Антимасочное

[ny_quant]

A 3,000 word deep dive into the evidence behind student mask mandates

Many countries around the world - with vax rates, case rates, and mortality above and below the US - do not require masks on students. Why does the US?

My latest for @NYMag https://t.co/r2nYIHVPNj

— David Zweig (@davidzweig) August 20, 2021

Canadian mannequin study finds mask filtration efficiencies of:

Cloth: 10%
Blue disposable: 12%
Fitted KN95: 46%
Fitted R95: 60%
KN95 with 3mm gaps: 3%

Even modest ventilation (2 air changes per hour) outperforms best mask.https://t.co/2GqCW50oyC

— Phil Kerpen (@kerpen) August 22, 2021

Comments

[misha-b.livejournal.com]

This is quite believable. I have suspected the cloth masks are barely better than nothing. It is hard to imagine how those large fibers would stop aerosols.

[alexanderr.livejournal.com]

this was available on the fda-dot-gov for a very long time.

they very clearly state that only properly fitted N95 works.
and they also note that N95 is impossible to properly fit on people with facial hair and on children.

there is really no point to wear the regular blue/cloth surgical mask, it was designed to protect against blood splashes etc, not to block the virus

[misha-b.livejournal.com]

I have not seen a study like that before.

[alexanderr.livejournal.com]

there's also that famous 2015 (pre-covid, so not politicized) Australian study. I have the link, but I think in this journal direct http links are banned

search for

A cluster randomised trial of cloth masks compared with medical masks in healthcare workers

[misha-b.livejournal.com]

2015 studies are not terribly relevant.

Surgical masks have significant effects on disease reduction according to a new and seemingly very serious study.
Cloth masks appear only marginally useful.
https://www.poverty-action.org/publication/impact-community-masking-covid-19-cluster-randomized-trial-bangladesh

[ny-quant.livejournal.com]

If you consider O(10%) effect significant than yes. Compared to vaccines that are factor of 10 - 100 significant this is nothing.

If they posed the right question - how do the masks help fully vaccinated people? - that answer would probably be not at all.

[misha-b.livejournal.com]

10% overall but they increased percentage of people wearying masks from about 10% to 40% -- by about 1/3. So for an individual the effect should be closer to 30%. It is not nearly as effective as good vaccines but nothing to sneeze on (pun intended).

> If they posed the right question - how do the masks help fully vaccinated people?

This is an important question but not necessarily _the_ right question. For example, in Bangladesh Pfizer/Moderna vaccines may not be available at all and Chinese vaccines do not seem to be good enough.

[polkovnik-isaev.livejournal.com]

Мой старший внук идет этой осенью в первый класс. 6 часов в масках и 15-минутный quiet lunch "where talking will be discouraged" и даже это решение было раскритиковано многими родителями, как излишне радикальное. Я предложил дочке, чтобы она на следующем school board meeting вынесла на обсуждение мою идею — всем детям купить маски со встроенной трубочкой (в Нордстроме продаются) и на ланч раздавать по бутылке Ensure.

[ny-quant.livejournal.com]

В каком смысле радикальное? А по-хорошему надо было бы как?

[polkovnik-isaev.livejournal.com]

Из всерьез обсуждаемых идей, вот такая, например: "Can they wear their masks and just slip bites of food underneath?"

[ny-quant.livejournal.com]

Вот же ж

[sydorov47.livejournal.com]

А на твиттере за такую ересь банят...

[ny-quant.livejournal.com]

Не, я это в Твиттере и нашёл.

[sydorov47.livejournal.com]

Видимо банят только избранных...
;-)

[xaxam.livejournal.com]

Я просмотрел статью в Physics of Fluids. Хирургическая маска примерно вдвое снижает число выдыхаемых микрокапель. Я в своё время устраивал опрос посетителей, где бы они поставили свою отметку, на шкале между 1.1 и 10, но никакой статистики не собрал 🤯

Если бустер даёт семикратную защиту от заражения, то лишняя двоечка — не так уж и плохо...

[ny-quant.livejournal.com]

Я глубоко не вникал, но понятно, что не микрокаплями едиными. Окончательные результаты в таблице III.

[misha-b.livejournal.com]

Surgical masks appear to be at least somewhat effective: https://www.poverty-action.org/publication/impact-community-masking-covid-19-cluster-randomized-trial-bangladesh