As COVID-19 cases continue to surge around the world and new highly infectious variants are on the loose, some people have started doubling up on masks by wearing two on top of each other. This might sound unnecessary or overly cautious, but many leading health experts are arguing it could help to further stop the spread of COVID-19.
The idea behind this is simple: COVID-19 is caused by an airborne virus and can spread by aerosolized droplets of salvia that have become laced with the virus. If you wear a covering across your nose and mouth, many of these droplets will be filtered and blocked from flowing into the surrounding air, reducing the risk of transmission of the virus. However, since these infectious droplets are so small, a mask can not stop 100 percent of the viruses seeping through into the surrounding air.
One solution to this problem is wearing an N95 mask, which is designed to achieve a very close facial fit and is around 95 percent effective at blocking tiny particles 0.1 to 0.3 microns in size. Alternatively, simply wearing two masks could help to add another layer of protection.
“A mask is like an obstacle course for particles to get through,” Linsey Marr, an expert in airborne virus transmission and a professor of engineering at Virginia Tech said speaking to the AARP focus group. “Adding a second mask adds another obstacle course, increasing the chance that the particle will be trapped before it gets through to the other side."
Marr published a study late last year looking at this question and found that simply wearing at least two layers of either a high-quality surgical mask or a tightly fitted fabric mask could block up to 90 percent of infectious particles – nearly as effective as an N95 mask.
Dr Anthony Fauci, director of the US National Institute of Allergy and Infectious Diseases, is also a backer of this idea. When TODAY asked him whether a “double mask” provides more protection, he replied: “You know, it likely does, because this is a physical covering to prevent droplets and virus to get in.”
“So, if you have a physical covering with one layer, you put another layer on, it just makes common sense that it likely would be more effective, and that’s the reason why you see people either double-masking or doing a version of an N95,” Dr Fauci added.
Whatever mask you wear, it's important to ensure it fits snuggly on the face and completely covers your nose and mouth. Not all face masks are created equal, however. A study published in the journal BMJ Open last year found that N95 masks were highly effective at filtering out ultrafine particles expelled at the velocity of a human cough, but vacuum bags were found to be even more effective, while other available materials were also comparable, with a few caveats. Lightweight t-shirt material was found to be the least effective face mask material, although it still blocked some particles. You can read more about this research right here.
For more information about COVID-19, check out the IFLScience COVID-19 hub where you can follow the current state of the pandemic, the progress of vaccine development, and further insights into the disease.