Multidimensional Approach for the Assessment of Environmental Pollution and Health Risk Associated With V, Ni, Cr, Cu, and Zn in the Recent Sediments of Kabini Interstate River, Southeastern Western Ghats, India

Abstract

The present work intends to study the variation of heavy metals (HMs) to scrutinize the scenario of pollution index and associated environmental risk, as well as source weathering conditions along the Kabini River. The decreasing order of concentration of HMs along the basin is Cr > V > Ni > Zn > Cu. The paper spotlights the pollution grade in sediments, assessed by the geo-accumulation index (I_geo), contamination factor (C_f), pollution load index (PLI), and enrichment factor (E_f). The assessment of ecological risk is studied as potential ecological risk index (RI), toxic risk index (TRI), and modified hazard quotients (mHQs). As per the I_geo and C_f, V and Cr concentrations are higher in the region. Further, PLI confirmed that 35% of samples exceeded the limits of sediment quality guidelines. The RI and TRI values show that a higher ecological risk is associated with Ni, V, and Cr and with Cu and Cr, respectively. Additionally, the 23% Ni and 20% Cu samples from mHQ indicate the severity of pollution in the aquatic environment. The inputs from anthropogenic and natural sources change the concentration of these HMs along the region. Moreover, the study of CIA and plagioclase index of alteration plots confirmed the low to intense weathering conditions. The statistical approach shows the linkage between Cr–V, Cu–Zn, and principal component analysis–derived prominent sources: industrial and agricultural runoff, as well as higher silicate weathering, contribute to the HMs concentration in the region. The Kabini River passes through different climatic and land-use domains of Kerala and Karnataka, which eventually regulate the HM concentration and geo-environmental processes in the region and affect the health risk to humans in one or the other way. The reference data generated from the present work are absolutely new and would be significant in the future for deriving sustainable development plans for the well-being of human beings and precious natural resources.