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.