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Which Masks Work the Best? 

person in a mask
(Image: Getty Images)

In order to tackle the COVID-19 pandemic scientists are asking new questions like which masks work the best to limit airborne transmission of the virus? Mask efficacy, or how well masks work to block large droplets and aerosols produced when talking, singing, or breathing, has been a hot topic recently. You may have read articles regarding the back and forth information on masks recently. Which masks work the best?

As you probably already know, COVID-19 is a respiratory disease. Like many viruses,  SARS-CoV-2 attacks the cells of your respiratory system preferentially, replicating in those cells and then when the cell ruptures and dies, spews more virus out into your respiratory system. That virus can hitch a ride on the moisture in your airways and float out of your body, on your breath. When we breathe on someone else, we are sharing those virus particles with them. That’s why we cover our coughs and sneezes, we stay home with the flu, and we should wear a mask during a viral pandemic!

By wearing a mask, we are preventing particles from our own respiratory system from getting into the air someone else breathes. Since none of us know if we have COVID-19 or not, we act like we do have it, and keep our breath to ourselves, we can prevent accidental or unknowing transmission and help everyone in our community. So, what kind of mask is most helpful in preventing transmission? There’s a lot of information on masks, and a lot of different kinds of masks. In this video, we review four of the most common mask styles and discuss their pros and cons. Viruses are super tiny, but they often travel in droplets of moisture on our breath, which are not quite as tiny, and we can catch and absorb that moisture with masks and prevent transmission of the virus.

For example, a study suggested that “gaiters,” or a type of face covering commonly used by runners, could potentially spread more droplets than wearing nothing at all. In reality, this was a report on a new way to test mask efficacy, not a peer-reviewed final publishing on mask efficacy. So, in effect, the results of their tests weren’t as reliable as other, more established forms of mask testing. But splashy headlines can play on our emotions and these results quickly alarmed a lot of people…including some aerosol scientists, who quickly responded to that article saying that the reporting didn’t convey the proper findings. Even the researchers of the study itself agreed: the measured mask efficacy was not the point of their work. Nonetheless, we hear a bit of news and it can quickly become concerning. 

Now, keep in mind it’s called RE-search, because it requires scientists to search and search and search, asking questions from different angles and gaining new perspectives. Peer review, or expert scrutiny of scientific results, is one way we ensure that research is accurate and reliable. Mask science is going through this process right in front of our eyes.

So what do we know as of now? Masks work. They prevent a large proportion of respiratory droplets from passing through them. This is the scientific consensus based upon a global research community. So, which masks work the best? Those tests are happening right now as scientists continue to ask new questions from all angles, conduct experiments, filter through data, and much more. But, currently, it seems like multi-layered cotton masks made from old t-shirts work quite well. 

A friendly reminder that science is an evolving construct, allowing the observable evidence to ultimately guide our knowledge. It’s important to keep up with the news, but be sure to do a little research yourself…check the sources and peer reviewed support to help prevent news anxiety. In the meantime, mask up and stay safe everyone!