Toxic effects of microplastic (polyethylene) exposure: Bioaccumulation, hematological parameters and antioxidant responses in crucian carp, Carassius carassius

The purpose of this study was to evaluate the toxic effects of polyethylene microplastics (PE-MPs) by measuring the bioaccumulation, hematological parameters, and antioxidant responses in crucian carp (Carassius Carassius) exposed to waterborne 22-71 mu m PE-MPs. C. carassius (mean weight, 24.0 +/- 2.1 g; mean length, 13.1 +/- 1.2 cm) were exposed to PE-MPs at concentration of 0, 4, 8, 16, 32, and 64 mg/L for 2 weeks. The accumulation of PE -MPs in each tissue of C. carassius was significantly increased in proportion to the PE-MPs concentration; the highest accumulation was observed in the intestine, followed by the gills and liver. Hematological parameters, plasma components and antioxidants responses were significantly affected by PE-MPs in a concentration -dependent manner. Exposure to >= 32 mg/L PE-MPs induced a significant decrease in red blood cells (RBCs), hemoglobin (Hb) content, and hematocrit values. However, exposure to >= 32 mg/L PE-MPs induced oxidative stress in the liver, gill, and intestine of C. carassius, thereby resulting in a significant increase in the levels of superoxide dismutase (SOD), catalase (CAT), and glutathione S-transferase (GST) and a decrease in glutathione (GSH) levels. The effects of interaction between the PE-MPs and exposure periods showed no significant changes