With the highly contagious Ômicron variant spreading across the world, experts consulted by CNN claim it’s time to rethink your mask options, especially if you’re still wearing a fabric mask.
“Cloth masks are little more than facial decorations. There is no place for them with the ‘micron’, says Leana Wen, medical analyst at CNN and professor of health policy and administration at the Institute School Milken, George Washington University.
“That’s what scientists and public health officials have been saying for months, many months actually,” Wen added in another telephone interview.
“We need to use at least a three-layer surgical mask”, said the expert about the type of disposable mask and can be found in most pharmacy and supermarkets. “You can wear a cloth mask on top of that, but don’t just wear a cloth mask.”
Ideally, in crowded places, “you should wear a KN95 or N95 (in Brazil, identified by the acronym PFF-2) mask,” adds Wen. Because they fit better and rely on certain materials — such as polypropylene fibers, which act as mechanical and electrostatic barriers — these masks prevent tiny particles from entering the nose or mouth and must conform to the face to function properly.
Shortage of PFF-2 is past
During the first months of the pandemic, health experts discouraged the general public from purchasing PFF-2 masks as medical professionals faced a shortage of personal protective equipment. But it’s been “many months since supplying the PFF-2 was an issue,” Wen said.
However, the most recent guidance from the US Centers for Disease Control and Prevention, for example, on the proper selection, use, cleaning, and storage of full-face masks recommended that people avoid PFF-2 masks and instead choose masks with two or more washable layers, breathable fabric, something Wen calls “a big mistake”.
“If we’re going to say that masks are mandatory – when we don’t come from a mask-wearing culture and people don’t like wearing masks – at least recommend that the most effective masks be used,” Wen said.
Other countries, including Germany and Austria, “have changed their standard to say that a face covering that should be worn in public must be at least a medical-grade surgical mask” in certain settings, he added.
Another factor driving the change in mask recommendations is a better understanding of Covid-19 and how it spreads, said Erin Bromage, associate professor of biology at the University of Massachusetts Dartmouth. “People take longer to understand the nature of airborne infections, which is not necessarily a hybrid infection, for example, like the flu, where droplets spread.”
“It seems that the main cause of infection (by the coronavirus) is shared air,” he continues. For this reason, cloth masks, encouraged at the beginning of the pandemic, can filter large drops, while more effective ones, such as PFF-2, which can filter both large drops and smaller aerosols, or potentially virus-laden particles in the air if there are people infected, explains Bromage.
A tissue facepiece has 75% “leakage” in and out, which is defined by the American Conference of Government Industrial Hygienists as the “percentage of particles entering the facepiece” and the “percentage of particles exhaled by a source, coming out of the mask”, respectively.
Properly fitted type N95 masks, approved by the US National Institute of Occupational Safety and Health, can filter up to 95% of airborne particles, according to the CDC. Surgical or disposable masks are about 5% to 10% less effective than N95, said Bromage.
Why the Ômicron variant was so successful in quickly infecting many people is “unknown at this point,” but it only underscores the role that quality masks can play, said Bromage.
“If less virus is needed [para contagiar terceiros], or if an infected person is spreading more virus, then the role of a mask is to reduce the amount you are actually breathing,” he added. “If you needed 1,000 virus particles to get infected and you’re using something that reduces 50% of things, now it’s going to take twice as long to get to 1,000. If you wear a mask that’s 90% effective, it will take at least 10 times longer before you get infected, when you’re around someone (who is infected).”
“We need to promote better, high-quality masks everywhere, because at the moment a single-layer fabric mask is not enough against Ômicron,” said former US Surgeon General Dr. Jerome Adams.
Change your fabric masks
The difference between the N95, KN95 and PFF-2 mask is where the mask is certified. The United States certifies the N95, while China approves the KN95, and Brazil the PFF-2. Approximately 60% of KN95 respirators in the US are counterfeit and do not meet NIOSH requirements, according to the CDC. “If they’re made to the standard and certified by the appropriate councils in your country, they’ll all do basically the same thing,” said Bromage. Expert advice to use better masks is not a suggestion to throw away cloth masks or “no masks” when you don’t have a medical grade mask available.
Studies with different face masks reveal that multi-layer fabric masks with higher thread counts “show superior performance compared to single layers of fabric with lower thread counts” but are still less effective than non-thread count masks. Wearing a cloth mask over a medical procedure mask, as Wen suggested, can better protect you and others, improving fit and therefore filtering ability, says the CDC.
“If all you have is a cloth mask, it’s better than nothing,” Wen said. “But you are not well protected and you should know that you are not well protected. So if you go into a crowded, closed place and all you have is a cloth mask, don’t go.”
This content was originally created in English.
original version
Reference: CNN Brasil
