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In a diving medical video a few months ago, a diving doctor when through the different mask and what they did and what they protected against. It did not get re

by belorn 5y ago

In a diving medical video a few months ago, a diving doctor when through the different mask and what they did and what they protected against. It did not get removed or censored by Youtube, through maybe it went under detection. Surgical masks do not prevent infection to the person who wears it. They prevent spread by catching droplets so they don't spread to others. They do not filter the air you breathe, but it reduce the risks that a person brings to others. A n95 mask with a valve has the opposite properties. They are poor at catching droplets because the valve let droplets out, but they filter the air you breathe. A n95 without a valve has properties of both, but tend to be quite expensive and reserve for medical personal only. In isolation it could be both true and false with the phrase "Most of the masks you get over the counter don’t work. They don’t prevent infection.". A surgical mask does not filter or block very small particles in the air that may be transmitted by coughs and sneezes. They do however protect others against respiratory emissions by the wearer, which result in an reduce infection rate by those near an infected wearer. Respiratory emissions by the wearer is reduced in a range of 0 to 90% depending on the quality and fit.

calvinmorrison 5y ago
> Respiratory emissions by the wearer is reduced in a range of 0 to 90% depending on the quality and fit. Ah the old $1.00 and up sales tactic
giantg2 5y ago
"A n95 without a valve has properties of both, but tend to be quite expensive and reserve for medical personal only." They are a couple of bucks and can be reused for some time. I think supply has caught up now, and they are no longer restricted. Many people have these doe things like wood working.
- 542458 5y ago
  I do believe supply has mostly caught up. I was able to buy a proper high-quality P100 respirator (99.9X filtration, as opposed to 95% on an N95 - and with oil resistance) from 3M a few months ago for not-far-above pre-covid prices. It’s a pretty fabulous device - even working with extremely fumey substances, with the mask on I can’t smell anything. I’ve taken to using it when cleaning the compost bin or spreading fertilizer as well. You do need to get the right size for your face, beards are a no-go, and glasses are awkward - but overall I’m very impressed.
slownews45 5y ago
I wear an N95 with valve, very comfortable, plenty of protection I think for user. And works in a self interested context. In cases where masks required I put a surgical over it - also still very wearable. Part of the mask rejection has been comfort. Other countries did better jobs here KN94 etc with three flaps. I'm not sure medical does nothing for wearer. I've warn a very tight fitting medical mask - I think it would certainly make some particle transmission more difficult.
- belorn 5y ago
  There are air simulations that demonstrate how surgical masks work. They draw air in from the top and bottom when you take a breath and not through the layer of cloth. Large air droplets have a harder time physically to go up and down inside the mask, through some emissions do also leak through the same place where air goes in. This basically becomes the leak rate. As a thought experiment, imagine having a crash test dummy head wearing a surgical masks. In the mouth you put CO2 smoke. The smoke is made from fine particular that you can physical feel as being wet and cold. What will happen? The smoke will escape from the bottom and top of the mask, with very little "clean" air coming out through the front. Do the same experiment but have a squirt gun shooting a few small burst of solid liquid. The solid liquid will mostly get stuck in the cloth until it is fully saturated.
throwaway5752 5y ago
Of course surgical masks reduce spread of covid. When they are required, everyone's chance of contracting it is lowered. It is a just a quid pro quo. I reduce your risk of catching it from me, and you do the same for me. Everyone benefits from the arrangement.
ishjoh 5y ago
Many wood working masks are n95, as you can imagine fine particles from wood working can do serious damage to your lungs. Before covid I was doing some home projects and picked up a package of 20 for < $5 US. As you can guess I wasn't able to buy any in all of 2020, but once supply goes back to normal I fully expect the prices will eventually get back to something like that.

by belorn 5y ago

calvinmorrison 5y ago

> Respiratory emissions by the wearer is reduced in a range of 0 to 90% depending on the quality and fit. Ah the old $1.00 and up sales tactic

giantg2 5y ago

"A n95 without a valve has properties of both, but tend to be quite expensive and reserve for medical personal only." They are a couple of bucks and can be reused for some time. I think supply has caught up now, and they are no longer restricted. Many people have these doe things like wood working.

542458 5y ago
I do believe supply has mostly caught up. I was able to buy a proper high-quality P100 respirator (99.9X filtration, as opposed to 95% on an N95 - and with oil resistance) from 3M a few months ago for not-far-above pre-covid prices. It’s a pretty fabulous device - even working with extremely fumey substances, with the mask on I can’t smell anything. I’ve taken to using it when cleaning the compost bin or spreading fertilizer as well. You do need to get the right size for your face, beards are a no-go, and glasses are awkward - but overall I’m very impressed.

slownews45 5y ago

I wear an N95 with valve, very comfortable, plenty of protection I think for user. And works in a self interested context. In cases where masks required I put a surgical over it - also still very wearable. Part of the mask rejection has been comfort. Other countries did better jobs here KN94 etc with three flaps. I'm not sure medical does nothing for wearer. I've warn a very tight fitting medical mask - I think it would certainly make some particle transmission more difficult.

belorn 5y ago
There are air simulations that demonstrate how surgical masks work. They draw air in from the top and bottom when you take a breath and not through the layer of cloth. Large air droplets have a harder time physically to go up and down inside the mask, through some emissions do also leak through the same place where air goes in. This basically becomes the leak rate. As a thought experiment, imagine having a crash test dummy head wearing a surgical masks. In the mouth you put CO2 smoke. The smoke is made from fine particular that you can physical feel as being wet and cold. What will happen? The smoke will escape from the bottom and top of the mask, with very little "clean" air coming out through the front. Do the same experiment but have a squirt gun shooting a few small burst of solid liquid. The solid liquid will mostly get stuck in the cloth until it is fully saturated.

throwaway5752 5y ago

Of course surgical masks reduce spread of covid. When they are required, everyone's chance of contracting it is lowered. It is a just a quid pro quo. I reduce your risk of catching it from me, and you do the same for me. Everyone benefits from the arrangement.

ishjoh 5y ago

Many wood working masks are n95, as you can imagine fine particles from wood working can do serious damage to your lungs. Before covid I was doing some home projects and picked up a package of 20 for < $5 US. As you can guess I wasn't able to buy any in all of 2020, but once supply goes back to normal I fully expect the prices will eventually get back to something like that.