Mooney_Driver wrote:
the constant European lie that masks don’t protect
In what sense is that a lie? The common type of face masks do not filter viruses — that’s a fact which there is no point to debate.
Such masks do provide a measure of protection to others against droplets from an infected wearer as the mask stops the droplets. As far as I know, no one has denied that.
But it will not protect the wearer from viruses. So if you follow orders/recommendations (depending on your country) of not leaving your home if you have a cough, then there is no point in wearing masks.
A mask must offer “some” protection to the wearer, because the virus is not floating by itself in the air. It floats on droplets of the stuff you have in your throat. So a mask which catches these ought to work, provided it filters 100% of the incoming air, which proper toxic paint masks do but the basic medical ones do not.
This one filters very close to 100% of the incoming air but allows unrestricted outflow which is probably not what everybody around you wants 
This one is even better and protects the eyes (good for really toxic stuff like 2K paint), but also has an unrestricted outflow
This type catches some high % of droplets in your outflow but certainly doesn’t offer much protection to the wearer, and is basically what most medical staff wear in the hospitals where they have run out kit
This offers really “perfect” protection for the wearer (positive pressure inside) but usually also doesn’t filter the outflow
Peter – I think it is like most of this stuff – the actual science is pitfully thin on the ground! Logic would suggest you are absolutely correct, as the virus is carried on particles, also there would seem to be some evidence that viral load is a vital factor. Never the less the science needs to be done, if it hasnt, before any conclusion can be reached.
I feel more and more strongly that the lack of being prepared is pitful – it is the most basic function of Government to prepare for those events the community would not otherwise, and, in that respect they have failed.
The issue, as ever, is Governments are here today, gone tomorrow. In the UK’s case, of course it is not the fault of the current Government, and, doubtless in due course that will be their excuse. Never the less the system requires change, and this must be taken out of the hands of Government in the future. Stress testing Banks is an example of what is necessary, and as long as this isnt subject to political whim, it is the approach that will be needed in the future, independently funded and managed so we are prepared for such an event again.
Cobalt wrote:
As was politely pointed out to me by a colleague when I had my first cold when living and working in Tokyo, it is socially compulsory to wear one if you even have the mildest sniffle or cough.
Yep. That may make a huge difference.
I suppose this is what we all should have done in addition to washing hands e.t.c. but there were no masks available and still are not.
Airborne_Again wrote:
Such masks do provide a measure of protection to others against droplets from an infected wearer as the mask stops the droplets. As far as I know, no one has denied that.
They protect others from infected people who wear them as you correctly say. So if everyone wears them, that would take care of those who have no sympthoms too.
“There are now more than 720,000 confirmed cases of coronavirus worldwide and more than 34,000 people have died.”
This is the kind of reporting I find infruiating from John Hopkins University and the BBC. Whether it was taken in context, I dont know.
This would suggest a mortality rate of 4.7% ish.
The report is marginally saved by adding the word “confirmed”, but it is never the less misleading in the extreme and irresponsible.
If it had said of 720,000 that have been tested postive, which represents an unknown percentage of those with the virus, more than .. .. ..
it would have been accurate, and required hardly any more thought as to reasonable journalism.
Mooney_Driver wrote:
They protect others from infected people who wear them as you correctly say. So if everyone wears them, that would take care of those who have no sympthoms too.
If you don’t have symptoms then you don’t cough. What, then, is the protection mechanism? If the air you exhale has virus, then the mask won’t help since it doesn’t filter virus. If you spread the virus by other means, e.g. from your hands, then again the mask won’t help.
One of the issues is droplet size. Some droplets are large in which case they splatter to the ground fairly quickly. Others are smaller in which case they aerosolise. Infected people can generate both large and small particles depending on what they are doing and what medical procedures you are doing for them. Coughing can generate aerosols, but most of the particles are still large and might still be caught by a surgical mask.
Surgical masks aren’t sealed to your face so do not prevent the wearer from breathing in aerosolised particles. Respirators are and do. There is quite a lot that is known about the virus and how it spreads and what the gold standard of care is. The question marks are about how to make the best use of a limited resource such as masks when you know there is a shortage and the gold standard is unattainable.
I did wonder whether Mr Dyson might be able to invent a mask running on the bagless vacuum cleaner principle, as it is apparently the non-availability of filter material which is holding up production.
This mask malarkey is actually a lot more complex than most bother to think of.
If you wear a mask, and it has prevented you from inhaling and contracting the virus, the mask is now contaminated.
Now you can’t touch it without disposing of it safely and washing your hands.
So you go shopping, wear your mask, get back in the car, take off the mask and contaminate the dashboard or seat and or steering wheel.
If you’re clever you will have used antibacterial gel before touching your car.
Was that before of after you touched your mask?
Clearly to do this properly you need a carefully thought through plan and a good supply of masks.
Peter if you use the mask you indicated for 2k, and it is appropriately rated for it, you still have an issue. In the small print it will say that the isocyanate will populate and eventually saturate the filter media and cause a breach.
Those masks must only be used for a very short time, or just once then the filters replaced or the mask disposed of.
That’s why we use the airfeed masks you indicate, fed from the compressor via a dedicated filter set.
Some more required reading: https://www.sciencedirect.com/science/article/pii/S0924857920300972
ABSTRACT
SARS-CoV-2, the novel coronavirus from China, is spreading around the world, causing a huge reaction despite its current low incidence outside China and the Far East. Four common coronaviruses are in current circulation and cause millions of cases worldwide. This article compares the incidence and mortality rates of these four common coronaviruses with those of SARS-COV-2 in Organisation for Economic Co-operation and Development countries. It is concluded that the problem of SARS-CoV-2 is probably being overestimated, as 2.6 million people die of respiratory infections each year compared with less than 4000 deaths for SARS-CoV-2 at the time of writing.
