Use of Masks to Help Slow the Spread of Covid-19

A common question in practice is whether people should be wearing face masks to protect themselves and others from COVID-19. We know a key transmitter of COVID-19 is via droplets that can fly out of our mouths when we speak, cough and sneeze. Public Health Ontario recommends wearing a mask if you have symptoms of COVID-19 or are caring for someone with COVID-19. Unless you have symptoms of COVID-19, there is no clear evidence that wearing a mask will protect you from the virus, however it may help protect others around you that may be sick.

There are different types of masks that you may have seen when out getting groceries or going for a walk and it is important to discuss the difference between these appliances. Medical masks include surgical and N95 masks. Surgical masks can block 95% of small particles but do not fit tightly around the face, therefore do not provide complete protection. N95 masks are respiratory devices designed to filtrate airborne particles.

Non-medical masks or “cloth masks” can act as an additional barrier for yourself and others around you when worn for short periods of time. Although non- medical masks provide an extra barrier, they may not be effective in blocking virus particles due to the loose fit and non- medical materials used. If you do choose to wear a non- medical mask you must wash your hands immediately before putting it on and taking it off, avoid touching your face while using it and make sure to change the mask as soon as it is damp or soiled.

Health Canada recommends that both surgical and N95 masks be reserved for healthcare workers or those providing care to COVID-19 patients since these are critical supplies. Wearing a cloth mask has not been proven to protect the person wearing it but it can be an additional measure to protect others around you when physical distancing is not possible in public settings. New preliminary evidence suggests that non- medical masks in combination with public health measures could help prevent the spread of COVID-19. But remember, strict handwashing and physical distancing are key in reducing exposure to COVID-19 and wearing a mask should never be a substitute for these measures.

References:
Public Health Ontario 2020 –https://www.publichealthontario.ca/-/media/documents/ncov/factsheet/factsheet-covid-19-how-to-wear-mask.pdf?la=en
Centre of Disease Prevention and Control 2020- https://www.cdc.gov/coronavirus/2019-ncov/prevent-getting-sick/diy-cloth-face-coverings.html
Government of Canada 2020- https://www.canada.ca/en/public-health/services/diseases/2019-novel-coronavirus-infection/prevention-risks/instructions-sew-no-sew-cloth-face-covering.html