An academic is urging people spending time indoors to think about the benefits of good ventilation when trying to limit the spread of Covid-19.

Dr John Campbell, whose lectures have been watched more than 50 million times on YouTube in the last few months, says businesses need to do more to keep people safe.

Dr Campbell, who is based in Lowry Hill in Carlisle, says most are abiding by the rules on wearing face coverings, but more needs to be done elsewhere.

“What is not happening anywhere enough is ventilation,” he explained. “The message about masks indoors, about washing hands and about social distancing is fine, but the message hasn’t got out there about ventilation. Areas with a breeze blowing through dilute the viral load.”

In other words, the concentration of coronavirus particles in the air is lower when there is a breeze to dilute it.

“We need ventilation in restaurants, pubs and shops,” continued Dr Campbell, who is a retired nurse teacher and A&E nurse who now spends his time studying and educating people on all forms of healthcare.

He asked his YouTube followers to come up with catchphrases to promote the need for ventilation, such as ‘to ventilate or ventilator – that is the question’.

The warning comes as the Prime Minister unveiled new coronavirus restrictions that will come into force on Monday aimed to tackle the rising number of cases.

The law on the legal limit on social gatherings will be reduced from 30 to six. It will apply both indoors and outdoors – including private homes, as well as parks, pubs and restaurants.

Gatherings of more than six will be allowed where the household or support bubble is larger than six, or where the gathering is for work or education. Exemptions will apply for weddings, funerals and Covid-secure organised team sports, with a full list yet to be published.

The Government is working towards mass antigen testing allowing those who get a negative result to mix without the need for social distancing, such as at sports events.

The PM announced that it was working towards mass anti-gen testing that would identify individuals who do not have coronavirus.

These “pregnancy style” tests would allow such people to attend things such as live sporting events without the need for social distancing.

However, the plan for a phased return of fans in October is now “under review”, the PM said.

The new rules come after the number of daily positive Covid-19 cases in the UK rose to almost 3,000 - figures not seen since May.

Ministers hope the change to the law will make it easier for the police to identify and disperse illegal gatherings. Failure to comply could result in a £100 fine, which will double on each repeat offence up to £3,200.