Airflow Videos Clearly Show Why Masks with Exhalation Valves Do Not Slow the Spread of COVID-19
Photo: Matthew Staymates/NIST.
Many people wear masks in public to slow the spread of COVID-19, as recommended by the Centers for Disease Control and Prevention (CDC). However, masks with exhalation valves do not slow the spread of the disease, and now, new videos from the National Institute of Standards and Technology (NIST) show why.
The videos, which show airflow patterns through masks with and without exhalation valves, were created by NIST research engineer Matthew Staymates. The videos were published, along with an accompanying research article, in the journal Physics of Fluids.
"When you compare the videos side ...