N95 masks are most effective, but fabric masks also work, according to researchers

Although N95 masks are most effective at blocking the transmission of coronavirus, drug and surgical masks also help, especially if everyone in a room wears them, experts and several studies say.

Masking in schools has been debated over the past week after Nassau County Executive Bruce Blakeman said most masks are ineffective while expressing his opposition to the state-wide indoor mandate. Blakeman issued a Jan. 6 notice telling schools they are free to ignore the mandate, even though Governor Kathy Hochul, the Nassau-Suffolk School Boards Association, the State Department of Education and others have said Blakeman does not have the legal authority to override the rule of state.

Jack Caravanos, clinical professor of environmental public health science at the NYU School of Global Public Health in Manhattan, said that while N95 masks are clearly more protective than fabric masks, especially with the highly contagious omicron variant, they have one major benefit: “Cloth masks are comfortable, and if they are comfortable, more people will wear them. “

N95s are effective mainly because, if worn properly, they sit tight, but because of the tight fit, “it’s not a particularly comfortable mask,” said Caravanos, who said he sometimes wears fabric masks.

Blakeman said parents should decide if their children wear masks. But that decision potentially affects other children’s health, experts said.

The risk of a mask-carrying child contracting coronavirus increases “significantly” if a nearby infected child who is not wearing a mask breathes or speaks and faces the mask-carrying child, said Ali Khosronejad, a assistant professor of civil engineering at Stony. Brook University, which studies the effectiveness of the mask.

If five people are in a room, “the risk of any of these people becoming infected decreases greatly” if one person has COVID-19, but all five wear masks because there would be fewer infectious particles in the air , said Caravanos.

He said mask use is generally more important among young school children than among adults because children are more likely to do things that emit more drops and aerosols that may contain coronavirus.

“I would probably say that if my students were not wearing a mask, it is not a problem,” said Caravanos, who is wearing a mask while teaching. “If I was a primary school teacher and the students were not wearing a mask, it’s a big deal because they talk and scream and play, versus college kids who want to sit there and take notes quietly, with very few aerosols formed.”

Research last summer and in 2020 the Khosronejad joint found that even normal breathing can lead to a “beam of saliva particles” which is invisible to the naked eye and which can travel more than 9 feet.

Indoors, “Just wearing a fabric mask, you can slow the spread to less than 2 feet away from the person,” Khosronejad said.

N95s are the most effective masks to block the spread of saliva particles and to prevent inhalation of the particles, followed by KN95s, surgical masks and fabric masks, he said.

The research was conducted before omicron, but, he said, “The physics of saliva particle transport should be the same for different variants.” In addition, although omicron infectivity means that especially cloth and surgical masks are less effective with omicron than with other variants, they still help reduce particle respiration and are better than no mask at all, he said.

A 2020 study by researchers at Northeastern University in Boston showed that fabric masks varied widely in effectiveness depending on the fit and shape of the mask, ranging from less than 30% particle removal to almost 90%.

A tighter fit and filtration material is why the N95s are better than other masks, Caravanos said.

“It’s about leakage” of air from the neck and cheek areas, he said.

N95s have straps that go on top of the head and neck, so “you put pressure so the mask sticks much better to the face,” he said.

KN95s have similar filtering capabilities as N95s, but they typically use ear straps, and ear straps do not provide as tight a fit, Caravanos said.

For any type of mask, users can check the fit by placing their fingers near the nose “to see if air is flowing out,” or by seeing if glasses are misting, he said.

For some people, including those with a low or overly high bridge of the nose, the fits may be less tight, he said.

The Centers for Disease Control and Prevention Guide encourages wearing masks with two or more layers of washable, breathable fabric that covers the mouth and nose, can be attached under the chin and sits tight – with a nose wire to prevent air from escaping.

But The Washington Post reported late Monday that the CDC is considering changing the guidelines to recommend people wear N95s or KN95s if they are able to do so consistently and correctly.

The CDC did not initially recommend N95s to the public due to lack of supplies for healthcare professionals. N95s are now widely available.

In addition to claiming that most masks are not effective, Blakeman said they can harm children’s breathing and potentially lead to long-term medical problems.

But Caravanos said there is no evidence that masks harm children’s or adults’ health.

“All of this has been disproved,” he said.

What to know

Although Nassau County Executive Bruce Blakeman bases its opposition to masking mandates largely on a claim that most masks are not effective, experts and several studies say otherwise.

N95 and KN95 masks are most effective, but cloth and surgical masks also provide some protection, especially if everyone in a room is wearing them, experts say.

Blakeman also says that masks potentially pose a danger children’s health, but an expert said claims that masks harm children’s or adults’ health are “nonsense” and have been refuted.


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