Indoor pub drinkers are potentially subjecting themselves to a build-up of infected droplets caused by poor ventilation and people having continuous conversations, often speaking more loudly to be heard over the din of a noisy bar, the academics warn.
Young people in the city are being targeted with a “Don’t kill Granny” message to slow the spread of the virus.
Council chiefs believe young people going out are catching the virus, and although they usually have fewer symptoms than most, they are taking it back home and infecting others in the community.
Aberdeen has also been placed in a fresh lockdown after an outbreak emerged of cases linked to bars.
Julian W Tang, honorary associate professor of respiratory sciences at the University of Leicester, said: “If the air space is poorly ventilated, that air that’s full of virus is not going to go anywhere. It’s going to linger there until the virus dries up and dies over time.”
The most common method of transmission in the UK is probably through conversations, he added.
“In a pub you go there to talk, you go there to do exactly what you need to do to transmit the virus to each other,” he said.
When people laugh, they produce a lot of air, so if someone in a group makes a joke, they are “massively exposed to exhaled air from the laughter around them”.
Asked whether being in a busy pub was similar to being on a plane in terms of risk, he said: “It’s even worse because the aeroplane has very good ventilation. Pubs don’t have very good ventilation.”
He added: “On a plane the danger is from your nearest neighbours because that air is not filtered away quickly enough before you inhale it.
“If you ask me would I rather fly on a plane or go to a pub, I’d rather fly on a plane.”
Pubs in Preston were said to be busy on Friday night despite the new lockdown introduced just hours earlier.
Dr Bharat Pankhania, senior clinical lecturer at the University of Exeter, told the PA news agency that after even one or two drinks people are likely to be less cautious.
“What do you do in the pub? Well you drink, and you have a conversation,” he said.
“But several conversations in a confined space equals incrementally raising your voice to be heard.” Talking more loudly results in the release of more droplets which may be carrying infection.
“So more droplets equals more chance of picking up one droplet that eventually infects the other person.
“It is a perfect storm aided and abetted by alcohol the enabler.”
Dr Pankhania pointed out that pubs attract sociable people who are likely to have met up with many others.
“So they are meeting a lot of people as well as meeting you in the pub. You might be meeting them only, but you don’t know how many they have met,” he said.
Even going to the pub alone is a risk because the virus could be in free circulation, he said.
As for restaurants, he said: “I personally think going into a restaurant indoors where there are lots of tables etc in a confined space, without any new attention to increased ventilation, I would say it’s best you avoid it.”
Additional reporting by PA