A recent study published in the journal Physics of Fluids has found that the two-meter social distancing recommended to protect against infection with SARS-CoV-2 is insufficient, even in outdoor settings. Thus, according to researchers from the University of Cambridge, mask wearing remains an essential tool to ward off potential infection.
By using computer modelling to measure how droplets exhaled by people spread when they cough, the scientists found that although most of larger droplets fall on the nearby surfaces, smaller droplets, or aerosols, can stay much more in the air and spread rapidly well beyond two meters.
According to study lead author, Dr. Shrey Trivedi, a researcher in Physics at Cambridge, different individual coughs can vary in terms of droplet distribution. “Each time we cough, we may emit a different amount of liquid, so if a person is infected with Covid, they could be emitting lots of virus particles or very few, and because of the turbulence they spread differently for every cough,” he explained.
Due to these findings, study co-author Epaminondas Mastorakos, an expert in Fluid Mechanics at Cambridge, is urging everybody to wear masks in order to defend themselves against the coronavirus.
“We’re all desperate to see the back of this pandemic, but we strongly recommend that people keep wearing masks in indoor spaces such as offices, classrooms, and shops. There’s no good reason to expose yourself to this risk as long as the virus is with us.”
Although there have been fierce debates regarding the usefulness of wearing masks, both laboratory tests and observational studies have shown that masks can stop infected people from exhaling up to 80 percent of the virus in the air, and can also protect wearers from inhaling up to 50 percent of the viral particles.
In future studies, the researchers aim to explore in more detail how SARS-CoV-2 is transmitted in specific indoor spaces, such as lecture halls in universities, and to assess more comprehensively the degree of protection offered by various types of masks.