Three out of 10 Los Angeles County residents and nearly half of adults in the U.S. don’t wear protective face masks when they are in close contact with people who live outside their households, according to findings of an ongoing study by researchers at USC.

The USC Dornsife Understanding Coronavirus in America Study found that 67 percent of Los Angeles County residents are likely to wear face masks when in contact with people from other households, and that 63 percent wear face masks while exercising outside, compared with the national average of 22 percent.

Los Angeles County residents were also less likely to come into contact with people outside of their households, according to researchers.

The study found that 83 percent of U.S. adults view wearing a mask as an effective way to stay safe from COVID-19, but that two-thirds of Americans reported being less than six feet from people outside their household in early December and that only 51 percent said they always or mostly wore a mask while doing so, researchers said.

The study also found that:

–White people were the least likely to consistently—always or most of the time—wear a mask (46 percent) while in close contact with people from other households, compared to 67 percent of Blacks, 63 percent of Latinos and 65 percent of people of other races;

–57 percent of people in urban areas reported wearing a mask always or most of the time while close to people outside their household compared with 52 percent of people in suburban locales and 42 percent of people in rural areas;

–Four in 10 Americans visited someone else’s home, with just 21 percent of them wearing a mask most or all of the time they were together;

–14 percent of Americans gathered in groups of 10 or more people, with only 46 percent wearing a mask most or all of the time they were together;

–81 percent of people shopped for groceries in early December, and 90 percent of them wore a mask.

“These findings indicate a need to redouble efforts to convey consistent messages about the overall importance of wearing masks, but more than that — where and when to wear them,” said Arie Kapteyn, director of the USC Dornsife Center for Economic and Social Research.