Now that most of us have acclimated to the idea of having to wear masks out in public until the coronavirus outbreak gets under control, it’s important to learn how far the different types of masks go towards stopping the spread of droplets so as to better protect ourselves and others.
Researchers currently believe the primary spread of COVID-19 is through droplets or aerosols generated by an infected person doing something simple like speaking or coughing moving through the air and infecting another person nearby.
What masks do is limit the amount of droplets that can escape from a person’s mouth or nose, something that becomes particularly imperative since we know people with COVID-19 might be infectious for days before showing any symptoms, if they ever show symptoms at all.
So a group of researchers at the University of New South Wales decided to put a couple of common masks to the test and see which ones did the best job blocking these particles.
Using an LED lighting system with a high-speed camera, they were able to record images of the droplets on camera, something we normally wouldn’t be able to see.
The top left image shows a person with no mask, the top right shows a person with a DIY single-layer cloth mask, the bottom left image is of a person wearing a a double-layer cloth mask, and the bottom right shows a person wearing a standard surgical mask.
Unsurprisingly, the test showed that sneezing causes the most droplets, followed by coughing, but that speaking still produces enough to be concerned about.
As for the difference between the masks themselves, the surgical mask easily appeared to be the most effective in containing droplets, followed by the double-layer cloth mask, with the single-layer mask as the final, least effective option. Of course, even a single-layer DIY cloth mask was a significant improvement over not wearing a mask at all.
The study also notes that a 12-layered cloth mask, while likely impractical, would approach the same effectiveness as a surgical mask. So in general, the more layers you have, the more effective your mask will be.
If you are using DIY cloth masks, the UNSW team recommends using a water-resistant fabric for the outer layer of your mask, choosing a fabric with a higher thread count, and to always wash your mask after using it. Oh, and don’t forget to actually wear it correctly — that means making sure it covers your mouth AND your nose, and that it seals as closely to your face as possible.