Science Daily
“The widespread use of cloth masks by healthcare workers may actually put them at increased risk of respiratory illness and viral infections and their global use should be discouraged, according to a UNSW study.
The results of the first randomized clinical trial (RCT) to study the efficacy of cloth masks were published in the journal BMJ Open.
The trial saw 1607 hospital healthcare workers across 14 hospitals in the Vietnamese capital, Hanoi, split into three groups: those wearing medical masks, those wearing cloth masks and a control group based on usual practice, which included mask wearing.
“….The study found respiratory infection was much higher among healthcare workers wearing cloth masks.
The penetration of cloth masks by particles was almost 97% compared to medical masks with 44%.”