The 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 randomised clinical trial to study the efficacy of cloth masks were published today 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.
Workers used the mask on every shift for four consecutive weeks.
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%.
Professor Raina MacIntyre, lead study author and head of UNSW’s School of Public Health and Community Medicine, said the results of the study caution against the use of cloth masks.
Fortunately, the Jacinda government has now removed the requirement for the NZ public to wear them on public transport — it’s hard to fathom why they were mandated in the first place. The products of respiration are carbon dioxide and moisture: recycling a significant amount of CO2 is bad for you and moisture can cause bacteria to thrive. —Eds