London, Jun 17 (PTI) While facial masks reduce the spread of COVID-19, their filtering efficiency is adversely affected by repeated coughing, according to a new study which recommends complete personal protective equipment for healthcare workers including helmets with built-in air filters, and face shields.

Scientists, including Talib Dbouk and Dimitris Drikakis from the University of Nicosia in Cyprus, used computer models to map out the expected flow patterns of small droplets released when a mask-wearing person coughs repeatedly.

Earlier computer simulations the researchers showed that droplets of saliva can travel 18 feet in five seconds when an unmasked person coughs.

In the current study, published in the journal Physics of Fluids, they used an extended model to consider the effect of multiple cycles of coughing on the filtering efficiency of face masks…