Researchers at the Universities of Bristol and Surrey have found that well-fitting three-layer fabric masks can be as effective in reducing the transmission of COVID-19 as surgical masks.
At the height of the COVID-19 pandemic, 139 countries made the use of face masks mandatory in public spaces such as supermarkets and public transport. The World Health Organization also advises the use of face coatings and offers advice on their effective features. Face coverings suppress the continued transmission of COVID-19 through exhalation and protect the wearer during inhalation.
In an article published by the Fluid physics journal, the researchers detail how they examined how liquid droplets are captured and filtered in fabric masks by examining and modeling filtration processes, including inertial impaction.
Inertial impaction doesn’t filter like a sieve or colander – it works by forcing the air in your breathing to twist and spin inside the mask to the point that the droplets cannot follow the path of the air. Instead, the droplets crash into the fibers inside the mask to prevent inhalation.
The team found that, under ideal conditions and depending on the fit, three-layer fabric masks can work the same as surgical masks to filter out droplets – both reducing exposure by approximately 50 to 75%. For example, if an infected person and a healthy person both wear masks, scientists believe it could lead to up to 94% less exposure.
Dr Richard Sear, co-author of the study and head of the Soft Matter Group at the University of Surrey, said:
“While wearing a simple and relatively inexpensive fabric face mask cannot eliminate the risk of contracting COVID-19, the measurements and our theoretical model suggest that they are very effective in reducing transmission. We hope our work inspires mask designs to be optimized in the future and we hope this will help remind people of the importance of continuing to wear masks while COVID-19 remains in the community. “
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Material provided by University of Surrey. Note: Content can be changed for style and length.