Heritage of cadmium and lead. A case study of a Swedish accumulator factory

In this study, cadmium and lead emissions from a Swedish point source (manufacture of nickel-cadmium accumulators and smelting of lead accumulators) have been calculated from local industrial statistics. Cadmium and lead concentrations present in soil were used to estimate the total load of these metals. Differences between both measured and calculated total amounts, together with soil metal concentration data from the early 1970s, give an opportunity to discuss the leaching rate for cadmium and lead in a soil profile. The downward transport of metals from the top soil has been going on for a minimum of 16 years (1974–1990) to 50 years (lead) or 80 years (cadmium). This gives a leaching rate for cadmium of 0.41–2.0% year−1 and for lead of 0.25–0.79% year−1 assuming a constant leaching process. Since the major part of the leaching has occurred during the last four decades (both cadmium and lead emissions were limited before 1950), the calculated leaching rates would be 0.8% year−1 (Cd) and 0.3% year−1 (Pb). Thus, there is an agreement in calculated cadmium rates with values reported in the literature but this study indicates a significantly higher leaching rate for lead.