Strontium Isotope Ratios of Human Hair Record Intra-City Variations in Tap Water Source

• NCJ Number: 255707
• Author(s): Brett J. Tipple; Luciano Valenzuela; James R Ehleringer
• Date Published: 2018
• Length: 6 pages
• Grant Number(s): 2011-DN-BX-K544
• Agencies: NIJ-Sponsored
• Publication Type: Research (Applied/Empirical); Report (Study/Research); Report (Grant Sponsored); Program/Project Description
• Award: Isotope Analyses of Hair as a Trace Evidence Tool to Reconstruct Human Movements: Combining Strontium Isotope with Hydrogen/Oxygen Isotope Data

Annotation

In order to better understand the impact of identified contributions to the spatial signal encoded within 87Sr/86Sr of hair, human hair was collected from three locations within Salt Lake City, Utah, along with the donor's sex.

Abstract

The oxygen (18O/16O) isotope analysis of hair is commonly applied to reconstruct an individual's residence history; however, region-of-origin as determined from oxygen isotope values (18O) alone is often spatially indistinct. Adding additional geochemical recorders can refine region-of-origin estimates. In this capacity, strontium (87Sr/86Sr) isotope analysis has attracted increased interest. Although 87Sr/86Sr reflects the influences of local geology, 87Sr/86Sr of hair includes both external environmental signals as well as the internal dietary indicators. In the current study, the 87Sr/86Sr and 18O of hair and local tap water were measured. There were no significant relationships between sex and either 18O or 87Sr/86Sr of hair, nor between collection location and the 18O of hair; however, the study found significant associations between collection location and 87Sr/86Sr of hair. These findings suggest that interactions with local water may be an important source of Sr to human hair and that the 87Sr/86Sr of hair may have the capacity to record differences in 87Sr/86Sr of tap waters on small spatial scales. (publisher abstract modified)