Note: As the body of knowledge regarding COVID-19 is evolving rapidly, please refer to the World Health Organization or your local public health agencies for the most up-to-date information.
Why is everybody talking about non-medical masks in the last few days? The Centers for Disease Control and Prevention (CDC) in the US released studies showing that the coronavirus was being transmitted by patients who were asymptomatic. It was known all along that some people were infected but asymptomatic, but new information indicates that they are more likely to spread the virus than previously thought.
Because of this new information, the CDC recommends “wearing cloth face coverings in public settings where other social distancing measures are difficult to maintain (e.g., grocery stores and pharmacies) especially in areas of significant community-based transmission.”
The CDC adds that “It is critical to emphasize that maintaining 6-feet social distancing remains important to slow the spread of the virus. CDC is additionally advising the use of simple cloth face coverings to slow the spread of the virus and help people who may have the virus and do not know it from transmitting it to others.”
The CDC offers advice on how to make a mask here.
The Government of Canada takes a different stance than the CDC. “Wearing a non-medical mask (for example a homemade cloth mask) in the community has not been proven to protect the person wearing it. Strict hygiene and public health measures, including frequent hand washing and physical (social) distancing, will reduce your chance of being exposed to the virus. Wearing a non-medical mask is an additional measure you can take to protect others around you.” They compare wearing a non-medical mask to coughing into your elbow or using a tissue when you cough – something that protects others from your germs.
The World Health Organization’s public advice on wearing masks states that:
- “If you are healthy, you only need to wear a mask if you are taking care of a person with suspected 2019-nCoV infection.
- Wear a mask if you are coughing or sneezing.
- Masks are effective only when used in combination with frequent hand-cleaning with alcohol-based hand rub or soap and water.
- If you wear a mask, then you must know how to use it and dispose of it properly.”
The same WHO page has a video on how to safely put on and remove a mask. The underlying principle with any personal protective equipment (PPE), including masks and gloves, is that as soon as you’ve got it on, you need to treat the outer surface as potentially contaminated.
The Government of Canada and the CDC make it very clear that surgical masks and N95 respirators should not be used by the general public, and need to be reserved for use by first responders who are working in close proximity to patients with COVID-19 and are likely to be exposed to their respiratory secretions.
So, in a nutshell? Wearing a non-medical mask has not been proven to protect the wearer from infection, and there are a couple of risks that go along with mask-wearing – the risk of actually getting infected from your mask, but more importantly, the risk that people will get lulled into a sense of security and not practice proper hand hygiene and social distancing.
If you wear a non-medical mask in this context, you are protecting other people from you, not yourself from others. As long as people are totally clear on that, go ahead and mask if you choose.
There’s more on pubic health in the Science Corner.