Human lead exposure in England from approximately 5500 bp to the 16th century ad

Abstract

Lead concentration and isotope ratio data are presented for the tooth enamel of 77 individuals buried in England and spanning approximately 5000 years from the Neolithic until the 16th century ad. Whereas other tissues may be affected by diagenesis in the burial environment, the Pb concentration of tooth enamel is directly related to childhood exposure. This record is preserved post-mortem and over archaeological time. Tooth enamel Pb concentrations in the prehistoric period appear to be variable within the range 0.04 to ∼0.4 ppm, with occasional higher levels. The Romano-British and medieval periods show a marked increase in Pb exposures with enamel concentrations reaching up to approximately 40 ppm. These exposures would today be associated with industrial pollution. Exposures appear to be highly variable compared with modern people, however, with many medieval individuals having very low enamel Pb concentrations comparable with prehistoric people. Lead isotope data refine this picture. We distinguish between the diverse isotopic ratios we believe to be characteristic of ‘natural’ exposure to Pb—from geological sources via the diet—and the much narrower isotopic range characteristic of exposure to technological Pb from ore sources. Taken together the data suggest that the maximum concentrations associated with ‘non-technological’ exposure at any period are ∼0.5–1.0 ppm, similar to that reported for modern people in England.