Choosing Best Mask To Protect You Unlisted Video

(CNN)It's official -- wearing a mask not only protects others from your expelled respiratory droplets, it protects you as well, according to new guidance from the US Centers for Disease Control and Prevention. "The evidence is piling up that masks work in terms of driving down the risk for everyone," said Harvard environmental health researcher Joseph Gardner Allen, who directs the Healthy Buildings program at the Harvard T.H. Chan School of Public Health. But what type of mask will offer you and others the best protection from any novel coronavirus circulating in the air?