Yesterday Canada’s chief public health officer, Dr. Theresa Tam provided further guidance on wearing masks to protect against the Coronavirus. Her new advice was Canadians should wear a mask as an “added layer of protection” whenever physical distancing is not possible. In doing so, Dr. Tam reinforced that she was not recommending that people wear masks at all times while in public.

This Health Canada recommendations did not please a minority of MDs who are demanding that masks be made mandatory. I have previously explained why health officials did not initially declare masks mandatory and feel it is time to update my post to clarify why this new Health Canada guidance makes sense in my eyes.

Let’s start with what has been recommended. Coronavirus is primarily transmitted by droplet transmission and those droplets are best transported through coughs and talking. At a distance of about 2 meters your likelihood of being affected by a neighbor’s cough or chatting is considered sufficiently low as to not be a concern.

I have little time for those cough chamber results that indicate that coughs may go farther than 2 meters. Those tests were conducted in sealed chambers with no air flow. We live in a world where air is constantly circulating. Find me a store with perfectly still air and the cough chamber results may be useful, until then I will trust the 2 meter rule.

In a crowded transit vehicle, or in a crowd, keeping that 2 meters distance is not always possible. In those situations a mask should be worn. This is official Health Canada policy and is not really up for debate. When you can’t socially distance you should wear a mask. The question is how to behave when you have room to socially distance.

When MDs argue for mandatory masks wearing they imagine that we are all the Conscientious Mask-Wearer (CMW). The CMW wears a fitted mask that they clean/replace regularly. The CMW practices good social distancing and when they get home they take off their mask and immediately put in in the laundry to avoid it cross-contaminating the household. Most-importantly the CMW practices good hand hygiene.

The CMW keeps their hands to themselves in stores. They only touch items that they will take home with them. They wash their hands regularly and, this is critical, don’t ever touch their mask when out of the house. The reason for this is a mask represents a potential reservoir for viral particles. Every time a wearer touches their mask their hands become potentially infected until their hands are disinfected again. So to be a CMW you have to resist touching your mask and if you touch that mask you need to disinfect your hands immediately. Now I think we can all agree that we should all be that virtuous because in a perfect world we would all be CMWs.

Dr. Tam and our health officials don’t imagine we are all that virtuous so they suggest another safe alternative: the Conscientious Non-Mask Wearer (CNMW). The CNMW knows how to socially distance and avoids crowds when shopping. The CNMW knows to cough into their cough pocket (the crook of their elbow). They do this because the cough pocket doesn’t come into contact with other surfaces and isn’t a place you tend to touch. This reduces the risk of contaminating their hands.

The CNMW also practices good hand hygiene just like the CNMW, but doesn’t have to worry about adjusting a finicky mask so keeps their hands away from their face after cleaning them. From a public health perspective the CNMW does not represent a significantly increased risk over a CMW.

The person Dr. Lam and public health officials are most worried about is the Non-Conscientious Mask Wearer (NCMW). The NCMW wears a mask but generally does everything else wrong. They don’t concentrate on socially distancing (because they are wearing a mask so they are already doing their part). The NCMW coughs into their mask and then adjusts the mask because it is uncomfortable. This makes their mask a potential biohazard. After touching their mask the NCMW doesn’t wash their hands and then touches things with those potentially infected hands. When not in use, the NCMW’s mask goes into their pocket, purse or car (thus cross-contaminating those items).

The NCMW presents a serious concern for health officials. Their hands and mask both represent potential sources of infection. Anything they touch becomes a point contact for touch transfer to others. They will infect PIN pads and doorknobs and their mask is a reservoir of viral particles, ripe for infection. Since their mask went into their pocket/purse/car seat those surfaces are now potential sources of contagion for their families as well.

If the NCMW is not infected, but touches an infected surface, then their habit of touching their mask will transfer the virus particles onto the surface of the mask and will turn that mask into a vapourizer for Coronavirus. Because their mask doesn’t actually block the movement of viral particles (its weave is not fine enough) it increases the likelihood that they will inhale viral particles and become infected.

Herein lies the challenge from a public health perspective. The conscientious wearer and conscientious non-wearer both represent an equal risk to the public but the non-conscientious wearer represents a public health threat.

What public health officials also know is using masks correctly is hard. It takes time and effort to get it right. I train employees to wear PPE and even when their employment is on the line I struggle to get them to leave their masks untouched. Masks are uncomfortable and people simply aren’t used to them.

From a training perspective it is a LOT easier to teach people to cough into their cough pockets and not touch things. This is because it builds on years of training we have all been given since kindergarten. Health officials aren’t training from scratch they are building on what our moms taught us from childhood: cough into your cough pockets; wash your hands; and keep your hands to yourself.

As for the people online who repeatedly claim that it is easy to teach people how to wear masks correctly. I welcome them to wander through my local grocery store and see how many people are wearing their masks correctly. Ask the gent in front of me wearing the gloves (don’t get me started with gloves) who keeps pushing into my personal space while touching every item on the shelf. When you can convince me that we can teach that gent how to do it right then get back to me.

The public health professionals know what they are talking about. Wear a mask when you can’t social distance but when in public at a safe social distance it is just as safe to not wear masks. To be clear, if you see me on a bus; I will be wearing a mask. If the store asks me to wear a mask; I will wear a mask because that is store policy. But in situations where I can safely social distance, I will follow our health professionals’ advice and keep my hands to myself while keeping a safe social distance and not wear a mask.