Researchers at Florida Atlantic University want to show the public that it is not a good idea to put on a visor or a mouth guard with a breathing valve during the pandemic, which is common in the USA, for example, but which also occurs in Sweden.
Coughing of disco smoke
They set up a doll's head in their lab and coughing was simulated with puffs of sterilized water with glycerin similar to smoke machine smoke.
The researchers illuminated the smoke with laser light, then it is clear how particles leak out of the breathing valve on the mouthguard with class N95.
These masks are intended to protect the wearer against air pollution, but release the breathing air unfiltered.
Mouthguard without valve is a safer virus protection.
The laser light reveals leakage of particles
In the study, they also examined how well just a visor worn without a mouth guard protects others from infection.
The laser light shows how many particles are scattered to the side and remain in the air.
Jakob Löndahl, who researches protection against airborne infections and particles at Lund University, does not believe that the study adds anything new scientifically, but that it is a good pedagogical tool so that everyone can see how virus particles can pass out of a respirator or past a visor.
In the clip above, he also answers the question of whether the public in Sweden should wear mouth guards or not during the corona pandemic.