Mandating indoor air quality for public buildings | Pixabay

We are increasingly aware of atmospheric pollution, and in recent years, policy reports have been carried out to recommend best practices, methods, data, and scientifically validated models. However, despite decades of research and advocacy, most countries do not have legislated indoor air quality standards. The COVID-19 pandemic made us realize how important indoor air quality is for human health. In an article published in Science, in which IDAEA participated, scientists propose that indoor air quality standards should be mandatory for public spaces, and homes should be designed and equipped so that they can meet these standards.

Indoor air pollution originates from both indoor sources (such as combustion, building products, and cleaning products) and outdoor pollutants. Controlling indoor emissions and preventing outdoor pollutants from entering buildings are necessary to meet indoor air quality standards. However, there is a lack of consistency in definitions and criteria, as well as political, social, and legislative challenges in creating these standards. It is not easy to monitor indoor air quality, since every space is different and every monitoring network operates differently.

“Implementing indoor air quality standards faces social, political, and economic challenges, as well as resistance from some industries. However, if we have been able to agree on implementing standards to fight outdoor air pollution, why can’t we agree on this?”, wonders Xavier Querol, IDAEA researcher and co-author of the article.

Now, experts have proposed an approach based on science, technology, and specific solutions, following the recommendations established on the Global Air Quality Guidelines, published by the World Health Organization (WHO):

Level Averaging time or set point
PM2.5, μg/m3 15 1 hour
CO2, ppm 800 (absolute value)
350(delta)		 Threshold

Threshold
CO, mg/m3 100
35
10		 15 minutes

1 hour

8 hours
Ventilation, litter/s per person 14 When the space is occupied

 

These levels may be adjusted to reflect local circumstances and priorities. The WHO recommends monitoring PM2.5 and CO as the most relevant pollutants for routine indoor air quality regulation due to their health impact. The best way to control indoor pollutants is effective ventilation, which helps reduce infection risk, and maintaining indoor air quality.

Proposed numerical standards for PM2.5 and CO2 levels provide benchmarks for indoor air quality regulation, reflecting the need for adequate ventilation to mitigate infection risks, especially in public spaces such as classrooms.

Introducing standards is complex, as the interests of different stakeholders must be balanced, and standards may have cultural or political implications. However, the normalization of indoor air quality standards could lead to significant benefits in terms of public health, well-being, and productivity, outweighing the initial investment costs.

Lidia Morawska et al., Mandating indoor air quality for public buildings. Science 383, 1418 – 1420 (2024). DOI:10.1126/science.adl0677