Genotoxicity in the goldfish of TiO2 nanoparticles combined with high CO2 levels.

TiO2 nanoparticles are photocatalytic, generate reactive oxygen, and can be harmful to aquatic biota. We have studied the toxic effects of nTiO2 combined with high CO2 levels in water. We exposed goldfish to environmentally relevant concentrations of nTiO2 and CO2 levels. Comet assay results showed that DNA breaks increased at high CO2 concentration, but no effect of nTiO2 concentrations was seen. Micronucleus assays showed no significant micronucleus formation. Histopathological alterations were seen in the gills but not in the liver.