Synergistic toxic effects of polyvinyl chloride nano-plastics and the anticipated global temperature rise in Nile tilapia

Abstract Global warming and nano-plastic pollution are widespread problems affecting the aquatic environment. Still, there are substantial gaps in their combined effects on aquatic species, which require further study. Thus, the present study investigates the biological alterations caused by the interactive toxicity between increasing water temperatures and polyvinyl chloride nano-plastics (PVC-NPs) in Oreochromis niloticus . Using hematological parameters, acetylcholinesterase activity (AChE), DNA damage, and histopathological alterations. Fish aquaria were divided into 0 mg/L and 10 mg/L PVC-NPs exposure groups at 30 °C, 32 °C, and 34 °C in a duplicate manner. After 4 days, the hematological parameters of groups subjected to PVC-NPs and temperatures exhibited a significant decrease. Additionally, AChE activity in the muscle and brain tissues of all groups was substantially reduced. DNA fragmentation rate also showed an elevation in all fish groups’ liver, gills, and brain tissues. The liver, gills, kidney, and brain exhibited various histological changes. These changes ranged from mild and moderate alterations to severe damage, especially in groups exposed to high temperatures with PVC-NP toxicity. Finally, all current results indicated a synergistic impact between temperature and PVC-NPs on O. niloticus .