Heavy metals in the Hamps and Manifold valleys, North Staffordshire, U.K.: Partitioning of metals in floodplain soils

Abstract

The catchments of the rivers Hamps and Manifold in North Staffordshire are contaminated with base metals; soils and sediments have been sampled from the floodplains and analysed. Periods of historic copper mining in the Hamps valley and lead and copper mining in the Manifold released metalliferous sediments and these were transported and incorporated into floodplains downstream. Sequential chemical extractions on the samples showed much of the cadmium to be easily exchanged (up to 70%), and there was evidence for the translocation of cadmium down a soil profile over some 100 years. Only low concentrations of lead and copper were extracted easily, and for lead the Fe/Mn oxide and the organic fractions were the most important (up to 75% and up to 70% in different instances). For copper the organic fraction dominated.