To wear a mask or not wear a mask? It’s a question of weighty importance these days, and one that is both situational and controversial.
Science is still learning about the effectiveness of masks in preventing the spread of SARS-CoV-2—the novel coronavirus that causes COVID-19 infection—particularly for general public use, although the unknowns decrease with each passing week. We enlisted the help of local surgeon, Dr. Roy Kirkpatrick, to help us sort through some of the research and recommendations.
What do we know now about how COVID-19 spreads?
We are learning more about this virus almost by the day, it seems.
The virus is primarily spread via droplets when someone who is infected is speaking, coughing or sneezing, and then someone else breathes in that same air.
The virus can also be spread when those droplets land on surfaces and someone touches them and then touches their mouth, nose or eyes.
People are most infectious in the earliest days of their infection when they either have no symptoms or mild ones—they could transmit the virus without knowing they are infected.
What is the current mask recommendation for those in healthcare settings?
For simplicity, we can say that there are basically three types of masks: N95 masks, surgical or procedural masks, and homemade cloth masks.
Only one of those—N95—will both protect the wearer, by preventing the virus from getting in, and others, by preventing the virus from getting out. These should be reserved for use by healthcare workers who are most likely to get the virus from caring for others—those who are intubating patients for example—and the fit needs to be tested for the people who wear them to ensure they are the correct size and shape.
Procedural masks should be used by others working in healthcare settings—like hospitals and long-term care homes.
Homemade masks aren’t recommended for healthcare settings.
What does the science say about the effectiveness of homemade masks for the general public?
There was an evidence review recently published about mask use*. Although it hasn’t been peer-reviewed—that’s when scientists other than the author(s) evaluate what’s been written—it does provide a good overview of the science that is out there right now.
What the authors found was that there is evidence that wearing a mask helps to reduce transmission of infected droplets. In short, household masks can “help people keep their droplets to themselves”, and that “places and time periods where mask usage is required or widespread have shown substantially lower community transmission”.
So although there have been contradictory reports in the past, the pendulum appears to be swinging in favour of more widespread mask use to prevent the spread of COVID-19. Further studies will tell us more.
*Howard, J.; Huang, A.; Li, Z.; Tufekci, Z.; Zdimal, V.; van der Westhuizen, H.; von Delft, A.; Price, A.; Fridman, L.; Tang, L.; Tang, V.; Watson, G.L.; Bax, C.E.; Shaikh, R.; Questier, F.; Hernandez, D.; Chu, L.F.; Ramirez, C.M.; Rimoin, A.W. Face Masks Against COVID-19: An Evidence Review. Preprints 2020.
What do public health agencies in Ontario and Canada recommend?
On May 20, Canada’s chief medical officer of health, Dr. Theresa Tam, recommended the use of masks where physical distancing isn’t possible. Ontario followed suit the same day.
On its website, the Public Health Agency of Canada adds that “wearing a mask alone will not prevent the spread of COVID-19. You must consistently and strictly adhere to good hygiene and public health measures, including frequent hand washing and physical (social) distancing.” The agency also acknowledges that homemade masks “do not provide complete protection from virus particles because of a potential loose fit and the materials used.”
Public Health Ontario notes, “Masks (either surgical masks or non-medical masks such as cloth masks, bandanas or other face coverings), can be worn to reduce the spread of COVID-19 to others (also known as source control). Source control masks could be considered if physical distancing is not possible.”
It’s important to remember that homemade cloth masks should be made of at least two layers of tightly woven fabric like cotton or linen and fit comfortably over the nose and mouth without gaping so that the wearer doesn’t have to adjust it frequently—by touching the mask you could inadvertently infect yourself if the virus is on your hands.
Single-use masks shouldn’t be reused—throw them into a garbage bin immediately after use. Washable masks should be changed if they are damp or dirty and not be worn for long periods of time. Immediately after use put them directly into the washing machine or a bag that can be emptied into the washing machine, wash with other items using a hot cycle with laundry detergent (no special soaps are needed), and dry thoroughly. In both instances, wash your hands or use an alcohol-based hand sanitizer after removing the mask.
Masks should not be used by children under the age of two, people with breathing problems, and people who are unable to remove a mask on their own.[Read Public Health Ontario’s factsheets “When and How to Wear a Mask” and “Mask Use For Non-Healthcare Workers“]
If someone wears a homemade cloth mask, what is important for them to remember?
You are wearing it to protect others—although there is some evidence now that it will provide you with some protection from the virus it can’t keep it out completely. So don’t be complacent when wearing one. Whether or not you choose to wear a mask, keep at least two metres distance from others whenever possible, avoid touching your face, and wash your hands frequently for at least 20 seconds.
How do you personally choose to wear a mask outside of a healthcare setting?
The reason people might want to wear a mask is to prevent transmission of the virus to others, and I support that. If you’re sick, you should stay home, but the virus can be transmitted before symptoms appear and some people will be infectious without ever developing symptoms.
In the absence of a requirement to wear a mask, we all have to make a decision based on the information we have, which is sometimes incomplete, as well as the circumstances we find ourselves in. We also need to recognize that some people may be unable to wear a mask.
Outside of a healthcare setting, I will continue to practise recommended control measures—remaining at least two metres away from others when possible, not touching my face, and washing my hands frequently—and will wear a mask in situations where keeping a distance from others isn’t possible.
Do you have a COVID-19 question you’d like answered? Email it to us at firstname.lastname@example.org and we will seek out answers to as many as we can.
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