Face coverings offer modest source control for COVID-19, study findsCloth or surgical facial masks reduced SARS-CoV-2 RNA 77% in exhaled coarse aerosol particles and 48% in exhaled fine aerosol particles, offering "modest" source control, according to a Clinical Infectious Diseases study yesterday.
The study also found that the Alpha (B117) COVID-19 variant contained 43-fold more fine-aerosol viral RNA compared with earlier virus strains.The study used breath samples collected using a Gesundheit II machine, which was developed by senior study author Donald Milton, MD, PhD, of the University of Maryland.
The machine measures viral shedding in exhaled breaths during talking and other vocalizations. "Source control" refers to covering the