Multi-element contamination of soils and plants in old mining areas, U.K.

Soils and plants were sampled from some old Pb-Zn mining and smelting areas in England. The results show that Pb, Zn, Cd, Ag, As, Sb and Hg concentrations in soils and plants from these areas are highly elevated compared with “normal background” levels and the control sites in this study. The enrichment and associations of metals are affected by three factors. (1) The nature of the underlying mineralised rock. (2) The mining activities which have produced widespread contamination. (3) The smelter pollution resulting in very high concentrations of metals in the immediate vicinity and downwind of smelters. The natural multi-element associations and multi-element contamination in these historical Pb-Zn mining and smelting areas are dominated by the presence of sulphide minerals. The typical trace element associations found are: in mining areas Pb-Zn-Cd-Ag-As-Sb-Hg; and in smelter sites Pb-Zn-Cd-Sb-As. These soil and plant results indicate that, in addition to Pb, Zn and Cd, the other toxic elements As, Sb, Ag and Hg are present as significant contaminants.