Biogeochemical and environmental study of the chromite-rich ultramafic terrain of Malakand area, Pakistan

The biogeochemical distribution of enzyme-bound metals in the plants and so il of the chromite-rich mineralized area of Malakand Agency and the non-min eralized area of Mardan (N.W.F.P., Pakistan) has been studied in regard to mineral prospecting and environmental pollution. Samples of lower plants ac companied with their associated soil samples were collected and analysed fo r copper, lead, zinc, nickel, chromium and cobalt. Considering the plant-so il chemical relationship, there is a weak correlation of Cu, Ni, Cr and Co relative to Pb and Zn. Among the five plant species, Verbascum thapsus has the greatest capability to accumulate Cr(VI) and Ni in its tissues by scave nging through the soil in which it is grown. This anomalous concentration o f Cr and Ni in Verbascum thapsus can be used for mineral prospecting; howev er, it can be a major environmental threat with regard to the health of the inhabitants of the area.