"Chris Hogg" wrote in message
...
On Sun, 16 Feb 2020 12:55:17 +0000, Martyn Barclay
wrote:

Waste of time & money:
Dr Nathalie MacDermott, a clinical lecturer at King's College London, told
Sky News there is "not any good evidence" to suggest surgical masks can
protect the general public from the virus but there are other methods.
She said: "Surgical masks are not designed with a very decent filter on
them
so they're not able to really filter out finer particles such as viruses.

"They also don't always fit ideally around the face to provide enough
protection for someone.
"We breathe out humidified air which essentially moistens the mask over
time and once that mask becomes moist, it's really no longer very
effective."
She said the more advanced FFP3 respirator "can filter much finer
particles including viruses" and has a valve on the front that releases
air so the mask does not become moist as quickly. But any mask really is
only as good as the person wearing it. If you were to wear a mask and then
take it off and not wash your hands and then touch your eyes or eat some
food, you've just risked contaminating yourself as well," she said.
"If you wear a mask you have to make sure you wash your hands afterwards.
SKY News.
https://news.sky.com/story/coronavir...t-you-11931121

I do wonder whether breath, splutter etc actually contains single
unattached free-floating viruses, rather than viruses in a fine gob of
spit, snot or whatever. While accepting that those masks might not be
sufficient to filter individual free-floating viruses (if they exist
in that form), they probably do a reasonable job of collecting the
gobs.

It seems to me the advice is confusing. On the OT1H we're told to
regularly wash our hands, and I always understood that the common cold
and flu viruses could be transferred that way by touch (door handles
etc), OTOH we're told this Corona virus is spread by coughs and
sneezes, in the spray emitted by same, but that you're pretty much OK
if you don't get closer than a couple of metres from an infected
person. Which is it? Touch or spray? Or both?

Both and the evidence for that is the few medical professionals
who have ended up infected with it even when wearing full protection.
The argument is that they likely managed to get infected by touch
from what ended up on the outside of the protection when taking
it off etc. And its unlikely that the vast number who are now
infected on the Diamond Princess cruise ship got that way by spray.