Wearing a mask in public, especially when social distancing is not feasible, is one of the main ways people can help slow the spread of the coronavirus. But are some better than others?
A recent study, conducted by researchers at Duke University, tested 14 commonly used face coverings, such as three ply surgical face masks, different homemade cotton versions, bandanas and neck gaiter type panties, for its effectiveness in stopping the spread of respiratory droplets. The researchers used a simple test to determine how well each mask performed, repeating the test 10 times, measuring the droplets spread by a user during normal speech, speaking in the direction of an expanded laser beam within a dark room. A computer algorithm was then used to count the drops on the video.
However, this study was intended as a demonstration of the technique to test mask effectiveness, not a systematic study of all types of masks, explained study author Martin Fischer. As part of that evaluation, they did a rough test of a few masks, and now that they have a method that works, they can move on to rigorous testing of different models.
Why are neck gaiter not effective?
The results showed that three-ply surgical masks and cotton masks were more effective to prevent the spread of droplets, while neck gaiter and bandanas did little to stop the spread of droplets. In fact, in this example, the neck gaiter in the test actually divide larger droplets into smaller droplets, which could allow them to spread more easily.
But that doesn't mean wearing sports pants is worse than wearing nothing, the researchers explained. If you have a thin panty (single layer) and you fold it over, you have a thicker panty or you can use two thin ones, and the results will probably be different.
When you wear a mask, you should make sure it fits snugly and that it cover your mouth and nose. It's important to note that this study wasn't designed to test whether panties were worse than nothing, so the results here could be false because they didn't reproduce well.
While it's not surprising that some work better than others, much more rigorous testing is needed before recommendations can be made for which types of masks to use and which to avoid. At this point, masks are mandatory in many parts of the world due to their effectiveness.
So the results don't mean you should stop using a face mask if the one you use didn't work as efficiently as others; the key is still keeping great distances between yourself and others.