Q&A: Your mask questions answered
An infectious disease expert explains how masks work and how best to use them
Public health officials have been saying for months now that face masks are the first line of defence against COVID-19.
Yet an Angus Reid survey found just one in five Canadians always wear a mask when they go out in public. Close to half said that they rarely or never wear a mask in public.
There's even a nascent anti-mask movement in Canada whose members have been holding rallies to voice their objections to both mask-wearing and physical distancing, as well as spreading misinformation about the pandemic.
Some are circulating fake exemption cards that suggest the holder has permission to forego wearing a mask for medical reasons.
Dr. Susy Hota, medical director for infection prevention and control at University Health Network in Toronto, said masks play a critical role in helping to control the pandemic.
She spoke to Dr. Brian Goldman, host of CBC podcast The Dose, to answer your most pressing questions about masks.
Here is part of that conversation.
Let's start with the basics: how do masks keep us safe from COVID-19?
We've long known that wearing a mask actually works as source control. So that means if you have a virus infection, and you're wearing a mask, you stop the large droplets that have the virus within them from being released and infecting those around you, at least to some degree.
What we're learning with COVID-19 now is that you might actually have individual protection from those around you as well if you wear a mask in public. We didn't have that information in the earlier parts of the pandemic. But now we're seeing, as we put all the data together, that masks can be broadly helpful in reducing transmission from person to person outside of health care settings and even just in the general community.
Medical masks, actually, are probably more effective at this than homemade or cloth masks. But even those types of masks have an ability to stop larger particles from getting to your nose and mouth. That's the main way that they work; they're barriers.
In a recent Angus Reid poll about mask-wearing, the number one reason provided for not wearing a mask was "because physical distancing offers enough protection." What would you say to those people?
I would say there are many circumstances where it's really hard to know what's going to happen in two minutes. So how predictable is your environment and especially when you're in indoor settings where it's a closed environment and you're all sharing the air. It is important to be aware of how many people are in that space and what the ventilation is like. Wearing a mask takes away some of that decision-making.
What do you think is at the root of this resistance to wearing masks?
I think some people feel like it's imposing another restriction on them. And there's a lot of fatigue. You know, we've asked people to do things differently through this pandemic for several months now. And it's not surprising that there's anger and people are feeling upset about it and maybe are manifesting it by blaming something — a mask. There's always resistance when you're trying to make change.
I just would like to see that we have a better uptake, and especially as we start moving into the fall, when we have other respiratory viruses that are also circulating, and we tend to spend more time indoors. This is really our kind of trial period through the summer to get this down before it becomes incredibly important.
What do you think are some of the best ways to make mask-wearing normal?
I think a part of it will be peer pressure and what we see other people around us doing so and role modeling. So if we see our leaders wearing masks, then that's going to be a lot more compelling for people. I think there are other strategies like turning it into the next fashion statement.
I want to talk to you about what we've seen coming from the United States and that's a certain amount of anti-mask rhetoric. Some from U.S. President Donald Trump and other political leaders. How much of that do you think is having an impact on attitudes here in Canada?
I think that people see that and it may help to fuel some of the negativity. I won't deny that at all. I'd like to think that the culture is different in Canada, though, and that people will see that what's happening in the United States is not what we want to see happening here in Canada.
The anti-mask rhetoric is occurring at a time when you're seeing explosive growth in COVID cases, in some areas that have even controlled it through the earlier parts of their wave. So I see that as a really unfortunate situation. I'm hoping that we can look to that as a lesson so that we avoid getting in a similar situation.
Here's an email we received from Beverley Burlock in Nova Scotia. "I had a hair appointment yesterday, during which I had to wear a mask for a little over three hours. Periodically during that time I had to lift the bottom edge, so I could catch my breath. My hair dresser also mentioned wearing her mask was making her much more tired. While breathing inside the mask, are we getting sufficient oxygen? Are we not breathing in too much carbon dioxide?
I think that there is a perception that you're not getting enough oxygen sometimes when you're wearing a mask. It gets warm in there. And you can also become a lot more conscious of your breathing itself. I think that makes people a little bit nervous at times, and you start to breathe faster and harder. But there is no evidence that you're actually reducing your oxygen. I think what people might want to consider if they're not comfortable in those situations is finding a mask where it's a little bit more breathable.
What would you say are valid reasons for not wearing a mask?
There aren't very many. It would really come down to people with serious lung diseases where it's difficult for them to breathe and wearing a mask might make it that much more difficult. There are also possibilities of allergic reactions to the kinds of fibers that you have on these masks, but because we are also permitting people to wear cloth masks, I think it's less likely you'll have someone who's allergic to every type of fabric.
The final thing is a little bit more challenging, and that's those with bad anxiety disorders who might actually have [anxiety attacks] precipitated by wearing something that feels like it's causing more resistance with the breathing. I think it's a case-by-case assessment by a physician who knows the individual to understand if they may be in that category of running into problems.
Should I be wearing a mask when I go for a run?
There's no need to be wearing a mask while you're exercising or running outdoors. You know that the important use of the mask is really going to be in those environments where it's indoors. It's a closed environment. It's less predictable when people are going to be coming into that area with you. You may not be able to maintain your physical distancing. You don't know what the ventilation is like. Outdoors you've got infinite exchanges of air around you, which means you're always being surrounded by fresh air.
We see a lot of restaurant and service industry workers wearing plastic face shields instead of cloth masks. How effective are they as an alternative?
We don't truly know yet how effective face shields are. I am really hoping we get that data together soon because it seems like it could offer a nice alternative to wearing a face mask. The one thing about face shields is most of them are open at the bottom. And so depending on if they shift and how they're positioned on your face, you may not get adequate coverage from below. But the positive is it also provides you with some eye protection. We talk a lot about the respiratory transmission... but you can also get droplets that splash onto your eyes and can lead to an infection.
More and more provinces are opening up bars where alcohol is being served. What's the risk for workers and patrons in that environment?
Bars really are, in my mind, one of the riskier environments for transmission. The challenge with bars is they are often … less ventilated areas. They're closed environments in many cases. And you get people who are there intending to socialize. So it's not like you're usually just in a fixed position when you're in a bar. Then you're there to drink and eat and talk to people, so masks are often off. All of it together is kind of like a convergence of different factors that make it pretty risky for transmission.
Written by Brandie Weikle. Produced by Jeff Goodes. Q&A has been edited for length and clarity.