Study of the Toxicological Effects of Acute and Chronic Exposure to Nano Polystyrene on Hematological and Oxidative Stress Indicators in Rats

This study investigated the toxic effects of nano polystyrene plastic particles in laboratory rats using hematological and biochemical analyses. In both acute and chronic exposures, hematological alterations were evident, with a marked increase in white blood cell (WBC) counts, indicating an activated immune response and systemic stress in the fish. In contrast, red blood cell (RBC) counts and hemoglobin (HGB) levels consistently declined, suggesting impaired erythropoiesis, reduced oxygen-carrying capacity, and possible hematological toxicity. These combined changes reflect a shift toward inflammatory and immune activation, alongside anemia-like effects, which may compromise physiological balance and overall health. In both acute and chronic exposures, oxidative stress biomarkers showed significant alterations, as catalase (CAT) activity and malondialdehyde (MDA) levels were markedly increased, reflecting enhanced lipid peroxidation and activation of antioxidant defense mechanisms in the cells. In contrast, superoxide dismutase (SOD) activity decreased, indicating a weakened primary antioxidant response and a reduced capacity to neutralize superoxide radicals. These combined changes suggest an imbalance in the oxidative/antioxidant system, where elevated oxidative damage and insufficient enzymatic defense contribute to cellular stress and potential tissue injury due to exposure to nano polystyrene. This study resulted in some behavioral and physiological alterations, including reduced appetite, weight loss, alopecia, lethargy, sleep disturbances, and heightened aggression, indicating that chronic exposure to nano polystyrene disrupts neurological, metabolic, and systemic functions, indicating its potential classification as a cumulative toxicant with progressive adverse effects. In summary, both acute and chronic exposure to nano polystyrene in rats disrupts hematological function and induces oxidative stress