OT: Inward and outward effectiveness of face masks

[Yusef]

Inward and outward effectiveness of cloth masks, a surgical mask, and a face shield

Jin Pan, Charbel Harb, Weinan Leng, Linsey C. Marr*

[T]

Hi Yusef,

I am not sure what to take of the study. It seemed very through. Its graphs started at 0.5 um (500 nm).

The Commie flu, which is transmitted by aerosol, is 60 to 140 nm, which is way under where the study measured.

I think this would be good for a good study for a large particle environment.

Here is a better study for the commie flu. other viruses and such:

Transmission of COVID-19 virus by droplets and aerosols: A critical review on the unresolved dichotomy

From teh aboe study, here is aerosol going straight through various masks, including N95's

-T

[trader_4]

The virus doesn't transfer mostly as individual virus particles, it transmits as aerosols and droplets. The size of the virus itself is largely irrelevant, which you would know if you really read and understood the article.

[Clare Snyder]

Any HEPA type filter bag - with (possible) caution to use them inside a cotton covering to prevent any fibers from the filter getting into your lungs. - particularly if fiberglass based. Many "experts" are reporting this danger has been over - emphasized. Synthetic HEPA filer medium sheds roughly 1/3 as many fibers as fiberglass - yet even the fiberglass produces less than 1/35th the WHO recommended particle limit. I would be comfortable using HEPA material as the filter insert in masks constructed to use an insert - for sure.

[micky]

The N95 masks have an internal layer that's not woven -- I don't know how air gets through -- and is -- I don't get this either -- electrostatically charged to attract the things the virus hangs on to.

I don't see how the charge can last very long, even when the mask isn't worn, and that might well mean that the unused masks I had for years before the virus aren't working fully now.