Heavy Metal Contamination in Major Indian River Basins: Sources, Spatio-Temporal Patterns, Pollution Assessment, and Integrated Remediation Strategies

Heavy metal contamination in Indian rivers poses a significant threat to aquatic ecosystems and human health. This study presents a systematic review assessing the extent of heavy metal contamination in Indian rivers, identifying its major sources, evaluating ecological impacts, examining spatial distribution patterns, and summarizing remediation strategies. Relevant scientific studies published between 2000 and 2024 were collected from major databases including Scopus, Web of Science, and Google Scholar, and a total of 67 studies were analyzed. The review identifies key sources of heavy metal pollution such as industrial effluents, urban runoff, agricultural activities, mining operations, and improper waste disposal. Several pollution hotspots, particularly in the Ganga and Yamuna river basins, were reported where metals such as Pb, Cd, Cr, and As frequently exceed permissible limits. Distribution patterns were evaluated considering river hydrology, geomorphology, and anthropogenic pressures. Many studies applied pollution assessment indices, including the Heavy Metal Pollution Index (HPI) and Pollution Load Index (PLI), along with statistical tools such as Principal Component Analysis (PCA) to assess contamination levels and identify potential pollution sources. Various remediation strategies—including physical, chemical, and biological approaches—are discussed with emphasis on their applicability in the Indian context.