In skeletons excavated from Woodland sites, copper and barium levels are found to have been contaminated by the soil environment. Electron microprobe scans show build-up along the outer surface of femur cross-sections. Copper and barium are lower in the femur or fibula than in the more porous rib. The distribution of copper in the surrounding soil is highly anisotropic. This indicates that copper and barium should not be used for dietary inferences about ancient populations without independent evidence that diagenesis is not important. See also AATA 16-1840.