Dec 13, 2020 A new study by scientists determines the effectiveness of face shields in protecting the wearer against Covid-19 transmission. Shockingly enough, the results are not resounding enough for those wearing only face masks to stay protected

A new study by scientists determines the effectiveness of face shields in protecting the wearer against Covid-19 transmission. Shockingly enough, the results are not resounding enough for those wearing only face masks to stay protected.

In a study now published in Physics of Fluids, researchers have simulated the airflow around a face shield when someone nearby sneezes. The research was performed to “examine the risk of virus infection when a medical worker wearing a face shield is exposed to a patient’s sneeze from the front,” the study notes.

Conducted by researchers at Fukuoka University in Japan, the study analyses vortex rings, a fluid phenomenon produced through sneezing. “A vortex ring is a donut-shaped vortex that is generated by an instantaneous ejection of fluid from a circular orifice,” said Fujio Akagi, lead author of the study. “This resembles bubble rings made by dolphins.”

Akagi and his team determined what would happen when a face shield wearer is exposed to a sneeze from an infected person standing 1 meter in front of them. The end goal was to determine if face shield were enough at their own to save one from germ transmissions.

Shocking results

The study, much like several others before this one, had a shocking implication. It showcased that the microscopic droplets generated during a sneeze had a way of reaching the upper and the lower end of the face shield being worn by the person in front.

“The vortex rings generated by the sneeze capture the microscopic droplets within the sneeze and transport them to the top and bottom edges of the face shield,” said Akagi. He further explained that the droplets droplets from the sneeze travel to the face shield wearer quickly — within 0.5 to 1 second after the start of the sneeze.