Would you systematically wear a face mask in public if you knew for sure that it would help eradicate the covid-19 pandemic? While face masks are mandatory in public places in many countries worldwide, their actual effectiveness continues to be a subject of debate. Now, researchers have revealed that the pandemic could be stopped if at least 7 in 10 people wore face masks consistently.
The findings, published by the American Institute of Physics , pertain specifically to wearing highly efficient masks like surgical masks consistently in public, and are based on the assumption that masks are worn correctly -- i.e., properly covering the nose and mouth. Wearing a mask over the mouth only, or worse, around the chin -- as sometimes seen in the street or in other public places -- is in no way effective.
Before coming to this conclusion, researchers from the Department of Mechanical Engineering at the National University of Singapore analyzed a plethora of studies on the different kinds of masks commonly used in public -- cloth masks, surgical masks and N95 masks -- to determine their effectiveness. The scientists point out that one key aspect of face mask function involves the size of fluid droplets expelled from people's noses and mouths when they talk, sing, sneeze, cough or even simply breathe.
They found that only N95 masks -- notably worn by healthcare workers -- are capable of filtering out aerosol-sized droplets. These are the smallest droplets, which the researchers consider to be "more dangerous," because they can stay suspended in the air for a long time. However, surgical masks can filter out larger droplets, which are also the most common.
The researchers went on to observe that face masks made of hybrid polymer materials could filter particles highly efficiently while simultaneously cooling the face. This is an interesting finding, considering that the more comfortable masks are to wear, the more likely users are to wear them consistently.
In their conclusions on the effectiveness of face masks in preventing the spread of covid-19, the study authors write: "The highly efficacious facemask, such as surgical masks with an estimated efficacy of around 70%, could
lead to the eradication of the pandemic if at least 70% of the residents use such masks in public consistently."
But that doesn't mean cloth masks are ineffective: they too can play a part in stamping out the pandemic. "The use of low efficacy masks, such as cloth masks with an estimated efficacy of 30%, could also lead to a significant reduction of covid-19 burden," conclude the National University of Singapore researchers.