Researchers at the American National Institute for Diabetes and Digestive and Kidney Diseases published the results of their new experiment in the journal Proceedings of the National Academy of Sciences.
The main conclusion of the scientists is that microdrops, which occur when a person speaks, can remain in the air in a confined space for more than ten minutes. This may play a role in the distribution of COVID-19. As an experiment, the researchers asked a person in a closed box to repeat the phrase “Stay healthy” for 25 seconds in a loud voice. In this case, the laser, whose rays were directed inside the box, illuminated the droplets arising during the pronunciation, allowing them to be observed and counted. On average, these drops remained in the air for 12 minutes.
Knowing the approximate concentration of coronavirus in saliva, scientists calculated that each minute of loud speech can generate more than 1000 virus-containing drops that can remain in the air if the speaker is in a confined space for eight or more minutes.
Especially dangerous are those who speak out loud: in an earlier work published in the New England Journal of Medicine, the same team of researchers reported that quiet speech produces fewer drops.