“A somewhat laughable measure” … The obligation to wear a mask outdoors leaves experts skeptical

Happy New Year and best masks to you! This Friday, wearing a mask becomes mandatory outside in Paris and several towns in Ile-de-France but also in Lyon and in the entire departments of Pyrénées-Orientales and Bouches-du-Rhône. An obligation already established for several weeks in about thirty other French departments.

2022 will therefore begin masked for a major part of the French population. A health measure that the authorities justify by the Omicron wave sweeping over France, with 120,000 cases of coronavirus per day on average over the past week and peaks at more than 200,000 on Wednesday and Thursday.

Contamination mainly indoors

However, the usefulness of wearing a mask outdoors is far from scientifically unanimous. The reason is simple: the overwhelming majority of contamination takes place indoors, where the air is not renewed. A study by the Institut de Pasteur on 77,208 participants infected with the coronavirus between October 1, 2020 and January 31, 2021 showed that only 5% of the contaminations were made outdoors, against 15% in a ventilated enclosed space ( with an open window, for example) and 80% in a closed place without any ventilation.

Results corroborated by another study by the same institute and the Sorbonne, this time covering the period from May 23 to August 13, 2021. The most contaminating places (bars, nightclub, wedding, restaurant, gym) were each time both closed places, and without wearing a mask.

“A somewhat laughable measure”

The explanation is simple: the coronavirus is transmitted mainly through the air we breathe, summarizes Dr. Corinne Depagne. As a result, when the air is massively renewed, as is the case outdoors, the chances of contamination are very low. The virus does not stagnate, it is dispersed, which helps prevent transmission. On the contrary, within an enclosed space, the air is not renewed and the virus remains in place, massively increasing the chances of contamination. Hence the interest of ventilating and opening windows frequently, and the importance of wearing a mask indoors.

Consequently, imposing the mask on the outside appears to be “a somewhat laughable measure”, breathes Corinne Depagne: “To think that we are going to reduce the circulation of the virus with this kind of action is totally illusory. “The caregiver repeats what the studies cited above say:” The real problem is confined spaces. Instead of tackling the outdoors, focus on better ventilation in bars, restaurants, etc. “Better ventilation that would be effective in the long run, even in a post-covid world, since it would help fight all airborne illnesses.

Limited utility

The mask on the outside is useful in certain specific cases. “In an extremely crowded street, or a line where people are crowded, it is not absurd to wear a mask”, abounds the epidemiologist Viviane Kovess-Masféty. Even if she recognizes a contrario that “in the almost deserted streets or at off-peak hours, it is absolutely useless. The problem for the epidemiologist being that it is difficult to impose it in certain places or at certain times and not in others, hence the idea of ​​generalizing it to the outside world.

Paris had tried to impose the mask only in certain streets last September, but had quickly abandoned the idea in front of the micmac of complications that this created, and had decided for a global obligation of the mask to all the streets only a few days after.

Typing next

Nevertheless, Corrine Depagne confirms and signs: “This measure is useless as long as the enclosed space is not attacked.” The obligation of the mask outside seems all the more incongruous to him in a France at 120,000 cases a day: “The virus circulates enormously, all the studies indicate to us where it is transmitted, and we tap next to outside. »

This kind of measure “does not bring anything like real impact on the epidemic, it just annoys the French and exhausts them needlessly instead of making real decisive choices”, concludes the caregiver. We remind you: wear the mask indoors when possible and ventilate frequently, especially in your New Years Eve parties this Friday evening. Happy New Year 2022 and we wish you the best of ventilation.