An archaeometric approach to biocontamination with manganese pigments in ancient marine hunter-gatherers of the Atacama Desert: health, ideological, and socioecononic considerations

Abstract

The use of poisonous pigments for mortuary preparation in ancient hunter-gatherers allows us to investigate the relationship between this practice with socio-economic organization, mortuary ideology, and potential impacts on human health from overexposure to these dangerous compounds. About 6000 years ago, the Chinchorro people, maritime hunter-gatherers in the Atacama Desert, northern Chile, began mining manganese to ornament the dead, representing the earliest form of artificial mummification in the world. We present the analysis of the bones from 68 Chinchorro mummies using flame atomic absorption spectrometry, revealing, for the first time, the presence of manganese in their bodies. We excluded the potential diagenesis by comparison of manganese concentration difference between the cemetery soils and outer coating of the mummy and by manganese source identification by SEM/EDX. Approximately 84% (57/68) of individuals have manganese concentrations beyond normal 1 ppm and 20.6% (14/68) were overexposed to levels of higher toxicity (≥ 10 ppm), with no sex differences, suggesting equal participation in manganese handling. We conclude that manganese exploitation and refining for the ritualistic treatment of the dead posed a serious occupational hazard for the living, with evidence that many of the Chinchorro people were likely involved in these activities. This is relevant, considering manganese dust inhalation produces neurological disorders and Parkinson-like symptoms. These findings open new avenues for research into the long history of anthropogenic pollution in the Americas and the importance of mineral gathering and processing as part of a broader subsistence spectrum undertaken by these ancient hunters, gatherers, and fishers.