Materials Science and Engineering Department, University of California Los Angeles , PO Box 951595, Engineering V, Los Angeles, CA 90095-1595, United States.
Anal Chem. 2014 Jan 7;86(1):521-6. doi: 10.1021/ac4024439. Epub 2013 Dec 19.
Pre-Columbian populations that inhabited the Tarapacá mid river valley in the Atacama Desert in Chile during the Middle Horizon and Late Intermediate Period (AD 500-1450) show patterns of chronic poisoning due to exposure to geogenic arsenic. Exposure of these people to arsenic was assessed using synchrotron-based elemental X-ray fluorescence mapping, X-ray absorption spectroscopy, X-ray diffraction and Fourier transform infrared spectromicroscopy measurements on ancient human hair. These combined techniques of high sensitivity and specificity enabled the discrimination between endogenous and exogenous processes that has been an analytical challenge for archeological studies and criminal investigations in which hair is used as a proxy of premortem metabolism. The high concentration of arsenic mainly in the form of inorganic As(III) and As(V) detected in the hair suggests chronic arsenicism through ingestion of As-polluted water rather than external contamination by the deposition of heavy metals due to metallophilic soil microbes or diffusion of arsenic from the soil. A decrease in arsenic concentration from the proximal to the distal end of the hair shaft analyzed may indicate a change in the diet due to mobility, though chemical or microbiologically induced processes during burial cannot be entirely ruled out.
居住在智利阿塔卡马沙漠塔拉拉帕卡河谷中部的前哥伦比亚人群在中海拔期和晚期中间期（公元 500-1450 年）表现出慢性中毒的模式，这是由于暴露于地质砷所致。通过对古代人发进行基于同步加速器的元素 X 射线荧光测绘、X 射线吸收光谱、X 射线衍射和傅里叶变换红外光谱显微镜测量，评估了这些人接触砷的情况。这些高灵敏度和特异性的组合技术能够区分内源性和外源性过程，这一直是考古研究和刑事调查中的一个分析挑战，因为头发被用作生前代谢的替代物。头发中检测到的高浓度砷主要以无机 As(III)和 As(V)的形式存在，这表明通过摄入受砷污染的水而不是由于亲金属土壤微生物的重金属沉积或土壤中砷的扩散导致的外部污染而导致慢性砷中毒。从头发轴的近端到远端分析的砷浓度下降可能表明由于迁移而导致饮食发生变化，尽管在埋葬过程中不能完全排除化学或微生物诱导的过程。
