Masks - yes or no?

Michael Hengartner is President of the ETH Board - and thus something like the chief researcher of Switzerland. In his column he explains interesting facts from the world of science. This week: What masks are good for.

Shall we - or shall we not? The question of protective masks is causing a lot of confusion in Switzerland. Among the population, but also among experts.

The first question is: What is the benefit of masks? The answer is ... not very simple. Protective masks are relatively effective against droplets. When I sneeze, a mask holds back many droplets that could otherwise fly in someone else's face. Against droplets that I might inhale, the mask also protects relatively well.

The situation is different with aerosols. Aerosols are tiny particles in the air. When I exhale, not only does clear mountain air leave my lungs, but also tiny particles (especially dust particles) that I have inhaled before. A mask filters part of the air I breathe - the rest goes through the cracks between the mask and my face. Whether the aerosols also carry corona viruses, whether I can infect someone like that, we simply do not know yet. That's the problem with Covid-19: There is a lot we don't know yet.

So masks are certainly of some use, but how much is not clear. In such cases, people in Switzerland like to say, "Use it, it's worth it", and play it safe. Nevertheless, the federal government has not (yet) made masks compulsory. For two reasons.

«Masks can give a false sense of security.»     

Firstly, there is no infinite amount of masks. Already today, around 2 million masks are consumed every day - mainly by doctors, nurses, midwives, Spitex collaborators and others who urgently need them. If the population also buys masks en masse, there may be too few in the end, and this might have dramatical results. In Switzerland, we definitely don't want to see pictures of doctors and nurses who have to protect themselves with improvised pseudo-masks because they don't get real ones.

The second problem is that masks can give a false sense of security. All of a sudden you keep less distance, wash your hands less thoroughly, touch your face more or stay at home less. Hygiene and staying at home are the best and safest ways to keep safe.

Whether you wear a mask or not, it is certain that we will need a lot of masks. The federal government expects that we will need about 135 million masks during the pandemic - just for medical staff. If the entire population is to wear masks, we will even need 360 million! Researchers are therefore working flat out to develop new masks that offer even better protection and can be used for longer.

At Empa, for example, Professor René Rossi is testing virus-repellent coatings and sterilization methods which extend the life of the masks. Special membranes which are impermeable to the virus are also being investigated at Empa. Rossi and his team are currently working practically day and night. I wish them every success!

The article originally appeared in SonntagsBlick.