Hygienic masks
Medical/anti-infectious masks
August 1, 2020 — September 20, 2021
This is not necessarily the same thing as particulate masks, at least as far as priorities. Obviously, some masks filter both well, but the priorities may differ. For example, particulate masks have a release valve, which AFAICT is not ideal for protecting other people from me if I wear it. Although, of course, protecting yourself from disease with a mask is not valueless to others in that you cannot transmit a disease you do not have.
Jeremy Howard, Cloth masks can protect the wearer:
As we all know now, the science shows that DIY masks are particularly good at protecting those around you in case you’re infected with COVID-19. But that doesn’t mean that you can’t do a lot to protect yourself too.
Unfortunately, many public health bodies still incorrectly claim that there is no evidence that DIY masks are useful at protecting the wearer. There’s actually plenty of evidence they can. Effective protection for the wearer of a mask depends on three critical things:
- Material: does the mask filter particles of the appropriate sizes?
- Fit: do particles squeeze in through the gaps of your mask?
- Sanitation: can you clean and re-use the mask?
Much more useful summary and advice there, now published (Brooks 2021).
Fixthemask notes some bonus hacks, including using a rubber band to keep masks snug. If you don’t want to hunt for weird filter types on eBay, there is the smart air guide which ranks normal fabrics and household filters.
How to Double Mask Correctly covers double masking, the latest, low-lift version of mask upgrades.
Enough practicalities! Here, have some silly fashion! Facemasks of your face. Glowing masks that are fibre optic!
Why so much confusion around masks? Probably several reasons, but here is an interesting one: The 60-Year-Old Scientific Screwup That Helped Covid Kill documents the argument and confusion about what size particles can transmit viruses and the lineage of some cargo-cult science that helped the misunderstandings take too long to settle.
Vendors for masks? Many on Etsy. Slightly more professional-looking, uglier ones at Top Masks. See also particulate mask vendors.
1 Particulate masks
i.e. against pollution. See particulate masks.
2 Efficacy
A difficult problem, due to the many confounders. At a population level, efficacy is unclear according to the best approximation to meta-reviews that can be contrived (Talic et al. 2021). Some studies report no effect for recent variants, which seems to be about the paucity of RCTs for this question. Certainly it is contentious (Vainshelboim 2021). Also, there are some interesting decision theory angles (Muller 2021).