Heavy Metal Contamination in Soils and Phytoaccumulation in a Manganese Mine Wasteland, South China

Abstract

Heavy metal contamination of minesoils is a widespread problem in China. In Pingle manganese mineland in Guangxi (south China), heavy metal concentrations in soils and dominant plants were determined, and soil contamination was assessed with pollution index (Pi) and index of geoaccumulation (I-geo). Pi showed the minesoil was heavily polluted by Cd and slightly polluted by Cr. I-geo showed a severer pollution for all metals (except for Mn) than Pi because I-geo tended to overestimate the real pollution effect of minesoil. Fresh tailings dam had both the highest Pi and I-geo among the four sites indicating a high metal contamination. All the “bio-available” fractions of the studied metals were below 5% of the totals. Dominant plants tended to accumulate higher Cd and Cr, and showed higher Mn translocation to aboveground parts. Besides the agricultural reclamation, more diverse restoration goals with lower environmental risks should be considered for the Mn mine wastelands in South China.