Masks also protect the wearer, CDC announces

Wearing a mask protects you, not only those around you, the Centers for Disease Control and Prevention said Tuesday in a significant update to its guidance on face coverings. The agency also noted that numerous studies have demonstrated the benefits of “universal masking policies.”

States the CDC: “Studies demonstrate that cloth mask materials can also reduce wearers’ exposure to infectious droplets through filtration, including filtration of fine droplets and particles less than 10 microns.

“The relative filtration effectiveness of various masks has varied widely across studies, in large part due to variation in experimental design and particle sizes analyzed. 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 .14,17-29

“Some materials (e.g., polypropylene) may enhance filtering effectiveness by generating triboelectric charge (a form of static electricity) that enhances capture of charged particles while others (e.g., silk) may help repel moist droplets and reduce fabric wetting and thus maintain breathability and comfort.”