A group of researchers asks to improve ventilation systems and the design of buildings
“The air in the buildings is shared, it is a public good,” they explain.
Humans of the 21st century we spend most of our lives indoorsBut the quality of the air that is breathed between four walls is not as well regulated, as it is with the food or the water we ingest. It is the paradox that 39 researchers from 14 countries expose in the journal Science, in a paper in which the Spanish aerosol expert from the University of Colorado, José Luis Jiménez, has participated. His conclusion is that you have to start regulating indoor air quality like food or water to avoid the next pandemic.
The air in the buildings is shared, it is a public good. We must start treating it as such
“The air can contain viruses as much as water or surfaces,” explains Shelly Miller, one of the co-authors of the text, published less than two weeks after the WHO changed its websites to finally recognize that SARS-CoV-2 it is predominantly airborne. The UN agency began by questioning the importance of aerosols and only ten months ago he recognized the risk of this type of contagion. These scientists are now asking for the next step, to prevent this type of contagion by applying a series of measures to improve indoor air quality.
Advancing scientific knowledge to protect health
They compare their proposal with the change it made in the 19th century, when cities began to build their sewerage systems to manage their wastewater. Or when Londoners died of cholera in the middle of that century and scientists of the time assumed that the disease was transmitted through the air, until the doctor John Snow discovered that the cause was microorganisms that contaminated the water. They also cite the moment when the Hungarian Ignaz Semmelweis showed that washing hands before attending childbirth reduced newborn deaths. These discoveries were met with some resistance in those years, but in the end they prevailed in the scientific consensus and helped improve health and save people’s lives.
The historical moment of aerosols
In the 20th century, public health expert Charles Chapin erroneously attributed the cause of respiratory disease transmission to large droplets emitted by infected persons. He focused on those emissions that fall to the ground due to gravity at a short distance and assured that transmission by aerosols (smaller and weightless particles) was almost impossible.
The authors cite as a precedent for their effort when In 1945, scientist William Wells regretted that no effort was made to purify the air of the interiors as it was done with the measures to guarantee the cleanliness of the water and the food. His research on measles and tuberculosis began to show the importance of aerosols, but did not change the understanding of the importance of the air we breathe indoors.
Buildings capable of containing pandemics
That moment seems to have come with the covid-19 pandemic. “Let’s not waste time until the next pandemic,” proposes Professor José Luis Jiménez. “We need an effort from society. When designing a building, we should not include as little ventilation as possible, but rather we should keep in mind respiratory diseases, such as the flu, and future pandemics ”.
The lack of recognition of the importance of aerosols in the transmission of pathogens has generated deficiencies in the design of buildings and their ventilation systems, with the exception of some specialized spaces such as hospitals. The design of the buildings has focused on the control of temperature, odors, and energy consumption. There are guidelines for the control of substances such as carbon monoxide, but not for bacteria or viruses.
“The air in buildings is shared, it is a public good. We must start treating it as such”says Miller.
The economic cost
Lidia Morawska, main author of the article, assures that the economic cost of the change proposed by these experts is acceptable. Argues that the monthly cost of the pandemic worldwide has been around one trillion dollars and the annual cost of influenza in the United States is more than 11,000 million dollars. According to their calculations, the cost of the necessary investments in the construction of buildings would represent an increase of less than 1% of the total cost of a conventional construction.
The ventilation systems must be able to be controlled on demand to adjust to the needs of the different spaces and rooms, and also to their uses, depending on the respiration rate it may be higher, as it happens in a gym. Spaces where the best ventilation is not possible should incorporate air filtration and disinfection systems.
As buildings represent a third of global energy consumption, largely due to the heating and cooling systems of the environment, Jiménez, proposes that it be possible to create a “pandemic mode” that would allow buildings to only use more energy when needed for health reasons.