8 ms·

Data do not back cloth masks to limit Covid-19, experts say

27 points by timr 7y ago

anorphirith 7y ago
The title is inaccurate, they acknowledge on the first paragraph that it captures large droplets. that's reason enough to wear the mask
- wegs 7y ago
  The title is 100% accurate, just misleading. "Data do not back" is intentional weasel language commonly used in university press releases. Data does not back that if you (anorphirith) shoot me (wegs) in the head with an AK47, I'll die. That particular study has never been done). But we know it's true. But a carefully-phrased headline gets picked up by the popular press and builds university branding. See also "significant" (which means "statistically significant," so might be a 0.000001% effect size with enough data, but which the public picks up to mean "big"). These are well-developed techniques for roping science-ignorant reporters.
- Someone 7y ago
  But large droplets drop to the ground rapidly, so if social distancing is done, they’re unlikely to infect anybody, anyways. Also, most governments advice people with a cold/fever/… to stay home. If they do, and given the current estimate of infection rate, those droplets aren’t likely to contain the virus.
kinkrtyavimoodh 7y ago
This mask discussion makes me think like I am taking crazy pills. Can someone explain to me how placing a barrier in front of your mouth and nose can possibly be a BAD idea when the purpose is to reduce the entry of particles into the system? Why do we need studies to prove this? If you are inhaling it is likely to stop some particles from getting in. If you are exhaling it is likely to stop some particles from getting out. Sure, particles might still get in or out but HOW CAN IT BE WORSE THAN LITERALLY BEING EXPOSED ALL THE TIME? This feels like the parachute example to me that was posted here a few days ago. You don't need to do a study to prove that a man hitting the ground at 10km/h would be more likely to survive than one hitting at 150km/h. Sure, parachutes can fail, but how can they be worse off than NOT wearing a parachute? It almost feels like the health agencies were caught with their pants down telling absolute lies about masks for over a month and are now scrambling to salvage some dignity from the affair by throwing studies at us. Just imagine how much we could have reduced transmission if Americans had started wearing masks in late February or at least early March. This lie has literally cost the world billions of dollars, not to mention thousands of lives.
- wegs 7y ago
  No one honest can, because masks do help. What's not clear is how much they help. They'd have a huge effect on large droplets, but potentially a very small effect on bioaerosols. Until we know more about how COVID19 typically spreads, we don't know how important they are. In contrast to the intentionally dishonest UMN fluff PR piece, that's what the NAP paper it claims to summarize says. The one really big effect not talked about is that it also means I can't unconsciously touch my mouth or nose. Remember the "don't touch your face" campaign?
  - timr 7y ago
    "In contrast to the intentionally dishonest UMN fluff PR piece, that's what the NAP paper it claims to summarize says." The article title is "data do not back cloth masks to limit Covid-19". The NAP paper says: "The evidence from these laboratory filtration studies suggests that such fabric masks may reduce the transmission of larger respiratory droplets. There is little evidence regarding the transmission of small aerosolized particulates of the size potentially exhaled by asymptomatic or presymptomatic individuals with COVID-19. The extent of any protection will depend on how the masks are made and used. It will also depend on how mask use affects users’ other precautionary behaviors, including their use of better masks, when those become widely available. Those behavioral effects may undermine or enhance homemade fabric masks’ overall effect on public health. The current level of benefit, if any, is not possible to assess." It seems like an entirely accurate summary of the contents of the paper.
- conqrr 7y ago
  Not arguing for/against masks, merely pointing out the analogy. For your parachute analogy. Imagine that its given the parachute will have very large holes (similar to the droplets being very very small). Its useless having a parchute in that case.
  - kinkrtyavimoodh 7y ago
    I am pretty sure that a parachute with holes will still have reduced terminal velocity than not having a parachute. I get your argument but unlike a man crashing to death, we are playing a probability game here. Viral load also matters, even if you can stop some of the virus from entering, it can only help.
wegs 7y ago
I suggest clicking through to the NAP paper, which unlike this reporting fluff/hype piece, is very reasonable. This is part of the standard academic fake science pipeline. The researchers did reasonable work (best summary: "We don't know how well they work"). The university PR departments turned that into hyped-up nonsense to gain publicity and brand recognition. Next step will be science reporting, which will exaggerate the press release, and finally, popular news, which will use this to bash random policy decisions. Direct link to the original paper: https://www.nap.edu/read/25776/chapter/1 https://www.nap.edu/read/25776/chapter/1 In general, NAP pieces tend to be well-researched and well-written summaries of what's known. This one is no exception.
- astrophysician 7y ago
  You forgot about the other half of the cycle: time passes, another wave of publicity bashes the initial hype, people assume the scientists themselves are responsible (even though they have been freaking out about their work being misrepresented), scientists lose funding, people don’t trust scientists.
  - pacala 7y ago
    You forgot about the third half of the cycle: scientists exceedingly rarely submit a correction note to tone down the hyped up claims made by the PR departments / science press. They are very good at keeping the freak out to themselves. A systemic problem, not sure how to solve for, if even there is a solution.
    - astrophysician 7y ago
      Yea right, it’s just so weird to deal with this problem as a scientist unless you do work that is regularly in the news and you have opportunities to learn how to better control what is written/said and deal with instances where the wrong message is getting out. Vast majority of scientists are doing work for an audience of themselves, other scientists and funding agencies, and are working for respect, not fame or media attention. So when a their research suddenly gets churned through this bullshit cycle, they’re really troubled but don’t necessarily know the most effective way to control the message once it gets out of their hands. It can be really unfair and stressful.
procrastitron 7y ago
This title seems misleading to me. The title implies that we have data showing cloth masks don’t work, but what the article actually says is just that we don’t have data.
paulsutter 7y ago
Masks are not a risky medical procedure. Anti-mask truthers are the ones who need extraordinary evidence, not mask supporters. Video of droplets blocked by a mask: https://twitter.com/i/status/1254535446509412353 https://twitter.com/i/status/1254535446509412353 Why we should all wear masks: https://masks4all.co/ https://masks4all.co/
- deleted 7y ago
  [deleted]
rladd 7y ago
What's really odd about the linked article is that it's supposed to be a summary of this paper: https://download.nap.edu/cart/download.cgi?record_id=25776 https://download.nap.edu/cart/download.cgi?record_id=25776 The actual paper consistently says that homemade masks really DO work, at least to some extent.
- deleted 7y ago
  [deleted]
gnusty_gnurc 7y ago
I feel like there's this bizarre impedance mismatch in communication - that the internet lends itself to passing around headlines without associating the proper context/nuance. So in effect, an academic article that ultimately says that there's no easy way to gauge the effectiveness of cloth masks is passed around as "Data do not back cloth masks." No one is lying or deceiving, but the perception received broadly will be wrong. This echos the same thing that happens with the WHO. And given that these are huge, central institutions - they need to take more care around how their pronouncements are received.
- citrin_ru 7y ago
  IMHO it happens mostly because of perverse incentives of AD supported media: controversial statements attract more clicks (and more revenue). Point that "masks don't work" (even if it is not stated directly, but assumed) is more controversial than: "we don't know if masks work". With COVID-19 I see fair amount of articles when a scientist says "We don't have (strong) evidence for X" and an article hints that X is not true (without saying this explicitily).
ttonkytonk 7y ago
I have heard that while the virus may spread via microparticles, that's probably not the main method of transmission or else it would have spread much more already. Therefore it seems reasonable to believe that homemade masks might help.
dkdk8283 7y ago
Masks have become a political issue, unfortunately. If everyone using masks doesn’t deprive healthcare workers of PPE I’m all for it. I don’t think it’s fair to criticize people who said masks aren’t effective, though. It happens everywhere I look. China’s anti-US propaganda video mentioned this. It’s even here on HN. The reality is we don’t know much yet, and this is supported by current research. My understanding is it’s a better safe than sorry measure. What really bothers me is this is just one example of people turning against each other. Now more than ever we need to be united, not fighting.
- ethanbond 7y ago
  “it’s a better safe than sorry measure” is itself a bold claim to be making. It’s entirely possible that cloth masks are net negative due to: 1. False sense of security meaning people interacting closer to each other or 2. People touching their faces nonstop adjusting their mask People had the same line of reasoning for treating people with HCQ, and it’s beginning to look like HCQ might be safe for healthy patients but a death sentence for COVID patients. Even if this ends up not being true, it is absolutely possible that it is — which is why we need to learn more and do so very carefully. Life sciences is full of counter-intuitive results, many of which were learned through tragedy. That’s why the scientific community is so gosh darn careful about statements like, “it’s better safe than sorry.” If we don’t know whether it works, then we also don’t know whether it’s better safe than sorry.
  - citrin_ru 7y ago
    False sense of security argument repeatedly used against the use of bicycle helmets, but I'm yet to see evidence, that having a helmet actually changes how a person rides a bike in any significant way. And I expect behavior with regard to masks to be very similar. In a short term a person without protective equipment (e. g. helmet) may behave more cautious, but after some time I expect behavior to regress to a normal pattern regardless the use of PPE: it is very hard to be on high alert for a long period of time.
    - ethanbond 7y ago

27 points by timr 7y ago

The title is inaccurate, they acknowledge on the first paragraph that it captures large droplets. that's reason enough to wear the mask

wegs 7y ago
The title is 100% accurate, just misleading. "Data do not back" is intentional weasel language commonly used in university press releases. Data does not back that if you (anorphirith) shoot me (wegs) in the head with an AK47, I'll die. That particular study has never been done). But we know it's true. But a carefully-phrased headline gets picked up by the popular press and builds university branding. See also "significant" (which means "statistically significant," so might be a 0.000001% effect size with enough data, but which the public picks up to mean "big"). These are well-developed techniques for roping science-ignorant reporters.
Someone 7y ago
But large droplets drop to the ground rapidly, so if social distancing is done, they’re unlikely to infect anybody, anyways. Also, most governments advice people with a cold/fever/… to stay home. If they do, and given the current estimate of infection rate, those droplets aren’t likely to contain the virus.

kinkrtyavimoodh 7y ago

This mask discussion makes me think like I am taking crazy pills. Can someone explain to me how placing a barrier in front of your mouth and nose can possibly be a BAD idea when the purpose is to reduce the entry of particles into the system? Why do we need studies to prove this? If you are inhaling it is likely to stop some particles from getting in. If you are exhaling it is likely to stop some particles from getting out. Sure, particles might still get in or out but HOW CAN IT BE WORSE THAN LITERALLY BEING EXPOSED ALL THE TIME? This feels like the parachute example to me that was posted here a few days ago. You don't need to do a study to prove that a man hitting the ground at 10km/h would be more likely to survive than one hitting at 150km/h. Sure, parachutes can fail, but how can they be worse off than NOT wearing a parachute? It almost feels like the health agencies were caught with their pants down telling absolute lies about masks for over a month and are now scrambling to salvage some dignity from the affair by throwing studies at us. Just imagine how much we could have reduced transmission if Americans had started wearing masks in late February or at least early March. This lie has literally cost the world billions of dollars, not to mention thousands of lives.

wegs 7y ago
No one honest can, because masks do help. What's not clear is how much they help. They'd have a huge effect on large droplets, but potentially a very small effect on bioaerosols. Until we know more about how COVID19 typically spreads, we don't know how important they are. In contrast to the intentionally dishonest UMN fluff PR piece, that's what the NAP paper it claims to summarize says. The one really big effect not talked about is that it also means I can't unconsciously touch my mouth or nose. Remember the "don't touch your face" campaign?
- timr 7y ago
  "In contrast to the intentionally dishonest UMN fluff PR piece, that's what the NAP paper it claims to summarize says." The article title is "data do not back cloth masks to limit Covid-19". The NAP paper says: "The evidence from these laboratory filtration studies suggests that such fabric masks may reduce the transmission of larger respiratory droplets. There is little evidence regarding the transmission of small aerosolized particulates of the size potentially exhaled by asymptomatic or presymptomatic individuals with COVID-19. The extent of any protection will depend on how the masks are made and used. It will also depend on how mask use affects users’ other precautionary behaviors, including their use of better masks, when those become widely available. Those behavioral effects may undermine or enhance homemade fabric masks’ overall effect on public health. The current level of benefit, if any, is not possible to assess." It seems like an entirely accurate summary of the contents of the paper.
conqrr 7y ago
Not arguing for/against masks, merely pointing out the analogy. For your parachute analogy. Imagine that its given the parachute will have very large holes (similar to the droplets being very very small). Its useless having a parchute in that case.
- kinkrtyavimoodh 7y ago
  I am pretty sure that a parachute with holes will still have reduced terminal velocity than not having a parachute. I get your argument but unlike a man crashing to death, we are playing a probability game here. Viral load also matters, even if you can stop some of the virus from entering, it can only help.

wegs 7y ago

I suggest clicking through to the NAP paper, which unlike this reporting fluff/hype piece, is very reasonable. This is part of the standard academic fake science pipeline. The researchers did reasonable work (best summary: "We don't know how well they work"). The university PR departments turned that into hyped-up nonsense to gain publicity and brand recognition. Next step will be science reporting, which will exaggerate the press release, and finally, popular news, which will use this to bash random policy decisions. Direct link to the original paper: https://www.nap.edu/read/25776/chapter/1 https://www.nap.edu/read/25776/chapter/1 In general, NAP pieces tend to be well-researched and well-written summaries of what's known. This one is no exception.

astrophysician 7y ago
You forgot about the other half of the cycle: time passes, another wave of publicity bashes the initial hype, people assume the scientists themselves are responsible (even though they have been freaking out about their work being misrepresented), scientists lose funding, people don’t trust scientists.
- pacala 7y ago
  You forgot about the third half of the cycle: scientists exceedingly rarely submit a correction note to tone down the hyped up claims made by the PR departments / science press. They are very good at keeping the freak out to themselves. A systemic problem, not sure how to solve for, if even there is a solution.
  - astrophysician 7y ago
    Yea right, it’s just so weird to deal with this problem as a scientist unless you do work that is regularly in the news and you have opportunities to learn how to better control what is written/said and deal with instances where the wrong message is getting out. Vast majority of scientists are doing work for an audience of themselves, other scientists and funding agencies, and are working for respect, not fame or media attention. So when a their research suddenly gets churned through this bullshit cycle, they’re really troubled but don’t necessarily know the most effective way to control the message once it gets out of their hands. It can be really unfair and stressful.

procrastitron 7y ago

This title seems misleading to me. The title implies that we have data showing cloth masks don’t work, but what the article actually says is just that we don’t have data.

paulsutter 7y ago

Masks are not a risky medical procedure. Anti-mask truthers are the ones who need extraordinary evidence, not mask supporters. Video of droplets blocked by a mask: https://twitter.com/i/status/1254535446509412353 https://twitter.com/i/status/1254535446509412353 Why we should all wear masks: https://masks4all.co/ https://masks4all.co/

deleted 7y ago
[deleted]

rladd 7y ago

What's really odd about the linked article is that it's supposed to be a summary of this paper: https://download.nap.edu/cart/download.cgi?record_id=25776 https://download.nap.edu/cart/download.cgi?record_id=25776 The actual paper consistently says that homemade masks really DO work, at least to some extent.

deleted 7y ago
[deleted]

gnusty_gnurc 7y ago

I feel like there's this bizarre impedance mismatch in communication - that the internet lends itself to passing around headlines without associating the proper context/nuance. So in effect, an academic article that ultimately says that there's no easy way to gauge the effectiveness of cloth masks is passed around as "Data do not back cloth masks." No one is lying or deceiving, but the perception received broadly will be wrong. This echos the same thing that happens with the WHO. And given that these are huge, central institutions - they need to take more care around how their pronouncements are received.

citrin_ru 7y ago
IMHO it happens mostly because of perverse incentives of AD supported media: controversial statements attract more clicks (and more revenue). Point that "masks don't work" (even if it is not stated directly, but assumed) is more controversial than: "we don't know if masks work". With COVID-19 I see fair amount of articles when a scientist says "We don't have (strong) evidence for X" and an article hints that X is not true (without saying this explicitily).

ttonkytonk 7y ago

I have heard that while the virus may spread via microparticles, that's probably not the main method of transmission or else it would have spread much more already. Therefore it seems reasonable to believe that homemade masks might help.

dkdk8283 7y ago

Masks have become a political issue, unfortunately. If everyone using masks doesn’t deprive healthcare workers of PPE I’m all for it. I don’t think it’s fair to criticize people who said masks aren’t effective, though. It happens everywhere I look. China’s anti-US propaganda video mentioned this. It’s even here on HN. The reality is we don’t know much yet, and this is supported by current research. My understanding is it’s a better safe than sorry measure. What really bothers me is this is just one example of people turning against each other. Now more than ever we need to be united, not fighting.

ethanbond 7y ago
“it’s a better safe than sorry measure” is itself a bold claim to be making. It’s entirely possible that cloth masks are net negative due to: 1. False sense of security meaning people interacting closer to each other or 2. People touching their faces nonstop adjusting their mask People had the same line of reasoning for treating people with HCQ, and it’s beginning to look like HCQ might be safe for healthy patients but a death sentence for COVID patients. Even if this ends up not being true, it is absolutely possible that it is — which is why we need to learn more and do so very carefully. Life sciences is full of counter-intuitive results, many of which were learned through tragedy. That’s why the scientific community is so gosh darn careful about statements like, “it’s better safe than sorry.” If we don’t know whether it works, then we also don’t know whether it’s better safe than sorry.
- citrin_ru 7y ago
  False sense of security argument repeatedly used against the use of bicycle helmets, but I'm yet to see evidence, that having a helmet actually changes how a person rides a bike in any significant way. And I expect behavior with regard to masks to be very similar. In a short term a person without protective equipment (e. g. helmet) may behave more cautious, but after some time I expect behavior to regress to a normal pattern regardless the use of PPE: it is very hard to be on high alert for a long period of time.
  - ethanbond 7y ago