A novel coronavirus can be suspended for more than 10 minutes in the enclosed space, a new study shows, which highlights the importance of voice transmission in the dissemination of new coronaviruses.
A team of researchers at the National Institute of diabetes, digestive and kidney disease (NIDDK) asked people to repeat the phrase “stay healthy” loudly in a closed box for 25 seconds, AFP reported. The laser that is projected into the box illuminates the droplets so that they can be seen and counted.
The study is published in the latest issue of the proceedings of the National Academy of Sciences (PNAs). Studies have shown that saliva droplets produced by speech stay in the air for an average of 12 minutes.
Given the known concentration of the new coronavirus in saliva, scientists estimate that speaking loudly every minute can produce more than 1000 droplets containing the virus, which can stay in a closed space for 8 minutes or more.
“This direct visualization shows how normal speech produces droplets in the air that can be suspended for a few minutes or longer and are very capable of spreading the virus in a limited space,” the researchers concluded
In another study, published in the New England Journal of medicine in April, the team found that the smaller the voice, the less droplets it produced.
If the infectivity level of the new coronavirus can be confirmed by voice, it can scientifically promote many countries to recommend people to wear masks and help explain the rapid spread of the virus.