This Biobank project is assessing whether exposure to perfluoroalkyl substances (PFAS) during pregnancy and through breastfeeding is associated with blood pressure in children at ages 7 to 13. The project also aims to determine whether the placenta plays a role in the relationship between PFAS exposure and blood pressure in adolescents. In addition, it assesses whether this relationship between PFAS and blood pressure depends on the child’s sex or childhood physical activity.