Calls for air quality to be regulated like food and water to prevent the next pandemic

The group of 39 researchers from 14 countries have called for a “paradigm shift” in combating airborne viruses such as Covid-19, especially greater recognition about the importance of improving indoor ventilation systems.

“Air can contain viruses just as water and surfaces do,” said co-author of the report Shelly Miller from the University of Colorado Boulder.

“We need to understand that it’s a problem and that we need to have, in our toolkit, approaches to mitigating risk and reducing the possible exposures that could happen from build-up of viruses in indoor air.”

The researchers have called on the World Health Organization and other governing bodies to extend their indoor air quality guidelines to include airborne pathogens and to recognise the need to control hazards of airborne transmission of respiratory infections.

They said that such a shift in standards should be similar in scale to the 19th century transformation that took place when cities started organising clean water supplies and centralised sewage systems.

“Let’s now not waste time until the next pandemic,” said co-author Jose-Luis Jimenez. “We need a societal effort. When we design a building, we shouldn’t just put in the minimum amount of ventilation that’s possible, but instead we should keep ongoing respiratory diseases, such as the flu, and future pandemics in mind.”

The long-standing misunderstanding of the importance of airborne transmission of pathogens has left a large gap of information in how to best construct and manage building ventilation systems to mitigate the spread of disease, the scientists said.

Instead, buildings have focused on temperature, odour control, energy use and perceived air quality. So while there are safety guidelines for chemicals such as carbon monoxide, there are currently no guidelines, globally or in the US, that regulate or provide standards for mitigating bacteria or viruses in indoor air resulting from human activities.

“Air in buildings is shared air – it’s not a private good, it’s a public good. And we need to start treating it like that,” said Miller.

Lead author Lidia Morawska also said there needs to be a shift away from the perception that we cannot afford the cost of control, noting that the global monthly cost from Covid-19 had been conservatively estimated as $1tr (£710bn) and the cost of influenza in the US alone exceeded $11.2bn annually.

While detailed economic analysis has yet to be done, estimates suggest necessary investments in building systems may be less than 1 per cent of the construction cost of a typical building.

Ventilation systems should also be demand-controlled to adjust for different room occupancies, and differing activities and breathing rates, such as exercising in a gym versus sitting in a movie theatre, according to Morawska.

For spaces that cannot improve ventilation to an appropriate level for the use of the space, she said air filtration and disinfection will be needed.

The researchers also call for national comprehensive indoor air quality standards to be developed and enforced by all countries, and for this information to be available to the public.