Uncovering the Sources of Elevated Arsenic in Classic Maya Human Remains: Implications from Antiquity to Modernity

Abstract

Arsenic is a common contaminant in potable waters throughout the world, and its bioaccumulation and associated health hazards are of major concern. While the origins of present-day As exposures can be traced directly, determining exposure levels and sources for ancient civilizations is more complex. Recent studies have revealed elevated As levels in Classic Maya ceramic vessels and osteological remains of humans and animals from Tikal, Guatemala. This study serves to associate these elevated As concentrations with potential exposure intensities and pathways, evaluating their implications for Maya society. The ubiquity of elevated As in the human and animal remains (as high as 0.3 ± 0.003 μmol g-1) indicates that overexposure of Maya to As was long-term, spanned all social classifications, and was greater for humans than for animals from the same region. Laboratory simulations of As incorporation into apatite, the primary component of bone, associated the maximum As concentration observed in Maya bones to ingestion levels of approximately 1 μmol L-1. Leaching tests from As-containing ceramic vessel fragments and soil samples from Tikal suggest that contaminated surface waters may have contributed to the Maya ingestion of As. Recent biomedical research suggests the possible health effects of this sustained exposure may have ranged from skin lesions to cancers. These results not only help in explaining the widespread elevated As levels observed in Maya remains, but also to provide a new lens through which to assess other mass arsenic poisonings throughout historical and contemporary contexts.