Exploration of polyacrylamide microplastics and evaluation of their toxicity on multiple parameters of Oreochromis niloticus

Due to the increased production of polyacrylamide microplastics in the environment impacting the adverse effects on aquatic organisms have become a global concern. The present study aimed to evaluate the toxicity of different concentrations (0.018, 0.03 0.09 g/1) of polyacrylamide microplastics on <i>Oreochromis niloticus.</i> Polyacrylamide microplastics were characterized by Fourier transform infrared and Raman spectroscopy. The FTIR technique revealed the spherical morphology and size range of polyacrylamide (0.1-0.4 mm) with 99 % purity. Raman Spectroscopy results showed peaks around (1100 cm^-1 and 1650 cm^-1) in gills, these peaks confirmed the presence of polyacrylamide microplastics in the gills of <i>Oreochromis niloticus</i>. Polyacrylamide microplastics significantly shortened the antioxidant enzymes (Catalase and Reduced glutathione) proceedings and the increase was observed in Malondialdehyde and Lipid peroxide levels in high-dose treated groups. Moreover, total protein contents were expressively increased, while other blood parameters (AST, ALP, ALT) were significantly decreased. Hemoglobin (g/dl), Erythrocyte (106/µl) and TLC (1x10⁹/l) levels were reduced significantly (<i>p <</i> 0.05) in high concentrations. The administration of polyacrylamide microplastics induced different histological changes in the gills, liver and intestine of <i>O. niloticus</i>. It was concluded that polyacrylamide microplastics are toxic agents having harmful effects on fish health.