Geospatial distribution and health assessment of a perennial river with special reference to heavy metals

Geospatial distribution of heavy metals (HMs) in surface water bodies has attracted global attention due to the associated environmental toxicity and threat to aquatic life. The present study aimed to investigate the concentration of 15 HMs (Al, As, Ba, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, Se, Sr, Zn, and Ag) by using inductively coupled plasma mass spectrometry (ICP-MS) in the water and sediment of the perennial river Basuhi. The average concentration of HMs in water was found to be in the order of Co < Cd < Se < Ag < As < Ni < Cu < Cr < Pb < Zn < Mn < Sr < Ba < Al < Fe, whereas in sediments it was found to be Cd < Ag < Se < As < Co < Pb < Cu < Ni < Cr < Zn < Sr < Ba < Mn < Fe < Al. The HM concentration at many places exceeded the safe limit recommended by WHO (1997) and BIS (2012), indicating the unsuitability of water for household activities. Heavy metal pollution index (HPI), degree of contamination (C_deg), and heavy metal evaluation index (HEI) ranged between 10.21–130.01, 2.84–16.62, and 15.11–137.19 in water, whereas, pollution load index (PLI), geo-accumulation index (I_geo), and potential ecological risk index (PERI) varied between 2.33–3.31, 1.48–3.99, and 0.591 and 9.99 in sediments, respectively. The findings were also subjected to Pearson correlation coefficient and principal component analysis. Intensive agricultural application around the region and the watershed’s geological structure were found to be the most important reasons for the heavy metal distribution in the river.