This image has been used for illustrative purpose.
Speaking without masks in confined spaces poses the greatest risk of spreading SARS-CoV-2, the virus that causes Covid-19, to others, according to a study.
The study published in the Journal of Internal Medicine describes how different sized respiratory droplets emitted while speaking span a continuum of sizes and can carry different amounts of virus.
Most concerning are intermediate-sized droplets that remain suspended in air for minutes and can be transported over considerable distances by convective air currents.
Since the beginning of the Covid-19 pandemic last year, researchers have argued that Covid-19 was not airborne. However, US Centers for Disease Control and Prevention (CDC), in May, announced that exposure to respiratory fluids -- very fine respiratory droplets and aerosol particles -- present in air and which carry viruses are the main reason for contracting Covid-19 infection.
The Indian government also in an advisory stated that aerosol and droplets are key modes of transmission of the virus.
It added that the aerosol can travel up to ten metres from the infected person, and that aerosol through the infected person can fall within two metres but can be carried to ten metres through the air.
The advisory said, to prevent it people should continue wearing masks, wear double masks or a N95 mask.
Introduction of cross ventilation and exhaust fans will be beneficial in curtailing the spread of the disease, it said.