Kanada: Covid-19 a maski

The debate over whether or not to wear a mask has been front and centre since the outset of the COVID-19 pandemic.

In early weeks, the consensus among health officials was that they were unnecessary — and even potentially dangerous if worn incorrectly.

As the science has evolved, things have changed dramatically. Now a growing number of cities and regions in the country are making masks mandatory in indoor public settings to control the spread of the coronavirus.

Infectious disease experts Dr. Susy Hota and Colin Furness took mask-related questions from the Checkup audience and guest host David Common. Here are some of their answers.

Should wearing a mask indoors be mandatory?

Dr. Hota, agreed that masks should be made mandatory in indoor public settings, as has recently been affirmed by cities like Toronto and Ottawa.

Hota — an infectious disease physician, clinician, and director at the University Health Network in Toronto — told Common that in the early days of the pandemic, researchers lacked evidence that showed masks slowed the spread of the virus.

„But I feel like the science has changed. Our understanding of the virus and how it transmits has changed,” she said.

Furness, an infection control epidemiologist and an assistant professor at the University of Toronto, said that in addition to protecting people, a mandatory mask law can serve as „a mnemonic” to remind people of the importance of maintaining public health and safety.

„I think that face coverings has two purposes. It’s maintaining or keeping your droplets close to you, but also serving as a constant reminder that we have to be vigilant,” he said.

Should masks be worn outside?

Common said he’s seen many people outside taking a walk or riding a bicycle while wearing a mask. Furness, however, said that it’s usually best to keep them off until you go indoors, as the wind helps disperse people’s mouth droplets.

„To put it another way, it’s pretty hard to tell who’s got bad breath when you’re outdoors. And that’s because the air currents get in the way,” he said.

He elaborated that masks are most useful when people are indoors with shared air, and that wearing a mask for too long can contaminate their surfaces.

Why are masks only effective 'one way?’

Checkup listener Jim Priebe asked why masks are said to help people from spreading the virus to other people, but not the person wearing the mask.

Furness said that when you exhale, you expel relatively large droplets. „Those are the ones we’re really worried about, because they’re more likely to contain a lot of virus in them,” he said.

„So you are exhaling small droplets through the mask, and you are inhaling small droplets through the mask. But a lot of what you exhale will stay close to you because of the mask.”

Can I reuse my masks?

Several callers and commenters asked whether you can properly clean and reuse a homemade cloth mask, or a protective N95 mask.

Hota said that most cloth masks can be reused, but they have to be handled carefully to avoid contaminating them. She said people should try to touch the fastening elastic, rather than touching the fabric, and storing them in a plastic bag or plastic container.

She cautioned, however, that N95 masks are designed for professional use and are meant to be disposable.

„So I would say your cloth mask is a safer option, as long as you’re using it correctly and cleaning it very regularly and frequently,” she said.