This year's edition of car-free Sunday gave a notable boost to air quality in Brussels, with environmental authorities pointing to a drop of up to 80% in the levels of main car pollutants.
Figures gathered by the Belgian Interregional Environment Agency (CELINE/IRCEL) showed a drop of between 70 to 80% in the concentrations of nitrogen dioxide and diesel soot, the main pollutants linked to car traffic.
Frans Fierens of CELINE/IRCEL said that while the drop was not a new phenomenon, figures gathered during car-free Sundays made differences in air quality "objectively measurable," according to VRT.
The event on Sunday also saw the year's lowest concentrations of nitrogen oxide in the Arts-Loi zone, one of the most heavily polluted areas in the heart of Brussels' European quarter.
Air quality monitors set up at the start of mobility week showed that the air in Arts-Loi was up to two times more polluted than the air in a different, pedestrian part of the city.
In addition to the drop in comparison to a regular day in Brussels, the numbers showed a decrease in air pollutant levels of roughly 30% compared to other places in Belgium where car-free Sunday was not organised.
Fierens said that the levels of air pollutants would quickly rise when cars were allowed back into the roads.
"When cars are admitted to Brussels on Sunday evening, the pollutants will quickly return to normal values," he said.
The Brussels Times