BONE LEAD LEVELS AND DELINQUENT-BEHAVIOR

Objective.-To evaluate the association between body lead burden and so cial adjustment. Design.-Retrospective cohort study. Setting.-Public s chool community. Participants.-From a population of 850 boys in the fi rst grade at public schools, 503 were selected on the basis of a risk scale for antisocial behavior. All of the 850 boys who scored in the u pper 30th percentile of the distribution on a self-reported antisocial behavior scale were matched with an equal number drawn by lot from th e lower 70% of the distribution. From this sample, 301 students accept ed the invitation to participate. Exposure Measure.-K x-ray fluorescen ce spectroscopy of tibia at subjects' age of 12 years. Main Outcome Me asures.-Child Behavior Checklist (CBCL), teachers' and parents' report s, and subjects' self-report of antisocial behavior and delinquency at 7 and 11 years of age. Results.-Subjects, teachers, and parents were blind to the bone lead measurements. At 7 years of age, borderline ass ociations between teachers' aggression, delinquency, and externalizing scores and lead levels were observed after adjustment for covariates. At 11 years of age, parents reported a significant lead-related assoc iation with the following CBCL cluster scores: somatic complaints and delinquent, aggressive, internalizing, and externalizing behavior. Tea chers reported significant associations of lead with somatic complaint s, anxious/depressed behavior, social problems, attention problems, an d delinquent, aggressive, internalizing, and externalizing behavior. H igh-lead subjects reported; higher scores in subjects' self-reports of delinquency at 11 years. High-lead subjects were more likely to obtai n worse scores on all items of the CBCL during the 4-year period of ob servation. High bone lead levels were associated with an increased ris k of exceeding the clinical score (T>70) for attention, aggression, an d delinquency. Conclusion.-Lead exposure is associated with increased risk for antisocial and delinquent behavior, and the effect follows a developmental course.