med-mastodon.com is one of the many independent Mastodon servers you can use to participate in the fediverse.
Medical community on Mastodon

Administered by:

Server stats:

363
active users

Dr. Lucky Tran :verified:

New study by Linsey Marr:

“We aerosolized SARS-CoV-2 & pulled it through masks. After 1hr we were able to recover infectious virus from fabric masks but not an N95 or surgical mask. When we pressed artificial skin against the masks we found viral RNA but no infectious virus on the skin.”

pubs.acs.org/doi/10.1021/acs.e

@luckytran

Very cool study, I've wondered about this.

Aside, omfg look at the COVID nebulizer. A lil nightmare machine, for science 😳 🧪

@nullagent @luckytran as long as you have the setup in a fume hood..

@nullagent @luckytran

Looks like the oxygen destroyer in Godzilla

@luckytran so yes, N95s work better if you happen to need to protect your individual self from random-ass people who are not masking.

HOWEVER

When everybody masks, no matter how crappily, there's no more infection happening at all.

This is the problem with the fucked-up, repulsive ideology of individualism. When masks, no matter how unofficial, no matter how cheap, are on EVERYBODY's face*, we end transmission, period, full stop. It's at that point where we can see about eradicating this thing, not just hoping a rich and lucky few can put up expensive walls so they can dodge it while others die.

*There are a few of our disabled comrades who can't do this, and they're the only exception we should permit.

QUESTION @luckytran so even though they found traces of the virus on the cloth masks, it was remnants of the RNA that were not infectious, correct?

am asking because N95s are not sustainable. they are a proprietary technology that doesn't use weaving for creating the plasticized paper used for the masks.

so the issue with the N95 is that they successfully leave people without a trace of the virus, as opposed to fabrics?

we need testing of fabrics based on their fibre composition and GSM.

@blogdiva @luckytran from the study: “After 1 h at 28 °C and 80% RH, SARS-CoV-2 infectivity was not detectable on an N95 and surgical mask, was reduced by 0.7 log10 on a nylon/spandex mask, and was unchanged on a polyester mask and two different cotton masks when recovered by elution in a buffer. SARS-CoV-2 RNA remained stable for 1 h on all masks.”

@tweetsjen @blogdiva @luckytran N95 masks and their relatives have an electrostatic charge which pull the viruses apart upon impacting the fibers. This same electrostatic charge does not exist on these other fabrics for multiple reasons.

@TransitBiker @tweetsjen @luckytran the N95 textile is not a fabric, it's plasticized fibres fused into a paper. so what's creating the charge, the fusing? the fibre? the little filaments on the surface?

these studies are great in proving masks work but none have yet looked at fabric masks from the POV of the fibre composition, weaving, grams per square meter (density) and actual weight of the fabric.

DENIM is cotton and so is gauze. most satins are plastics. silk can be antiseptic, etc.

@blogdiva
N95 masks aren't plasticized, they're PLASTIC: polypropylene plastic, extruded into ultra-thin threads forming a mass, like felt. I don't know how they get the charge, but it's destroyed by the touch of water.
Silk can carry a little electrostatic charge, but nowhere near as much as the polypropylene does.
I suspect we'd do better to work on recycling than on trying to duplicate plastic with a natural fiber.
@TransitBiker @tweetsjen @luckytran

@blogdiva @luckytran That’s a great question and I don’t think this study will have an answer–unless I’m reading it wrong, it’s looking at the external surface of the masks, not the transmission through them. I suspect this study is specifically addressing the “masks are dangerous because they collect viruses and then you touch your mask and get sick” idea, which was one of the … more unusual objections to masking.

I agree with you on n95 sustainability, though, but I haven’t seen any studies that actually look at commonly-available textiles comparatively. There are also some cleaning products (I’m thinking Swiffers and their competitors, and dryer sheets) that use similar electrostatic action to work, but afaik, they’re also using petrochemical fabrics. I wish I knew my physics better so I could give better insight here.

@luckytran but there are a number of very good large scale epidemiologic studies that actually look at transmission, not just whether masks can result in surface transmission- and they all show that even n95 and medical masks when used by medical professionals have MARGINAL EFFECTIVENESS at best and cloth masks have negtative effectiveness

so saying "masks work" is simply wrong, especially based on this study, which doesn't even try to answer that question

@luckytran How much of the virus passed through the beard and whiskers and past the nose without getting trapped on the mask?

I eagerly await your figures.

I suppose you know this horse is dead but get something out of flogging it a little while longer. Not a good look in any event dude.

@kallemp. From the opening sentence

"Widespread masking during the Covid-19 pandemic has renewed questions about the potential for masks to act as fomites by harboring virus that could be transferred to a susceptible host"

The study's purpose is quite clear. Can masks harbor virus and transfer to hosts through contact. While there are studies that focus on your question, this doesn't appear to be one of them.

@luckytran

@JayDub @kallemp @luckytran You made my day. It's refreshing to read something by a person who read a study & understood that it was to test specific hypotheses. I feel surrounded by people who generalise, undermine and misunderstand science altogether.

@luckytran though surgical masks, even though their fabric may filter efficiently, are pretty usesless because unlike FFP2/N95, they don't offer an airtight fit.

@amberage @luckytran They're helpful for protecting other people from your bigger particulates (spittle etc.) and you from some dust and spray but not much else!

@amberage @luckytran even given that, they are usefully better than nothing at all.

@luckytran @hjhornbeck But that’s just science… What does god say about all this, eh?

@aral @luckytran @hjhornbeck god made science and science say mask work. Tada

@gkrnours @luckytran @hjhornbeck You know, I really did think I could get away with not having a sarcasm tag on the post. Alas… :)

@aral @luckytran @hjhornbeck I was 80% it was sarcasm and I kinda leaned in it.

like, I don't know if there is a god or not. If there is, I think it a funny story. You have a believer in a flood. They have water up to their ankle, cop come in, offer to evacuate them, no god will help them. They are on their roof, ship come in, offer to help them, no god will help them. They are drowing, helicopter come in. No god will help them. They see god in heaven, get angry. God say I helped 3 times.

@aral It's all going according to Loki's plan, I reckon. :masto_wink: