Copper exposure in medieval and post-medieval Denmark and northern Germany: its relationship to residence location and social position

Abstract

For medieval and post-medieval Denmark and northern Germany, trace elements can potentially contribute to our understanding of diet, migration, social status, exposure to urban settings, and disease treatment. Copper, of particular interest as a marker of access to everyday metal items, can be used to clarify socioeconomic distinctions between and within communities. Postmortem alteration of bone (diagenesis), however, must be ruled out before the elements can be used to characterize life in the past. Femoral cortical bone samples of ca. 40 mg were thoroughly decontaminated, and the concentrations of Al, Ca, Mn, Fe, Cu, As, Sr, Ba, and Pb were measured using inductively coupled plasma mass spectrometry. The concentrations of these elements were quantified in bone samples from 553 skeletons from 9 rural and urban cemeteries, and 34 soil samples obtained near three burials. Copper, the primary element of interest in this work, is generally absent from the femoral cortical bone of rural people, although it occurs in high concentrations in the skeletons of the inhabitants of towns. The Cu in medieval to post-medieval bones likely originated from everyday objects, notably kitchen utensils. A rural to urban distinction in Cu concentrations, found repeatedly at two sites, likely resulted from differential access to much-desired, although still utilitarian, household items. An uneven distribution of metal objects used in domestic contexts, demonstrated through bone chemistry, was greater between rural and urban communities than it was within urban centres, at least among the socioeconomic positions sampled in this study.

Trace element distribution in human cortical bone microstructure: the potential for unravelling diet and social status in archaeological bones

“…In Ribe X1029/KLR-10831, all concentration values are higher than those in the unburied samples, especially for Mn but also Fe and Ba. Copper and Pb are higher than in the non-interred individuals, but they are within the range of archaeological Danish skeletons reported elsewhere [37]. The Spearman correlation matrix shows that in X1256/KLR-10810 there are strong correlations between Sr and Ba (r = 0.94), as well as Cu and Pb (r = 0.79) (Additional file 2).…”

“…Previous work has shown that there is an explicable pattern in Cu and Pb concentrations in bulk bone samples from medieval to post-medieval skeletons interred in cemeteries in Denmark and northern Germany [37,52]. The distribution of these elements among the different bone microstructural elements is perhaps the strongest reason to believe a biogenetic signal is retained that is not masked by diagenetic processes [1].…”

“…This concern-and there are indeed reasons to be troubled by diagenesis-led to a general dismissal of the use of trace-element chemistry for dietary purposes in the 1990s. But it is also true that, with proper pre-treatment, some elements, notably Sr and Ba, are thought to yield reliable dietary and provenance information [1,29,[33][34][35][36][37]. Furthermore, Pb and Cu can reveal much about environmental exposure to these elements, including the social position of people in the past [37][38][39][40][41].…”

Comparison of trace element chemistry in human bones interred in two private chapels attached to Franciscan friaries in Italy and Denmark: an investigation of social stratification in two medieval and post-medieval societies

“…Copper concentrations in archaeological bones have been used as a palaeodietary indicator to identify a diet rich in meat [85][86][87], but the relationship between Cuuptake and dietary composition is still unclear [88,89]. The impact of Cu-exposure on medieval and post-medieval populations through the use of kitchen utensils and environmental factors have been investigated and it has been argued that the Cu concentrations in bones indicate either a higher social class or a higher degree of urbanisation (see [90] and references therein).…”

“…Lead was used throughout medieval Europe for glazing ceramics; a glaze which could release Pb 2+ ions into the foodstuff if the food had a low pH. Copper was utilised in the medieval period and post-modern time as a very abundant material for large cooking pots and food containers in wealthy homes [90]. The estimated time-period for the burials in both chapels are 17th to 18th century, where the use of Cu utensils is expected to have been widespread in large parts of both societies.…”