Cloth masks act as “source control” to block virus particles exhaled by the wearer and provide “filtration for personal protection” by blocking incoming infectious droplets from others, the CDC said in its new guidance.
In several scenarios, when officials told people to wear masks, infections and deaths fell significantly, the CDC pointed out.
“Adopting universal masking policies can help avert future lockdowns, especially if combined with other non-pharmaceutical interventions such as social distancing, hand hygiene, and adequate ventilation,” the CDC said.
The agency cited an economic analysis that found a 15% increase in universal masking could prevent losses of up to $1 trillion.
“The relationship between source control and personal protection is likely complementary and possibly synergistic, so that individual benefit increases with increasing community mask use,” the CDC said.
Some cloth masks are nearly as good as surgical masks at blocking droplets, the CDC said. Polypropylene may generate a static charge that captures particles, the CDC said, while silk might repel moist droplets and be more comfortable.
“Multiple layers of cloth with higher thread counts have demonstrated superior performance compared to single layers of cloth with lower thread counts, in some cases filtering nearly 50% of fine particles less than 1 micron,” the CDC said.
“It’s a two-way street,” Dr. Anthony Fauci, National Institute of Allergy and Infectious Diseases director, said Tuesday on MSNBC. “You protect others, their mask protects you, and your mask also protects you.”