IAQ-label for Belgian public spaces: Monitoring in 11 public spaces

In 2022, a new law was passed by the Belgian federal government with the purpose to enhance the indoor air quality in public spaces in the aftermath of the COVID-19 pandemic. This new law, among other things, requires publicly accessible spaces to apply a CO2 meter and provides the option to have an IAQ label in place that informs the visitor about the indoor air quality of that space. Since then, the Belgian Federal Public Health Service has been developing the more detailed, practical implementation of this new law, in consultation with stakeholders and research institutes. 
In support of the development of the IAQ label a measurement campaign was set up to obtain a better understanding of the IAQ achieved in public spaces. There is typically a lack of this data since public buildings such as restaurants, bars, sports infrastructure or theaters are studied less frequently in IAQ literature than e.g. offices or dwellings. 
In this new monitoring campaign, measurements of CO2, Temperature, RH, PM2.5 and PM10 were carried out in 11 Belgian public spaces with a variety of functions for a duration of at least 7 days in March 2024. At the same time the spaces were inspected to obtain information about the use, potential sources of pollutants and possible ventilation systems in place. 
The measurements show a broad range of IAQ-parameters depending on use, presence of specific sources and presence of a ventilation systems in the building. Specific sources of PM can dramatically change the indoor concentration to levels well above WHO Air Quality Guidelines for extended periods of time. Bars/restaurants have obtained the worst IAQ-parameters while most other locations, all equipped with mechanical ventilation systems, were able to achieve acceptable CO2 and PM levels. The measurements highlight the complexity in the development of one consistent label applicable for all public spaces.