Droplets generated by speech could be another mode of transmission for the new coronavirus, as a new study finds droplets created when speaking normally can linger in the air for up to 14 minutes, according to The New York Times.
For the study, published in The Proceedings of the National Academy of Sciences journal, researchers used a sheet of laser light to visualize bursts of speech droplets produced when people repeated spoken phrases. Volunteers spoke the word "stay healthy" into a cardboard box through the open end of the box.
Each second of speech produced 2,600 small droplets, the researchers found. And though the droplets start to reduce in size once they leave a person's mouth, they can linger in the air for eight to 14 minutes.
The researchers did not examine speech of people with the virus, but previous research has shown that coronaviruses can be transmitted via respiratory droplets.
Previous research also has shown that coronavirus genetic material can be found in oral fluids of patients, the Times reports. Using studies that pinpointed the exact amount of coronavirus genetic material in patients' oral fluids, researchers of the current study estimated that one minute of loud speaking could create at least 1,000 droplets that contain the virus' genetic material.
"These observations confirm that there is a substantial probability that normal speaking causes airborne virus transmission in confined environments," the researchers wrote.
Researchers said they do not know whether all respiratory droplets carrying coronavirus particles are equally infectious, according to the Times.