The goal of the HOME Study is to quantify the impact of low-level fetal and early childhood exposures to environmental toxicants including lead, mercury, and other metals, pesticides, polychlorinated biphenyls (PCBs), persistent organic pollutants (PBDEs/PFCs), phthalates, phenols, environmental tobacco smoke, and alcohol on child development, neurobehavior, health, and growth. The HOME Study will also evaluate meconium as a biomarker for fetal exposure and test the effectiveness of home repairs to control lead hazards and injuries in early childhood.