Please add links in this thread and I’ll incorporate them as they arrive.
A fantastically well argued and scientific YouTube dissection of the value of masks, and COVID-19 itself - everything you need is here. 35 minutes
Note: I might remove replies once I’ve harvested the links to keep this readable
There’s no clear guidance in the UK about use of facemasks for the general public, and a lot of energy went into telling the public that they offered no protection/were needed for the medical professionals etc, that they wouldn’t protect the wearer and the main benefit would be in protecting others from you if you were shedding virus (a pretty useful benefit, you might think) – to that end there’s not much face mask use in evidence publicly in the UK
However, with the emerging compelling evidence of the high proportion of viral spreading by asymptomatic carriers maybe that should change?
Mask or respirator?
See an overview here but you’ll find that sometimes medical masks and N95 respirators are mixed up in even government guidelines (!) – much of this documentation is being rushed out, and adapted as the situation develops
For the purposes of home manufacture we’re likely talking about a device that approximates a medical mask: a thin material that covers the mouth and nose but does not meet the level of PPE (we’ll see: some very resourceful makers out there!)
Evidence and official guidance
This is from the CDC, but the link went wandering…
HCP use of homemade masks:
In settings where facemasks are not available, HCP might use homemade masks (e.g., bandana, scarf) for care of patients with COVID-19 as a last resort. However, homemade masks are not considered PPE, since their capability to protect HCP is unknown. Caution should be exercised when considering this option. Homemade masks should ideally be used in combination with a face shield that covers the entire front (that extends to the chin or below) and sides of the face.
A small study scientific from 2008
Any type of general mask use is likely to decrease viral exposure and infection risk on a population level, in spite of imperfect fit and imperfect adherence, personal respirators providing most protection. Masks worn by patients may not offer as great a degree of protection against aerosol transmission
The World Health Organisation guide on medical face masks
Notes on the contents:
- It’s strongly recommended for people with symptoms to wear medical masks.
- WHO include very mild symptoms in their definition (including a slight fever and runny nose)
- if you take the WHO guidance and then overlay it with the evidence that the majority of cases may be spread by asymptomatic carriers, this could be seen as strong case for widespread use of medical masks
- they’re not talking about respirators or makeshift masks here
WHO-2019-nCoV-IPC_Masks-2020.2-eng.pdf (702.8 KB)
[Phenomenal online doc] curated by https://twitter.com/jeremyphoward (https://docs.google.com/document/d/1HLrm0pqBN_5bdyysOeoOBX4pt4oFDBhsC_jpblXpNtQ/preview) collating scientific studies and the evidence base for wearing masks