However, this is the first study to simultaneously analyze and compare five matrices (maternal hair and blood, cord blood, infant hair and meconium) to determine the optimum matrix or combination of matrices to detect antenatal pesticide exposure. For the infant matrices (cord blood, infant hair or meconium), meconium was the best matrix for this purpose. Of eleven pesticides analyzed, eight were detected in meconium with a high prevalence rate for propoxur (23.2%). In contrast, cord blood and infant hair were each only positive for a single pesticide, propoxur and chlorpyrifos, respectively. Furthermore, the concentrations of the pesticides detected were also significantly
higher in meconium than cord blood and infant hair.