Do microplastics pose health hazard?: A laboratory study by Oreochromis niloticus

Microplastics (MPs) are pervasive environmental contaminants, particularly in aquatic ecosystems, yet their wide-ranging human and environmental hazards remain poorly understood. To address this, our study aimed to quantify the total polymer risk index (H) and associated health risk levels based on MP concentrations. A tank based approach was introduced to evaluate this objective. Total 150 tilapia ( Oreochromis niloticus ) were equally distributed in 15 glass tank (5 treatment group, 3 tank for each group). FTIR analysis, hazard ranking model and health risk assessment model were utilized. 12 different MP polymers were determined by FTIR analysis in organs of tilapia fish in all the experimental tanks. Among them, PVC and PC possessed the highest hazard score (Sn) 10551 and 1177 respectively. Polymeric and health risk index results showed that fish organs of TG-2 contained highest polymer risk index (H=1526.62) with category IV health risk which was attributed to very high level of risk. Estimated daily and annual index results from tilapia muscles revealed MPs exposure by different population in the following manner: children>elderly>pregnant women>adult. Though the number of MPs exposure was found to be relatively low, the risk level of detected polymers e.g. PC cannot be neglected due to its very high hazard score. Thus this study offers a primary set of data that is crucial for MP contamination in tilapia fish for several interconnected reasons, primarily revolving around food safety, environmental protection, and human health .