Testing the Efficacy of Homemade Masks: Protection in Influenza Pandemic? (2013) [pdf]
researchgate.net
researchgate.net
https://medium.com/@matthiassamwald/promoting-simple-do-it-y...
The upshot is, masks work, and the simple ones are particularly effective for protecting other people from transmission of infectious droplets from the person wearing the mask.
I realise it’s fairly ineffective, but I think it will help me avoid touching my mouth and face.
I have a beard anyway, which I’ve heard makes masks pretty ineffective anyway.
Wish me luck! Haha
Note: I would have bought one... but you know. Everyone else decided their need for them to sit in their cupboard at home was greater.
Even my need is lower than anyone in a medical position.
1) output
2) input
3) social proximity
it's already great
I do understand, however, that my point is moot when you consider direct contact with an infected person who is coughing and/or sneezing without cover (and again vice versa).
The other benefit of masks (and probably the main one of DIY masks) would be that it decreases the chance of the wearer infecting others.
It would be an easier sell to people if I could just say ,"it's not 100% effective but estimates by studies show it to be about 20% effective"
I'm all for this. Can't hurt and might help.
If a mask doesn't harm the wearer, doesn't take away from the supply needed by medical and other essential personnel, and can help stop or minimize spread from asymptomatic carriers, why not wear one?
It seems that masks might harm the wearer if warn incorrectly. Well, here's some information - https://www.info.gov.hk/info/sars/en/facemask.htm - looks like there are already lots of videos as well. (And they would need to be adequately cleaned, no question.)
Taking away from essential personnel - don't think that's applicable to cloth ones.
And i think most studies show they reduce spread of viruses. Probably not eliminate, but reduce.
So, I certainly intend to wear one - I have 2 on order. And I hope others will too. It won't solve the entire problem, but it can help.
- they're too hard to use so only medical professionals should have them (including chastising people who had masks laying around for whatever reason)
- they don't do anything anyways
- they only stop you from spreading so nobody should wear them in public (even though asymptotic spreading is known to occur)
There's anecdotal evidence from places like Taiwan and Hong Kong that masks are somewhat helpful and very little real evidence that they're harmful except in terms of making masks unavailable to frontline health workers. I firmly believe that in hindsight, public health agencies in the west will realize they did a lot of harm by saying masks were worthless.
We're not saying that. We're saying masks make you touch your face, and that without training and correct fitting the minimal protection they give is probably countered by the increased risk.
https://www.nih.gov/news-events/news-releases/new-coronaviru...
> If the viability of the two coronaviruses is similar, why is SARS-CoV-2 resulting in more cases? Emerging evidence suggests that people infected with SARS-CoV-2 might be spreading virus without recognizing, or prior to recognizing, symptoms. This would make disease control measures that were effective against SARS-CoV-1 less effective against its successor.
https://www.nejm.org/doi/10.1056/NEJMc2004973
> We found that the stability of SARS-CoV-2 was similar to that of SARS-CoV-1 under the experimental circumstances tested. This indicates that differences in the epidemiologic characteristics of these viruses probably arise from other factors, including high viral loads in the upper respiratory tract and the potential for persons infected with SARS-CoV-2 to shed and transmit the virus while asymptomatic.3,4 Our results indicate that aerosol and fomite transmission of SARS-CoV-2 is plausible, since the virus can remain viable and infectious in aerosols for hours and on surfaces up to days (depending on the inoculum shed). These findings echo those with SARS-CoV-1, in which these forms of transmission were associated with nosocomial spread and super-spreading events,5 and they provide information for pandemic mitigation efforts.
1. Do frontline healthcare workers also "touch [their] face" when wearing these masks for the same reasons regular people do? I imagine it's to adjust the fit? If the answer is no, is it because they have been educated not to? People, at least where I am in Canada, are being told not to touch our faces already. Can we not just extend the messaging to be "avoid touching your face, even when wearing a mask"?
2. If increased face touching when wearing a mask is truly a problem, would we not expect Hong Kong and Taiwan to have a worse community spread situation? Why is it that they have this contained? Again, the example is anecdotal. But coincidentally, they're both locations that learned from SARS and H1N1 and mask wearing is a foundational part of their public health response.
"Porton Down opened in 1916 as the War Department Experimental Station, shortly thereafter renamed the Royal Engineers Experimental Station, for testing chemical weapons in response to German use of this means of war in 1915. The laboratory's remit was to conduct research and development regarding chemical weapons agents used by the British armed forces in the First World War, such as chlorine, mustard gas, and phosgene."
Sounds like common sense
Also wearing a mask, any mask helps normalize wearing masks in public.
Unless it causes people to touch their face more.
TL;DR of the results though: homemade mask filtered ~50-70% and surgical mask ~90-95%. Homemade mask reduced transmission into the air by ~75-80%, surgical mask by ~85%.
I bought 60 HEPA bags a month before this disaster started.