TOKYO: Face mask without mask-free COVID-19 is less effective in preventing infection, according to a new study.
A study published in the journal Liquid Physics shows that the number of people who use face masks in place of face masks in schools, universities, restaurants and the service industry is increasing.
However, scientists, including those at Fukuoka University in Japan, have created a so-called vortex ring that can hold microscope particles and cross the shield barrier.
Fujio Akagi, a co-author of the study at Fukuoka University, explained: “It’s like a dolphin ring.”
In the study, the scientists evaluated what happened when the face-wearer faced a meter of silence in front of the infected person.
“The turbulent rings generated by the shake capture the microscope droplets inside the shake and deliver it to the top and bottom edges of the face shield,” Akagi said.
He added that the drops travel quickly to the wearer of the face shield – within 0.5 to a second.
“If this arrival time is in line with breathing, the shield-bearer will absorb the drops,” he said.
According to the analysis, a drop of shake is carried not only by the high-velocity airflow caused by the descent, but also by the vortex ring generated by the shake.
The microscope droplets, which are carried by the vortex ring, can enter through the upper and lower edges of the shield, they said.
“Some of the particles – in this case, 4.4% of the droplets released into the face shield – have already reached the periphery,” the scientists wrote in the study.
Researchers believe that only the face shield is not effective in preventing COVID-19 infection.
However, by better understanding the vulnerability of the face shield, they hope to enhance protection by reducing the flow inside the shield.
“We are currently developing and demonstrating a number of improved shields,” Akagi said.
“We want to contribute to preventing people from becoming infected, and we believe that in the near future, medical personnel will be able to prevent infection by using only face masks and regular masks, or better yet, only face masks.” He said.
