Coronavirus variants - it's time to wear better masks

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Coronavirus variants - it's time to wear better masks

At a time when new more contagious variants of the coronavirus spread, it becomes necessary to wear better quality masks, respecting more strict standards, according to many experts.

Scientists agree today that the virus is mainly disseminated in the air, rather than via contaminated surfaces.And there is more and more evidence than very thin droplets, which can be projected up to several meters when someone speaks or breathes - a bit like cigarette smoke - may be enough to transmit the disease.

To make sure, some variants, such as the Briton, are transmitted today more easily than the virus that has been circulating so far, in the opinion of many experts.

At the start of the pandemic, when the authorities recommended carrying masks, they were not produced in large quantities, and the "homemade" protections from fabrics, sometimes recovered from old t-shirts,were encouraged.

But these solutions are far from ideal.So how to do better?

Filtration et ajustement

"The effectiveness of a mask depends on two things: filtration, and its adjustment," said AFP Linsey Marr, professor at Virginia Tech University who studied diseases transmitting by air.

"A good filtration prevents as many particles as possible to pass, and a good adjustment means that there is no leaks on the edges of your mask, by which air, and therefore the virus, can pass",she adds.Even a small space can lead to a reduced efficiency of 50%, according to her.

The best materials to block very fine particles include unwanted polypropylene, used in many surgical masks or more filter masks like KN95.

Coton très serré

As for fabrics, very tight cotton is what works best, according to Linsey Marr.

"You should feel your mask being sucked inward when you inspire, and if you place your hands on the sides, you should not feel out when you expire," explains the scientist.

The masks with a metal rod allow you to better marry the shape of the nose, and they are better adjusted when the elastic bands go around, and not only of the ears.

Deux masques valent mieux qu’un

"If you wear a fabric mask, choose one that has multiple layers, ideally with a small pocket that allows you to slip a good filter inside," recommends the researcher."Or you can double it, wearing a surgical mask under a fabric mask.»»»»

Surgical masks are made of a material that filters well, but they tend to be loose enough.Adding a fabric mask can therefore keep your edges against the face, thus reducing leaks.

Add a layer also improves filtration - if a layer retains 50% of the particles, adding one second will reach 75%.

Mais «nous ne recommandons pas de porter plus de deux masques»»»» l’un sur l’autre, ajoute-t-elle."This can compromise the ability to breathe well.Now it must remain easy to breathe, otherwise, the air will be more likely to escape by the holes on the sides of the mask.»»»»

Masques KN95 et FFP2

Another option: KN95, or FFP2 masks depending on the country, often so far reserved for caregivers.These are the most filter masks.

«Ils procurent tous un niveau similaire de filtration, pour les particules qui entrent comme pour celles qui sortent»»»», explique Ranu Dhillon, médecin au Brigham and Women’s Hospital et à la Harvard Medical School.

He has campaigned in favor of better masks since spring, and regrets the little information given to the public on their profits.

«Il n’y a pas eu d’effort concerté pour vraiment les produire et les distribuer en masse»»»», déplore-t-il.

Masques pour toujours ?

Even once the coronavirus crisis has passed, the masks may well remain.

Before the pandemic, Donald Milton, professor at the University of Maryland, as well as other scientists, studied the flu and concluded that it could also be transmitted via the fine particles rejected by speaking or breathing.The role of sneezing, coughing and surface transmissions is lower than initially estimated, according to them.

At the time, their research had aroused controversy, but they were relaunched by the COVVI-19.Wearing the mask could therefore remain encouraged in the future during the flu season.

Afpe

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