Use of Pb and Sr isotopes in human teeth as an indicator of Pacific Islander population dynamics

The study involved the investigation of ancient dental enamel derived from former inhabitants of Pacific Islands: a population whose movements were necessarily more restricted than their mainland counterparts. Lead and strontium isotope analysis of human teeth were undertaken using TIMS and MC-LAM-ICPMS. Exposure information was obtained from elemental concentrations of lead and strontium using LAM-ICPMS, GFAAS and ASV. Isotopic measurements of lead within the dental enamel of these individuals suggest that the dominant source of biogenic lead exposure in these and other pre-metallurgical societies derived from the local water supply. Data from these ancient populations are compared with measurements made on ‘moderns’ based at Broken Hill, NSW, as well as from other UK-based post Iron Age populations. Results of this study indicate that the concentration of ancient lead within crystalline dental enamel in both ancient and modern populations can in certain circumstances be approximately the same, even when the degree of lead exposure is very high. The study proposes reasons for the discrepancies between these results and those obtained in previous studies, as well as discusses the implications of these analytical results for future studies in lead exposure in human populations