Subclinical Lead Toxicity

A group of 45 male adolescents and young adults, beginning treatment for behavior disorder or learning disability, was found to exhibit increased systolic blood pressure, decreased hand-eye coordination as measured by the Pursuit-Rotor, shortened reaction times, and lowered lactic dehydrogenase, all significantly correlated with tissue (hair) lead concentrations considered to be in the normal range. None of the subjects was ever suspected of having been lead poisoned, and none had ever lived in the innercity slum housing where plumbism is most frequently reported. Degradation in hand-eye coordination was clearly seen to begin at 10 parts per million of lead in the hair. This is probably less than the average lead burden in the U.S., and implies far more widespread toxicity than had been previously supposed.