Comparison of zinc metal concentration in chronic exposure to zinc oxide nanoparticles alone and in combination with silver nanoparticles in different tissues of zebrafish (Danio rerio)

The level of toxicity of contaminants undergoes changes in simultaneous exposure to other environmental pollutants and can cause different damages compared to their single exposure in aquatic animals. Therefore, this study aimed to quantitatively evaluate the uptake, elimination, and bioconcentration of zinc in exposure to zinc oxide nanoparticles in the presence and absence of silver nanoparticles in the gill, intestine, and liver tissues of zebrafish using toxicokinetic modeling. In the present study, 216 pieces of zebrafish (Danio rerio) were exposed to a non-lethal concentration of ZnO NPs (10 mg L-1), and two combined treatments of non-lethal concentrations of ZnO NPs and Ag NPs (10 mg L-1 of ZnO NPs + 0.02 or 0.04 mg L-1 of Ag NPs) along with the control were placed in three replications. After the completion of different sampling periods, the concentration of zinc metal in water and different tissues was measured. The results of this research showed that the concentration of zinc in the presence of Ag NPs was higher in gill > intestine > liver tissue, respectively. Also, the shortest half-life of zinc metal was observed in the gill tissue and the combined treatment of Ag NPs. The findings showed that in addition to the tissue, exposure time, and concentration, the presence of Ag NPs also affects the concentration of zinc metal.