Jharkhand is a mineral-rich state and there are many possibilities in pisciculture. Fish is the staple food of Jharkhand because of its nutritional values. In the present study, water, sediment, and the most favorite fish species (Labeo rohita, Catla catla, Cirrhinus mrigala, Cyprinus carpio, and Ctenopharyngodon idella) were collected from the lentic reservoirs and analyzed for assessing the ecological and human health risk assessment. The mean concentrations of Cd, Cr, Cu, Pb, and Zn in water samples varied within the ranges of 0.001–0.004 mg/L, 0.02–0.04 mg/L, 0.004–0.007 mg/L, 0.023–0.081 mg/L, and 0.003–0.12 mg/L, respectively. In sediment samples, the metal concentrations were recorded within the following ranges: 109.15–411.48 mg/kg for Zn, 0.79–22.87 mg/kg for Cd, 22.71–34.79 mg/kg for Pb, 93.44–581.38 mg/kg for Cr, and 19.61–129.09 mg/kg for Cu. The average concentrations of metals in fish were observed as follows: 82.98 − 91.81 mg/kg of Zn, 20.91 − 31 mg/kg of Cd, 81.48 − 91.81 mg/kg of Pb, 442.68 − 482.50 mg/kg of Cr, and 35.91 − 68.57 mg/kg of Cu. Ecological health assessment based on sediment indices shows the prevalence of Cd in the lentic ecosystems and their bioaccumulation (biota-sediment accumulation factor > 2) in fish species. Among the four reservoirs, HD is the most contaminated site. Local population, especially, children of Ranchi district, consuming fish species are prone to health risk due to the metal contamination. Conclusively, this study provides valuable data on metal concentrations in fish species, supporting future ecotoxicology research and policymaking for any mineral-rich state. © The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature 2025.
