The U.S. CDC recently provided a neat summation of what a year if research into coronavirus transmission has taught us. This is that mask-wearing, worker pods and good air flow are far more important than surface disinfection, temperature checks and plexiglass barriers in places like offices and restaurants.
With face masks it has been established that medical respirators such as N95s, (U.S. standard) KN95 (the Chinese standard), disposable K94 (the South Korean standard) and FFP2 (the European standard) are reasonably efficient at protecting the wearer in addition to helping prevent onward transmission. For those still seeking empirical evidence, the wearing of masks demonstrably reduced rates of confirmed coronavirus infections among health-care workers at the Mass General Brigham health-care system in Massachusetts, U.S.
However, can this efficiency be improved by double masking?
Arguments for ‘double masking’, as set out in the Wall Street Journal, are based on the premise that by wearing one mask over another, this blocks more particles through the use of two layers. Furthermore. the fit becomes more tighter, improving the seal around the face and resulting in their being fewer gaps.
Indeed, double masking if favoured by Dr. Anthony Fauci, the U.S. infectious disease expert. Fauci says it “just makes common sense” that two masks may be more likely to protect against COVID-19.
This is also backed up by academic study. Research published in the journal Matter found that a single mask is 50 percent effective at filtering out aerosols. A second face covering is up to 90 percent effective. The study is titled “Quantitative Method for Comparative Assessment of Particle Removal Efficiency of Fabric Masks as Alternatives to Standard Surgical Masks for PPE.” A second study from Virginia Tech finds a similar outcome (“Inward and outward effectiveness of cloth masks, a surgical mask, and a face shield”).
Not all health experts agree. According to Dr. John Conly, medical director of the Research and Innovation Centre at the Cumming School of Medicine, “double-masking” is unnecessary. Yet the consensus seems to be heading towards the double-mask concept.
Does the face fit?
It remains important that people ensure that the mask they wear fits properly. For example, when a person breathes in, the mask should press in or flex into the face with the air flow. When the person breathes out, it is important there are no gaps. This means when you breathe in, the mask should press in or flex into your face with the air flow. You can also breathe out. There should be no gaps of air coming out of the sides of your mask. If your glasses fog up, that means air is escaping around the top of your mask by the nose bridge gaps of air coming out of the sides of your mask. For those who wear glasses, there is a simple test to ensure the mask is fitted properly. Here, on exhaling, if your glasses fog up, that means air is escaping around the top of your mask by the nose bridge and the mask has not been fitted properly.
