Cotton masks best at slowing Covid spread, says US study

GAITHERSBURG – Researchers in the US have discovered that masks made of cotton are about a third more effective at slowing the spread of Covid-19 than those made of polyester. The researchers found cotton fabrics become better filters when exposed to humid conditions, in contrast to synthetic fabrics. A study team tested fabrics under conditions that mimic the humidity of a person’s breath in order to obtain measurements that more accurately reflect how the fabrics perform when “worn by a living, breathing person.”