The potential for Covid-19 to spread through airborne transmission by lingering in the air is being underplayed by the World Health Organization, a group of scientists have said.

In an open letter due to be published this week, 239 scientists from 32 countries call for greater acknowledgement of the role of airborne spread of Covid-19 and the need for governments to implement control measures.

WHO guidance states that the virus is transmitted primarily between people through respiratory droplets and contact. Aerosol transmission involves much smaller particles that can remain in the air for long periods of time and can be transmitted…