BMJ stresses importance of ventilation and air quality in Covid 19 prevention

MORE emphasis needs to be placed on proper ventilation and air quality in the reduction of Covid-19, says the BMJ in a recent editorial.

In the editorial published in its 14 April issue, the journal states that the role and importance of aerosol transmission for SARS-CoV-2 “receives only a cursory mention in some infection control guidelines”.

It points out that wearing masks, keeping your distance, and reducing indoor occupancy will all impede the usual routes of transmission but added emphasis on ventilation is needed as suspended aerosol viral particles can remain airborne for hours and constitute an important route of transmission. This lends added importance to air replacement or air cleaning mechanisms – most specifically opening windows or installing or upgrading heating, ventilation, and air conditioning systems.

The editorial also highlights the importance of mask quality, with both high filtration efficiency and a good fit needed to protect against aerosol infiltration. Tiny airborne particles can find their way around any gaps between mask and face.

Dr Chaand Nagpaul, BMA chair of council, commented: "There has been much discussion by the Government and in the media about ‘hands, face and space’ but much less about the critical importance of fresh air and throughflow in buildings and on public transport. As restrictions are eased, and there is greater mixing between people in enclosed spaces, it is vital that measures are taken to ensure adequate ventilation.

"This should include explicit specifications on ventilation requirements in public and work settings, including in the hospitality sector such as restaurants, bars and pubs. Investment will also be needed to make sure our hospitals, clinics and GP surgeries are ventilated correctly and that our NHS workers and patients are kept as safe as possible.

"A failure to ensure adequate levels of ventilation in indoor areas runs the serious risk of a rebound increase in Covid-19 infections."