RT @jeremyphoward: The key insight is that most discussions assume that the purpose of the mask is to protect the wearer, since this is what all doctors learn about in medical school. But actually masks work *far* better at blocking the infection at the source. This is called “source control”

The key insight is that most discussions assume that the purpose of the mask is to protect the wearer, since this is what all doctors learn about in medical school. But actually masks work *far* better at blocking the infection at the source. This is called "source control"

— Jeremy #Masks4All Howard (@jeremyphoward) April 13, 2020