Cover your mouth — when you talk?
That’s the suggestion by some doctors, at least during the coronavirus pandemic. Alarming new research claims that chatting is more likely to spread the virus that causes COVID-19 than coughing or sneezing. Conversations with friends, family, colleagues or other members of the community pose the greatest danger, researchers say. They suggest that masks should be worn in offices, shops, vehicles and other confined spaces. This can reduce risk of infection more than eightfold — if both individuals are covered.
Tiny aerosols of the virus emitted when speaking linger in the air for longer than larger droplets from a cough or sneeze. Researchers say their review shows “solid evidence” that talking is the “dominating” source for transmission.
“We have all seen some spit droplets flying when people talk, but there are thousands more, too small to be seen by the naked eye,” says senior author Dr. Adriaan Bax, a chemical physicist at the National Institutes of Health, Bethesda, Maryland. “When the water evaporates from such speech generated, potentially virus rich droplets, they float in the air for minutes, like smoke, thus putting others at risk.” Catching Covid depends on a range of factors including how much of the aerosol is breathed in, whether it is indoors, levels of ventilation and the distance between the people involved.
“Unmasked speech in confined spaces represents the activity that poses the greatest risk to others. Since eating and drinking often take place indoors and typically involve loud speaking, it should come as no surprise that bars and restaurants have become the epicenter of multiple recent superspreading events,” the review reads. “Next to vaccination, mitigation strategies should emphasize the use of face masks when speaking and ensuring adequate ventilation to flush out long-lived aerosols that might otherwise accumulate in closed environments and enhance the risk of more serious LRT infections.”