Synergistic impact of temperature rises and ferric oxide nanoparticles on biochemical and oxidative stress biomarkers in Oreochromis niloticus: relevant environmental risk assessment under predicted global warming

Global warming and contamination of freshwater environments with nanoparticles (NPs) pose a global threat to biodiversity. Numerous studies demonstrated the effects of increasing temperatures and NPs separately, but their combined impact on aquatic life remains poorly understood or unstudied, particularly under predicted rising temperatures resulting from global warming (+ 2 and + 4 °C). So, the present study aims to determine how the temperature rises affect the toxicological characteristics of ferric oxide nanoparticles (Fe₂O₃ NPs) on the prevalent freshwater fish, Nile tilapia (Oreochromis niloticus). Fish samples were randomly put into six glass aquaria groups: 0 mg/L Fe₂O₃ NPs and 25 mg/L Fe₂O₃ NPs groups at 30 °C, 32 °C, and 34 °C with duplicated aquaria per group for 4 days. Hydrodynamic size and zeta potential evaluations revealed that Fe₂O₃ NPs' aggregation in water decreases with high temperature. Additionally, increasing the temperature and exposure to Fe₂O₃ NPs led to a significant rise in total proteins, albumin, globulin, plasma aspartate aminotransferase (AST), plasma alanine aminotransferase (ALT), plasma alkaline phosphatase (ALP), creatinine, and uric acid. We also noticed alterations in the amounts of malondialdehyde (MDA), glutathione reduced (GSH), and catalase (CAT) in the fish's liver and gills. Finally, our findings indicated that Fe₂O₃ NPs' toxicity in fish escalated with increasing temperature, peaking at 34 °C due to particle property changes caused by temperature elevation. Therefore, it should not ignore the impact of the projected global increasing temperatures on NPs toxicity in freshwater habitats.