The 10th of September, Brussels Environment has installed an air quality monitoring station at De Brouckère. The station – that measures in real-time the concentration of nitrogen dioxide – is on the pedestrian zone, but in a place where traffic is always present. The results are not good. In thirteen days, the European threshold of 40μg / m³ has been exceeded 9 times.
At certain times, the concentration is higher in the pedestrian zone than in Sainte-Catherine. This can be explained by the winds, the traffic jams or the presence of nearby sites that release nitrogen dioxide.
Brussels Environment has still to carry out a complete analysis of the measures, but at first sight, the air is not purer on the pedestrian zone. Only one exception has been registered during the free car day.