Excellent Preservation of Archaeological, Mercury-Enriched Dental Remains: Archaeological, mercury-enriched dental remains

In this study, we assessed the notable preservation of mercury-enriched ancient dental remains. The studied specimen belonged to a 30-year-old woman, and it was collected from Temple XIII at the archaeological site of Palenque, Mexico (17 degrees 29'2.32"N, 92 degrees 2'46.78"W; a UNESCO World Heritage Site). The preservation of an ancient molar was studied by high-resolution scanning electron microscopy and energy-dispersive X-ray spectroscopy (HRSEM-EDS), and the obtained results were compared to those recorded for contemporary tooth specimens. Measured and conventional carbon ages for the ancient molar were 1000 +/- 30 and 1260 +/- 30 bp, respectively. Energy-dispersive spectroscopy (EDS) analysis showed that the accumulated Hg in the ancient molar was 66% (by weight). In contrast, the Hg content in the contemporary molar was observed to be below the analytical detection limits. Clearly, Hg accumulated preferentially in ancient dental structures. Aging favoured the overall exchange of Hg for structural Ca; namely, chemical migration from one dental compartment to the other, mineral transformations, enamel hypoplasia, and the accumulation of Hg and Al in bio-organic structures. Overall, we observed excellent preservation of biogenic material with varying physiological function(s), including abundant odontoblasts (tubules and spheres), dentinal tubules and nervous system fibrils.