'Burnt toast' argument for keeping windows open to tackle COVID

A virology expert has said people should ventilate indoor areas to stop COVID transmission by acting like they have burnt their toast.

Dr Julian Tang, consultant virologist at the Leicester Royal Infirmary and honorary associate professor in the Department of Respiratory Sciences, emphasised the importance of indoor ventilation – especially when restaurants and pubs open up to customers for indoor service.

He told Sky News: “If you think about it, if you burn your toast in the kitchen, if you open the windows and doors, the back door, it clears very quickly.

“So you keep the windows open even halfway most of the time, then you can improve that ventilation rate in the indoor area and that reduces the overall airborne concentration that you can actually then reduce the risk of transmission from.

“So I think this is a really kind of addition to what people are doing, the social distancing, the masking.

“But if you’re indoors having a drink or eating, you can’t mask, you can’t maintain social distance, so the ventilation becomes much more important precautionarily.”

Watch: Pubs and hairdressers open as lockdown restrictions ease

Tang also said the “garlic-breath distance” can indicate whether someone is close enough to another person for coronavirus transmission to occur.

He added: “The way this virus transmits is really through conversational distance, within one metre.

“When you’re talking to a friend or sharing the same air as you’re listening to your friend talking, we call it the garlic-breath distance.

“So if you can smell your friend’s lunch you’re inhaling some of that air as well as any virus that’s inhaled with it.

“And this is why we say that masking is fine, social distancing is fine, but the indoor airborne environment needs to be improved and that can be done with ventilation.”

Tang highlighted that coronavirus could become a seasonal virus, and said that ventilation was “a kind of backup to everything else we’re doing to maintain that degree of safety that we’re all looking for”.

Many businesses in England – including pubs and restaurants – opened up their doors on Monday for the first time in months, as part of Boris Johnson’s roadmap out of lockdown.

However, customers are only allowed to sit outside in groups, with indoor dining still prohibited until May.

Fears were raised after crowds of people were seen gathering in city centres, including London, with little social distancing.

Westminster City Council said it was aware of “isolated incidents of crowding” and that it was working with businesses to ensure they are operating “responsibly and safely in line with guidance”.

Lawrence Young, a virologist and professor of molecular oncology at Warwick Medical School, described “a joyous day” but warned people should remain cautious.

He said: “The current reduction in cases and hospitalisations is not only due to the success of the vaccine rollout but also the impact of lockdown in preventing virus spread.

“So while taking the opportunity to enjoy shopping and outside hospitality, we must remain cautious – the virus is still out there and very infectious."

Watch: How England will leave lockdown