One-liner: Speaking in indoor spaces without wearing a mask poses the greatest risk of spreading SARS-CoV-2, the virus that causes Covid, to others, a study has found.

The research, published in the Journal of Internal Medicine, describes how different sized respiratory droplets emitted while speaking have a range of sizes, and can carry different amounts of virus

Droplets in air: According to the researchers of the study, the most concerning droplets are those of intermediate size that remain suspended in air for minutes.

These droplets can be transported over considerable distances by air currents

"We've all seen some spit droplets flying when people talk but there are thousands more, too small to be seen by the naked eye.” – Adriaan Bax, of the US National Institute of Diabetes and Digestive and Kidney Diseases

"When the water evaporates from such speech-generated, potentially virus-rich droplets, they float in the air for minutes, like smoke, thus putting others at risk."

The researchers reviewed many studies on the physical and medical aspects of aerosol droplets in virus transmission that have appeared since the start of the Covid pandemic