Updated evidence suggests masks may reduce risk for SARS-CoV-2 infection in community and health care settings

The final and major update to a rapid, living review of published evidence suggests that masks may be associated with a small reduction in risk for COVID-19 infection in community settings versus no mask use and both surgical masks and N95 respirators may be associated with similar infection risk in routine patient care settings. However, a beneficial effect of N95 respirators could not be ruled out in the health care setting. The review is published in Annals of Internal Medicine.

Face Shape Influences Mask Fit, Suggests Problems with Double Masking Against COVID-19

In Physics of Fluids, researchers use principal component analysis along with fluid dynamics simulation models to show the crucial importance of proper fit for all types of masks and how face shape influences the most ideal fit. They modeled a moderate cough jet from a mouth of an adult male wearing a cloth mask over the nose and mouth with elastic bands wrapped around the ears and calculated the maximum volume flow rates through the front of mask and peripheral gaps at different material porosity levels.