tim's experiment

This face mask business is getting really confusing. Should we all wear one, and when, and how often, if at all, should we change it?

The line on face masks has varied according to which authority you listen to. At one extreme we have the view that you should not wear one at all because it makes very little difference and the mask you are wearing could be used by a health professional who really needs it.

At the other extreme is the view that you are dicing with death unless you have at least two new face masks a day.

Then there is the rather backhanded view that the mask is useful, but only because it stops you touching your face with your hands, which apparently quite a lot of us do without noticing it.

The WHO’s advice is ambiguous, like so much about that busy body. Face masks are only effective if combined with other measures, like frequent hand washing and avoiding contact with other people, some of which are not in the power of face mask wearers to change, like closing schools and sports venues.

The popular notion seems to be that face masks are an important protection against breathing air which has been breathed by strangers. But that hardly explains some things you see, like people hiking in face masks.

A similar confusion reigns over what mask is best, and what to do with it. Doctors recoil with horror at the idea of reusing one, but then they are a prosperous bunch. For the less prosperous among us the alternative to reusing a mask may be not using a mask at all.

A bewildering variety are on offer. Reading some of the comments on recycling disposable masks it is difficult to see how it could be acceptable to use a non-reusable mask with a replaceable filter inside it. But they are widely available.

Some of the confusion may result from the fact that different people use masks in different contexts. If you are going to open a patient’s bonnet and conduct running repairs inside then you want the whole room to be a sterile as possible. Clearly in this case the solution is to have a brand new mask taken out of its wrapper by a sterile nurse just before you use it.

The purpose of the mask in this context is to ensure that you do not cough microbes all over your victim’s appendix. In other words the important filtering is from inside to outside.

If you are working in a ward with patients who have an infectious disease, on the other hand, the shoe is on the other foot. Lethal microbes are floating about and the purpose of the mask is to filter what is going from the outside to the inside, so that the air you are breathing is not polluted by whatever the ailing patients are exhaling.

In this particular context it clearly makes sense to tell people not to touch the outside of the mask once you have used it, and to dispose of the thing promptly and carefully when you have finished with it. The outside of the mask has collected the poison. That is what it is there for.

The question which then arises is how many of the rules which rightly govern the use of masks in these medical contexts need to be transferred to a situation in which everyone is wearing masks whenever they go out in public.

Some people would, it seems, like to apply them all. I felt a rare twinge of sympathy for Carrie Lam (I know she has a shit job but the pay and perks are unbelievable) when she was scolded by commentators for mask abuse. In a press conference she had taken off her mask, sipped some water and put it back on again.

Those of us who still visit restaurants do routinely doff the mask, eat, and put it back on again. What else are we expected to do?

It does appear that the wearing of masks in public is not primarily, at least for a lot of wearers, a matter of avoiding Wuflu. After all there isn’t that much of it about. The wearing of a mask has become a way of wordlessly communicating that you are a public-spirited person supporting the effort to repel new viruses. And whatever you’ve got, you are taking some care to ensure that nobody gets it from you. The mask has become a signal of virtue.

Of course if almost everyone wears one this does not really work. Not wearing a mask becomes the signal, and it suggests that the non-wearer is not public-spirited, not with the programme, not a team player.

Some people have taken this to its logical conclusion. They wear a mask of the “reusable but change the filter” kind, leave the filter out and wash the mask every night. Only the most gross pollution will be intercepted but public respectability is achieved.

Other people wear masks which are clearly intended as fashion items and presumably do not meet the famous European Union standard for surgical masks.

This brings us to the controversy over Ann Chiang’s suggestion that people should sterilise used masks and use them again. I am not accustomed to agreeing with Ms Chiang about anything, but the abuse heaped on this suggestion seems unwarranted.

The Centre for Health Protection adamantly opposes the idea, and says used masks are “contaminated with pathogens” and should be disposed of in a bin with a lid. This seems a bit pessimistic. Unless you have been very unlucky in your choice of travelling companions the only pathogens in the mask are the ones which emerged from you.

It is apparently generally accepted that the usual surgical masks are intended to be disposable. But it is also known that in poor countries where there is a shortage they are commonly reused.

Like Ms Chiang I agree it would be best if everyone had enough face masks to put on a fresh one every day. But this may not be an affordable solution for everyone.

Given this state of affairs I am not sure that it is a valid criticism of other solutions that they do not meet the EU’s standards for medical face masks, which are intended for masks to be used in surgical contexts, not social ones.

But this is a tricky area for non-scientists. We lay people may at least, perhaps, plead for a simple and realistic explanation of what to do and what for, instead of the current out-of-tune chorus of contradictory advice and opinions.