Time to re-think indoor air quality?

Antoine Flahault - From Cholera to COVID-19: time to re-think indoor air quality?

With this pandemic we are experiencing a transition period which may lead to dramatic changes in the way we are conceiving indoor spaces, building, housing and public transportation. In 1854, during an outbreak of cholera in London, John Snow, a British physician, realized that cholera was transmitted through contaminated water drunk by inhabitants from a pump which tapped polluted water directly from the Thames. When he obtained to switch off the pump, he cut any further transmissions.

It took about 50 more years to see his discovery recognized and to see decision makers undertaking major infrastructure investments aimed to separating drink water from waste water, and to purifying or filtrating waste water to make it drinkable.

From the recent experience of COVID-19 pandemic, we observed that more than 99% of contaminations do occur in close poorly ventilated and crowded settings where people spend hours. Epidemiologists obtained to temporarly lockdown some of these places, succeeding to dramatically cut transmissions. However, as Londoners needed to drink water to survive, inhabitants of the planet need also to convene in indoor settings to live, work or move.

Lockdowns are not sustainable option to fight against coronavirus, and as many other pathogens, it will continue to spread through aerosols in poorly ventilated contaminated indoor settings. We will not escape considering large investments to dramatically improve indoor air quality, to make it as safe, in terms of microbiological risk, as outdoor air.

We can expect from indoor air quality improvement to cut up to 99% of transmissions of any airborne pathogens, including coronavirus with any of its variants, influenza viruses, tuberculosis and many others.

Antoine Flahault, PhD in biomathematics, is professor of public health at Faculty of Medicine, University of Geneva, where he is the founding director of the Institute of Global Health, at Campus Biotech (since Jan. 2014). Pr Flahault will join us for an eye-opening talk about indoor air quality.