Mixture toxicity of PFAS in zebrafish larvae and HepG2 cells

PFAS (Per‐ and poly‐fluoroalkyl substances) are organofluorine compounds, that are widely used in commercial and industrial products due to their unique physical and chemical properties. They are considered persistent organic pollutants in different environmental matrices and can cause toxic effects on humans and other organisms. In this study, we aimed at investigating the mixture toxicity of important PFAS, both in vitro and in vivo. Perfluorohexanesulfonic acid (PFFIxS), perfluorononanoic acid (PFNA), perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS) were tested as single compounds and in binary, ternary and quaternary mixtures after 48 h treatment in zebrafish larvae and after 4 h treatment in FlepG2 cells. Eendpoints were mortality in zebrafish larvae and cytotoxicity in HepG2 cells. The experimental data was compared with the data predicted by the concentration‐addition‐model to understand the putative toxicity interaction including addition, synergism or antagonism. The results of the individual compound tests indicate a clear concentration‐dependent increase of the zebrafish larval mortality and cytotoxicity in FlepG2 cells for all four tested compounds. The half‐maximal lethal concentration (LC 50 ) for zebrafish larvae and the half‐maximal inhibitory concentration (IC 50 ) for FlepG2 cells were determined and were the basis for composition of the respective mixtures. We conclude that most mixtures of the four tested PFAS predominantly lead to additive effects. Binary mixtures with PFOS tend to exhibit a slight antagonism, and ternary mixtures with PFNA show a slight synergism.