Double-masking: Why some infectious disease experts say it's a good idea

Wearing a mask is crucial in slowing the spread of COVID-19, and now some infectious disease experts say it's a good idea to wear two.

"This idea of double-masking is something I've been doing for months now," said Timothy Sly, an epidemiologist and professor emeritus at Ryerson University's school of public health.

People wearing two masks might be something you'll start to see more often.

When asked about double-masking during an interview on NBC's Today show on Monday, Dr. Anthony Fauci, director of the U.S. National Institute for Allergy and Infectious Diseases said, "If you have a physical covering with one layer, youput another layer on, it just makes common sense that it likely would be more effective."

Sly says while at the start of the pandemic there was confusion about the benefits of masking, they can help protect the person wearing the mask and those they come in contact with.

"If both people wear a mask, then of course you've got an enormously good, very effective barrier."

Sly says he personally wears an N95 style of mask typically used for construction work to help protect him,then layers it with a high-quality cloth mask or surgeon's mask to protect others.

When looking to double up, he suggestspeople usetwo different types of materials e.g.wearing a surgeon's procedure mask, or three-layer disposable mask, with acotton mask on top.

"One set of fibres will trap in a certain way, the other set on the other will trap another way soyou're going to get the best of both worlds,"Sly said. "By putting two surgeons masks, one on top of another, I don't think that's such a good idea. You're not going to optimize your choices there."

He says wearing two of the disposable surgeons masks you often see could result in you drawing in more air from the sides, which means you might not be increasing your own protection.

"Mix the media up would be the best advice I think."

Sly thinks the emergence of more infectious variants first identified in the United Kingdom, South Africa and Brazil are a serious concern and one of the reasons people might be more interested in talking about double-masking. Cases of the new variants have already been detected in Canada.

• What's different about the coronavirus 'variants of concern' flagged by WHO

"What stops a hospital functioning is not how severe the patients are, but it's the number of patients who are hospitalized. That's what collapses it."

While nothing is 100 per cent, he says the idea should be to layer as many protections as possible to slow the spread of COVID-19, including masking, physical distancing, testing and vaccines.

"This virus doesn't hang around on street corners, or fly around like a fruit fly," Sly said. "It goes from person A to person B within seconds typically. And so all we can do to stop that, the pandemic will be brought down."

Dr. Allan Ronald, a retired professor who specialized in infectious diseases and internal medicine, worries the virus will continue to spread, particularly with the variant found in the U.K.

That means people need to be more committed to limiting infections,he says.

"We are going to have to take more precautions and that's going to include, I think, double-masking as part of our efforts."

I think the evidence is, it's what comes out of our chests through our nose and mouth that is the primary source of spread, and that's what we have to really be conscious of and try to interfere with.- Dr. Allan Ronald, retired professor who specialized in infectious diseases

Ronald says he has a variety of masks, including some well fitted N95 masks that have not deteriorated.But when wearing a cloth mask, he plans to start doubling up.

"I think the evidence is, it's what comes out of our chests through our nose and mouth that is the primary source of spread, and that's what we have to really be conscious of and try to interfere with."

To try to limit the spread of the new more infectious variants, Premier Brian Pallister announced that, starting Friday, anyone travelling into Manitoba will now have to self isolate for 14 days.

• 14-day quarantine will be mandatory for all entering Manitoba

"These measures are necessary to protect us from a more deadly version of the coronavirus that is not, as some would sadly hope, a short-term thing," Pallister said.

When asked about double-masking earlier this week, Manitoba's acting deputy chief public health officer, saidthe province isn't changing its current recommendations, which is to wear a non-medical face mask with at least two layers.

"I think we've seen the impacts of wearing a mask properly and mitigating the spread of COVID-19," said Dr. Jazz Atwal. "Is double-maskingbetter than a single mask? I haven't seen the evidence on that we do review these things on a regular basis."

The federal government recommends wearing a non-medical mask with at least three layers.

• Canada's top public health doctor now recommends 3-layer non-medical masks