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Better masks for greater protection

As new, more contagious variants of the coronavirus spread, it becomes necessary to wear better-quality masks, meeting stricter standards, or failing that, a surgical mask overlaid on a fabric mask, according to many experts.

As new, more contagious variants of the coronavirus spread, it becomes necessary to wear better-quality masks, meeting stricter standards, or failing that, a surgical mask overlaid on a fabric mask, according to many experts.

(AFP) – Do all masks protect effectively? No, answer the experts. At the start of the pandemic, when the authorities recommended the wearing of masks, they were not produced in sufficient quantities, and the protections “homemade” from fabrics, sometimes recovered from old T-shirts, were encouraged. But these solutions are far from ideal.

“The effectiveness of a mask depends on two things: filtration, and its fit,” Linsey Marr, a professor at Virginia Tech University who has studied airborne diseases, told AFP. “Good filtration prevents as many particles as possible from passing through, and a good fit means that there are no leaks around the edges of your mask, through which air, and therefore virus, can pass”, she adds. Even a small space can lead to efficiency reduced by 50%, she said.

The best materials for blocking very fine particles include non-woven polypropylene, used in many surgical masks or more filtering masks like KN95. When it comes to fabrics, very tight cotton works best, according to Linsey Marr. “You should feel your mask being sucked in as you breathe in, and if you put your hands to the sides, you shouldn’t feel any air coming out as you breathe out,” says the scientist. Masks with a metal shank allow a better fit of the nose, and they fit better when the rubber bands wrap around the head, not just the ears.

Two masks are better than one

“If you wear a fabric mask, choose one that has multiple layers, ideally with a small pocket that allows a good filter to slip inside,” recommends the researcher. “Or you can double it up, by wearing a surgical mask under a cloth mask.” Surgical masks are made of a material that filters well, but they tend to be quite loose.

Adding a fabric mask can therefore help keep its edges against the face, reducing leakage. Adding a layer also improves filtration – if one layer retains 50% of the particles, adding a second will achieve 75%. But “we don’t recommend wearing more than two masks” on top of each other, she adds. “It can compromise the ability to breathe well. However, it must remain easy to breathe, otherwise, the air will have a better chance of escaping through the holes on the sides of the mask. ”

Medical grade masks

Another option: KN95 or FFP2 masks depending on the country, often reserved for caregivers. These are the most filtering masks. “They all provide a similar level of filtration, for particles entering and exiting,” says Ranu Dhillon, a physician at Brigham and Women’s Hospital and Harvard Medical School. He has been campaigning for better masks since the spring, and regrets the lack of information given to the public on their benefits. “There was no concerted effort to really produce and distribute them en masse,” he laments.

Even after the coronavirus crisis has passed, the masks may well partially remain. Before the pandemic, Donald Milton, a professor at the University of Maryland, along with other scientists, studied the flu and concluded that it could also be transmitted via the fine particles released by speaking or breathing. The role of sneezing, coughing and surface transmissions is less than initially estimated, they say.

At the time, their research had sparked controversy, but it was revived by covid-19. Wearing a mask may therefore continue to be encouraged in the future during the flu season.

In Europe, faced with variants, some countries have decided to ban the least effective masks, such as Austria, which requires the wearing of the FFP2 mask in public transport and shops. In Luxembourg, if mouth protection has been mandatory in public transport since mid-April, there is no question for the government to force to wear one model of mask rather than another.


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