Seasonal variation in heavy metal contaminations in water and sediments of Jamshedpur stretch of Subarnarekha river, India

Subarnarekha river, a rain fed peninsular river, passes through the city of Jamshedpur is an important industrial centre of Jharkhand, India. The aim of the study was to investigate the seasonal variability in the water and sediment quality status and to assess the impact of metals contamination in various seasons due to mining and industrial discharge. Concentrations of Zn, Pb, Cr, Cd, Ni, and Cu were determined using ICP-MS. Concentrations of Pb, Ni, and Cd were found quite higher than Indian drinking water standards. Heavy metal concentrations in sediment were found much higher than river water, which was further supported by high contamination factors (C-f > 6) for Cd and Pb for all sites in pre-monsoon whereas, high degree of contamination (C-d > 24) further ensured heavy pollution. Pollution load index values were found >1 which suggest progressive deterioration of sites whereas, geoaccumulation index recommended sediment quality towards moderately to very strongly polluted condition. Principle component analysis (PCA) was conducted separately for pre- and post-monsoon seasons. PCA (with eigen value >1 focused on two components, irrespective of seasonal variation with 55.21-58.77 % variance) indicated that high metals loading are due to anthropogenic origin, and Zn, Pb, Ni, and Cr have significant loading. Coupling of bioremediation technology with other economically efficient methods could help in solving the problem.