In 2023, the air quality significantly improved in Belgium’s biggest cities (Antwerp, Brussels, Ghent, and Charleroi). According to figures from the Interregional Cell for the Environment (Ircel), Belgium is well on its way to achieving the recommended value of the World Health Organization (WHO). It showed the lowest nitrogen dioxide and particulate matter emissions in 15 years.

The presence of nitrogen dioxide in the air is traffic-related. In places with a lot of traffic, there is a direct link between NO2 concentrations and local (diesel) traffic.

Several reasons

Due to the corona crisis in 2020, emission levels reached a low point and later rose again. But in 2023, we achieved a lower level for the first time in the four urban measuring locations, approximately half lower than fifteen years ago.

An explanation is to be found in the stricter emission standards, the low-emission zones, the fewer diesel cars in traffic, the cleaner diesel engines of the latest generation, and the weather. The wet spring and autumn and the gloomy and wet months of July and August of 2023 resulted in generally (very) favorable weather conditions for air quality.

Particles and ozone

The existing European standards for particulate matter have also been respected for some time. The particulate matter concentrations in the four urban measuring points have never been as low as in 2023. As for NO2, the favorable weather conditions in 2023 help explain the low concentrations in 2023.

The summer of 2023 was characterized by a very sunny and warm month of June with a prolonged heat wave of ten days. However, the months of July and August were very gloomy and wet. July had four ‘ozone days’; July, August, and September had no ozone days. An ozone day is a day with at least one measuring point in Belgium exceeding the European information threshold of 180 µg/m³.

Discussions are underway between the European Commission, the European Parliament, and the European Council about the European Commission’s proposal for a new air quality directive with stricter limit values compared to the current directive from 2008.