| Lead Exchange in Teeth and Bone--A Pilot Study Using Stable Lead Isotopes Brian L. Gulson
1,2
and Barrie R. Gillings
3
1
Graduate School of the Environment, Macquarie University, Sydney, Australia
2
CSIRO/EM, North Ryde, Australia
3
Faculty of Dentistry, University of Sydney, Sydney, Australia Abstract
Stable lead isotopes and lead concentrations were measured in the enamel and dentine of permanent ( n = 37) and deciduous teeth ( n = 14) from 47 European immigrants to Australia to determine whether lead exchange occurs in teeth and how it relates to lead exchange in bone. Enamel exhibits no exchange of its European-origin lead with lead from the Australian environment. In contrast, dentine lead exchanges with Australian lead to the extent of ~1% per year. In one subject, trabecular bone from the tooth socket exchanged almost all its European lead with Australian lead over a 15-year period (turnover of ~6% per year) , similar to the ~8% per year proposed for lead turnover in trabecular bone. The repository characteristics of intact circumpulpal dentine were investigated by analyses of four sets of contiguous slices from six teeth: 1) a set consisting of slices with intact circumpulpal dentine and cementum ; 2) a set in which these areas were removed ; 3) another set consisting of slices with intact circumpulpal dentine and cementum ; and 4) a set without cementum. These analyses show relatively small differences in isotopic composition between contiguous slices except that circumpulpal dentine appears to be the dominant control on lead concentration. There is a significant correlation ( R 2 = 0.19, p = 0.01, n = 34) of dentine lead concentration and rate of exchange with residence time from the country of origin and Australian lead, but there is no such correlation with enamel lead concentration. Analyses of permanent and deciduous teeth of subjects from other countries who have resided in Australia for varying lengths of time should resolve some of the questions arising from this pilot study. Key words: bone exchange, isotopes, lead, teeth. Environ Health Perspect 105:820-824 (1997) Address correspondence to B.L. Gulson, Graduate School of the Environment, Macquarie University, Sydney, NSW 2109 Australia. We wish to acknowledge financial support for part of this investigation from the NIEHS under contract NO1-ES-05292. We thank Karen Mizon for some analyses ; Michael Korsch for maintaining the mass spectrometers in peak operating condition ; Gary Lenard for identification of some of the teeth ; Graham Lowe for logistical assistance ; various dental practitioners in Sydney for supplying the teeth, especially John Anticevich, Peter Etcell, and those from the Westmead Dental School ; and Bill Jameson for critical comments on the manuscript. Received 2 January 1997 ; accepted 18 March 1997.
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