, there was no control group that was just hand washing. Doesn't it seem much more reasonable to assume that the benefits are from hand-washing, rather than hand-washing and masks combined, since the mask-only group saw little to no benefit? And if so, why are we using this paper to prove that masks work?
- Tagbert 6y ago
  Flu transmission and Covid transmission are not identical. Covid seems to be mainly transmitted by relatively large respiratory droplets. The expiration and transmission of those droplets is greatly reduced by a mask, even if some leakage occurs around the edges. Perhaps because the drops are more likely to just drop as a result. Most of the studies have been done in high risk, high exposure situations. The high concentration and repeated exposure over extended periods of time greatly increase the chance of infection. This does not reflect the lower concentrations and shorter duration of most civilian exposures. It generally takes more than a single virus to actually result in infection. Since there are indications that wearing masks does give you some protection and does give significant protection to those around you, why not accept the minor inconvenience and wear one?
  - jtbayly 6y ago
    "Since there are indications that wearing masks does give you some protection and does give significant protection to those around you..." This is precisely what I'm trying to find evidence of. So far, I've clicked through to one summary of the research, followed by three papers linked in there, which supposedly support the claim, and found that there is almost no support for those claims. And as I already said above, I do wear one. Edited to add: Also, I've been reading more and more articles questioning the claim that Coronavirus is mostly limited to the larger droplets.
    - jakeogh 6y ago
      "There is no benefit and there may even be negative impact." https://www.dailymail.co.uk/news/article-8583925/The-land-no-face-masks-Hollands-scientists-say-theres-no-solid-evidence-coverings-work.html https://www.dailymail.co.uk/news/article-8583925/The-land-no... Not remotely surprising. The fake masks are basically dirty sponges stuck in the most important air stream. https://news.ycombinator.com/item?id=24045096 https://news.ycombinator.com/item?id=24045096
    - roel_v 6y ago
      You're right, from an evidence-based medicine perspective there is little to no proof that masks work, and some indication that they are counter-productive. There are plenty of people posting links with dozens of papers claiming to prove that they do work, but very few if any of those people seem to have actually read anything on those lists, as none of them claim what the people posting the links claim they claim. (note that I'm not claiming here people should or should not wear them, this is a position-neutral meta observation). That said, at this point wearing/'believing in' face masks is a political issue, not an evidence based rational choice. It's tribal signaling. Noboby really knows a or b, but choosing to believe a or b has become (yet another) aspect of identity politics. Which is what worries me the most, because now that position has become entrenched, regardless of whether we reach any conclusive findings at some point in the future.

ahelwer 6y ago

Take a look at this story, where covid-positive hairdressers interacted with over a hundred clients (all involved wearing masks) without infecting any of them: https://www.cdc.gov/mmwr/volumes/69/wr/mm6928e2.htm https://www.cdc.gov/mmwr/volumes/69/wr/mm6928e2.htm Masks are tremendously effective. They protect you from others a small amount, but protect others from you a huge amount. They are absolutely not theatrical. When it comes to stopping transmission, we don't have to get 100% effectiveness. We just need to get the r-value below 1 and the disease will die out. It's a game if probabilities, not absolutes. Masks have a very low cost for the tremendous benefit they confer.

CharlesW 6y ago

> Why does anybody think that masks actually help? If you know of scientific studies that show that masks don't make a significant difference, please share them. Here's a list of 70 scientific papers (including reviews/meta-analysis and individual studies) on the efficacy of masks: https://threader.app/thread/1279144399897866248 https://threader.app/thread/1279144399897866248

mdorazio 6y ago

I understand why you would think that given the really poor recommendations and information handling at the beginning of the pandemic. However, take a look at [1], then refer to your choice of studies on this topic via Google Scholar, perhaps [2]. Cheap masks will of course not prevent you from inhaling microparticles, but they drastically cut down on how many particles are pushed into the air and how far they travel. You should think of them as spread limiters rather than infection preventers. [1] https://twitter.com/vaccinologist/status/1247510457323343874?lang=en https://twitter.com/vaccinologist/status/1247510457323343874... [2] https://www.sciencedirect.com/science/article/pii/S0163445320302358 https://www.sciencedirect.com/science/article/pii/S016344532...

ExThermoGuy 6y ago

You shouldn't get down-voted for an honest question. Especially since the messaging from our (US) experts was, in my opinion, criminally confused. There is a lot of theater going on but: 1. masks do help in aggregate 2. theater can also help (I won't address that). For the record I am a physicist, not a physician or a biologist. Everything I'm writing below are conclusions I arrived at from an understanding of physics, not biology. But it turned out that my conclusions were largely correct. Let's assume this is, primarily, a respiratory disease. Therefore, the virus is present in the respiratory tract -> let's assume that it will exploit that power of exhalation (to jump out) and inhalation (to establish) to spread itself. I think my assumptions are fair. As you point out, there are two types of masks: N95 vs. surgical masks. In fact, there is an important subtype of mask, the N95 with valve. These last ones are great for individuals, but are very dangerous overall. The cheap surgical masks with wide openings on the sides doesn't protect you very much. It's not meant to. It's meant to protect others from you. It does this by destroying the kinetic energy of the droplets so that they mostly come into contact with you (and you're already sick, so who cares?). Also if the virus needs droplets to survive, the mask will dry them out. The N95 with a valve only protects you, not others. The N95 mask seals your face and forces all inhaled air through a filter that the virus cannot penetrate. But the valve forces the unfiltered air in am accelerated jet aimed at whoever you are facing. The N95 mask without a filter protects others and yourself. Now, there is mounting evidence that the COVID virus is aerosolized, meaning that it doesn't need a droplet. Still, the face coverings are important because the exhaled air is slower and therefore limited in its spread. I arrived at these conclusions in late January, and was able to buy a few N95 masks in time. I didn't buy many because I didn't want to be an asshole (and I couldn't find them already). I planned to re-use them and I have. In five months my wife and I have lost two to due wear, so at this rate we have enough to last about a year, year and half. I never believed the admonition that you cant re-use masks. You can, if done right, and Dr.s have been forced to do so at work.