Dentine lead concentration as a predictor of neuropsychological functioning in inner-city children.

Cumulative lead exposure in 193 inner-city Black children was evaluated by measuring lead concentrations in the primary dentine and the circumpulpal dentine of their deciduous teeth. The children's dentine lead levels were comparable to those reported in population studies of low-income children living in inner-city areas. The results of neuropsychological tests administered at age 7 were available for children in the sample; we performed further neuropsychological assessments when their teeth were shed (10-14 yr of age). Higher dentine lead concentrations were associated with deficits in neuropsychological test performance at both testings, with performance abilities more strongly affected than verbal abilities. Moreover, the negative effects of lead on neuropsychological functioning were more evident when lead concentrations in circumpulpal dentine, rather than in primary dentine, was used as the index of lead exposure. Based on this finding, we suggest that circumpulpal dentine and primary dentine should be assayed separately in order to yield a more sensitive estimate of exposure to lead.