Unmasking the Mask Debate
I kid. In fact, this post will not be on whether masks are useful or not. Because we have ample evidence to show that masks, when used appropriately, reduces the transmission of SARS-CoV-2 (the virus that causes Covid-19). Instead, today I want to spend some time discussing what kinds of masks are effective, and what arenโt.
While medical ๐ก๐ต๐ฑ ๐บ๐ฎ๐๐ธ๐ are the most effective, these as well as medical surgical masks should be allocated to those in clinical and healthcare settings only.
๐๐๐ฏ๐ฟ๐ถ๐ฑ ๐บ๐ฎ๐๐ธ๐ โ combining two layers of 600-thread count cotton paired with another material such as silk, chiffon or flannel are the next best. These filter 94% of small particles and 96% of larger particles.
๐ง๐๐ผ ๐น๐ฎ๐๐ฒ๐ฟ๐ of 600-thread count cotton are a close second, filtering out large particles effectively but not as effective in filtering out smaller particles.
What are ๐ก๐ข๐ง ๐ฒ๐ณ๐ณ๐ฒ๐ฐ๐๐ถ๐๐ฒ:
1- ๐ฆ๐ฐ๐ฎ๐ฟ๐๐ฒ๐, ๐ฏ๐ฎ๐ป๐ฑ๐ฎ๐ป๐ฎ๐: use these as a last resort if you are caught off-guard without a mask handy. They filter under 50% of large and small particles.
2- ๐ฉ๐ฒ๐ป๐๐ถ๐น๐ฎ๐๐ฒ๐ฑ ๐บ๐ฎ๐๐ธ๐: These are masks that have a valve in the front. These masks do not filter air that you exhale, making them ineffective in reducing transmission.
3- ๐ก๐ฒ๐ฐ๐ธ ๐ด๐ฎ๐ถ๐๐ฒ๐ฟ๐: These unfortunately seem to convert large particles into smaller droplets, using this is actually worse than not having a mask on!
4- ๐ฃ๐น๐ฎ๐๐๐ถ๐ฐ ๐บ๐ผ๐๐๐ต ๐ด๐๐ฎ๐ฟ๐ฑ๐/๐๐ต๐ถ๐ฒ๐น๐ฑ๐: There is simply no point in this, itโs a complete waste of money. They do not protect yourself or others as droplets escape easily from all sides.
๐ช๐ต๐ฒ๐ฟ๐ฒ ๐๐ฒ ๐น๐ฎ๐ฐ๐ธ ๐ถ๐ป๐ณ๐ผ๐ฟ๐บ๐ฎ๐๐ถ๐ผ๐ป:
๐๐ฎ๐ฐ๐ฒ ๐๐ต๐ถ๐ฒ๐น๐ฑ๐: Not enough data to compare efficacy of wearing just a face shield vs a mask. These likely protect against direct large droplets, but will have no efficacy on smaller suspended in air particles. In airflow visualization studies, face shields were only able to block 68% of small particles. In addition, there exists a few case reports of infections in individuals wearing just a face shield.
Where face shields can help are for a double layer of protection in conjunction with a mask, ie ๐ฏ๐ผ๐๐ต ๐บ๐ฎ๐๐ธ ๐ฎ๐ป๐ฑ ๐ณ๐ฎ๐ฐ๐ฒ ๐๐ต๐ถ๐ฒ๐น๐ฑ. In these situations, face shields protect against direct forceful expulsion of large particles, and are especially useful in protecting eyes.
๐ฆ๐๐ฎ๐ ๐๐ฎ๐ณ๐ฒ ๐ฎ๐ป๐ฑ ๐บ๐ฎ๐๐ธ ๐๐ฝ!
Signed,
Unambiguous Science
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References:
Masks:
Face shields: