[ptliddle]

The title is misleading. The study found duckbill N95 masks "blocked 99% of large virus particles and 98% of small ones". This is important because the issue with masks was always to do with fit and longterm ware habits, not that N95 material was ineffective at blocking viral particles.

[delecti]

> To reflect the general public's use of masks, study volunteers were not fit-tested for their masks or trained how to properly wear them

I think your cynicism is not supported by the study.

[ptliddle]

Read further down in the study. It discusses exactly what i'm referring to in that air was pushed out the sides with KN95 masks and one of the reasons cloth masks performed better then KN95s was a better fit.

[ajross]

> the issue with masks was always

No it wasn't. It was "I don't want to wear one"[1]. And the frame of the argument was fit to the desire. It was true then and remains true now that the single best protection for You Personally (absent isolation) is to put on and wear a mask. That remains true whether or not the "fit" is ideal or on the state of "longterm wear habits" of the rest of society.

[1] Though eventually the politically reframed corrolary of "You can't make me wear one" got more play.

[legitster]

And an important clarification: even if a virus particle is too small to make it through the mask - it is always riding some sort of host to transmit - water partical or something that help it transmit through the air.

Everything was moot though if you ripped off the mask and wiped your hands all over your face when you were done.

[ceejayoz]

> Everything was moot though if you ripped off the mask and wiped your hands all over your face when you were done.

No, probably not. There's very little evidence of transmission via surface contact; you have to breathe a significant amount into the nose/lungs, and the surgical and N95 masks are additionally statically charged to keep viral particles stuck to them; this is how they block viruses much smaller than their own pores. (https://www.wired.com/story/the-physics-of-the-n95-face-mask...)

[jvanderbot]

Honest question: Why do we need it to block _viruses_. Surely the virus isn't flying around with wings. Doesn't it travel on water droplets? Doesn't the mask do most of its good work by keeping water droplets in (or out)?

[bee_rider]

Generally the design and testing of the masks tries to take that into account.

I only looked into it informally during the early pandemic, so recollection is a bit hazy. But IIRC different amounts of virus travel on different sized droplets. Different sized droplets also can have different behaviors. Big enough and it doesn’t get through the mask. I think there’s also a “small enough” point where they don’t penetrate very well because they basically bounce around with brownian-like motion, don’t really create much flow. Also, IIRC larger droplets carry more viral load, but I’m pretty sure the smaller ones stay suspended in the air longer.

It is a pretty complex space I think.

[ceejayoz]

This varies from virus to virus; some generate droplets, some generate smaller particles ("aerosols" / airbone transmission). Measles is so infectious because it travels in smaller particles that linger in the air longer.

[lesuorac]

That's generally what people mean.

However, it doesn't matter how good the N95 material is if the virus travels on a water droplet _around_ the mask. This is what all the comments about fit means.

[thsksbd]

Depends on the virus. Not all need a droplet

[wordofx]

The main issue is people think masks prevent you getting sick. Rather they are designed to prevent you making others sick.

[leptons]

>Rather they are designed to prevent you making others sick.

Except N95 masks weren't designed for that at all. N95s and better masks have been worn for decades to protect the wearer from all kinds of airborne problems, from dust to virus particles. They have proven quite effective at that task. But maybe you think all those workers in the Ebola ward are just wearing masks as a fashion statement?

Masks do prevent the wearer from getting sick, far more than wearing no mask at all. Is it 100% protection? No, but nobody should be complaining about that. I'll take 95% protection or even 50% protection over no protection at all.

[hollerith]

Not true of masks that comform to NIOSH's N95 specification such as the ones routinely worn in hospitals to provide care to COVID patients and which are readily available for $2 per mask without a prescription.

[monksy]

The public health initive was a collective one that tried to incentivize widespread usage as opposed as personal protective equipment (as that good masks are).

Unfortunately the initiave was a (many)day(s) late, and $1(00000000) short. Other nations [that used a higher standard of mask] did not have nearly as bad of numbers as the US had under the mask usage policies/regulations.

[lesuorac]

Did you read the article? The issue of fit was addressed.

> (To reflect the general public's use of masks, study volunteers were not fit-tested for their masks or trained how to properly wear them.)

[ptliddle]

Read further down in the study. It discusses exactly what i'm referring to. The title says "N95 Masks Nearly Perfect at Blocking COVID" that's not what the study found. It found that duckbill N95s were nearly perfect at blocking COVID.