Recently, Canada’s chief public health officer Dr. Theresa Tam provided further guidance on wearing masks to protect against COVID-19. 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 people wear masks at all times while in public.
This did not please a minority of MDs who are demanding masks be made mandatory. I have previously explained why health officials did not initially declare masks mandatory and feel it’s 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 two meters, your likelihood of being infected by a neighbour’s cough or chatting is considered sufficiently low as to not be a concern.
I have little time for cough chamber results that indicate that coughs may go farther than two meters. Those tests were conducted in sealed chambers with no air flow. In essentially all real world conditions, air is constantly circulating. Find me a store with perfectly still air and the cough chamber results may be useful; until then I’ll trust the two meter rule.
In a crowded transit vehicle, or in a crowd, keeping two 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 do have room to socially distance.
When MDs argue for mandatory masks wearing they imagine 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, 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 they will take home. They wash their hands regularly and, this is critical, don’t ever touch their mask when out of the house.
A mask represents a potential reservoir for viral particles; every time a wearer touches their mask, their hands become potentially infected until disinfected again. So to be a CMW, you have to resist touching your mask. And if you do, need to disinfect your hands immediately.
In a perfect world, we’d all be CMWs. But 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 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, but doesn’t have to worry about adjusting a finicky mask, and so keeps their hands away from their face. From a public health perspective the CNMW does not represent a significantly increased risk over a CMW.
The person officials most worry 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; after all, they’re wearing a mask – they’re already doing their part. The NCMW coughs into their mask and then adjusts the mask because it’s uncomfortable, making 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.
The NCMW presents a serious concern for health officials. Their hands and mask both represent potential sources of infection. They will infect PIN pads and doorknobs, and their mask is a reservoir of viral particles. 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, their mask-touching habit transfers the virus onto the surface, turning that mask into a vapourizer for Coronavirus. Because their mask doesn’t actually block the movement of viral particles (its weave isn’t fine enough) it increases the likelihood they 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 – but the non-conscientious wearer represents a public health threat.
Public health officials know using masks correctly is hard. It takes time and effort to get it right. I train employees to wear PPE, and even with their employment on the line, I struggle to get them to leave their masks untouched. Masks are uncomfortable; people simply aren’t used to them.
From a training perspective it’s a LOT easier to teach people to cough into their cough pockets and not touch things. It builds on years of training we have since kindergarten: cough into your arm; wash your hands; and keep hands to yourself.
For those who claim it’s easy to teach people how to wear masks correctly, just wander through my local grocery store. See how many wear their masks correctly. Ask the gent in front of me wearing gloves (don’t get me started with gloves) who keeps pushing into my personal space, while touching every item on the shelf.
Public health professionals know what they’re talking about. Wear a mask when you can’t social distance – but when in public at a safe social distance, it’s just as safe to not wear one.
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, because that’s store policy. But in situations where I can safely social distance, I will follow our health professionals’ advice: keep my hands to myself while keeping a safe social distance and not wear a mask.
Blair King is an environmental scientist who works out of Langley and blogs at the website A Chemist in Langley on evidence-based environmental decision-making.
SWIM ON:
- Blair King last wrote a plea asking driveway cops to stand down - they were doing more harm than good.
- Blair wrote about mask usage and public health advice before.
- Jody Vance also tackled the question of whether to mask - or not to mask?
