Scientists call for more focus on ventilation in stopping Covid

Photo: Brandon Hartley

A group of 39 scientists from all over the world, including the Netherlands, are calling on governments to pay more attention to the role of good ventilation in the battle against coronavirus.

In an article in leading academic journal Science, they suggest that good ventilation can prevent coronavirus being spread by aerosols, or tiny droplets which hang in the air. In the Netherlands, ventilation does not yet have a major role in the official strategy to combat infection.

‘In other countries they have spotted this problem earlier and have been looking at the ventilation options much longer,’ Delft University professor Philomena Bluyssen, one of the authors, told current affairs show Nieuwsuur. ‘The RIVM is one of the few groups that has not yet clearly recognized the importance of the aerosol route,’ Bluyssen said.

The RIVM website states that ventilation helps to limit the transmission of respiratory infections, such as coronavirus. ‘However, the degree to which ventilation (refreshing the air) specifically inhibits the transmission of Covid-19 is unknown,’ the website says.

The World Health Organisation said at the end of April the virus can spread via aerosols over distances of more than a metre in poorly ventilated, busy indoor spaces. The CDC, the US equivalent of the RIVM has also made similar comments.

The Science article is largely signed by physicists and engineers who study the behaviour of droplets. But epidemiologists have doubts about the role of aerosols and ventilation, and say that almost all infections are caused by close contact with an infected person.

Contribution

‘It is not about whether the virus can be spread via aerosols or not,’ Nieuwsuur quoted RIVM director Jaap van Dissel as saying earlier this week. ‘It is about what is the relative contribution made by this route of infection. The measures taken during the first wave focused on preventing transmission via large droplets not aerosols and they proved to be very effective.’

The authors of the article also call for closer cooperation between different academic disciplines to combat the virus. ‘Physicists, technical experts and doctors should work on this together,’ Marcel Loomans, co-author of the article and a civil engineer attached to Eindhoven University, told Nieuwsuur.

The government’s Outbreak Management Team is currently composed of experts with a background in medicine.