As scientists and public health officials learn more about the novel coronavirus, new advice is emerging about the question on everyone’s minds: should you wear a mask when you leave your house?
According to Dr. Theresa Tam, Canada’s chief public health officer, masks — both medical and non-medical — can be effective in preventing the spread of COVID-19.
People who don’t have symptoms can wear non-medical masks when in public as “an additional measure” to protect other people, Tam said in a news conference Monday.
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There is growing evidence that people infected with the virus are able to transmit it before they develop symptoms, she said.
It may also be possible that people who have the virus but never develop symptoms are able to transmit the virus as well.
“Wearing a non-medical mask, even if you have no symptoms, is an additional measure that you can take to protect others around you in situations where physical distancing is difficult to maintain, such as in public transit or maybe in the grocery store,” Tam said.
Below, experts answer your most pressing questions about masks during the coronavirus pandemic.
Types of masks
There are two kinds of medical-grade masks.
The first is a surgical mask, which is a disposable, loose-fitting mask that covers your nose mouth and chin.
The second is an N95 respirator, which is a tight-fitting face mask that can filter the air particles breathed through it, according to the Centre for Disease Control and Prevention.
A “non-medical mask,” according to Tam, is one made at home with material from cotton shirts, sheets or bandannas, and connected to one’s ears by elastic bands or hair ties.
“A non-medical mask can reduce the chance of your respiratory droplets coming into contact with others or land on surfaces.”
Wearing a non-medical mask in the community, however, “has not been proven to protect the person wearing it,” Tam reiterated.
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In a news conference on Tuesday, both Tam and federal health minister Dr. Patty Hajdu said they would wear non-medical masks in situations where physical distancing is impossible.
How to wear a mask properly
The only way masks are effective is if they cover both your mouth and your nose, said Dr. Jeff Kwong, an infectious diseases epidemiologist and professor at the Dalla Lana School of Public Health at the University of Toronto.
That’s true of both medical masks (surgical masks and N95 masks), as well as non-medical masks made at home.
“What I find a bit funny … is when you go out and see people wearing the mask around their neck, near their chin. It’s covering the mouth but not the nose,” Kwong said.
“You’re not getting the full benefit of wearing the mask.”
This was a concern raised by Hajdu on Tuesday.
“For people who haven’t worn one before, it isn’t a comfortable experience and there will have to be some self-awareness about the tendency to want to adjust it.”
While wearing a mask, public health officials say it’s crucial that you don’t touch your face. This can counteract any benefits the mask may have.
There’s very little data on the efficacy of homemade masks. Kwong predicts they’re probably not as effective as medical masks, “but I still think some protection is still better than no protection,” he said.
Masks do not replace physical distancing, hand hygiene
Masks (medical and non-medical) do not replace the public health measures already put in place to help curb the spread of COVID-19, Tam said Monday.
“You must continue to practise physical distancing and good hygiene by frequent handwashing and regularly disinfect high-touch surfaces,” she said.
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Whether masks can prevent the spread of COVID-19 has been a topic of debate among Canadians in recent months.
According to infectious disease expert Dr. Isaac Bogoch, nothing is as effective as staying home as much as possible. If you must go out, physical distancing and good hand hygiene are your next strongest lines of defence.
However, experts believe there are some circumstances in which people can unknowingly transmit the virus — namely, people with only mild symptoms who don’t seek medical help, as well as folks who are still a few days away from developing symptoms.
In those situations, a mask can help to prevent the spread of COVID-19.
“If you’re sick and you put on a mask, it can certainly help prevent the spread of an infection,” Bogoch said. “Dr. Tam has been saying this since January.”
This is especially true when physical distancing is near impossible — like when you’re at the grocery store.
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“If you want to wear a cloth mask in the community setting where you’re not able to do physical distancing or practise hand hygiene, this may help prevent the spread of infection to others,” Bogoch said.
He reiterates that masks are not a substitute for physical distancing and hand hygiene.
“It’s extremely important to tell the whole story,” Bogoch said of the mask debate happening in Canada. He worries Canadians will wear homemade masks and develop a false sense of security.
“We’re hearing anecdotal evidence that people are wearing masks and not practising physical distancing,” he said.
It’s also important to remember that Canada is suffering from a shortage of masks and other Personal Protective Equipment (PPE) for healthcare workers on the frontlines of the pandemic.
For this reason, Kwan says Canadians should not purchase new masks. If you have some at home, he recommends donating them to your local healthcare facility.
— With files from Global News’ Beatrice Britneff
Questions about COVID-19? Here are some things you need to know:
Health officials caution against all international travel. Returning travellers are legally obligated to self-isolate for 14 days, beginning March 26, in case they develop symptoms and to prevent spreading the virus to others. Some provinces and territories have also implemented additional recommendations or enforcement measures to ensure those returning to the area self-isolate.
Symptoms can include fever, cough and difficulty breathing — very similar to a cold or flu. Some people can develop a more severe illness. People most at risk of this include older adults and people with severe chronic medical conditions like heart, lung or kidney disease. If you develop symptoms, contact public health authorities.
To prevent the virus from spreading, experts recommend frequent handwashing and coughing into your sleeve. They also recommend minimizing contact with others, staying home as much as possible and maintaining a distance of two metres from other people if you go out.
For full COVID-19 coverage from Global News, click here.
Meghan.Collie@globalnews.ca