Study using actual #SARSCoV2, showing masks both prevent transmission and also protect uninfected people from inhaling the virus. Both cotton and surgical masks blocked 50% of transmission, and even a cotton mask was able to reduce uptake by 20-40%.
(As usual) elegant work by Yoshi Kawaoka team, using a model for aerosol transmission to study use of facemasks
“We found that cotton masks, surgical masks, and N95 masks all have a protective effect with respect to the trans- mission of infective droplets/aerosols of #SARSCoV2 and that the protective efficiency was higher when masks were worn by a virus spreader.”
This is much more recent, but appears incontrovertible