Dose-Dependent Toxicological Effects of Polyvinyl Chloride and Polystyrene Microplastics on Wistar Albino Rats

Microplastics (MPs), diameter < 5 mm, are becoming a major environmental health concern issue but there is still less information available about the exposure and toxicity of MPs on mammal health. In the current study, we assessed the effects of MPs, Polyvinyl chloride (PVC), and Polystyrene (PS) toxicity on body weight, blood glucose, different blood parameters, and oxidative stress of Wistar albino rats. SEM analysis was performed for the characterization of PVC and PS MPs. In in vivo analysis, the rats were divided into five groups and four groups; Groups 2 to 5 were exposed to PVC and PS at different doses (300 and 1000 mg/kg), and Group 1 was used as a control group. After 8 weeks of exposure, the change in body weight and blood parameters was determined, which showed a significant alteration in the animals' bodies. The addition of polyvinyl chloride and polystyrene to the rats showed a significant decline in body weight (PVC 0.0021: PS 0.0055) and an increase in blood glucose (PVC 0.0006; PS 0.0009). The harmful effect was also analyzed on internal organs which depicted the increase in total cholesterol (PVC 0.0006; PS 0.0009), triglyceride (PVC 0.0001; PS 0.0026), low-density lipoprotein (PVC 0.0226; PS 0.0051), alanine transaminase (PVC; PS < 0.0001), albumin (PVC 0.0037; PS 0.0001), creatinine (PVC; PS < 0.0001), uric acid (PVC 0.0009; PS 0.0014), superoxide dismutase (PVC 0.0025; PS 0.0017), malonaldehyde (PVC; PS < 0.0001) whereas decrease in high density lipoprotein (PVC 0.0255; PS 0.0057), alkaline phosphatase (PVC; PS < 0.0001) and catalase (PVC 0.0095; PS 0.030). Also, the histopathological analysis of the renal and hepatic tissue showed the toxicological effect of PVC and PS. The outcomes of the current work depicted that the MPs, PVC, and PS have toxic effects on animals and humans.