LONGITUDINAL RELATIONSHIP BETWEEN DENTIN LEAD LEVELS IN CHILDHOOD ANDBONE LEAD LEVELS IN YOUNG ADULTHOOD

A retrospective cohort study was conducted to examine the relationship between tooth lead in children and bone lead levels in young adults. Members of a cohort of young adults were reassessed 13 y after initial examination at an ambulatory clinical research center. Dentin lead le vels were measured by anodic stripping voltammetry during the years 19 75-1978, and bone lead levels of the tibia and patella were measured b y K-xray fluorescence technique during 1989 and 1990. A total of 63 su bjects who had no history of chelation or had no missing information o n potential confounders were studied. The median follow-up interval wa s 13.2 y. Dentin lead levels averaged 13.4 mu g/g (standard deviation [SD] = 10.7 mu g/g range 2.9-51.8 mu g/g), and bone lead levels averag ed 1.3 mu g/g (SD = 4.4 mu g/g, range = -9-13 mu g/g) for tibia and 5. 4 mu g/g (SD = 8.4 mu g/g, range = -10-25 mu g/g) for patella. The aut hors controlled for age, sex, race, and mother's socioeconomic status, and dentin lead levels were predictive of higher tibia, patella, and mean bone lead levels in 32 subjects (follow-up interval of 11.8-13.2 y). A correction for measurement errors in dentin lead measurements wa s made, and it was determined that a 10-mu g/g increase in dentin lead levels in childhood was predictive of a 1-mu g/g increase in tibia le ad levels, a 5-mu g/g increase in patella lead levels, and a 3-mu g/g increase in mean bone lead levels among the young adults. It was concl uded, therefore, that lead exposure in early life may be used to predi ct elevated body burden up to 13 y later.