Based on Aart’s link, the N95 masks seem to be very good, and – certainly recently – you could pick them up on Ebay, “apparently genuine” 3M, for about £5.
These have an “open exhaust” so your breath comes up unrestricted, which is much nicer for extended wear but obviously not quite in the spirit of the mask wearing principle which is to stop you infecting others. But fairly obviously it will still stop a sneeze flying a huge distance.
MedEwok wrote:
A good summary. The catch remains of course that for masks to really work well, everyone in a given setting were people are close to each other hss to wear them AND you need to dispose / wash the mask properly after using it AND wash or disinfect your hands afterwards before AND after removing the mask.
I dont entirely follow this.
IF everyone were wearing a mask, it seems to me there is a very good chance most stuff would be caught in the wearer’s maks – after all the virus has to get airborn and ideally in aersol form with water and salivia to become infectious.
Therefore if everyone were wearing a mask, and even if you didnt replace the mask regularly, it isnt serving to trap the virus from others, because that equally is now finding it very hard to become air born in the first place.
It would be very interesting to see some proper science as to what concentration the virus needs to achieve in aersol to arrive in someone’s respiratory track to prove infective. I am still not convinced this agent is so contageous that the amounts that might escape a mask, in open spaces and maintaining a reasonable distance from other people is any where close enough to become infective.
Some people seem to be extra good at spreading it. Just read of a guy in Split, Croatia, who met 37 people and infected 22 of them.
Not sure it has been posted already
For those who believe gloves work…
Therefore if everyone were wearing a mask, and even if you didnt replace the mask regularly, it isnt serving to trap the virus from others, because that equally is now finding it very hard to become air born in the first place.
There are two types of masks in use: surgical masks which protect others but not the wearers (these are the ones hospital staff wear most often) and those which are designed to protect the wearer but not others such as the one a few posts above. So everybody can be wearing a mask of some description and there can still be a lot of virus hanging around in the air.
There are 3m PP3 masks that have no exhalation valve. They’re less pleasant to wear as you rebreathe a higher proportion of your recently exhaled breath and the work of breathing is increased. I have worn one for a few hours at a time and you start to feel a little blunted by the end – not surprising if you are inhaling high concentrations of CO2.
It can be quite hard to communicate effectively in any kind of mask – particularly for people who are hard of hearing.
I found this report of an outbreak affecting a community choir interesting.
kwlf wrote:
There are two types of masks in use: surgical masks which protect others but not the wearers (these are the ones hospital staff wear most often) and those which are designed to protect the wearer but not others such as the one a few posts above. So everybody can be wearing a mask of some description and there can still be a lot of virus hanging around in the air.
Indeed, but where is the research? It seems to me a lot of the research is directed at the use of masks in a hospital or clinical enviroment, where, by necissity exposure is at close quarters and prolonged. In the outside enviroment we are still assuming social distancing is required to the same extent, a very different enviroment. So, you would think the aerosol levels are a great deal less to start with, there is more air circulating, there is much greater distance between people, and the length of exposure is much less.
I just wonder whether there is any persuasive research in this enviroment, as to how effective much more basic masks are, not least because, they prevent large amounts (relatively) of aerosol in the first place.
Indeed, it seems to me we know very little about actually where respiratory viruses are transmitted in the first place. Is it largely in confined spaces – offices, public transport, bars, resteraunts, any where people come together closely – you would have thought there was more than enough of that in normal circumstances to do the job, or is it when you are out walking for example. I am not sure we really know, do we? What amount of virus particles needs to be breathed in to infect a person, is there a level where our mucus can deal with it? Again, I am not covinced there has been much research.
It seems odd that we simply apply the same distancing, regardless of the enviroment. It also seems odd we have set certain “rules” without perhaps actually knowing if they are effective or not. If people work in an open plan office and all sit six feet apart, dont move from their chairs, and have no other interaction, are we certain respiratory viruses will not still spread? I have a feeling we dont know – it is all guess work!
I think the purpose of wearing cloth or paper masks is as a symbol of compliance and solidarity with government policy. It highlights those who are not in solidarity, as a tool in driving public behavior. Otherwise, it seems to me there is little to no science behind it.
On the other hand I am reminded occasionally to think about the people I know who are in government positions of this type, consider their intellectual level, and not to confuse incompetence with malice. It is a fair point, but the unprecedented and uncontested removal of rights is regardless disturbing.
For those who believe gloves work…
They do work if you avoid making stupid mistakes like the video shows 
They’re less pleasant to wear as you rebreathe a higher proportion of your recently exhaled breath and the work of breathing is increased.
This can be addressed partially with this style
and they do exist without an exhaust. But they cost a lot more, and there is no practical way to disinfect them.
The exhaust is ok if the wearer can be tested for the virus.
The only proper solution is an air fed mask. They cost even more and you have to walk around with an air cylinder. But, outside the health sector, nobody would seriously use anything else if working with suitably hazardous chemicals, and this is what I can’t understand. With the presently used equipment, it is certain that some % will be infected and thus some will die.
Peter wrote:
The only proper solution is an air fed mask. They cost even more and you have to walk around with an air cylinder. But, outside the health sector, nobody would seriously use anything else if working with suitably hazardous chemicals, and this is what I can’t understand. With the presently used equipment, it is certain that some % will be infected and thus some will die.
and the evidence for this?
Which bit are you looking for evidence for?
