Ingestion of Polyvinylchloride Powder Particles Induces Oxidative Stress and Hepatic Histopathological Changes in Oreochromis niloticus (Nile Tilapia)—A Preliminary Study

Plastic debris is considered an emerging aquatic pollutant as an alarming number of reports are indicating the environmental contamination with such agents. Ichthyofauna has been subjected to increasing plastic pollution over the past years, which has led to detrimental effects in the food chain, and consequently to the general health of ecosystems. In this study, we exposed juvenile specimens of Oreochromis niloticus to polyvinyl chloride (PVC) in powder form. Specimens and water parameters were closely monitored for 40 days before tissue samples were collected for histological and biochemical analysis. Structural hepatic alterations were observed in specimens from the exposed groups, such as intercellular corridors, dilation of sinusoidal capillaries, hyperchromatic nuclei, nuclear hypertrophy, and cytoplasm vacuolization. Low catalase activity was observed in the case of 1000 mg of PVC/kg feed group, as well as high levels of malondialdehyde compared to the control group, indicating oxidative stress. Glutathione peroxidase activity was also significantly decreased in the 500 and 1000 mg/kg feed group compared to the control group. These findings suggest that a midterm exposure to PVC particles can significantly affect the activity of antioxidative enzymes in O. niloticus specimens and induce changes of hepatic tissue structure.