(ALBANY, N.Y.) — New York City Mayor Bill De Blasio asked New Yorkers to wear a face covering when they go outside and will be near other people.
He cited research showing asymptomatic people could be spreading the virus without realizing it.
“When you put on that face covering, you’re protecting everyone else,” he said.
The mayor said it could be a scarf or a bandanna or anything homemade, but it should not be a surgical mask needed by medical workers.
A recent study by researchers in Singapore became the latest to estimate that somewhere around 10% of new infections may be sparked by people who carry the virus but have not yet suffered symptoms.
A bandanna might not prevent someone from coming into contact with the virus, but it could help a person who has it not give it to others when the sneeze, cough or breathe.
The mayor of Los Angeles also told everyone in the city to start wearing masks on Wednesday.