Effects of coal mining activities on soil properties with special reference to heavy metals

Abstract

Soil physico-chemical properties and concentrations of heavy metals in the soils around Jharia coalfield in Jharkhand state of India were determined to quantify the levels of contamination in the area.The extensive coal mining in the area altered physico-chemical properties of the soil.Sites near coal mining areas were heavily contaminated with all the measured heavy metals.The average concentrations of Fe, Mn, Zn, Pb, Cu, Ni, Cd and Cr were higher compared to the critical soil concentrations.At the sites near coal mining areas, Mn, Cu and Ni were near the toxic limits of the respective metals.Soil pollution assessment was carried out using enrichment factor, geoaccumulation index and pollution load index.Higher enrichment factor for Mn, Zn, Pb, Cu, Ni and Cd indicated significant inputs from mining activities in the soil.The geo-accumulation index values revealed that Cu, Pb and Ni are significantly accumulated in the study area.The pollution load index derived from contamination factor indicated that the sites near coal mining areas are most polluted.Multivariate statistical analyses, principal component and cluster analyses suggested that Ni, Cu and Pb were derived from anthropogenic sources, particularly coal mining activities and vehicular transport.