Lead exposures initiated during development, whether occurring in utero or post-birth, affect brain mesocorticolimbic dopamine/glutamate systems, the hypothalamic-pituitary-adrenal axis, and auditory systems. Alterations of all three of these substrates have been linked to adverse effects on attention-related behaviors, cognition, and delinquency/aggression—three reliable behavioral manifestations of developmental lead exposures. Later onset effects have included brain abnormalities in young adults. A hypothesized integration of these effects suggests that attention deficit may serve as a behavioral mechanism for both the cognitive and delinquency effects associated with lead exposure as a result of effects on any or all of the three neurobiological substrates of lead. However, it is likely that deficits in any one of these behavioral outcomes will further adversely influence the others. Key feasible intervention points for children may be early and repeated tests for auditory impairment and for attention deficit.
