Masks have been found to be one of the most effective safety measures against the spread of COVID-19.?
A new research now maps this effectiveness based on the material, design and length of face masks being used.
Now published in the journal Physics of Fluids, the new study summarizes the prevalent knowledge of the way face masks filter or block the virus. In doing so, the researchers were able to highlight the design issues in face masks that still need to be addressed.
A key aspect kept into consideration while evaluating the different types of face masks was the size of fluid droplets expelled from the nose and mouth of a person. While larger droplets (5-10 microns) are the most common, smaller droplets (< 5 microns), are possibly more dangerous as they can become aerosolized and remain suspended in air for long.
Among the various types of masks in use, including cloth masks, surgical masks, and N95 masks, only N95s are capable of filtering out aerosol-sized droplets.
In addition, the scientists also found that face masks made of hybrid polymer materials had a high efficiency of filtering out particles, while simultaneously cooling the face of the wearer. This is because the fibers used in these masks are transparent to infrared radiation, allowing heat to escape from beneath the mask.
"There could be some relation between breathing resistance and the flow resistance of the face mask which will need to be studied for a face mask-wearing interval," said study co-author Heow Pueh Lee.
The common notion that came out of the study is that a wide adoption of face masks by the population of a region can significantly reduce the chances of COVID-19 transmission.
"The results suggest that the consistent use of efficient face masks, such as surgical masks, could lead to the eradication of the pandemic if at least 70 per cent of the residents use such masks in public consistently," said co-author Sanjay Kumar from the National University of Singapore.
"Even less efficient cloth masks could also slow the spread if worn consistently," Kumar added.
(With inputs from IANS)