Renal and Hepatotoxic Effects of Polyethylene Terephthalate Microplastics in Chronically Exposed Albino Rats

Abstract

Background: Plastics pollution has emerged as a serious environmental and health problem, with microplastics (plastic particles less than 5 mm in size) being a major concern due to their pervasive presence in the environment serving as a potential source of toxicity affecting organs of the body which may include the kidney and liver. Aim: This study was conducted to evaluate the effects of chronic exposure to microplastics from polyethylene terephthalate (PET), a commonly used plastics on renal parameters and hepatic enzymes in albino rats. Materials and Methods: Forty-seven (47) albino rats weighing 150–170g were used for the study. Twelve (12) rats were used for pilot study, while 35 rats were randomly assigned into 5 experimental groups (n=7) after 14 days of acclimatisation. Polyethylene terephthalate pellets were crushed to microplastics, dissolved in water and filtered before use. Group B, C, and D rats received 40mg/kg, 80mg/kg, and 120mg/kg PET-microplastics respectively, administered orally for 90-days. Group E rats were given water stored in PET-containers exposed to sunlight for 30 days, while Group A served as the control. After the treatment, blood samples were analysed for serum urea, creatinine, sodium, potassium, aspartate aminotransferase (AST), alanine aminotransferase (ALT) and alkaline phosphatase (ALP) using standard biochemical methods. Data were analyzed using GraphPad Prism 9.0.0, with significance at p<0.05.  Results: Polyethylene terephthalate microplastics caused a significant dose-dependent increase in creatinine, urea, potassium, AST, ALT and ALP levels compared to the control rats (p<0.05). However, the plasma levels of these parameters except creatinine do not differ significantly in rats treated with water stored in PET compared to the control rats. There was no significant difference in sodium levels after exposure to PET microplastics (p>0.05). Conclusion: Chronic PET microplastic exposure induces nephrotoxic and hepatotoxic effects, highlighting the potential public health risks that may be associated with microplastic exposure.