Maternal plasma polychlorinated biphenyl levels in cynomolgus monkeys (Macaca fascicularis) affect infant social skills in mother-infant interaction.

Polychlorinated biphenyls (PCBs) are endocrine disrupting chemicals that disturb normal development of embryonic brains. In the present study, we evaluated the relationship between maternal plasma PCB concentration and infant behavioral characteristics in mother-infant interactions. We grouped 20 pregnant cynomolgus monkeys (Macaca fascicularis) into higher and lower PCB exposure groups; monkeys in the higher PCB group had PCB concentrations above 15 pg/g, which is representative of natural exposure levels. Maternal PCB concentration correlated negatively with infant behaviors (approach, look, proximity, locomotion) at the age of 6 months (p < .05), when an increase in these behaviors should normally occur. These results suggest that maternal PCB exposure may affect the development of infant social behavior in cynomolgus monkeys. Furthermore, this study provides primate evidence to support observations of associations between behavioral and learning disabilities and prenatal exposure to PCBs in humans.