Lethal and sub-lethal effects of nanosized titanium dioxide particles on Hydropsyche exocellata Dufour, 1841

Nanosized titanium dioxide particles (nTiO₂) are one of the most widely used nanoscale engineered materials. Evidence of the presence of nTiO₂ in freshwater systems has been reported by recent ecotoxicological studies, which indicated the potential toxic effects of nTiO₂ to aquatic organisms. This study aimed at exploring lethal and sub-lethal endpoints of aqueous exposure of the aquatic insect Hydropsyche exocellata Dufour, 1841 (Trichoptera, Hydropsychidae) to nTiO₂ at different concentrations. Abdominal contractions significantly increased with nTiO₂ exposure. Levels of lipid peroxidation (LPO) increased with nTiO₂ dose, whereas the opposite was recorded for the antioxidant enzyme catalase activity (CAT). Moreover, the highest exposure (50.0 mg/L) resulted in the highest mortality (56% of mortality two weeks after pulse exposure to nTiO₂). Overall, our results show that nTiO₂ has potential toxic effects on H. exocellata at concentrations of 50.0 mg/L.