Photo: Marie-France Coallier Archives The Duty
If the mask craft prevents the particles out, prevent it as their entry to the mouth and the nose?
Public health authorities now recommend wearing a mask not medical in the public spaces where it is impossible to stand two metres from others. This habit toilet allows, we are assured, reduce the progression of the epidemic while avoiding the spread of infected droplets. “When one puts on a mask, it is to protect others”, as explained, for example, François Legault, last Tuesday. But if the mask craft prevents the particles out, prevent it as their entry to the mouth and the nose? The mask non-medical protects that the person who wears it?
First, let us note that more and more studies come to the conclusion that the masks are effective to limit the projection of droplets in the environment. The authors of a scientific article published in April in the journal Nature Medicine, he pointed out, for example, that the surgical masks (non-waterproof, so similar to masks craft) disposing essentially the viral load excreted by the patients. In the New England Journal of Medicine, researchers have reported, after experiments with lasers, that the masks were blocking almost all of the droplets projected by someone who is speaking.
That is it for personal protection? Of course, the masks of fabric to block the droplets, as they arrive from the front or the rear. However, once these droplets will fail in the outer surface of the mask, they can remain active for hours. To avoid being contaminated, the person must remove his mask with great care and avoid touching it. This problem does not arise for the person potentially asymptomatic or présymptomatique who wants to avoid contaminating others. This one is already sick: back to the house, she can remove his mask without special precautions.
“If the masks are effective in hospitals [to protect those who wear them], this is in part because they are often changed and adjusted correctly, and in part because the employees of the health know how to remove the mask without being infected by their outer surface, which may harbour viruses,” explained to the subject in The Guardian, professor of epidemiology David Heymann, of the London School of Hygiene & Tropical Medicine.
Despite the problem of the outer face of the mask, other experts believe that it is wrong to claim that this accessory does not protect the wearer at its outputs. “Let’s be honest: the masks can protect the whole world against the diseases transmitted by droplets, such that the COVID-19. The only difference is that the general public has a risk to be relatively lower exposure to the virus that health care workers”, argued in an open letter to the Globe and Mail the‘epidemiologist retired Felix Li, who has worked for 23 years at the public health Agency of Canada. According to him, the recommendations, which provide a protection that is imperfect to a large number of people, such as wearing a mask, often have a greater impact than strategies that were very targeted to vulnerable people.
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