Air pollution around Brussels schools is declining

While air pollution remains a problem in every school in Brussels, the peaks are levelling off and fewer schools are being exposed to high levels of nitrogen dioxide (NO₂), according to a study by Les Chercheurs d’Air.

At the same time, pollution levels in all schools are still higher than the World Health Organisation’s recommended limit of an annual average of 10 µg/m³, and exceeding this level is associated with significant health risks.

“It’s unacceptable that going to school in Brussels should go hand in hand with air pollution,” said Renaud Leemans of Les Chercheurs d’Air. 

“We don’t accept damp or asbestos in classrooms. So why should we accept air pollution that contributes to asthma and certain types of cancer?”

NO₂ is a toxic gas, half of which is caused by road traffic and is found mainly in the immediate vicinity of that traffic, which makes it particularly suitable for mapping differences in air pollution.

Les Chercheurs d’Air used a tool developed by UCL university to generate the most recent figures.

It noted that while exposure to NO₂ in all Brussels schools remains higher than the recommended WHO standard, variations occur between different schools in the capital.

For example, in 2022, nine out of 10 schools in Brussels still recorded levels that were 50% above the WHO’s recommended standard. Two years later, that figure had already fallen to nearly three in 10 schools. 

The differences between municipalities are striking. NO₂ levels in all schools in Saint-Josse were still 50% above the recommended standard in 2024, but this was not the case for a single school in greener neighbourhoods in Watermael-Boitsfort, Berchem-Sainte-Agathe, Koekelberg, Auderghem and Woluwe-Saint-Pierre.

Les Chercheurs d’Air advocates retaining the timetable for the extension of the Low Emission Zone (LEZ) in Brussels. 

The timetable was amended by the Brussels parliament during the previous term of office, until the Constitutional Court overturned the measure. 

The non-profit also advocates for the creation of more traffic-calmed or traffic-free school streets across the region.