Modern society is inhabited by beings who spend most of their time indoors, but the air we breathe inside buildings is not regulated to the same extent as the food we eat and the water we drink.
A group of 39 researchers from 14 countries believe this measure is indispensable to reduce disease transmission and prevent the next pandemic viruses.
In an article published today in Science, the pool of scientists is calling for a real "paradigm shift" in the fight against airborne pathogens such as SARS-CoV-2, the virus that causes COVID-19. They demand universal recognition of prevention through indoor ventilation systems. A main way, they reiterate, against respiratory infections, old and new viruses.
Air contains viruses, just like water and surfaces
“We need to understand that this is a serious problem,” says the co-author Shelly Miller, professor of mechanical and environmental engineering. "We need to adopt approaches to mitigate the risk and reduce the possible exposures that could occur from the accumulation of old and new viruses in indoor air."
The document comes less than two weeks after WHO acknowledged on its website that transmission of SARS-CoV-2 occurs predominantly in the air (I talked about it months ago reading several studies on the subject). Researchers, who have long raised the alarm, now call on WHO and other governing bodies to extend its guidelines to include airborne pathogens, and to recognize the need to control the risks of airborne transmission of infections. respiratory.
It is a huge change, what we need. Same as when we started providing clean water and centralized sewage systems in the 19th century. For all these decades we have neglected the air, a serious error, even of scientific perception.
Controlling the air against new viruses: a natural evolution of our societies
When Londoners died of cholera in 1850, scientists of the time thought the disease came from the air. The English doctor John Snow (yes, that's what it was called), however, he discovered that it was the microorganisms in the contaminated water that brought the infection. Likewise, the Hungarian doctor Ignaz Semmelweis showed that washing hands before childbirth significantly reduces postpartum infections. Discoveries that met with resistance in those times, but in the end made it possible to understand that (in those cases) the water and the hands, not the air, were the vectors of the disease.
We have to get to 1945 to see articles denouncing the incredible carelessness of the air to prevent new viruses. The scientist William Wells published a scientific article complaining that while investments were made in water disinfection and food hygiene, nothing was done about air quality. His research on measles and tuberculosis (caused by airborne pathogens) has stimulated the world, but it has not convinced him to act.
Now that research on SARS-CoV-2 has finally revealed that many respiratory diseases can be transmitted through the air, researchers say it's already too late to take action.
We have to do it now, because we had to do it before.
Now let's not waste time until the next pandemic. We need a social effort. When designing a building, we should not only put in the least amount of ventilation possible, but should instead keep in mind ongoing respiratory diseases, such as the flu, possible new viruses and future pandemics.Jose-Luis Jimenez, co-author of the study and professor of chemistry.
The long-standing misunderstanding about the importance of airborne transmission of new viruses and pathogens has left a large information gap. We do not know, in fact, how to best construct and manage the ventilation systems of buildings to mitigate the spread of the disease. Only some manufacturing, research and medical facilities are able to do this. Buildings focused on temperature, odor control, energy use. There are safety guidelines for chemicals such as carbon monoxide, but there are no guidelines or standards for mitigating bacteria or viruses in indoor air.
Air control against new viruses: it must be done at any cost. Because it is not a cost.
“The air in buildings is shared air. It is not a private good, it is a public good. And we have to start treating it this way, ”Miller said.
Lidia Morawska she is another co-author of the paper and directs the Queensland University of Technology International Laboratory for Air Quality and Health. He says we need to move away from the idea that we can't afford the cost of air control. The global monthly cost of Covid, he notes, is much higher than what one would face to prevent old and new viruses with air quality.
Estimates suggest that the required investment in construction systems could be less than 1% of the construction cost of a typical building.
What to do in practice?
According to the researchers, ventilation systems should also be controlled on demand to adapt to different uses of an environment, different activities and respiratory rates. For example, the ventilation and sanitation of a gym would be different from that of a cinema, just as the breathing of those who exercise and those who sit is different.
Again: buildings consume more than a third of energy globally, largely by heating or cooling the outside air. It would therefore be useful to design a “pandemic mode”, which would allow buildings to use more energy only when needed.
There is also a need for all countries to develop and implement comprehensive national indoor air quality (IAQ) standards and for this information to be publicly available to tackle old and new viruses.