Bioarchaeology of Arsenic, an Invisible Natural Pollutant, and Its Effect on the Mitimaes of Camarones Cove, Arica, during Inca Times

Abstract

During the expansion of Tawantinsuyo, the Inca Empire sustained its hegemony by using multiple strategies, including moving specialized groups called mitimaes to their conquered territories. This study examines bioarchaeological evidence from the Camarones 9 (CAM-9) Inca period cemetery at the mouth of the Camarones Valley in northern Chile. The waters in this valley contain concentrations of arsenic that are 100 times above the norm (10 μg/L) for human ingestion, causing serious health consequences. We study the environmental health effects on this population, using atomic absorption spectrometry and hydride generation to investigate arsenic concentration in the bone tissues of 16 individuals sampled from this burial site. Three of four individuals presented arsenic levels in their bones that were beyond the standard 1 μg/g, with a median of 3.6 μg/g; in some, the levels were nine times higher than those currently recommended by the World Health Organization. Considering previous and current bioarchaeological evidence, especially the high arsenic levels found in these individuals, we postulate that the CAM-9 site population corresponds to mitimaes who settled on the Camarones coast. This study is relevant to all regions of the world that present ecotoxic loads.