While health officials around the globe recommend wearing face masks to prevent the spread of COVID-19, a new study reveals that frequent coughing into a mask can greatly reduce its efficiency. The study, published in the journal Physics of Fluids, used detailed computer models to show that fluid leaked out the sides of the masks when the wearer repeatedly coughed.
According to Ladders, scientists already have determined that when you cough without a mask, that saliva droplets can travel up to 18 feet in 5 seconds. The authors of the new study found that the droplets can escape and travel up to one meter when a person coughs while wearing a mask.
“Although masks will reduce droplet transmission, we should not ignore that several droplets will be transmitted away from the mask. The use of a mask will not provide complete prevention from airborne droplet transmission.” the authors said, according to Ladders. “Therefore, social distancing remains essential when facing a pandemic.”
According to WTKR, researchers at Wake Forest Baptist Health found that the fabric of homemade masks also contributed to their effectiveness. Dr. Scott Segal, chair of anesthesiology at Wake Forest, said that the best homemade masks were made of two layers of high-quality, heavyweight fabric with a high thread count. These actually filtered more particles — 79%– than surgical masks which only filter 62-65%.