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 call for universal recognition of prevention through indoor ventilation systems. A main path, they reiterate, against respiratory infections, old and new viruses.
The air contains viruses, just like water and surfaces
“We need to understand that this is a serious problem,” the co-author says Shelly Miller, professor of mechanical and environmental engineering. “We need to take approaches to mitigate risk and reduce possible exposures that could occur from the accumulation of old and new viruses in indoor air.”
The document comes less than two weeks after the WHO acknowledged on its website that transmission of SARS-CoV-2 occurs predominantly in the air (I talked about it months ago reading various studies on the topic). The researchers, who have long raised the alarm, are now calling on the 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's 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 left out the air, a serious error, even of scientific perception.
Controlling the air against new viruses: a natural evolution of our societies
When Londoners were dying of cholera in the 1850s, scientists of the time thought the disease came from the air. The English doctor John Snow (yes, that's exactly what it was called) discovered, however, that it was the microorganisms in the contaminated water that caused the infection. Likewise, the Hungarian doctor Ignaz Semmelweis showed that washing your hands before giving birth significantly reduces postpartum infections. Discoveries that met with resistance at the time, but ultimately made it possible to understand that (in those cases) water and hands, not air, were the vectors of the disease.
We have to go back to 1945 to see articles denouncing the incredible carelessness in the air to prevent new viruses. The scientist William Wells published a scientific article complaining that while investments were being made in water disinfection and food hygiene, nothing was being done for air quality. His research on measles and tuberculosis (caused by airborne pathogens) energized the world, but did not convince him to act.
Now that research on SARS-CoV-2 has finally brought to light that many respiratory diseases can be transmitted through the air, researchers say it is already late to act.
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 minimum amount of ventilation possible, but should instead keep in mind ongoing respiratory diseases, such as influenza, possible new viruses, and future pandemics.Jose-Luis Jimenez, co-author of the study and professor of chemistry.
Long-standing misunderstanding of the importance of airborne transmission of new viruses and pathogens has left a large information gap. In fact, we do not know how to best construct and manage building ventilation systems to mitigate the spread of the disease. Only some manufacturing, research and medical facilities are capable of doing this. Buildings focused on temperature, odor control, energy use. There are safety guidelines for chemicals like carbon monoxide, but there are no guidelines or standards for mitigating bacteria or viruses in indoor air.
Control of the air against new viruses: it must be done at all costs. Because it's not a cost.
“The air in buildings is shared air. It is not a private good, it is a public good. And we need to start treating it that way,” Miller said.
Lydia Morawska is another co-author of the paper and directs the International Laboratory for Air Quality and Health at the Queensland University of Technology. She 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, she notes, is much higher than what would be faced to prevent old and new viruses with air quality.
Estimates suggest that the necessary investments in building 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 from the heating or cooling of outside air. It would therefore be useful to design a “pandemic mode”, which would allow buildings to use more energy only when necessary.
We also need all countries to develop and implement comprehensive national indoor air quality (IAQ) standards and for this information to be available to the public to combat old and new viruses.