Effects of temperature on the toxicity of waterborne nanoparticles under global warming: Facts and mechanisms

Global climate change is predicted to increase the average temperature of aquatic environments. Temperature changes modulate the toxicity of emerging chemical contaminants, such as nanoparticles (NPs). However, current hazard assessments of waterborne NPs seldom consider the influence of temperature. In this review, we gathered and analyzed the effects of temperature on the toxicity of waterborne NPs in different organisms. There was a general decrease in bioavailability with increasing temperature in algae and plants due to NPs aggregation, thus, reducing their toxicities. However, the agglomerated large particles caused by the increase in temperature induce a shading effect and inhibit algal photosynthesis. The toxicity of NPs in microorganisms and aquatic animals increases with increasing temperature. This may be due to the significant influence of high temperature on the uptake and excretion of chemicals across membranes, which increase the production of reactive oxygen species and enhance oxidative damage to organisms. High temperature also affect the formation and composition of a protein corona on NPs, altering their toxicity. Our results provide new insights into the toxicity of NPs in the context of global warming, and highlight the deficiencies of current research on NPs.