Talking can spread more than 1,000 COVID-19 particles per minute, study finds
It’s known that the new coronavirus can spread by droplets released from coughs and sneezes, but new research says those coming from speech can be just as harmful in transmitting the disease, even from people who aren’t showing symptoms.
The study suggests that normal speaking in closed environments such as homes and restaurants can contribute “substantially” to the spread of COVID-19 — the disease the coronavirus causes — according to the researchers.
The paper was published Wednesday in the journal Proceedings of the National Academy of Sciences.
“Our laser light scattering method not only provides real-time visual evidence for speech droplet emission, but also assesses their airborne lifetime,” the researchers said in their study. “This direct visualization demonstrates how normal speech generates airborne droplets that can remain suspended for tens of minutes or longer and are eminently capable of transmitting disease in confined spaces.”
To measure the size and quantity of speech-related droplets, the researchers had people repeat the phrase “stay healthy” in a loud voice and then used a “highly sensitive” sheet of laser light to scan the droplets in the air.
The results showed that about 2,600 droplets are expelled from a person’s mouth per second, the study said.
What’s more, the researchers said one minute of loud speaking could generate more than 1,000 virus-containing droplets that could float in the air for 8 minutes or longer.
Experts say mucousy fluid in the lungs can escape from thin blood vessels and fly out when someone exhales, according to Live Science. The same happens when people talk and their vocal cords vibrate to create different sounds.
Some people also spit when they speak.
“These observations confirm that there is a substantial probability that normal speaking causes airborne virus transmission in confined environments,” the study said.
However, researchers aren’t sure if particles coming from talking and breathing infect more people than larger droplets from coughs and sneezes, Live Science reported.
The Centers for Disease Control and Prevention says that COVID-19 spreads primarily through coughs and sneezes, noting “these droplets can land in the mouths or noses of people who are nearby or possibly be inhaled into the lungs.”
The agency also says that spread is more likely to happen when within six feet of another person.
One study revealed that certain words can prove more harmful in spreading pathogens.
The “E” sound in the word “need” expels more droplets than the “A” sound in the word “saw,” a paper published in January in the journal PLOS ONE said.
Can a mask help?
If a mask is not perfectly fitted to your face, like the N95 respirators used by health professionals, then you are not provided “complete protection from germs and other contaminants because of the loose fit between the surface of the face mask and your face,” the U.S. Food and Drug Administration says.
If worn properly, however, a do-it-yourself mask can “help block large-particle droplets, splashes, sprays or splatter that may contain germs,” according to the agency.
Simply put, wearing a mask doesn’t protect you from infection, but helps curb the spread of the coronavirus, especially by asymptomatic individuals.
This story was originally published May 13, 2020 at 5:16 PM with the headline "Talking can spread more than 1,000 COVID-19 particles per minute, study finds."
