The effect of nano plastic toxicity on the gill tissue of goldfish (Carassius auratus)

With the increase in plastic pollution in aquatic ecosystems, nanoplastics have become an emerging pollutant, raising serious environmental concerns. Among these pollutants, polystyrene nanoplastics are of particular importance due to their very small size, high stability, and ability to penetrate biological tissues. The aim of this study is to investigate the effects of polystyrene nanoplastic toxicity on histological changes in goldfish gills, as one of the most sensitive respiratory and ionic regulation organs in fish. In this study, fishes were randomly divided into group control and two treatments with different concentrations (0.5 mg/L and 1 mg/L) of polystyrene nanoplastics and were exposed to these particles for 10, 15, and 20 days. After the end of the exposure period, gill samples were collected and, after fixation and appropriate staining, tissue changes were examined microscopically. The results of the study showed that exposure of fish to polystyrene nanoplastics leads to significant pathological changes in gill tissue, which increase with increasing nanoplastic concentration. In conclusion, it can be said that polystyrene nanoplastics caused structural damage to gill tissue, disrupt respiratory function and ionic balance in fish, and can be considered a serious threat to aquatic animal health and the sustainability of aquatic ecosystems.