Prior research indicates a link between early lead exposure and risk for delinquent behavior. In this study, we follow a large birth cohort from the Cincinnati Lead Study into early adulthood to determine whether this increased risk persists. Outcome measures include official arrest records, diagnoses of Substance Abuse Disorder and Antisocial Personality Disorder, self-report of delinquent behavior, and a psychopathy scale. Predictors include pre-natal and post-natal blood lead levels. Multivariate statistical methods will control for potential confounders/covariates.