In this article, we review evidence from the social and medical sciences on the causes and effects of lead exposure. We argue that lead exposure is an important subject for sociological analysis because it is socially stratified and has important social consequences - consequences that themselves depend in part on children's social environments. We present a model of environmental inequality over the life course to guide an agenda for future research. We conclude with a call for deeper exchange between urban sociology, environmental sociology, and public health, and for more collaboration between scholars and local communities in the pursuit of independent science for the common good.