Histology Based Whole Effluent Chronic Toxicity Testing of Noodles Processing Company Waste, Using the Kidney of Clarias gariepinus as a Biomarker

Background: Industrial effluents discharged into aquatic environments pose significant ecological and biological threats, particularly to aquatic species like Clarias gariepinus. This study investigated the chronic toxicity of effluents from a noodle food industry, focusing on the environment water quality and its histological impact on the kidney of Clarias gariepinus. Materials and Method: The following known aquatic contaminants from food industries were selected as the effluent target chemical (TC) of concern: cadmium (Cd), copper (Cu), chromium (Cr), lead (Pb), nickel (Ni) and polyaromatic hydrocarbons (PAH). Effluent samples were analyzed for TC constituents, and their effects on fish kidney were assessed under varying concentrations (6.25%, 12.5%, 25%, 50%, and 100%). Results: Results revealed that most effluent parameters, such as copper, chromium, and nickel, were within NESREA and USEPA limits, while cadmium levels (0.037 mg/L) exceeded permissible thresholds, highlighting significant pollution concerns. Histological analysis revealed significant kidney damage, including tubular necrosis, glomerular damage, and inflammation.