Bianucci Raffaella, Jeziorska Maria, Lallo Rudy, Mattutino Grazia, Massimelli Massimo, Phillips Genevieve, Appenzeller Otto
Laboratory of Anthropology, Department of Animal and Human Biology, University of Turin, Turin, Italy.
PLoS One. 2008 Apr 30;3(4):e2053. doi: 10.1371/journal.pone.0002053.
This report on a male head revealed biologic rhythms, as gleaned from hydrogen isotope ratios in hair, consistent with a South-American origin and Atomic Mass Spectrometry radiocarbon dating (AMS) compatible with the last pre-Hispanic period (1418-1491 AD, 95.4% probability). Biopsies showed exceptionally well-preserved tissues. The hair contained high levels of toxic elements (lead, arsenic and mercury) incompatible with life. There was no evidence for lead deposition in bone consistent with post-mortem accumulation of this toxic element in the hair. We propose that the high content of metals in hair was the result of metabolic activity of bacteria leading to metal complexation in extra cellular polymeric substances (EPS). This is a recognized protective mechanism for bacteria that thrive in toxic environments. This mechanism may account for the tissues preservation and gives a hint at soil composition where the head was presumably buried. Our results have implications for forensic toxicology which has, hitherto, relied on hair analyses as one means to reconstruct pre-mortem metabolism and for detecting toxic elements accumulated during life. Our finding also has implications for other archaeological specimens where similar circumstances may distort the results of toxicological studies.
这份关于一名男性头颅的报告显示，从头发中的氢同位素比率可看出生物节律，这与南美洲起源相符，且放射性碳测年（AMS）结果与西班牙前最后一个时期（公元1418 - 1491年，概率为95.4%）一致。活检显示组织保存异常完好。头发中含有高浓度的有毒元素（铅、砷和汞），这与生命状态不符。没有证据表明骨骼中有铅沉积，这与死后头发中该有毒元素的积累情况一致。我们认为，头发中高含量的金属是细菌代谢活动导致细胞外聚合物（EPS）中金属络合的结果。这是在有毒环境中生存的细菌公认的一种保护机制。这种机制可能解释了组织的保存情况，并暗示了头颅可能被埋葬的土壤成分。我们的研究结果对法医毒理学有影响，迄今为止，法医毒理学一直将头发分析作为重建生前代谢和检测生前积累的有毒元素的一种手段。我们的发现对其他考古标本也有影响，在类似情况下，这些标本可能会扭曲毒理学研究的结果。
