6 ms·

something that i don't fully understand - as a healthy person does wearing a mask has any effect? or the masks work only for reducing the chance of transmitting

something that i don't fully understand - as a healthy person does wearing a mask has any effect? or the masks work only for reducing the chance of transmitting the virus if already infected?

dlandis 7y ago
> something that i don't fully understand - as a healthy person does wearing a mask has any effect? Yes, of course it has an effect. Why do you think health care workers wear them?
- Angostura 7y ago
  "Yes, of course it has an effect. Why do you think health care workers wear them?" Because they will be closer than 6ft to infected people.
  - ceejayoz 7y ago
    So, if they work at less than six feet, they probably work at six feet or greater too, right?
  - 0xffff2 7y ago
    So am I every time I go grocery shopping. There are still a lot of people out shopping and not taking the distancing guidelines seriously. Enough so that when I went shopping earlier this week I found myself in multiple situations where it was impossible to maintain 6 feet.
jartelt 7y ago
Wearing a mask helps block airborne droplets from the cough or sneeze of an infected person. That said, you need to aware that a mask is not perfect and you should still stay at least 6 feet away from other people. You also need to fit the mask properly and should avoid frequently adjusting the mask and touching your face with unwashed hands.
oski 7y ago
> as a healthy person does wearing a mask has any effect? This all depends on the type of mask and how tightly it fits against one's face. A mask made from cotton has been shown to be ~70% effective at filtering a virus from droplets in the air: 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...
- swader999 7y ago
  Vacuum bag filter material can come very close to N95. Anything that reduces viral load has benefits. Viral load being how much of it you are blasted with at once. Less is more survivable.
ceejayoz 7y ago
1. Yes, it'll stop at least some droplets that could potentially be carrying viruses. It's not perfect, but it's certainly better than nothing. 2. Asymptomatic coronavirus cases don't know they're not healthy, so mask wearing protects others from those people.
- deepsun 7y ago
  However, it's still unclear whether asymptomatic people contribute significantly to the transmission. Last comment on that I heard from CDC interview by WSJ: "patient becomes contagious either after symptoms appeared, or right before that (couple hours)". And using common sense, if a person doesn't cough or breathe hard with air droplets, then they must be way less contagious naturally.
  - standardUser 7y ago
    There are also reports of people being completely asymptomatic throughout the entire infection. And of people being contagious after all symptoms have ceased.
Symmetry 7y ago
When a person talks or sneezes they'll send out a range of different particle sizes which travel different distances and take different amounts of time to fall out of the air. Larger particles called droplets carry most of the virus load from any particular sneeze and are what cause most infections that don't involve hand to face contact. They send to only go 2 meters in talking and sneezes into an elbow but they can go further in an uncovered sneeze. A surgical mask should be generally protective against these getting into your mouth or nose but your eyes are still vulnerable to being infected this way. There are also smaller particles called aerosols that linger in the air for longer but don't travel very quickly. A much smaller fraction of the virus particles in a typical infected person's exhalations end up in these. In this case a surgical mask will only stop 4/5 or so of the particles you would otherwise breath in - better than nothing but not to be relied upon. In dealing with Coronavirus patients doctors and nurses usually rely on something called an N95 mask that's guaranteed to stop 95% of any sized non-oil particle and in practice seems to stop something like 99% of particles like a coronavirus. These are especially important for medical professionals because some procedures, like the intubations many Covid-19 patients need to survive, tend to cause way more aerosols than normal. In terms of protecting others surgical masks seem to be a bit less protective with aerosol transmission for outgoing air than incoming air. I would guess because potitive pressure causes surgical masks to puff out a bit and leak more while negative pressure improves the seal. In the one study I've read on the matter it was a 1/3 difference which is noticable but they still make a big difference. More importantly surgical masks seem to stop outbound droplet transmission. On the outbound side the fact that someone's eyes aren't covered will also be irrelevant and someone wearing a mask won't have their droplets land on surfaces causing later hand to face transmission. Wearing a home made mask is a lot like a surgical masks but a bit less likely to stop aerosols. For the overall result, Ian Lipkin in a recent interview mentioned a study done in Beijing where they found that people who regularly wore masks were 70% less likely to get SARS in the original outbreak. That's nice but isn't anything like being invincible so measures like social distancing are still important. If you've got a N95 masks then please give it to someone who's going to be doing things like intubation where it's aerosol stopping power is critically important and just wear a normal cloth mask otherwise. Remember that if your mask stopped some incoming virus particles those particles will still be on the outside of the mask and treat that danger with respect.
Gibbon1 7y ago
My final thoughts on this is that the general public should be expected to wear masks anytime there is a novel epidemic until told otherwise. Ordinary people shouldn't be expected to second guess any of this. As for shortages that's a logistical failing that should be corrected before next time. Like how about require that first aid kits contain 5 masks.

something that i don't fully understand - as a healthy person does wearing a mask has any effect? or the masks work only for reducing the chance of transmitting the virus if already infected?

dlandis 7y ago

> something that i don't fully understand - as a healthy person does wearing a mask has any effect? Yes, of course it has an effect. Why do you think health care workers wear them?

Angostura 7y ago
"Yes, of course it has an effect. Why do you think health care workers wear them?" Because they will be closer than 6ft to infected people.
- ceejayoz 7y ago
  So, if they work at less than six feet, they probably work at six feet or greater too, right?
- 0xffff2 7y ago
  So am I every time I go grocery shopping. There are still a lot of people out shopping and not taking the distancing guidelines seriously. Enough so that when I went shopping earlier this week I found myself in multiple situations where it was impossible to maintain 6 feet.

jartelt 7y ago

Wearing a mask helps block airborne droplets from the cough or sneeze of an infected person. That said, you need to aware that a mask is not perfect and you should still stay at least 6 feet away from other people. You also need to fit the mask properly and should avoid frequently adjusting the mask and touching your face with unwashed hands.

oski 7y ago

> as a healthy person does wearing a mask has any effect? This all depends on the type of mask and how tightly it fits against one's face. A mask made from cotton has been shown to be ~70% effective at filtering a virus from droplets in the air: 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...

swader999 7y ago
Vacuum bag filter material can come very close to N95. Anything that reduces viral load has benefits. Viral load being how much of it you are blasted with at once. Less is more survivable.

ceejayoz 7y ago

1. Yes, it'll stop at least some droplets that could potentially be carrying viruses. It's not perfect, but it's certainly better than nothing. 2. Asymptomatic coronavirus cases don't know they're not healthy, so mask wearing protects others from those people.

deepsun 7y ago
However, it's still unclear whether asymptomatic people contribute significantly to the transmission. Last comment on that I heard from CDC interview by WSJ: "patient becomes contagious either after symptoms appeared, or right before that (couple hours)". And using common sense, if a person doesn't cough or breathe hard with air droplets, then they must be way less contagious naturally.
- standardUser 7y ago
  There are also reports of people being completely asymptomatic throughout the entire infection. And of people being contagious after all symptoms have ceased.

Symmetry 7y ago

When a person talks or sneezes they'll send out a range of different particle sizes which travel different distances and take different amounts of time to fall out of the air. Larger particles called droplets carry most of the virus load from any particular sneeze and are what cause most infections that don't involve hand to face contact. They send to only go 2 meters in talking and sneezes into an elbow but they can go further in an uncovered sneeze. A surgical mask should be generally protective against these getting into your mouth or nose but your eyes are still vulnerable to being infected this way. There are also smaller particles called aerosols that linger in the air for longer but don't travel very quickly. A much smaller fraction of the virus particles in a typical infected person's exhalations end up in these. In this case a surgical mask will only stop 4/5 or so of the particles you would otherwise breath in - better than nothing but not to be relied upon. In dealing with Coronavirus patients doctors and nurses usually rely on something called an N95 mask that's guaranteed to stop 95% of any sized non-oil particle and in practice seems to stop something like 99% of particles like a coronavirus. These are especially important for medical professionals because some procedures, like the intubations many Covid-19 patients need to survive, tend to cause way more aerosols than normal. In terms of protecting others surgical masks seem to be a bit less protective with aerosol transmission for outgoing air than incoming air. I would guess because potitive pressure causes surgical masks to puff out a bit and leak more while negative pressure improves the seal. In the one study I've read on the matter it was a 1/3 difference which is noticable but they still make a big difference. More importantly surgical masks seem to stop outbound droplet transmission. On the outbound side the fact that someone's eyes aren't covered will also be irrelevant and someone wearing a mask won't have their droplets land on surfaces causing later hand to face transmission. Wearing a home made mask is a lot like a surgical masks but a bit less likely to stop aerosols. For the overall result, Ian Lipkin in a recent interview mentioned a study done in Beijing where they found that people who regularly wore masks were 70% less likely to get SARS in the original outbreak. That's nice but isn't anything like being invincible so measures like social distancing are still important. If you've got a N95 masks then please give it to someone who's going to be doing things like intubation where it's aerosol stopping power is critically important and just wear a normal cloth mask otherwise. Remember that if your mask stopped some incoming virus particles those particles will still be on the outside of the mask and treat that danger with respect.

Gibbon1 7y ago

My final thoughts on this is that the general public should be expected to wear masks anytime there is a novel epidemic until told otherwise. Ordinary people shouldn't be expected to second guess any of this. As for shortages that's a logistical failing that should be corrected before next time. Like how about require that first aid kits contain 5 masks.