Since the industrial age, humans have added new compounds and elements (toxicants) to the environment in far greater concentrations than ever before and they are changing our biology (reproduction, growth, development, disease, and health profile) and our social structure. Heavy metals (e.g., lead and mercury) are neurotoxicants. Lead can delay sexual maturation in girls. Polychlorinated biphenyl burden is associated with girls' faster sexual maturation and with lower testosterone levels in adolescent males as well as with deficits in cognitive performance. Obesity and diabetes are associated with toxicant burdens also. Many toxicants have not been studied and the full range and depth of their effects is not known. Toxicant burdens are far greater among the disadvantaged in society and are transferred across generations; effects of toxicants hinder cognitive, economic, and social development from birth. Multigenerational toxicant effects are one pathway that sustains social distinction. Social distinctions reinforce pathways of toxicant exposure.