Author(s)

Adriana Wigh¹, Selim Aït-Aïssa², Nicolas Creusot², Hugo Terrisse^3,4, Marie-Laure Delignette-Muller^3,4, Alexandre Bergé⁵, Emmanuelle Vulliet⁵, Bruno Domenjoud⁶, Adriana Gonzalez-Ospina⁶, Vanessa Brosselin¹, Alain Devaux¹, Sylvie Bony¹

¹Université de Lyon, INRA USC 1369, CNRS UMR 5023 LEHNA, Vaulx-en-Velin, France.
²INERIS, Unité d’Ecotoxicologie in vitro et in vivo (ECOT), Verneuil-en-Halatte, France.
³Université de Lyon, CNRS, UMR 5558, Laboratoire de Biométrie et Biologie Evolutive, Villeurbanne, France.
⁴Université de Lyon, Vet Agro Sup Campus Vétérinaire de Lyon, Marcy l’Etoile, France.
⁵Université de Lyon, Institut des Sciences Analytiques, UMR5280 CNRS, Villeurbanne, France.
⁶SUEZ International-Treatment Infrastructure, Wastewater Technical Division, Rueil-Malmaison, France.

Toxicity of wastewater treatment plant (WWTP) effluents is usually assessed with standardized bioassays, as e.g. the Fish Embryo Toxicity test (FET), but assessment of sub-lethal toxic effects requires to develop more adapted tests. The present work aimed to add the recording of several sub-lethal endpoints in exposed zebrafish embryo-larval stages in order to increase the sensitivity of residual toxicity evaluation of WWTP effluents using a semi-quantitative method (iFET score). This approach was complemented with the genotoxicity assessment on the exposed embryos, a sub-acute hazard particularly relevant to evaluate a potential chronic toxicity risk of low and multi-contaminated environmental matrices. Additionally, endocrine activities of effluents were quantified using human reporter cell lines. This test battery was applied to the assessment of the residual toxicity of five biological treatment effluents, further treated or not using various ozonation treatments intended to improve pharmaceutical compounds removal. Acute toxicity towards zebrafish embryos was very low. However, iFET score approach proposed was able to reveal residual toxicity through the presence of developmental abnormalities in all samples tested. Additionally, a low residual genotoxicity was measured in embryos exposed to two of the WWTP effluents when all excepted one exhibited a residual endocrine activity potential in the ng/L range providing complementary information on the occurrence of endocrine active chemicals and their reduction by different processes. To sum up, such a simplified and ecologically relevant test battery was found sensitive enough to characterize and differentiate various residual effluent’s ecotoxicity at contaminant levels of environmental concern.

Wastewater, Ozonation, Genotoxicity, Endocrine Activity, Zebrafish, Early Life Stage, Pharmaceutical, Surfactant

Wigh, A. , Aït-Aïssa, S. , Creusot, N. , Terrisse, H. , Delignette-Muller, M. , Bergé, A. , Vulliet, E. , Domenjoud, B. , Gonzalez-Ospina, A. , Brosselin, V. , Devaux, A. and Bony, S. (2018) Assessment of Ozone or Not-Treated Wastewater Ecotoxicity Using Mechanism-Based and Zebrafish Embryo Bioassays. Journal of Environmental Protection, 9, 325-346. doi: 10.4236/jep.2018.94022.