Arsenic in the hair of mummies from agro-ceramic times of Northern Chile (500 BCE–1200 CE)

Abstract

Arsenic (As) is an abundant trace element in groundwaters in the Andes and arsenicism has been detected in modern as well as ancient populations. As poisoning has been reported in archaic and preceramic mummies from Camarones, in line with high concentrations of As found in them and in the Camarones river. The aim of the present work is to compare hair As concentrations (hAs) of individuals belonging to pre-Hispanic communities from northern Chile with different cultural traditions, showing different spectra of diet, mobility and settlement patterns, and who had access to water of different origins and qualities. Ninety-two pre-Hispanic naturally mummified individuals recovered from Pica 8 (Tarapacá), Topater (Loa river) and San Pedro de Atacama cemeteries were studied. Significant differences in hAs were found between the groups studied, but mean values were not correlated with As concentrations in local water. Taken together with stable isotope analysis, the results point to the importance of discussing hAs not only in terms of As in drinking water but also in terms of As in diet, and also support a foreign origin of some individuals with deviant hAs. The present work points to arsenic analysis in hair as a useful tool in the study of living conditions and patterns of mobility in ancient populations, particularly when the results are complemented with stable isotope analysis and genetic analysis.