Participants in Belgium

Urine and hair was collected from 128 mothers and 129 children, so that the pollutants they contain could be measured. In Belgium, children were recruited in schools from three regions : in two sparsely populated regions in Flanders and Wallonia (around Braken en Ellezelles/Frasnes) and in the densely populated Brussels-Capital Region.

The sparsely populated regions met the selection criteria of the European study, namely < 15000 inhabitants, <295 inhabitant/km², absence of important emission sources and industries, <5% industrial zone and school situated >=500m from main roads. Both rural regions are located 10 to 15 km from each other, 50 to 65 km south west of the capital Brussels. The Brussels-Capital Region was chosen as an urban area because it has more that 150 000 inhabitants and a density of population of at least 5000 inhabitants/km².

Illustration: overview of the number of participants in each region where recruiting took place.