ATLANTA — For the first time, the Centers for Disease Control and Prevention is acknowledging that face masks can help prevent the spread of the coronavirus for both the people wearing them as well as those in close proximity. 

The CDC previously only said masks could help the person wearing it from infecting others — also known as “source control.” It has noted that people who are presymptomatic or asymptomatic are estimated to account for more than half of transmissions.

But on Tuesday, the public health agency updated its guidance to say that masks can also help the wearer from inhaling infectious droplets.

“Multi-layer cloth masks can both block up to 50-70% of these fine droplets and particles and limit the forward spread of those that are not captured,” the CDC said, adding that cloth masks in some studies performed on par with surgical masks as barriers for source control.

It’s difficult to put a number on just how effective cloth masks can be because there are various designs. The CDC, however, noted that multiple layers of cloth with higher thread counts have outperformed single layers with lower thread counts.                

But the CDC guidance’s larger point is that mutual mask-wearing is sure to drive down infection rates. 

As of early Wednesday afternoon, the U.S. had recorded nearly 10.3 million COVID-19 cases and 240,000 related deaths. The country has entered its third — and worst — wave of the pandemic, with eight straight days of more than 100,000 new daily cases. On Tuesday, the U.S. set a new single-day record with 136,325 cases, according to data compiled by Johns Hopkins University.

The CDC cited a number of cases supporting its claim, among them two Missouri hair stylists who had COVID-19 and interacted with 139 clients over eight days. The stylists and their customers all wore masks, and there were no additional known infections.

The agency also pointed to seven studies that demonstrated that “following directives from organizational and political leadership for universal masking, new infections fell significantly.”

The CDC also made an economic case for masks, saying an analysis using U.S. data found that “increasing universal masking by 15% could prevent the need for lockdowns and reduce associated losses of up to $1 trillion or about 5% of gross domestic product.”