(NEXSTAR) – An experiment using a fluorescent substance and black lights shows just how quickly a virus like COVID-19 might spread in a restaurant or cruise ship setting.

The study was performed by experts on contact infection and Japan’s NHK, the country’s national public broadcaster.

During the experiment, one of the ten participants played the infected person.
The fluorescent paint was applied to that person’s palms to replicate what might happen after a sneeze was covered with the hands.

All ten then enjoyed a buffet-style meal for 30 minutes before a black light was used to track the spread of the “virus.” Traces of the fluorescent paint had spread to numerous dishes, the faces of three people and the hands of all participants.

John Nicholls, a clinical professor in pathology at the University of Hong Kong, told CNN the video demonstrates the coronavirus’ efficiency at spreading on surfaces and to people. “I think it really highlights the need of what people have been saying about hand hygiene to stop the spread of disease,” Nicholls said.

Nicholls also noted, however, that the amount of fluorescent substance on the “infected” subject wasn’t necessarily an accurate representation of the amount of germs on someone’s hand after a sneeze.

In a second experiment, all of the subjects washed their hands before and during eating, and workers disinfected commonly touched surfaces, according to CNN. When researchers turned on the black light, none of the “virus” had spread to the other diners.