Coronavirus: New Facts about Infection Mechanisms – NHK Documentary
In a recent interview with the Japanese Association of Infectious diseases, NHK released a study made by a group of scientists of Tokyo University to better understand how particles released by an infected patients disseminate in a closed space.
The experiment used high resolution cameras to follow the trace of very small particles (in the order of 1/1O00 millimetres). This team found that these very small particles, that can transport the virus, stay in the air for several hours. They have also found that we release these particles not only when we caught or sneeze but also when we talk louder or breath heavily.
With the use of computational fluid dynamics this same team demonstrated that, in a closed class room size space with 10 people, the smallest particles released when one cough will spread throughout the room in just 20 minutes.
This study demonstrates the absolute necessity of good a ventilation system in closed spaces and the use of face masks.
Source: NHK WORLD-JAPAN