Isotopic and Elemental Analysis of the William Bass Donated Skeletal Collection and Other Modern Donated Collections.

摘要

sotopic and elemental characteristics of human bone, teeth, and hair have been demonstrated as useful biomarkers for forensic anthropologists and criminal investigators. These biomarkers trace locations and movements of the individuals, and aid in the identification of human remains. This project analyzed multiple isotopes (carbon, oxygen, hydrogen, strontium, and nitrogen), and trace elements in modern human bone, teeth, and hair from the William Bass Donated Skeletal Collection (WBDSC), the Maxwell Museum Documented Skeletal Collection (UNM), and the Texas State University-San Marcos Forensic Research Facility (TSU-SM). The WBDSC represents the largest modern donated osteological collection in the United States and is located at the University of Tennessee Forensic Anthropology Center. Samples from individuals with self-or family-reported birth locations and movement histories were used for this study. In addition, individuals with unknown natal histories were compared against the known residential history data set. Sample preparation and isotope analyses were conducted at the University of Tennessee Stable Isotope Laboratory, the University of Alabama-Huntsville, the R. Ken Williams '45 Radiogenic Isotope Geosciences Laboratory at Texas A&M University, and the University of Alabama Stable Isotope Laboratory in Tuscaloosa. Trace element analysis was conducted at the Mississippi State University Department of Chemistry Laser Ablation Unit. A total of 290 individuals were sampled for a combination of stable isotope and trace element analyses. The samples included: powdered enamel for strontium analysis, bone collagen extraction for carbon and nitrogen analyses, bone apatite and Ag3PO4 enamel precipitate for oxygen analysis, and bulk hair samples for hydrogen analysis. Results from the study indicate that the enamel δ18O values from the WBSC collection are overall reflective of individuals’ birth locations, whereas hair keratin δ2H values are influenced by individuals’ death locations, which is consistent with isotope studies of forensically derived human samples. This suggests that the application of dual isotopes (O and H) provides a clear picture of residential history by spatially locating the beginning (tooth) and the ending (hair) of the individual life journey. Although the correlation coefficient of the enamel δ18O values with local water is not as high as the previously reported values, the relationship does follow the trend of earlier results. A potential influence of the elevated δ18O values may result from the isotopic pattern of tap water when compared to precipitation. Isotope results were built into a publicly available database, Forensic Isotopes Nation Database (FIND), which is accessible to various researchers that can serve as a repository for human derived isotopic information from anatomical collections with residential histories or for resolved forensic cases involving bone, enamel, or hair isotope data. This project has generated a national isotope database derived from the WBDSC and the other donated skeletal collections; provided forensic anthropologists and criminal investigators a comparative isotopic database of known residence from various sampled tissues; and has evaluated the effectiveness of implementing multiple isotopic analyses to estimate movement histories for modern forensic cases.