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

Abstract.

The biogeochemical distribution of enzyme-bound metals in the plants and soil of the chromite-rich mineralized area of Malakand Agency and the non-mineralized area of Mardan (N.W.F.P., Pakistan) has been studied in regard to mineral prospecting and environmental pollution. Samples of lower plants accompanied with their associated soil samples were collected and analysed for copper, lead, zinc, nickel, chromium and cobalt. Considering the plant–soil 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 scavenging through the soil in which it is grown. This anomalous concentration of Cr and Ni in Verbascum thapsus can be used for mineral prospecting; however, it can be a major environmental threat with regard to the health of the inhabitants of the area.