Distribution and Chemical Speciation of Arsenic in Ancient Human Hair Using Synchrotron Radiation

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• 作者：Ioanna Kakoulli ; Sergey V. Prikhodko ; Christian Fischer ; Marianne Cilluffo ; Mauricio Uribe ; Hans A. Bechtel ; Sirine C. Fakra ; Matthew A. Marcus
• 刊名：Analytical Chemistry
• 出版年：2014
• 出版时间：January 7, 2014
• 年：2014
• 卷：86
• 期：1
• 页码：521-526
• 全文大小：370K
• ISSN：1520-6882

文摘

Pre-Columbian populations that inhabited the Tarapac谩 mid river valley in the Atacama Desert in Chile during the Middle Horizon and Late Intermediate Period (AD 500鈥?450) 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.