Author: Pralay Mahapatra & Dr. Aashi Dixit
Abstract: Chromium (Cr) is a widely used industrial metal that has emerged as a significant aquatic pollutant due to its extensive application in tanning, electroplating, dye, textile, and metallurgical industries. In freshwater ecosystems, chromium occurs predominantly in trivalent [Cr(III)] and hexavalent [Cr(VI)] forms, with the latter being highly toxic, mobile, and biologically available. Chronic discharge of chromium-containing effluents into rivers and lakes has raised serious concerns regarding aquatic biodiversity and fish health. Freshwater fish are particularly vulnerable to chromium exposure due to their continuous interaction with contaminated water and sediments, making them valuable bioindicators of metal pollution.
This review synthesizes current knowledge on chromium uptake, bioaccumulation, and toxicity in freshwater fish, with a focus on oxidative stress–mediated biochemical disruptions and histopathological alterations in target organs such as gills, liver, and kidney. The review highlights acute and sub-lethal toxicity thresholds, discusses the role of antioxidant defense systems in chromium-induced stress, and evaluates the usefulness of integrated biomarkers for environmental monitoring. By consolidating mechanistic insights and identifying research gaps, this review aims to support biomarker-based risk assessment frameworks and contribute to the sustainable management of chromium-contaminated freshwater ecosystems.
Keywords: Chromium Toxicity; Freshwater Fish; Bioaccumulation; Oxidative Stress; Histopathology; Aquatic Ecotoxicology.
Page No: 129-142