Droplets generated by people talking while infected with the novel coronavirus could linger in the air for several minutes, potentially triggering new infections, according to researchers.
A new estimate by researchers at the National Institutes of Health and the University of Pennsylvania finds that talking loudly for one minute in a confined space could generate at least 1,000 "speech droplets" containing Covid-19 particles.
Those droplets could remain in the air for more than eight minutes, according to the study published Tuesday in the open-access journal PNAS.
According to other research, that could be enough to generate an infection if someone inhaled them.
To conduct the experiment, the researchers had a person repeat the phrase "stay healthy" into a port connected to an enclosure, simulating a closed, stagnant air environment.
The phrase was chosen, the researchers said, because the "th" in the word "healthy" efficiently generates speech droplets.
The researchers then used a laser to watch what happened to the person's speech droplets after exiting the mouth.
Large droplets shrunk as they partially evaporated and hung in the air.
Based upon the researchers' observations, they concluded, in real life such particles could be inhaled by others and cause new coronavirus infections.