Neither surgical nor cotton masks are effective at stopping the new coronavirus from spreading when a person coughs, a study suggests. The authors of the paper, published in the journal Annals of Internal Medicine, said more research is needed to determine whether such masks prevent the bug that causes COVID-19 from being passed on.
To test whether certain masks prevent the spread of SARS-CoV-2, the virus that causes COVID-19 (not to be confused with the SARS virus), researchers asked four COVID-19 patients in South Korea to enter negative-pressure isolation rooms. The volunteers, aged between 35 and 82, were asked to cough four times each on to five separate Petri dishes positioned 20 cm (7.9 inches) from their mouths. The first time they wore no mask, then a surgical mask, followed by a cotton mask, and again no mask. The disposable surgical masks used in the study measured 180 mm × 90 mm and had three layers, while reusable cotton masks measured 160 mm × 135 mm and were comprised of two layers