6 ms·

"Are masks effective" is the completely wrong question, anyway. The question should be "how effective are masks?" Preferably, "How effective are masks against

"Are masks effective" is the completely wrong question, anyway. The question should be "how effective are masks?" Preferably, "How effective are masks against X under Y circumstance?" In relation to Covid, I think it's likely masks reduced transmission. But, under normal social environments, did they reduce it by 5% or by 50%? It makes a big policy difference. It seems that studies are coalescing around masks having a 'real but small' effect, but I get it's a hard thing to study.

marcosdumay 2y ago
> did they reduce it by 5% or by 50% Either one would cause a dramatic reduction on the (exponential) virus spread. For the actual policy, it shouldn't make a difference. It had feedback mechanisms anyway, because the conditions always change.
- frognumber 2y ago
  Well, no. It makes a big difference: 1) If the exponent is >1, it doesn't make much difference. Everyone will catch "it," for whatever disease. 2) It makes sense to have interventions prioritized by ROI 3) Many interventions are individual, and there is no exponent. Should I, as a [doctor / immuno-compromised-individual / patient / etc.] wear a mask?
  - marcosdumay 2y ago
    > It makes sense to have interventions prioritized by ROI The thing about masks is that the investment is minimal. Those 5% are still an incredibly large number that makes it a non-brainier. If it decreases another order of magnitude, it may need some analysis. The OP has a point, but it's way beyond the plausibility window.
    - zeroonetwothree 2y ago
      As an individual I would not wear a mask to reduce infection risk by 5%. If it’s more like 90% then that’s something.
      - threeseed 2y ago
        But those who are the most likely to be affected i.e. older and vulnerable people would. So in fact whether you wear one or not is far less relevant.
        deleted 2y ago
        [deleted]
        triplesec 2y ago
        You misunderstand the utility of masks, where it is significantly more an infected wearer of the mask who protects others by their wearing. So, being infections before you have symptoms is the problem, which is why people should - as is standard in Japan, for example - wear masks in public whenever they feel unwell or feel a 'cold' coming on.
      - TheOtherHobbes 2y ago
        Masking during a pandemic is never just about individual risk. Collective action has an exponential effect on prevalence, so the real risk goes down by far more than 5%. Not taking action to reduce risk of illness or death is irrational.
        dilap 2y ago
        There's a trade-off between doing things you enjoy (or don't enjoy) and the risk of death, and it's a personal trade-off, not something that can be assessed rationally.
    - frognumber 2y ago
      First-world thinking. A quality mask costs around $1. Per-capita GDP is about $33 per day worldwide. Or put another way, with 8 billion people in the world, a mask a day runs around $3 trillion annually. The world is interconnected. I like masks since, aside from viruses, they filter pollution and allergens. I feel a lot better post-2020. However, universal HEPA filters and covid masks are very much for the rich.
      - PeterStuer 2y ago
        Don't masks have to be swapped way more than once per day to reach the perscribed efficiency? More like once every 30 minutes?
        hollerith 2y ago
        No. I've been using N95s since the start of the pandemic and have spent a fair amount of time learning about them, e.g., reading the written material that comes with the box of masks, and I've never seen that kind of recommendation. The written materials say things like, "throw the mask away as soon as it becomes stained or discolored." I use each of my masks for probably at least 10 hours before throwing it away, and I've never gotten covid except once (in Jan or Feb 2020) before I started wearing masks (in fact, before anyone in my country -- the US -- knew about covid). (I have to write "probably" because I don't actually keep written records of how long I have each mask on. I rarely have one on for more than an hour at a time.) I've used mainly 3M 8511 masks. The most important distinction between mask models is that some models have valves / vents and some do not. Hospitals use ones without valves. The lack of a valve means that the part of the mask that filters the air gets a lot more damp than it would if a value were present (because exhaled air is damp) which might drastically reduce how long the mask will last, so that might be why some hospitals instruct their employees to use a new mask for each new patient contact.
        frognumber 2y ago
        > The most important distinction between mask models is that some models have valves / vents and some do not. The most important distinctions also include: 1) Fit. This matters a lot. 2) Nano versus electrostatic technology. 3) Filtration level. "N95" advertised isn't always 95% in reality, and some are 99+%. 4) Impedance to airflow #4 is more than just comfort it determines how much air goes around the mask.
- amluto 2y ago
  > dramatic reduction on the (exponential) virus spread. Check your assumptions, please! If you are comparing e^(kt) to e^(0.5 kt), sure, they’re very different. But Covid didn’t spread like that at all. It grew exponentially-ish until the fraction infected was no longer negligible, and then the dynamics changed dramatically, as they must have. After all, you can’t have 1 million times the entire population infected after a couple years.
postepowanieadm 2y ago
> I think it's likely masks reduced transmission And your belief is based on what?
- warcher 2y ago
  Common sense? Restricting exhalation to reduce transmission of airborne disease? Have you never been taught to cover your mouth when you sneeze or cough? Like it would be remarkable if it did nothing. THAT would be a blockbuster result. The thing worth studying is if the effect is worth the trouble or not. It could be worth doing or it could effectively be a waste of time due to whatever other factor.
  - pandaman 2y ago
    Many people have been taught to say "Bless you!" when somebody sneezed too, would it also surprise you that it doesn't affect any airborne virus?
    - amanaplanacanal 2y ago
      Aye, that brings up another issue. What exactly does “airborne” mean? The assumption early on was that Covid was not airborne, and required droplets of a certain size, though I think that changed over time.
      - pandaman 2y ago
        We might never know this about COVID as further studying it can only uncover more malfeasance at this point, but traditional airborne stuff like smallpox or measles won't be affected by a dirty bandana on one's mouth or, even, over the nose.
  - neilwilson 2y ago
    Common sense says if you put your hand over your mouth and breath out you will be able to. That says the pressure is overcoming the blockage. The other way round is far more difficult. If you leak then you are wasting your time because in a static air environment you’ll delay the critical level build up by a few minutes at most. Medicine doesn’t like aerosolisation because it sounds too much like miasmia theory. So we have too much focus on droplets and fomites. Fundamentally this should have been sorted with a properly designed trial with the correct protocol of sufficient size to answer the question. Given what was on the line why has it not been done?
u32480932048 2y ago
[flagged]
- supplied_demand 2y ago
  == Instead of getting everyone on the same page, == Your post seems to be continuing this trend. Nobody called anyone “deplorable schmucks” or “puppy kicking grandma killer” but you. Your victimhood really comes out in the language you choose to describe others.
  - throw-the-towel 2y ago
    FWIW I remember this very forum flinging this kind of accusations in 2020.
    - supplied_demand 2y ago
      Even without any examples, I don’t see how revisiting it today gets anyone on the same page. It feels like a way to play the victim.
      - ipaddr 2y ago
        [flagged]
        ceejayoz 2y ago
        [flagged]
        pfannkuchen 2y ago
        I have no opinion on this thread but I find it weird when people dig through others’ comment history and try to use it as an argument. If you read the rest of that thread GP states that he was thinking of a specific different police brutality case and mistakenly referred to the George Floyd case instead. I also have no idea what he means by black supremacists there but the ridiculous part of your quote was essentially a typo by GP (allegedly anyway).
580515975 2y ago
https://journals.aps.org/rmp/abstract/10.1103/RevModPhys.95.045001 https://journals.aps.org/rmp/abstract/10.1103/RevModPhys.95.... is one article that provides some insight. It describes the nature of viral particles exhaled in different activities, and explains how effective different masks are at preventing these particles from being inhaled. Separately, I was surprised to see that OP's article looked at studies starting in 1978, since modern electrostatic filtering masks were only patented in 1995--so I'm not sure how meaningful it is to lump studies on older mask technologies in with modern masks.
chaostheory 2y ago
Another question most of these studies fail to ask is what is the effectiveness of each type of mask? An N95 mask is going to have a big difference in efficacy vs a surgical mask without a seal. Another issue is that most of these studies are just surveys. Did participants actually use their masks for x hours? Did they use their masks correctly?

marcosdumay 2y ago

> did they reduce it by 5% or by 50% Either one would cause a dramatic reduction on the (exponential) virus spread. For the actual policy, it shouldn't make a difference. It had feedback mechanisms anyway, because the conditions always change.

frognumber 2y ago
Well, no. It makes a big difference: 1) If the exponent is >1, it doesn't make much difference. Everyone will catch "it," for whatever disease. 2) It makes sense to have interventions prioritized by ROI 3) Many interventions are individual, and there is no exponent. Should I, as a [doctor / immuno-compromised-individual / patient / etc.] wear a mask?
- marcosdumay 2y ago
  > It makes sense to have interventions prioritized by ROI The thing about masks is that the investment is minimal. Those 5% are still an incredibly large number that makes it a non-brainier. If it decreases another order of magnitude, it may need some analysis. The OP has a point, but it's way beyond the plausibility window.
  - zeroonetwothree 2y ago
    As an individual I would not wear a mask to reduce infection risk by 5%. If it’s more like 90% then that’s something.
    - threeseed 2y ago
      But those who are the most likely to be affected i.e. older and vulnerable people would. So in fact whether you wear one or not is far less relevant.
      - deleted 2y ago
        [deleted]
      - triplesec 2y ago
        You misunderstand the utility of masks, where it is significantly more an infected wearer of the mask who protects others by their wearing. So, being infections before you have symptoms is the problem, which is why people should - as is standard in Japan, for example - wear masks in public whenever they feel unwell or feel a 'cold' coming on.
    - TheOtherHobbes 2y ago
      Masking during a pandemic is never just about individual risk. Collective action has an exponential effect on prevalence, so the real risk goes down by far more than 5%. Not taking action to reduce risk of illness or death is irrational.
      - dilap 2y ago
        There's a trade-off between doing things you enjoy (or don't enjoy) and the risk of death, and it's a personal trade-off, not something that can be assessed rationally.
  - frognumber 2y ago
    First-world thinking. A quality mask costs around $1. Per-capita GDP is about $33 per day worldwide. Or put another way, with 8 billion people in the world, a mask a day runs around $3 trillion annually. The world is interconnected. I like masks since, aside from viruses, they filter pollution and allergens. I feel a lot better post-2020. However, universal HEPA filters and covid masks are very much for the rich.
    - PeterStuer 2y ago
      Don't masks have to be swapped way more than once per day to reach the perscribed efficiency? More like once every 30 minutes?
      - hollerith 2y ago
        No. I've been using N95s since the start of the pandemic and have spent a fair amount of time learning about them, e.g., reading the written material that comes with the box of masks, and I've never seen that kind of recommendation. The written materials say things like, "throw the mask away as soon as it becomes stained or discolored." I use each of my masks for probably at least 10 hours before throwing it away, and I've never gotten covid except once (in Jan or Feb 2020) before I started wearing masks (in fact, before anyone in my country -- the US -- knew about covid). (I have to write "probably" because I don't actually keep written records of how long I have each mask on. I rarely have one on for more than an hour at a time.) I've used mainly 3M 8511 masks. The most important distinction between mask models is that some models have valves / vents and some do not. Hospitals use ones without valves. The lack of a valve means that the part of the mask that filters the air gets a lot more damp than it would if a value were present (because exhaled air is damp) which might drastically reduce how long the mask will last, so that might be why some hospitals instruct their employees to use a new mask for each new patient contact.
        frognumber 2y ago
        > The most important distinction between mask models is that some models have valves / vents and some do not. The most important distinctions also include: 1) Fit. This matters a lot. 2) Nano versus electrostatic technology. 3) Filtration level. "N95" advertised isn't always 95% in reality, and some are 99+%. 4) Impedance to airflow #4 is more than just comfort it determines how much air goes around the mask.
amluto 2y ago
> dramatic reduction on the (exponential) virus spread. Check your assumptions, please! If you are comparing e^(kt) to e^(0.5 kt), sure, they’re very different. But Covid didn’t spread like that at all. It grew exponentially-ish until the fraction infected was no longer negligible, and then the dynamics changed dramatically, as they must have. After all, you can’t have 1 million times the entire population infected after a couple years.

postepowanieadm 2y ago

> I think it's likely masks reduced transmission And your belief is based on what?

warcher 2y ago
Common sense? Restricting exhalation to reduce transmission of airborne disease? Have you never been taught to cover your mouth when you sneeze or cough? Like it would be remarkable if it did nothing. THAT would be a blockbuster result. The thing worth studying is if the effect is worth the trouble or not. It could be worth doing or it could effectively be a waste of time due to whatever other factor.
- pandaman 2y ago
  Many people have been taught to say "Bless you!" when somebody sneezed too, would it also surprise you that it doesn't affect any airborne virus?
  - amanaplanacanal 2y ago
    Aye, that brings up another issue. What exactly does “airborne” mean? The assumption early on was that Covid was not airborne, and required droplets of a certain size, though I think that changed over time.
    - pandaman 2y ago
      We might never know this about COVID as further studying it can only uncover more malfeasance at this point, but traditional airborne stuff like smallpox or measles won't be affected by a dirty bandana on one's mouth or, even, over the nose.
- neilwilson 2y ago
  Common sense says if you put your hand over your mouth and breath out you will be able to. That says the pressure is overcoming the blockage. The other way round is far more difficult. If you leak then you are wasting your time because in a static air environment you’ll delay the critical level build up by a few minutes at most. Medicine doesn’t like aerosolisation because it sounds too much like miasmia theory. So we have too much focus on droplets and fomites. Fundamentally this should have been sorted with a properly designed trial with the correct protocol of sufficient size to answer the question. Given what was on the line why has it not been done?

u32480932048 2y ago

[flagged]

supplied_demand 2y ago
== Instead of getting everyone on the same page, == Your post seems to be continuing this trend. Nobody called anyone “deplorable schmucks” or “puppy kicking grandma killer” but you. Your victimhood really comes out in the language you choose to describe others.
- throw-the-towel 2y ago
  FWIW I remember this very forum flinging this kind of accusations in 2020.
  - supplied_demand 2y ago
    Even without any examples, I don’t see how revisiting it today gets anyone on the same page. It feels like a way to play the victim.
    - ipaddr 2y ago
      [flagged]
      - ceejayoz 2y ago
        [flagged]
        pfannkuchen 2y ago
        I have no opinion on this thread but I find it weird when people dig through others’ comment history and try to use it as an argument. If you read the rest of that thread GP states that he was thinking of a specific different police brutality case and mistakenly referred to the George Floyd case instead. I also have no idea what he means by black supremacists there but the ridiculous part of your quote was essentially a typo by GP (allegedly anyway).

580515975 2y ago

https://journals.aps.org/rmp/abstract/10.1103/RevModPhys.95.045001 https://journals.aps.org/rmp/abstract/10.1103/RevModPhys.95.... is one article that provides some insight. It describes the nature of viral particles exhaled in different activities, and explains how effective different masks are at preventing these particles from being inhaled. Separately, I was surprised to see that OP's article looked at studies starting in 1978, since modern electrostatic filtering masks were only patented in 1995--so I'm not sure how meaningful it is to lump studies on older mask technologies in with modern masks.

chaostheory 2y ago

Another question most of these studies fail to ask is what is the effectiveness of each type of mask? An N95 mask is going to have a big difference in efficacy vs a surgical mask without a seal. Another issue is that most of these studies are just surveys. Did participants actually use their masks for x hours? Did they use their masks correctly?