Lead is a ubiquitous toxic agent that is especially damaging to the young child and the developing fetus. Currently, because of growing evidence of lead toxicity at lower concentrations, the U.S. Centers for Disease Control and Prevention recently lowered its lead-exposure guideline to 10 ug/dl lead in blood from 25 ug/dl. This book addresses the public health concern about the logistics and feasibility of lead screening in infants and children at such low concentrations.