title: Reconstructing the life-time lead exposure in children using dentine in deciduous teeth.
abstract: Data are presented to demonstrate that the circumpulpal dentine of deciduous teeth can be used to reconstruct a detailed record of childhood exposure to lead. By combining high spatial resolution laser ablation ICP-MS with dental histology, information was acquired on the concentration of lead in dentine from in utero to several years after birth, using a true time template of dentine growth. Time corrected lead analyses for pairs of deciduous molars confirmed that between-tooth variation for the same child was negligible and that meaningful exposure histories can be obtained from a single, multi-point ablation transect on longitudinal sections of individual teeth. For a laser beam of 100 μm diameter, the lead signal for each ablation point represented a time span of 42 days. Simultaneous analyses for Sr, Zn and Mg suggest that the incorporation of Pb into dentine (carbonated apatite) is most likely controlled by nanocrystal growth mechanisms. The study also highlights the importance of discriminating between primary and secondary dentine and the dangers of translating lead analyses into blood lead estimates without determining the age or duration of dentine sampled. Further work is in progress to validate deciduous teeth as blood lead biomarkers.
authors.affiliation: School of Earth and Environment, University of Leeds, Leeds LS2 9JT, UK. shepherdtj@aol.com
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Shepherd
authors.forename: Wendy
authors.initials: W
authors.lastname: Dirks
authors.forename: Charuwan
authors.initials: C
authors.lastname: Manmee
authors.forename: Susan
authors.initials: S
authors.lastname: Hodgson
authors.forename: David A
authors.initials: DA
authors.lastname: Banks
authors.forename: Paul
authors.initials: P
authors.lastname: Averley
authors.forename: Tanja
authors.initials: T
authors.lastname: Pless-Mulloli
mesh_terms: D015415:Biomarkers / Q000032:analysis; D002648:Child; D003804:Dentin / Q000737:chemistry*; D003809:Dentin, Secondary; D004781:Environmental Exposure / Q000032:analysis*; D006801:Humans; D053685:Laser Therapy; D007854:Lead / Q000032:analysis* / Q000493:pharmacokinetics / Q000633:toxicity*; D008274:Magnesium / Q000032:analysis; D013058:Mass Spectrometry / Q000379:methods*; D013324:Strontium / Q000032:analysis; D014094:Tooth, Deciduous / Q000737:chemistry* / Q000187:drug effects; D015032:Zinc / Q000032:analysis
chemical_list: D015415:Biomarkers; D007854:Lead; D008274:Magnesium; D015032:Zinc; D013324:Strontium