Assessment of metal contamination in sediments of a perennial river in India using pollution indices and multivariate statistics

The heavy metal contamination of river sediments by domestic, industrial, and agricultural waste is a major ecological and environmental problem. Therefore, heavy metal concentration and its associated risk were assessed in the sediments from the entry point of Sutlej River in Indian Punjab to its tail end when the river leaves India. The sediment samples (N = 47) were collected from the Sutlej River during April, 2018 and analyzed for heavy metals (As, Cd, Cr, Co, Cu, Fe, Mn, Ni, and Zn). Results showed that the metal concentration in sediments was higher along the transboundary of the river. The average concentration of metals in sediments was in the order: Fe > Mn > Cu > Zn > Cr > Co > Ni > Cd > As. The concentration of Cd in the sediments only exceeded the threshold values of metal concentration. Principle component analysis indicated that geogenic sources are primarily associated with metal concentration in sediments before river’s entry point in Punjab. In contrast, agronomic and industrial sources are related to the origin of metals in the river flowing in Indian state of Punjab. The contamination factor and potential ecological risk index results showed that Cd is the primary contaminant in the sediments of the Sutlej River. Spatial distribution maps of risk indices showed the higher risk values along the transboundary of the river in Indian Punjab. These results suggest that strategic management practices and policies across municipal, industrial, and agricultural sectors are required to reduce the metal concentration in the Sutlej River.