The COVID-19 pandemic could be stopped if at least 70 percent of the public wore face masks consistently, according to a research that suggests that the type of material used and the duration of face mask use play major roles in their effectiveness.
The research, published in the journal Physics of Fluids, assessed studies on face masks and reviewed epidemiological reports on whether they reduce the number of people an infected person spreads the pathogen to – the reproduction number of the virus.
“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% of the residents use such masks in public consistently,” said Sanjay Kumar from the National University of Singapore.
"Even less efficient cloth masks could also the spread if worn consistently," Kumar added.
According to the scientists, one key aspect of face mask function involves the size of fluid droplets expelled from the nose and mouth when a person talks, sings, sneezes, coughs or even breathes.
Larger droplets, with sizes around 5-10 microns, are the most common. These droplets are still quite small, however. To compare, a human hair is about 70 microns in diameter.
In comparison, the scientists said the human hair is about 70 microns in diameter.
Among the many types of face masks in use, such as cloth masks worn for many hours, such as by health care or other essential workers, impact how effective overall mask wearing can be, thermal comfort is an important issue, especially in hot and humid environments, the researchers added.
Scientists found that face masks made of hybrid polymer materials could filter particles at high efficacy while simultaneously cooling the face since the fibers used in these special 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 Heow Pueh Lee, another co-author of the study.
"Also. the environmental condition in the compartment space within the face mask will need to be more accurately quantified using miniaturised sensors and the development of human replicas for such studies," Lee said.
Based on the analysis, the researchers underscored the importance of consistent use of efficient face masks, such as surgical masks.