Assessment of potentially toxic elements' contamination in surface soils of Kulsi River Basin in North East India

The assessment of potentially toxic elements' contamination in surface soils of Kulsi River Basin in North East India has been studied based on the analysis of 50 soil samples collected from the basin. The average concentrations of Co (2.30 mg/kg), Ni (7.26 mg/kg), Pb (9.41 mg/kg), and Zn (22.7 mg/kg) surpassed the background levels prescribed for sedimentary rocks which indicated anthropogenic contribution of these metals. The average values of enrichment factors for different elements under study followed the order as Co > Ni > Zn > Pb > As > Fe > Cr. Results of multi-element indices revealed significant contamination at many sites; however, computed values for potential ecological risk index indicated only low ecological risk at all the sampling sites. The contribution of individual toxic elements toward the potential ecological risk followed the order as Co > Ni > As > Pb > Zn > Cr. The study recommends that suitable measures need to be taken for checking any further contamination in the area.