Trophic transfer potential of nTiO₂, nZnO, and triclosan in an algae-algae eating fish food chain

Little is known about the trophic transfer of nanoparticles and personal care products via dietary exposure in an algae-algae eating fish food chain. The bioaccumulation of nano-TiO₂ (P25 - nTiO₂), nano-ZnO (nZnO), and triclosan (TCS) in eight different combinations were explored in this study through algae, Asterococcus superbus, to fish, Gyrinocheilus aymonieri. Results found the bioaccumulation of TCS changed with algal biomass, while the bioaccumulation of Ti and Zn varied with the amount of lipids and proteins in algal cells. In algae, Ti was in the form of nTiO₂ and Zn in the form of zinc ion. Due to dietary exposure, Ti and Zn quantity in fish was closely related to that in algae. The quantity of Ti and Zn in algae and fish exposed to the interaction of nTiO₂ * nZnO* TCS was higher than that in other treatments. The uptake of Ti and Zn in algae exposed to the interaction of nTiO₂ * nZnO had been inhibited, and the corresponding fish also had less Ti and Zn in their tissues. nTiO₂-containing treatments had higher Ti proportion in muscle than gill in fish. Treatment nZnO had the most Zn in gill, whereas nZnO * TCS-containing treatments had higher Zn proportion in gut than other tissues. No observation of TCS in fish in all treatments suggested the removal and metabolism of TCS might be induced by tissue recovery and acclimation. This is the first report on trophic transfer of mixed nanoparticles and personal care product in an algae-algae eating fish two-stage food chain.