Lead in their teeth.
D002648:Child; D004197:Disease Reservoirs; D006801:Humans; D007854:Lead / Q000032:analysis*; D007855:Lead Poisoning / Q000453:epidemiology; D010414:Pennsylvania; D012959:Socioeconomic Factors; D014094:Tooth, Deciduous / Q000032:analysis*
D007854:Lead