222 Belgian schools took part in Greenpeace's "My air, my school" investigation. Only seven schools were found to have air quality of a satisfactory level. At 76 schools the air quality was acceptable, but at all others there was at least cause for concern.
As a result of higher exhaust emissions nitrogen dioxide concentrations were 13% higher during school hours.
For four weeks nitrogen dioxide levels in the air were measured at the school gate, on the playground and in the class. Schools took part on a voluntary basis and were not selected as representative. Still each school will receive its individual findings as well as a set of recommendations.