London, May 29 (IANS): Researchers, including one of Indian-origin, have found that the lack of adequate ventilation in many indoor environments - from the workplace to the home - increases the risk of airborne transmission of Covid-19.

In a study, published in the City and Environment Interaction journal, experts from the University of Surrey (UK) said that preventing airborne transmission of Covid-19 should be the next front of the battle against the virus.

The World Health Organisation (WHO) had declared the infectious spread of SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) a pandemic after its initial outbreak in Wuhan (China). "These past months, living through the Covid-19 crisis, has been truly unprecedented, but we must turn this global tragedy into an opportunity to better prepare for similar threats," said study author Prashant Kumar, Professor at the University of Surrey.

Improved indoor ventilation is an important step that can be taken to reduce the risk of infection.

"However, more must be done to recognise and understand the airborne transmission of Covid-19 and similar viruses, to minimise the build-up of virus-laden air in places typically containing high densities of people," Kumar added.

According to the researchers, Covid-19, like many viruses, is less than 100 mn in size but expiratory droplets (from people who have coughed or sneezed) contain water, salts and other organic material, along with the virus itself.

Experts have noted that as the water content from the droplets evaporates, the microscopic matter becomes small and light enough to stay suspended in the air and over time the concentration of the virus will build-up, increasing the risk of infection - particularly if the air is stagnant like in many indoor environments.

The study highlights improving building ventilation as a possible route to tackling indoor transmission of Covid-19. "We discuss the need to acknowledge the airborne spread of COVID-19 inside built spaces under eased movement restrictions and the potential steps that can be taken to control it," the study authors wrote.

As of Friday morning, the overall number of global coronavirus cases has topped 5.8 million, while the deaths have increased to more than 360,000, according to the Johns Hopkins University.