The experimentation proves the thesis already emerged in a previous work. Researchers from the National Institute of Diabetes and Digestive and Kidney Diseases and the University of Pennsylvania have used a green laser highly sensitive to track the ‘droplets’, the oral fluid droplets: in the study a person who speaks loudly emits thousands per second, to be precise 2,600. The team asked a volunteer to repeatedly say the phrase ‘Stay healthy’ in a box for 25 seconds. The words were chosen on purpose, because the tone in which they are said is normally high. In a closed and non-aerated environment, simulated using the box, the droplets remain suspended for 8 to 14 minutes before degrading.
“These results – explain the researchers – confirm that there is one substantial probability that a normal conversation can cause the transmission of the virus in closed spaces. Speaking, the issue of doplets that can remain is generated suspended in the air for about 10 minutes or even more and who are capable of transmitting the disease indoors ”if they come, for example, from an asymptomatic person who does not know he has Covid. Based on these conclusions, the study highlighted the importance of keep the recommended distances and, above all, to wear the mask.