Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Face masks effectively limit the probability of SARS-CoV-2 transmission

science.sciencemag.org

Post reply on HN
Print view View original

71–80 of 387 posts

Re: Face masks effectively limit the probability of SARS-CoV-2 transmission

#71

Post by slver »

sschueller wrote: post #17

N95/FFP2 seem to be very effective. I wish the media and government would have spent more time in educating people in things like how N95 masks work and that it isn't like a coffee filter. Even thought the pores are larger than a virus the masks are statically charged causes smaller things to get trapped. Many people don't know this but probably had an interaction with static electricity sometime in school and would…

Bless your soul, but what I've learned from the way we handled the pandemic worldwide (and are still handling it) is that information that's readily available and should in theory reach everyone, flows ridiculously slowly, even among specialists and political figures, it's easily corrupted and distorted, and a loud ignorant minority counts as much in the public discourse, as the voices of millions of reasonable people.

I'd say we have more evolving to do. Both biologically and socially. Individually (some) of us are relatively smart. Together we're as dumb as a piece of wood.

Re: Face masks effectively limit the probability of SARS-CoV-2 transmission

#72

Post by mulmen »

mhb wrote: post #60
sschueller wrote: post #17

N95/FFP2 seem to be very effective. I wish the media and government would have spent more time in educating people in things like how N95 masks work and that it isn't like a coffee filter. Even thought the pores are larger than a virus the masks are statically charged causes smaller things to get trapped. Many people don't know this but probably had an interaction with static electricity sometime in school and would…

I don't think people need to know how they work. They just need to know that those are what doctors wear and that they are very, very effective. And much better than a mask you make from ad hoc materials. Once N95 masks became readily available and cheap, it was (and is) mysterious why people weren't being told to wear them to protect themselves instead of wearing whatever was at hand to sort of protect themselves an…

If you tell me how something works and it fits within my mental model of the world then I will trust you. I will add this information to my mental model of the world.

If you tell me something works but can't explain how I will consider if the claim is worth evaluating then attempt to understand it myself before accepting it.

If you tell me to trust you with no explanation I will immediately distrust you.

Re: Face masks effectively limit the probability of SARS-CoV-2 transmission

#73

Post by goatcode »

splitrocket wrote: post #3

Not that this will settle anything. Anecdotally, I've not gotten even a slight cold while being socially distanced while consistently masked.

>got a cold

That's because the cold virus is spread by surfaces, and you likely touched something with it, then scratched your eyes. You can be 80 miles from someone, but if you touch something he touched, you're potentially getting his cold.

Re: Face masks effectively limit the probability of SARS-CoV-2 transmission

#74

Post by joshuaengler »

The VAST majority of mask wearing I have seen in California has been average cloth-covers. I have only seen a handful of people out of thousands actually wearing N95 masks, so perhaps N95 is highly effective at stopping viruses, but I see basically nobody wearing that. Stores, offices, buildings, all are completely fine with you wearing a bandana over your face. There is effectively no point in even mandating mask laws unless you actually mandate the TYPE of mask that must be used. The coffee filters people are wearing over their face will do close to nothing, if not even make everything worse for their own personal health (lung issues, bacterial infections, etc.)

Re: Face masks effectively limit the probability of SARS-CoV-2 transmission

#75

Post by rsj_hn »

tgsovlerkhgsel wrote: post #39

This entire study seems to be centered around a theoretical, mathematical model, and I didn't see any attempt to actually validate that model. Basically, the authors seem to assume that the virus behaves according to their formulas, and show that under their assumptions, face masks work, but don't actually prove that their assumptions match reality - or did I miss something?

Indeed this is the money paragraph:

"The effectiveness of masks, however, is still under debate. Compared to N95/FFP2 respirators which have very low particle penetration rates (around ~5%), surgical and similar masks exhibit higher and more variable penetration rates (around ~30-70%) (2, 3). Given the large number of particles emitted upon respiration and especially upon sneezing or coughing (4), the number of respiratory particles that may penetrate masks is substantial, which is one of the main reasons leading to doubts about their efficacy in preventing infections. Moreover, randomized clinical trials show inconsistent or inconclusive results, with some studies reporting only a marginal benefit or no effect of mask use (5, 6). Thus, surgical and similar masks are often considered to be ineffective. On the other hand, observational data show that regions or facilities with a higher percentage of the population wearing masks have better control of the coronavirus disease 2019 (COVID-19) (7–9). So how to explain these contrasting results and apparent inconsistencies?

Here, we develop a quantitative model of airborne virus exposure that can explain these contrasting results and provide a basis for quantifying the efficacy of face masks. "

So they are left with a conundrum that places which use surgical masks seem to be better off, whereas randomized control studies of surgical masks show little to no benefit. This is what they try to explain with a mathematical model.

Re: Face masks effectively limit the probability of SARS-CoV-2 transmission

#76

Post by neither_color »

matz1 wrote: post #54
sschueller wrote: post #17

N95/FFP2 seem to be very effective. I wish the media and government would have spent more time in educating people in things like how N95 masks work and that it isn't like a coffee filter. Even thought the pores are larger than a virus the masks are statically charged causes smaller things to get trapped. Many people don't know this but probably had an interaction with static electricity sometime in school and would…

The problem is wearing mask is annoying and uncomfortable. If I have to choose, I'll choose the increased risk of covid all the time rather than wearing mask.

I'm my state we have a choice now and I still wear one most places except the gym. That's where my comfort vs risk threshold crosses. On that note one thing that's odd that I've observed in mixed mask rooms is that I don't like exposing my face to people who aren't exposing theirs. It's like my smile, a sign of peace, can't be reciprocated so I'm making myself vulnerable at their expense. I'll don a mask in mixed mask rooms not because of conformity per se, but what feels like defensiveness. My simian brain is thinking "you don't know if these are friendlies." I'm looking forward to any future psychological studies that explain this phenomenon.

Re: Face masks effectively limit the probability of SARS-CoV-2 transmission

#78

Post by Marsymars »

awb wrote: post #12
andrew_ wrote: post #9

Earlier quoted context omitted.

My 2yo would like to sneeze on you and flip that anecdote on its head.

Years ago my entire family got sick and I was determined not to contract it through distancing and frequent hand washing and sanitizing. It worked until I bent down to tie my toddler’s shoes only to look up and mid-sentence have him cough directly into my open mouth. All it takes is one mistake. Needless to say I got sick shortly after.

A few years ago I went on vacation for a week with a half-dozen friends in an Airbnb and spent the entire time miserably sick with some kind of respiratory illness. I was similarly determined not to get anyone else sick (and I was sick from the start, so avoided any asymptomatic period). I was fastidious about distancing and sanitizing, and any time I needed to cough I'd step outside of the house. Nobody else got sick. Is the sample size here large enough to determine anything? No idea, but I like the anecdote.

Re: Face masks effectively limit the probability of SARS-CoV-2 transmission

#80

Post by admissionsguy »

tgsovlerkhgsel wrote: post #39

This entire study seems to be centered around a theoretical, mathematical model, and I didn't see any attempt to actually validate that model. Basically, the authors seem to assume that the virus behaves according to their formulas, and show that under their assumptions, face masks work, but don't actually prove that their assumptions match reality - or did I miss something?

Working down from the conclusion to find the necessary assumptions is the standard approach to COVID-related questions.
Post reply on HN