What does science find about use of #masks ?

Here is a meta-analysis:

"None of the studies established a conclusive relationship between mask/respirator use and prevention of influenza transmission."

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5779801/

However,. . . 1/

However, N95 masks are worn in a surgical setting. Why?

Because bacteria are at least 10 times bigger than viruses, and can often actually get trapped in the tight weave of a N95 mask. This helps prevent hospital-acquired infections such as staph & strep. But, . . . 2/

But viruses are much smaller and easily pass through N95 masks, let alone masks with much larger pores, such as paper surgical masks and cotton masks.

In fact, the pores of cotton masks even enlarge after washing, and are then even less of an obstacle than a #coronavirus, 3/

Which is why none of the above masks can be relied on to do any of these functions:

- Stop a virus that is 1/1000 the width of a human hair,

OR
- Allow you to breath adequately,

OR
- Protect your lungs from the extra bacteria & viruses that have accumulated on your #mask. 4/

Here's how #masks INCREASE risk of viral infections:

Wear mask -->
Less oxygen available to lungs -->
Hypoxia through body -->
The body makes hypoxia inducible factor-1 (HIF-1) -->
HIF-1 lowers CD-4 T-cell function -->
But CD-4 T-cells are needed to fight viral infections! /5