Behavioral Sexual Dimorphism in School-Age Children and Early Developmental Exposure to Dioxins and PCBs: A Follow-Up Study of the Duisburg Cohort

Background: Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and polychlorinated biphenyls (PCBs) are persistent organic pollutants that have been characterized as endocrine-disrupting chemicals (EDCs).Objectives: Within the Duisburg birth cohort study, we studied associations of prenatal exposure to PCDD/Fs and PCBs with parent-reported sexually dimorphic behavior in children.Methods: We measured lipid-based and WHO2005-TEQ (toxic equivalents established in 2005 by the World Health Organization)–standardized PCDD/Fs and PCBs in maternal blood samples and in early breast milk using gas chromatography/high-resolution mass spectrometry. At the child’s age of 6–8 years, parents (mostly mothers) reported sex-typical characteristics, preferred toys, and play activities using the Pre-School Activities Inventory (PSAI), which was used to derive feminine, masculine, and difference (feminine – masculine) scores. We estimated exposure–outcome associations using multivariate linear regression. A total o...