To keep the big chunks of saliva and mucus from the doctor out of open incisions.
It's a percentage game. If you reduce the viral/bacterial/fungal load on a patient by a 1000 times, you reduce the risk of infection proportionally.
As they are worn today, they are more of a talisman than an actual medical device, at best they remind the wearer and those around them to practice a little social distancing, and keep their hands and fingers out of their mouths and noses.
And they do filter out the big chunks, except for the air that goes around the poorly sealed edges!
Truth be told most of the infectious agents aren't traveling nekked, they are in blobs of snot and spit, those can get filtered out. A viral particle by itself? A mask is as effective against them as a chain link fence is against mosquitoes.
Still, once again, it's a percentage game, reduce the viral load, give the body more time to fight a small invasion, reduce the odds of an overwhelming infection.
Compare the results of the Nazis invading the US by submarine drop off with a half dozen saboteurs to D-Day...
That being said, I wear a mask, I'm in my sixties, an obese, diabetic, hypertensive, cancer survivor. I wear a mask not because I think it will guarantee my (and by extension, my elderly mom's) health, but because it's required to go into any business in this benighted state.
I also wear a seatbelt. If I didn't I'd have a pile of click it or ticket citations, as to the seatbelt's lifesaving function, I've only needed it a few times in 50 years of driving...
Is that even vaguely what you thought I think? (just curious, there are no wrong answers to that one.)
read the study. All of it.
I’m a 63 yo stage 4 renal cancer patient that works full time in the emergency room.
So I have a vested interest in this as well.
The “percentages” are actually what I was talking about and what the study says. (if you care to read it all). It states that NO SIGNIFICANT REDUCTION OF CULTURE POSITIVE INFLUENZA WAS NOTED WITH MASK.
It also states that mechanism SHOULD work but doesn’t.
Care to know why?
Because if you look at the public and even the most “careful”, they contaminate everything and prevent NOTHING.
1. The masks are NOT kept in brown paper bags that are sterile or individual use.
2. They are kept in pockets, purses, wrapped on rear view mirrors, center consoles and gear shifts.
3. Hands are not washed and gloves used to put the mask on.
4. Once the mask is in place and people touch the environment (handles, desks, phones, cash, wallets, groceries, mail packages...etc) they touch the mask again and contaminate the outside of the mask as they adjust it for fogged glasses and fit.
5. If the mask is touched on the inside (touching your face) it is not disposed of, but .....nothing. People still use it and it’s contaminated.
6. Removal of the mask is NOT done with gloves and hands are not cleaned before and after glove use.
7. The mask is not sterilized especially cloth ones, with Virex, ozone or UV light after each use or if used for more than 20-30 minutes. (recomendations of manufacturers and infection control).
8. By touching the mask (who you and others think has “trapped” the virus or droplets) you have contaminated your hands and will touch your glasses, eyes, ears, mouth and nose.... thereby giving you a nice concentration of viral particles.
9. Placing the mask (once removed) in the purse, pocket, center console or gear shift.... it is now contaminated. If you use it multiple times...well then multiple viral loads are place in those areas and now you can see why IN SPITE of masks wearing and social distancing we have continued spread of Covid.
As we will because it’s a novel virus and we have no herd immunity, vaccine or treatment. ...same as it ever was......same as it ever was.
If you read the study it states specifically that the public is AT GREATER RISK of infection because of improper usage of masks..... that’s near the end of the article.
I “play the percentage’ as well.
I have over the last 37 years of emergency medicine played the percentages. Guess what?
I’ve been exposed to Ebola, MERs, H1N1, Tuberculosis, AIDs, Pneumonic Plague (hunters in New Mexico bitten by fleas from field mice), Influenza, Croup, plain old community acquired pneumonia, strep throat, mono and on and on....but yet in spite of working Level 1 and Level 2 trauma centers and averaging 20-30 patients a shift, I only have had one illness and I don’t think Renal Cell Carcinoma is contagious.