lhpirnie wrote:For me I cannot believe that research has not been done to measure the effectiveness of facemasks, and to improve technology where they are ineffective or uncomfortable to wear. They are not a new invention. It is obviously difficult to pioneer a vaccine or anti-viral drugs, because the virus is new. But facemasks are about air and water droplets, which aren't new concepts. I'm afraid the scientists haven't distinguished themselves in this crisis.
that bolded part is a bit much. just because a perfect solution can't be magicked out of thin air. a huge and remarkable amount of work has been done on understanding the virus in a short space of time. mask efficacy is not just a question of air and water droplets. it is also dependent on the virus properties, environmental factors, human behaviour, compliance rates etc.
there has been research on masks but the conclusions are conditional since they are based mostly on laboratory conditions or using other viruses. doing proper controlled trials in a real world setting is difficult, and even impossible in the case of a novel pathogen before widespread infections occur.
face coverings are probably somewhat effective at limiting spread from droplet transmission by the wearer, and might offer some protection to the wearer. higher grade masks like n95 are better and can limit aerosols but need specialised fitting and training to use.
i think the anti-masker types tend to overstate the degree to which the uncertainty matters, treating 'we can't be sure' as 'just flinging rubbish at the wall to see what sticks'. but the costs and risks are low; so on balance masks are probably worthwhile - but ultimately that's a matter for policy not science.
lhpirnie wrote:I actually wore a facemask myself in China last time I was there, and it's quite common in big cities. But there may be a pollution aspect to it. China is such a big place it's impossible to generalise of course.
aye, tha's what i mean. people mostly wore outdoors because of pollution. but took off in the air conditioned office - where if you were worried about infection you'd keep it on.