Stable isotopes are valuable biogeochemical markers for solving problems faced by society today,... more Stable isotopes are valuable biogeochemical markers for solving problems faced by society today, such as distinguishing authentic from adulterated foods and beverages or tracing the origins of illicit drugs. Hydrogen and oxygen isotopes in water exhibit distinct continental patterns (isoscapes), which provide useful region-of-origin information. We ourselves reflect the stable isotope ratios of the water we drink and the food we eat: our hair records any isotopic changes to our diets, which can often be related to location. This latter aspect can be of interest to law enforcement in determining the origins and travel histories of unidentified murder victims.
ABSTRACT The application of stable isotope analysis has provided novel approaches for provenancin... more ABSTRACT The application of stable isotope analysis has provided novel approaches for provenancing unidentified human remains from forensic contexts. Stable isotope ratios measured in human tissues provide a record of the foods consumed during life as well as the geographic location where drinking water or food was obtained. This study begins with an overview of the application of stable isotope analysis for provenancing human remains, followed by three cases that illustrate how chemical signatures in bone reflect a probable region of origin. Using stable carbon and nitrogen isotopes of human bone, we test whether human skeletal remains recovered by the Joint POW/MIA Accounting Command-Central Identification Laboratory (JPAC-CIL, or CIL) reflect a geographic origin within North America or Asia. Stable carbon and nitrogen isotopes of human bone collagen and stable carbon isotopes of bone apatite reflect consumption of food resources that are expected to vary between world regions due to cultural dietary differences. Based on the isotopic differences, a testable hypothesis of geographic origin can be applied, determining if the remains are more likely of a U.S. service person or of an indigenous local. We believe that this approach can provide useful information for narrowing search parameters in unidentified persons cases; can contribute to human rights cases where an unknown individual is thought to originate from a different geographic area; and, in human remains cases of unknown geographic provenience, can determine whether a person is local or nonlocal.
ABSTRACT Analyses of stable isotope ratios of pollen present within complex matrices may be usefu... more ABSTRACT Analyses of stable isotope ratios of pollen present within complex matrices may be useful in sample provenance or climate change applications. We developed a method for separating pollen from honey and preparing pollen for hydrogen and oxygen stable isotope ratio analysis. The method combined several treatments: ethanol dilution to separate pollen; hexane washing to remove wax; and acetolysis to digest all but the external layer of pollen granules. There were large isotopic effects associated with treatments but effects were consistent between replicate applications of the method. We used the method to separate pollen from 45 honey samples from across the United States. Pollen δ2H and δ18O isotope values were significantly positively correlated (P 2H values explained by δ18O values (r 2 = 0.17). Pollen δ2H values were significantly correlated with δ2H values of precipitation predicted for hive locations (P r 2 = 0.24), but there was no significant correlation between pollen and precipitation δ18O values (P = 0.34, r 2 = 0.03). These results suggest hydrogen and oxygen stable isotope analysis of pollen may not be as useful as analysis of liquid honey or beeswax in investigating provenance.
Science & justice : journal of the Forensic Science Society, 2015
We investigated a novel application of stable isotope abundance analysis of nitrogen ((15)N), car... more We investigated a novel application of stable isotope abundance analysis of nitrogen ((15)N), carbon ((13)C), hydrogen ((2)H), and oxygen ((18)O) to characterize pen ink. We focused on both ballpoint and gel pen inks. We found that the isotope ratios of ink from pens purchased together in a package were similar and within-package stable isotope ratio variability was not significantly larger than the variability of isotope reference materials used during analysis. In contrast, the isotope ratios of ink from pens of the same brand purchased in three states of the continental USA were significantly different from each other and there was isotope ratio variation among pens of the same brand but different, unknown production periods. The stable isotope ratios of inked paper were statistically distinguishable using measured δ(15)N values. Paper inked with different gel pens was statistically distinguishable using measured δ(2)H values. The capacity of stable isotope ratios to differentiat...
Humans have become a significant agent within the hydrological cycle, and impact hydro-and ecosys... more Humans have become a significant agent within the hydrological cycle, and impact hydro-and ecosystems through their manipulation of water fluxes and reservoirs. In the same way that stable water (H and O) isotopes serve as excellent tracers of many processes in the natural hydrological cycle, these isotopes offer a unique potential to contribute to the study of human water cycle modification and its role in ecosystem change. Surveys of modern tap water isotope ratios throughout the United States document spatial and temporal patterns ...
17 O-excess is the deviation from the average relationship between delta 18 O and delta 17 O valu... more 17 O-excess is the deviation from the average relationship between delta 18 O and delta 17 O values in meteoric waters. This parameter is similar to d-excess in that it is sensitive to relative humidity during evaporation, but unlike d-excess it is largely insensitive to temperature. Therefore, 17 O-excess may be used to provide independent information on relative humidity during evaporative processes in hydrological and climatic models. Here we report the first national-level survey of 17 O-excess of tap waters collected from 92 ...
Stable isotopes are valuable biogeochemical markers for solving problems faced by society today,... more Stable isotopes are valuable biogeochemical markers for solving problems faced by society today, such as distinguishing authentic from adulterated foods and beverages or tracing the origins of illicit drugs. Hydrogen and oxygen isotopes in water exhibit distinct continental patterns (isoscapes), which provide useful region-of-origin information. We ourselves reflect the stable isotope ratios of the water we drink and the food we eat: our hair records any isotopic changes to our diets, which can often be related to location. This latter aspect can be of interest to law enforcement in determining the origins and travel histories of unidentified murder victims.
ABSTRACT The application of stable isotope analysis has provided novel approaches for provenancin... more ABSTRACT The application of stable isotope analysis has provided novel approaches for provenancing unidentified human remains from forensic contexts. Stable isotope ratios measured in human tissues provide a record of the foods consumed during life as well as the geographic location where drinking water or food was obtained. This study begins with an overview of the application of stable isotope analysis for provenancing human remains, followed by three cases that illustrate how chemical signatures in bone reflect a probable region of origin. Using stable carbon and nitrogen isotopes of human bone, we test whether human skeletal remains recovered by the Joint POW/MIA Accounting Command-Central Identification Laboratory (JPAC-CIL, or CIL) reflect a geographic origin within North America or Asia. Stable carbon and nitrogen isotopes of human bone collagen and stable carbon isotopes of bone apatite reflect consumption of food resources that are expected to vary between world regions due to cultural dietary differences. Based on the isotopic differences, a testable hypothesis of geographic origin can be applied, determining if the remains are more likely of a U.S. service person or of an indigenous local. We believe that this approach can provide useful information for narrowing search parameters in unidentified persons cases; can contribute to human rights cases where an unknown individual is thought to originate from a different geographic area; and, in human remains cases of unknown geographic provenience, can determine whether a person is local or nonlocal.
ABSTRACT Analyses of stable isotope ratios of pollen present within complex matrices may be usefu... more ABSTRACT Analyses of stable isotope ratios of pollen present within complex matrices may be useful in sample provenance or climate change applications. We developed a method for separating pollen from honey and preparing pollen for hydrogen and oxygen stable isotope ratio analysis. The method combined several treatments: ethanol dilution to separate pollen; hexane washing to remove wax; and acetolysis to digest all but the external layer of pollen granules. There were large isotopic effects associated with treatments but effects were consistent between replicate applications of the method. We used the method to separate pollen from 45 honey samples from across the United States. Pollen δ2H and δ18O isotope values were significantly positively correlated (P 2H values explained by δ18O values (r 2 = 0.17). Pollen δ2H values were significantly correlated with δ2H values of precipitation predicted for hive locations (P r 2 = 0.24), but there was no significant correlation between pollen and precipitation δ18O values (P = 0.34, r 2 = 0.03). These results suggest hydrogen and oxygen stable isotope analysis of pollen may not be as useful as analysis of liquid honey or beeswax in investigating provenance.
Science & justice : journal of the Forensic Science Society, 2015
We investigated a novel application of stable isotope abundance analysis of nitrogen ((15)N), car... more We investigated a novel application of stable isotope abundance analysis of nitrogen ((15)N), carbon ((13)C), hydrogen ((2)H), and oxygen ((18)O) to characterize pen ink. We focused on both ballpoint and gel pen inks. We found that the isotope ratios of ink from pens purchased together in a package were similar and within-package stable isotope ratio variability was not significantly larger than the variability of isotope reference materials used during analysis. In contrast, the isotope ratios of ink from pens of the same brand purchased in three states of the continental USA were significantly different from each other and there was isotope ratio variation among pens of the same brand but different, unknown production periods. The stable isotope ratios of inked paper were statistically distinguishable using measured δ(15)N values. Paper inked with different gel pens was statistically distinguishable using measured δ(2)H values. The capacity of stable isotope ratios to differentiat...
Humans have become a significant agent within the hydrological cycle, and impact hydro-and ecosys... more Humans have become a significant agent within the hydrological cycle, and impact hydro-and ecosystems through their manipulation of water fluxes and reservoirs. In the same way that stable water (H and O) isotopes serve as excellent tracers of many processes in the natural hydrological cycle, these isotopes offer a unique potential to contribute to the study of human water cycle modification and its role in ecosystem change. Surveys of modern tap water isotope ratios throughout the United States document spatial and temporal patterns ...
17 O-excess is the deviation from the average relationship between delta 18 O and delta 17 O valu... more 17 O-excess is the deviation from the average relationship between delta 18 O and delta 17 O values in meteoric waters. This parameter is similar to d-excess in that it is sensitive to relative humidity during evaporation, but unlike d-excess it is largely insensitive to temperature. Therefore, 17 O-excess may be used to provide independent information on relative humidity during evaporative processes in hydrological and climatic models. Here we report the first national-level survey of 17 O-excess of tap waters collected from 92 ...
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Papers by Lesley Chesson