THE TRANSFER AND FATE OF CD, CU, PB AND ZN FROM 2 HISTORIC METALLIFEROUS MINE SITES IN THE UK

Monitoring of heavy metal transfers, aerial deposition and fluvial tra nsport to soil, stream sediment and vegetation compartments surroundin g two former Pb-Zn mines are reported. Results show that 80-100 a afte r the closure of the mines relatively large amounts of Cd, Pb, Zn and, in once case, Cu are entering the soil and fluvial systems. Aerial de position of heavy metals within a 300 m radius of the centre of the ta ilings heaps is shown to be contributing up to 3.3 kg Cd, 71 kg Cu, 37 3 kg Pb and 1041 kg Zn annually to the surrounding soil and vegetation compartments. It is shown that more than 4.2 kg Cd/a and 1387 kg Zn/a are being transferred from the tailings heaps via the streams in the form of dissolved load. However, the greatest quantities of Cu (38 kg/ a) and Pb (74 kg/a) are transported from the heaps as wash load. Trans fers calculated as percentages of the total metal quantities in the ta ilings heaps highlight the greater relative mobility within the fluvia l system of Cd and Zn compared to Cu and Pb. Outside of the tailings h eaps, the greatest accumulation of metals is in the surrounding soil, while the smallest was observed to occur in the surrounding mixed gras sland vegetation. The most important implications of these findings ar e in the long-term release and partitioning of pollutant metal species from historic metalliferous mine tailings within the terrestrial and fluvial environments. This information is of major ecotoxicological an d agronomic importance and is necessary for the effective reclamation and remediation of such contaminated sites.