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It's very irritating because people don't understand the concept of defense in depth. Are surgical masks going to give you total protection? Of course not, but

It's very irritating because people don't understand the concept of defense in depth. Are surgical masks going to give you total protection? Of course not, but as you say they provide SOME benefit. Saying "masks don't work because they don't fully stop the virus and users misuse them" is basically equivalent to saying "code review is a waste of time because it won't catch every bug and because devs don't do it correctly". The solution isn't stop doing code review, it's to teach people how to do it and to understand it's limitations.

deelowe 7y ago
What's more frustrating is the exact same logic applies to "social distancing." Social distancing will not completely stop people from getting sick. It'll just slow the spread. So, according to the CDC, an imperfect solution for quarantine is totally fine, but when it comes to masks, only n95 or better are worth pursuing.
- XorNot 7y ago
  It's quite likely that in all the scenarios a mask may have a useful effect, N95 or better is the only time it works. For medical professionals in close contact with patients and dealing with airborne-protocol pathogens (which is what a droplet-mediated pathogens like SARS2 becomes classed as once patients are coughing and being intubated) then a bad mask is quite probably worse then no mask (this has precedent: ineffective masks obstruct breathing, which makes you take deeper breaths and draw more particles in deeper in your lungs - it's a big problem when dealing with fine dusts in construction).
  - ceejayoz 7y ago
    It's highly likely that even basic surgical masks have some impact. A fit-tested N95 is the gold standard, but the widespread use of surgical masks in Asia during the SARS epidemic does seem to have had an impact. https://wwwnc.cdc.gov/eid/article/10/2/03-0730_article https://wwwnc.cdc.gov/eid/article/10/2/03-0730_article
  - dahart 7y ago
    > It’s quite likely that in all the scenarios a mask may have a useful effect, N95 or better is the only time it works. You’re saying you think anything less than an N95 has 0 effectiveness. Why do you believe this is likely? Are you aware of the data that says otherwise? https://news.ycombinator.com/item?id=22655436 https://news.ycombinator.com/item?id=22655436 https://www.researchgate.net/publication/258525804_Testing_the_Efficacy_of_Homemade_Masks_Would_They_Protect_in_an_Influenza_Pandemic https://www.researchgate.net/publication/258525804_Testing_t...
    - kps 7y ago
      N95 Respirators vs Medical Masks for Preventing Influenza Among Health Care Personnel: A Randomized Clinical Trial https://jamanetwork.com/journals/jama/fullarticle/2749214 https://jamanetwork.com/journals/jama/fullarticle/2749214 “As worn by health care personnel in this trial, use of N95 respirators, compared with medical masks, in the outpatient setting resulted in no significant difference in the rates of laboratory-confirmed influenza.” To be clear, this trail was for outpatient care — not necessarily applicable to shoving tubes down throats, but probably applicable to people walking down the street.
      - dahart 7y ago
        That quote is saying that N95 masks are no better than medical masks, not that medical masks have 0 effectiveness.
    - mbreese 7y ago
      The data from the Davies paper is not very convincing. The home made solutions offered significantly less protection and and had major problems with fit. Even their conclusions were — it’s better than nothing, but not a proper substitute. > However, these masks would provide the wearers little protection from microorgan- isms from others persons who are infected with respiratory diseases. As a result, we would not recommend the use of homemade face masks as a method of reducing transmission of infection from aerosols.
      - dahart 7y ago
  - eecc 7y ago
    This is about Influenza but I doubt it’s that different from Corona: https://pubmed.ncbi.nlm.nih.gov/20497389/ https://pubmed.ncbi.nlm.nih.gov/20497389/
    - giggles_giggles 7y ago
      Are you a doctor? Can you explain why a study about influenza would apply to SARS-CoV-2? Or is your doubt baseless speculation?
      - tzs 7y ago
        SARS-CoV-2 is a spheroid with a diameter of about 120 nm. There's a lot of variation in influenza viruses, but most are spheroids or ellipsoids with a diameter from 80-120 mm. For simple mechanical filtering, such as with a mask, they are going to behave pretty similar.
- davrosthedalek 7y ago
  That's not necessary so. While "not doing social distancing right" will not increase your risk compared to not trying, with masks it's not so clear cut: You have to touch your face to put them on and take them off, and people might touch their face more often to adjust them etc. That increases the risk, at least if you wear them to protect yourself. And people might take greater risks because they feel safe. If this is not counterbalanced by the risk reduction through wearing a mask, it's a problem. Additionally, if there is a mask shortage, it might increase the risk indirectly, even for those who don't want to spread it.
- kps 7y ago
  > So, according to the CDC … only n95 or better are worth pursuing. Current CDC guidance is “facemasks are an acceptable alternative when the supply chain of respirators cannot meet the demand”.¹ ¹ https://www.cdc.gov/coronavirus/2019-ncov/infection-control/control-recommendations.html https://www.cdc.gov/coronavirus/2019-ncov/infection-control/...
- aaavl2821 7y ago
  The CDC does not say that only n95 or better are worth pursuing https://www.cdc.gov/coronavirus/2019-ncov/hcp/ppe-strategy/face-masks.html https://www.cdc.gov/coronavirus/2019-ncov/hcp/ppe-strategy/f...
  - dahart 7y ago
    Agree & upvoted; this needs to be better understood. Especially noteworthy is the section you linked to is written for health-care workers, and they’re confirming that a homemade mask is better than nothing (while also recommending the homemade mask dead last.) Unfortuately, the CDC really is giving out conflicting guidance here. For example, higher up in the section for lay-people is this: “You do not need to wear a facemask unless you are caring for someone who is sick (and they are not able to wear a facemask). Facemasks may be in short supply and they should be saved for caregivers.” https://www.cdc.gov/coronavirus/2019-ncov/prepare/prevention.html https://www.cdc.gov/coronavirus/2019-ncov/prepare/prevention... (In “How to Prepare | Protect Yourself”)
    - aaavl2821 7y ago
      I don't see a contradiction. The CDC is trying to maximize public health benefit. They recommend stronger protection for people with more exposure to higher levels of the virus. Coincidentally, the people with higher levels of exposure also happen to be health care workers, who need the best available protection to save lives If you are not exposed to high levels and are not required to put yourself at risk to care for patients, you are at low risk. You can protect yourself with milder measures like social distancing and face protection that is not as effective but not in such short supply
      - dahart 7y ago
        Maybe I misread your intent. I thought you were mostly pointing out the section titled “When No Facemasks Are Available, Options Include”, which would mean we’re talking about something that is not in short supply. I thought you were pointing out that, among other things, the CDC is saying that home-made masks are better than nothing, even for health care professionals, and even if it’s a last resort. I mean I agree, of course, that they’re trying to maximize public health benefit, I just don’t think the guidance is at all clear to the public. The idea that anything less than N95 is useless is pervasive, you can see it right here on HN. My parents and co-workers believe it because it’s been reported in the mass media in the last weeks: “the CDC said masks don’t protect you!”. For people who need to work or shop in public places, any kind of masks at all might well be statistically significant alternatives for people who are unable to practice social distancing. China seems to be doing it effectively right now; people are required to wear masks to go to work. They’re not telling the public to avoid masks because doctors need them, they’re telling the public not to leave the house and not to enter a work building without something over your face. It seems like the CDC is saying the opposite, you should not wear a mask unless you’re a doctor. If a bandana is even 50% or 30% or even 5% effective, and they want to maximize public health benefit, why aren’t they recommending people start with what they have at home for times when public exposure is necessary? Seems like that would both increase public health and deflect demand for surgical masks & N95 masks at the same time, no?
ellius 7y ago
If there are two "mental tools" I wish we could teach every person, they are exponential growth and statistical thinking. Neither is intuitive, but they would help people understand this whole situation (and many others) a lot better.
- ceejayoz 7y ago
  My high school math teacher introduced exponential growth by asking the class if we'd take $1M now or $0.01 doubled daily for a month. We, as most people do, wanted the $1M, but the penny turns into more than $5M. Had to explain this to someone yesterday. They literally wouldn't believe me until I screenshotted an Excel spreadsheet of the daily doublings, despite a finance degree.
  - ellius 7y ago
    I think that's exactly the issue. People can't picture it. You can show them a curve on a graph, but that doesn't translate for people without a mathematical/scientific background into "a shitload of people will get ill very quickly." Our brains seem not to be very well wired to make the connection between mathematical abstractions and reality, and aside from the minority of people who seem to just "get it," people don't understand without a good explanation from a very good teacher.
    - mindslight 7y ago
      We technology people don't just inherently "get it", but rather have experience traveling up and down in powers of two for things that are meaningful to us. A month has 30 days - that's easily recognizable as a giga (2^10 ~= 10^3). And a billion isn't even that large to us.
  - deleted 7y ago
    [deleted]
- fsagx 7y ago
  I remember how it was taught in high school math class. It was some variation on the "rice on the chessboard" story: https://en.wikipedia.org/wiki/Wheat_and_chessboard_problem https://en.wikipedia.org/wiki/Wheat_and_chessboard_problem
seanwilson 7y ago
> Are surgical masks going to give you total protection? Of course not, but as you say they provide SOME benefit Face protection must surely have the side-benefit as well that it signals to others to keep your distance and that this is a serious situation.
- davrosthedalek 7y ago
  Or they see a mask and think: Ok, cool, I can come close, I'm protected by the mask the person is wearing. Don't forget, people ate tide-pods.
  - fspeech 7y ago
    People in Asia still ride crowded public transportations. So yes, if everyone wears a mask everyone is protected.
ardy42 7y ago
> Are surgical masks going to give you total protection? Of course not, but as you say they provide SOME benefit. Saying "masks don't work because they don't fully stop the virus and users misuse them" Surgical masks aren't about protecting the wearer from everyone else, they're about protecting everyone else from the wearer [1]. They may provide the wearer some protection, but that's not really the point. The emphasis in the rhetoric about masks needs to change. It should not be about individualist self-protection, but about doing your part to protect the community. I think they should be recommended for that reason [2]. [1] Respirators are devices for protecting the wearer, and the N95 type has been much discussed. Everyone should learn the difference to de-confuse the general conversation in this topic: https://www.youtube.com/watch?v=JR2uLfEVD2w https://www.youtube.com/watch?v=JR2uLfEVD2w https://multimedia.3m.com/mws/media/956213O/differences-between-respirators-and-masks.pdf https://multimedia.3m.com/mws/media/956213O/differences-betw... [2] If there's enough supply. It seems like surgical masks are getting drafted into the role of PPE for medical personnel (which they're poorly suited to) due to the N95 shortage. It's unfortunate that the US hasn't developed a culture where you wear a mask to protect others from your illnesses, so they're not widely available outside of healthcare settings.
- take_a_breath 7y ago
  In a scenario where we don’t have enough tests to determine who does and doesn’t have this virus, shouldn’t be we encourage more mask wearing?
- Consultant32452 7y ago
  >Surgical masks aren't about protecting the wearer from everyone else, they're about protecting everyone else from the wearer [1]. They may provide the wearer some protection, but that's not really the point. I think you're confusing the normal use for these masks with what they are actually capable of doing. Yes, in a surgical setting the masks are worn primarily to protect the patient from the surgeon, but the masks do work both ways. Here's a citation from an infectious disease specialist: https://www.health.com/condition/cold-flu-sinus/surgical-mask-flu-prevention https://www.health.com/condition/cold-flu-sinus/surgical-mas... >“Yes, a surgical mask can help prevent the flu,” Sherif Mossad, MD, an infectious disease specialist at the Cleveland Clinic, tells Health. “Flu is carried in air droplets, so a mask would mechanically prevent the flu virus from reaching other people.” It would work both ways, says Dr. Mossad, preventing transmission of the flu virus to others and for keeping a mask-wearer from picking up an infection.
gvjddbnvdrbv 7y ago
BUT. Not meeting someone is 100% protection at this poin we need 100% protection for everyone not 100% needed to keep the lights on and people fed. So yes once you've removed all non essential contact masks add another layer. But people are fairly stupid on average and need simple messages right now.

deelowe 7y ago

What's more frustrating is the exact same logic applies to "social distancing." Social distancing will not completely stop people from getting sick. It'll just slow the spread. So, according to the CDC, an imperfect solution for quarantine is totally fine, but when it comes to masks, only n95 or better are worth pursuing.

XorNot 7y ago
It's quite likely that in all the scenarios a mask may have a useful effect, N95 or better is the only time it works. For medical professionals in close contact with patients and dealing with airborne-protocol pathogens (which is what a droplet-mediated pathogens like SARS2 becomes classed as once patients are coughing and being intubated) then a bad mask is quite probably worse then no mask (this has precedent: ineffective masks obstruct breathing, which makes you take deeper breaths and draw more particles in deeper in your lungs - it's a big problem when dealing with fine dusts in construction).
- ceejayoz 7y ago
  It's highly likely that even basic surgical masks have some impact. A fit-tested N95 is the gold standard, but the widespread use of surgical masks in Asia during the SARS epidemic does seem to have had an impact. https://wwwnc.cdc.gov/eid/article/10/2/03-0730_article https://wwwnc.cdc.gov/eid/article/10/2/03-0730_article
- dahart 7y ago
  > It’s quite likely that in all the scenarios a mask may have a useful effect, N95 or better is the only time it works. You’re saying you think anything less than an N95 has 0 effectiveness. Why do you believe this is likely? Are you aware of the data that says otherwise? https://news.ycombinator.com/item?id=22655436 https://news.ycombinator.com/item?id=22655436 https://www.researchgate.net/publication/258525804_Testing_the_Efficacy_of_Homemade_Masks_Would_They_Protect_in_an_Influenza_Pandemic https://www.researchgate.net/publication/258525804_Testing_t...
  - kps 7y ago
    N95 Respirators vs Medical Masks for Preventing Influenza Among Health Care Personnel: A Randomized Clinical Trial https://jamanetwork.com/journals/jama/fullarticle/2749214 https://jamanetwork.com/journals/jama/fullarticle/2749214 “As worn by health care personnel in this trial, use of N95 respirators, compared with medical masks, in the outpatient setting resulted in no significant difference in the rates of laboratory-confirmed influenza.” To be clear, this trail was for outpatient care — not necessarily applicable to shoving tubes down throats, but probably applicable to people walking down the street.
    - dahart 7y ago
      That quote is saying that N95 masks are no better than medical masks, not that medical masks have 0 effectiveness.
  - mbreese 7y ago
    The data from the Davies paper is not very convincing. The home made solutions offered significantly less protection and and had major problems with fit. Even their conclusions were — it’s better than nothing, but not a proper substitute. > However, these masks would provide the wearers little protection from microorgan- isms from others persons who are infected with respiratory diseases. As a result, we would not recommend the use of homemade face masks as a method of reducing transmission of infection from aerosols.
    - dahart 7y ago
- eecc 7y ago
  This is about Influenza but I doubt it’s that different from Corona: https://pubmed.ncbi.nlm.nih.gov/20497389/ https://pubmed.ncbi.nlm.nih.gov/20497389/
  - giggles_giggles 7y ago
    Are you a doctor? Can you explain why a study about influenza would apply to SARS-CoV-2? Or is your doubt baseless speculation?
    - tzs 7y ago
      SARS-CoV-2 is a spheroid with a diameter of about 120 nm. There's a lot of variation in influenza viruses, but most are spheroids or ellipsoids with a diameter from 80-120 mm. For simple mechanical filtering, such as with a mask, they are going to behave pretty similar.
davrosthedalek 7y ago
That's not necessary so. While "not doing social distancing right" will not increase your risk compared to not trying, with masks it's not so clear cut: You have to touch your face to put them on and take them off, and people might touch their face more often to adjust them etc. That increases the risk, at least if you wear them to protect yourself. And people might take greater risks because they feel safe. If this is not counterbalanced by the risk reduction through wearing a mask, it's a problem. Additionally, if there is a mask shortage, it might increase the risk indirectly, even for those who don't want to spread it.
kps 7y ago
> So, according to the CDC … only n95 or better are worth pursuing. Current CDC guidance is “facemasks are an acceptable alternative when the supply chain of respirators cannot meet the demand”.¹ ¹ https://www.cdc.gov/coronavirus/2019-ncov/infection-control/control-recommendations.html https://www.cdc.gov/coronavirus/2019-ncov/infection-control/...
aaavl2821 7y ago
The CDC does not say that only n95 or better are worth pursuing https://www.cdc.gov/coronavirus/2019-ncov/hcp/ppe-strategy/face-masks.html https://www.cdc.gov/coronavirus/2019-ncov/hcp/ppe-strategy/f...
- dahart 7y ago
  Agree & upvoted; this needs to be better understood. Especially noteworthy is the section you linked to is written for health-care workers, and they’re confirming that a homemade mask is better than nothing (while also recommending the homemade mask dead last.) Unfortuately, the CDC really is giving out conflicting guidance here. For example, higher up in the section for lay-people is this: “You do not need to wear a facemask unless you are caring for someone who is sick (and they are not able to wear a facemask). Facemasks may be in short supply and they should be saved for caregivers.” https://www.cdc.gov/coronavirus/2019-ncov/prepare/prevention.html https://www.cdc.gov/coronavirus/2019-ncov/prepare/prevention... (In “How to Prepare | Protect Yourself”)
  - aaavl2821 7y ago
    I don't see a contradiction. The CDC is trying to maximize public health benefit. They recommend stronger protection for people with more exposure to higher levels of the virus. Coincidentally, the people with higher levels of exposure also happen to be health care workers, who need the best available protection to save lives If you are not exposed to high levels and are not required to put yourself at risk to care for patients, you are at low risk. You can protect yourself with milder measures like social distancing and face protection that is not as effective but not in such short supply
    - dahart 7y ago
      Maybe I misread your intent. I thought you were mostly pointing out the section titled “When No Facemasks Are Available, Options Include”, which would mean we’re talking about something that is not in short supply. I thought you were pointing out that, among other things, the CDC is saying that home-made masks are better than nothing, even for health care professionals, and even if it’s a last resort. I mean I agree, of course, that they’re trying to maximize public health benefit, I just don’t think the guidance is at all clear to the public. The idea that anything less than N95 is useless is pervasive, you can see it right here on HN. My parents and co-workers believe it because it’s been reported in the mass media in the last weeks: “the CDC said masks don’t protect you!”. For people who need to work or shop in public places, any kind of masks at all might well be statistically significant alternatives for people who are unable to practice social distancing. China seems to be doing it effectively right now; people are required to wear masks to go to work. They’re not telling the public to avoid masks because doctors need them, they’re telling the public not to leave the house and not to enter a work building without something over your face. It seems like the CDC is saying the opposite, you should not wear a mask unless you’re a doctor. If a bandana is even 50% or 30% or even 5% effective, and they want to maximize public health benefit, why aren’t they recommending people start with what they have at home for times when public exposure is necessary? Seems like that would both increase public health and deflect demand for surgical masks & N95 masks at the same time, no?

ellius 7y ago

If there are two "mental tools" I wish we could teach every person, they are exponential growth and statistical thinking. Neither is intuitive, but they would help people understand this whole situation (and many others) a lot better.

ceejayoz 7y ago
My high school math teacher introduced exponential growth by asking the class if we'd take $1M now or $0.01 doubled daily for a month. We, as most people do, wanted the $1M, but the penny turns into more than $5M. Had to explain this to someone yesterday. They literally wouldn't believe me until I screenshotted an Excel spreadsheet of the daily doublings, despite a finance degree.
- ellius 7y ago
  I think that's exactly the issue. People can't picture it. You can show them a curve on a graph, but that doesn't translate for people without a mathematical/scientific background into "a shitload of people will get ill very quickly." Our brains seem not to be very well wired to make the connection between mathematical abstractions and reality, and aside from the minority of people who seem to just "get it," people don't understand without a good explanation from a very good teacher.
  - mindslight 7y ago
    We technology people don't just inherently "get it", but rather have experience traveling up and down in powers of two for things that are meaningful to us. A month has 30 days - that's easily recognizable as a giga (2^10 ~= 10^3). And a billion isn't even that large to us.
- deleted 7y ago
  [deleted]
fsagx 7y ago
I remember how it was taught in high school math class. It was some variation on the "rice on the chessboard" story: https://en.wikipedia.org/wiki/Wheat_and_chessboard_problem https://en.wikipedia.org/wiki/Wheat_and_chessboard_problem

seanwilson 7y ago

> Are surgical masks going to give you total protection? Of course not, but as you say they provide SOME benefit Face protection must surely have the side-benefit as well that it signals to others to keep your distance and that this is a serious situation.

davrosthedalek 7y ago
Or they see a mask and think: Ok, cool, I can come close, I'm protected by the mask the person is wearing. Don't forget, people ate tide-pods.
- fspeech 7y ago
  People in Asia still ride crowded public transportations. So yes, if everyone wears a mask everyone is protected.

ardy42 7y ago

> Are surgical masks going to give you total protection? Of course not, but as you say they provide SOME benefit. Saying "masks don't work because they don't fully stop the virus and users misuse them" Surgical masks aren't about protecting the wearer from everyone else, they're about protecting everyone else from the wearer [1]. They may provide the wearer some protection, but that's not really the point. The emphasis in the rhetoric about masks needs to change. It should not be about individualist self-protection, but about doing your part to protect the community. I think they should be recommended for that reason [2]. [1] Respirators are devices for protecting the wearer, and the N95 type has been much discussed. Everyone should learn the difference to de-confuse the general conversation in this topic: https://www.youtube.com/watch?v=JR2uLfEVD2w https://www.youtube.com/watch?v=JR2uLfEVD2w https://multimedia.3m.com/mws/media/956213O/differences-between-respirators-and-masks.pdf https://multimedia.3m.com/mws/media/956213O/differences-betw... [2] If there's enough supply. It seems like surgical masks are getting drafted into the role of PPE for medical personnel (which they're poorly suited to) due to the N95 shortage. It's unfortunate that the US hasn't developed a culture where you wear a mask to protect others from your illnesses, so they're not widely available outside of healthcare settings.

take_a_breath 7y ago
In a scenario where we don’t have enough tests to determine who does and doesn’t have this virus, shouldn’t be we encourage more mask wearing?
Consultant32452 7y ago
>Surgical masks aren't about protecting the wearer from everyone else, they're about protecting everyone else from the wearer [1]. They may provide the wearer some protection, but that's not really the point. I think you're confusing the normal use for these masks with what they are actually capable of doing. Yes, in a surgical setting the masks are worn primarily to protect the patient from the surgeon, but the masks do work both ways. Here's a citation from an infectious disease specialist: https://www.health.com/condition/cold-flu-sinus/surgical-mask-flu-prevention https://www.health.com/condition/cold-flu-sinus/surgical-mas... >“Yes, a surgical mask can help prevent the flu,” Sherif Mossad, MD, an infectious disease specialist at the Cleveland Clinic, tells Health. “Flu is carried in air droplets, so a mask would mechanically prevent the flu virus from reaching other people.” It would work both ways, says Dr. Mossad, preventing transmission of the flu virus to others and for keeping a mask-wearer from picking up an infection.

gvjddbnvdrbv 7y ago

BUT. Not meeting someone is 100% protection at this poin we need 100% protection for everyone not 100% needed to keep the lights on and people fed. So yes once you've removed all non essential contact masks add another layer. But people are fairly stupid on average and need simple messages right now.