Diagenetic arsenic uptake in archaeological bone: Can we really identify copper smelters?

Abstract

In a recent paper Oakberg, Levy & Smith (2000) reported measurements of arsenic concentrations in bone from the Chalcolithic site of Shiqmim, Israel. They inferred that since elevated levels of As had been found in the bone of modern copper smelter workers in Sweden, high concentrations in archaeological bone could be used to infer copper smelting activities in the past. However, their argument ignores the effects of post-depositional mobility of arsenic between soil, groundwater and bone. Here, we outline the processes influencing mobilization of As and post-depositional As incorporation in bone. We argue that the As concentrations reported by Oakberg, Levy & Smith (2000) can be accounted for by diagenetic uptake and are unlikely to reflect biogenic As concentrations. We therefore conclude that the data presented by Oakberg, Levy & Smith (2000) cannot be used to infer past copper smelting.