Lead in the Bones of Cows from a Medieval Pb-Ag Metallurgical Settlement: Bone Mineralization by Metalliferous Minerals

Pb contents (13-53 mg kg−1) and pathological changes in almost complete cow skeletons discovered in graves adjacent to Pb and Ag smelting furnaces active in the Silesian-Cracovian region, in the mid-12th century are reported in the article. In addition to Pb, elements such as Zn, Cd, Fe, Mn, Cd, and Ba characteristic of Zn-Pb-Ag ores in the region were identified. Bone fragments and the soil in which they had lain for almost 800 years were examined by SEM, EDS. XRD was used to identify minerals present in soils. The enrichment of the bones with Zn, Pb, Fe, Mn, and Cd is associated with the remobilisation of elements from soil contaminated with primary and synthetic phase-rich metals. In biotic material (e.g. bones) taken from soils heavily contaminated by mining or metallurgical processes, it is not possible to determine whether a given metal was even partly incorporated into the bone structure during life using the above methods. However, the importance of comprehensive geochemical and submicroscopic data for any inference based on the results of chemical tests on biological material is clearly indicated.