“We do know that SARS-CoV-2, the virus that causes Covid, can remain viable, can remain infectious, in these very small droplets so that raises the possibility and indeed the likelihood that Covid can be transmitted through these small particles that can travel through the air.”
Recent polling by Ipsos MORI indicates that three in ten British adults feel “very concerned” about their personal risk from the virus.
Professor Barlcay’s comments come ahead of the week in which the government may extend the mandatory use of facemasks, which are currently compulsory only on public transport.
Face coverings were made compulsory in shops in Scotland from last Friday.
Professor Barclay said: “The use of face masks is really about protecting other people from you in case you’re infected, we do think this virus is breathed out in droplets, whether or not these droplets are large or small it’s quite likely that a face mask will remove some of them from your breath.”
She also emphasised the importance of ventilation that replenished the air in a room, rather than air conditioning systems which re-circulate the air.
When asked about the resumption of recreational activities such as gyms and choir practices, Prof Barclay added: “There have been a number of outbreaks associated with choirs, for example, and it’s quite possible that we generate more of these small droplets when we talk loudly or sing, or perhaps when we’re exercising.
Prof Linda Bauld, an expert in public health at the University of Edinburgh, said the evidence on the importance of face coverings in public places had improved throughout the pandemic.
“A number of new studies and systematic reviews have persuaded most researchers and public health officials that they should be worn, including those who were sceptical a few months ago,” she said.
“Growing evidence on potential airborne transmission of the virus adds to the case for face coverings.”