Schools need guidelines on improving ventilation in classrooms to reduce risk of Covid spread, scientists say

Improving air quality in schools should be as important as social distancing, doctors from Imperial College London say

Scientists have said guidelines over how to improve ventilation in classrooms are needed (Getty Images)

Schools urgently need guidelines on how to improve ventilation in classrooms to reduce the risk of coronavirus transmission, scientists have said.

Improving air quality in classrooms should be as important as social distancing, wearing masks and washing hands, according to a new paper, written by doctors from Imperial College London and a secondary school headteacher in Middlesex. 

The authors said schools could look towards the airline industry, saying the risk of catching coronavirus on a flight was currently lower than in a classroom. 

Dr Kaveh Asanati, the lead author, said a “multi-layer risk reduction strategy” appears to be “working efficiently” in this industry.

He said this includes testing passengers, using face coverings, and “more importantly, maintaining clean air by circulating a mix of fresh air and recycled air through High-Efficiency Particulate Air (HEPA) filters”. 

David Nabarro, an expert at the World Health Organisation, said last summer air travel was “relatively safe” when it comes to the spread of coronavirus due to modern aircrafts’ air filtration systems.

The International Air Transport Association says most modern jets have HEPA filters, which “have similar performance to those used in hospital operating theatres and industrial clean rooms” and are 99.9 per cent effective at removing viruses, bacteria and funghi. 

While few school buildings have HEPA filtration, school could look at using portable HEPA filtration units, the new paper in the Journal of the Royal Society of Medicine suggested.

One study from a hospital room of coronavirus patients found researchers detected SARS-CoV-2 in aerosols only when air samplers without a HEPA filter on the inlet tube were used, the authors said.

“To keep schools open, there is an urgent need to implement more effective on-site mitigation strategies, with particular attention to ventilation and testing,” Dr Asanati from the National Heart & Lung Institute, Imperial College London, said. 

“In addition, it is essential that teachers and other school staff should be added to the priority list for vaccination,” the paper's leader author said.

The authors called for more research into better ventilation and filtration systems in schools.

They suggested schools keep doors and windows open for as much as possible in the meantime. 

The Department for Health and the Department for Education have been contacted for comment.