Assessment of children's exposure to currently used pesticides in wallonia, Belgium.

In spring 2016, a study was carried out to characterize currently used pesticide (CUP) exposure among children living in Wallonia (Belgium). Pesticides were measured in both first morning urine voids of 258 children aged from 9 to 12 years and in ambient air collected close to the children's schools. Out of the 46 pesticides measured in the air, 19 were detected with frequencies varying between 11 % and 100 %, and mean levels ranging from <0.04 to 2.37 ng/m³. Only 3 parent pesticides were found in 1-10% of the urine samples, while all the metabolites analyzed were positively detected at least once. The captan metabolite (THPI) was quantified in 23.5 % of the samples, while 3,5,6-trichloro-2-pyridinol (chlopryrifos metabolite) was detected in all urines with levels ranging from 0.36-38.96 µg/l. 3-phenoxybenzoic acid (3-PBA), trans-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropane carboxylic acid (t-DCCA) and diethylphosphate were the most abundant pyrethroid metabolites and dialkylphosphate measured. The air inhalation was demonstrated to be a minor route of exposure for the selected CUPs. Statistical regressions highlighted predictors of exposure for some pesticides such like consumption of grey bread, presence of carpets at home or indoor use of pesticides, although no clear source was identified for most of them.