Yes. Wearing a cloth mask over a surgical one can significantly reduce COVID-19 transmission. Even if you double mask, do not let your guard down. Wear them safely and dispose of them properly.
On a recent appearance on the “Today” show, Dr. Anthony Fauci, the chief medical adviser on COVID-19 for US President Joe Biden said that double masking “just makes common sense” and is “likely” to provide more protection against the transmission of COVID-19. So is double masking really a good idea? When and how should you go about doing it?
In the middle of 2020, some experts have already espoused the idea. In fact, I have been double masking since December last year. In theory, double masking helps control the spread of COVID-19 and now, there’s evidence. According to a recent study from the US Centers for Disease Control and Prevention (US CDC), if everyone double-masked, they could reduce COVID-19 exposure by 96.4%.
The rationale for wearing two masks is that you’re adding more layers of filtration thereby increasing filtration efficiency. However, wearing two masks may give people a false sense of security. If a person is wearing two low-quality masks or masks with holes on top of each other, it may not be very effective. If not done properly, wearing two masks might increase a person’s risk by allowing leakage around the edges. If the two masks are worn in a way that compromises the fit on the face, unfiltered air may be allowed to leak through gaps.
In the experiment, the CDC simulated what would happen when a person coughs when they and another person in their proximity are wearing various mask combinations. The combinations included: no mask, a 3-ply medical mask alone, a cloth mask alone, double masks, an unknotted mask, and knotted and tucked medical mask. All in all, 10 different combinations were tested.
They found that the unknotted medical mask alone blocked 40.2 percent of particles from the simulated cough, while the cloth mask alone blocked 44.3 percent. When the two were combined, with the cloth mask over the medical mask, the particles blocked jumped to 92.5 percent.
In a second experiment, researchers found that adding a cloth mask over a medical mask reduced the exposure of the receiver by 82.2 percent. In addition, knotting and tucking a medical mask reduced this exposure by 62.9 percent. When the source of the cough was unmasked, but the receiver was wearing a double mask or a tucked medical mask, the receiver’s exposure was reduced 83 percent and 64.5 percent respectively. The best results were obtained when both the source and receiver were double-masked or wearing knotted and tucked medical masks.
If you double mask, you should choose a good quality mask that maximizes filtration. Make sure it creates a good seal on your face so that unfiltered air doesn’t leak around the mask. One thing to remember, double masking can potentially make it more difficult to breathe. More layers of filtering materials mean more resistance to airflow. Try it out first and see if you are fine with it. In case you are not comfortable with double masks, just wear one – the right kind of mask (no holes, no valves). Wear them safely with clean hands. Dispose of them properly. The more we take this seriously, the more each of us benefit. The virus is evolving, let’s up our game too!
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Dr. Melvin Sanicas (@Vaccinologist) is a physician-scientist specializing in vaccines, infectious diseases, and global health.