title: Embryotoxic and genotoxic effects of sewage effluents in zebrafish embryo using multiple endpoint testing.
abstract: Wastewater treatment plant (WWTP) effluents are often complex mixtures of various organic and inorganic substances. Quality control of wastewaters and sludges has been regulated with measuring several physico-chemical parameters and sometimes using biological methods with non-specific responses, while synergistic action mechanisms of contaminants in such complex mixtures is still unknown. Toxic effects of wastewaters within and downstream of the WWTP in City of Virovitica, Croatia, were tested on zebrafish Danio rerio using a set of biomarkers that enabled an insight in wastewaters toxic potential on embryos at the cellular, tissue and the whole organism level during an early ontogenesis (24 and 48 hpf). Exposure of embryos to the wastewater samples from WWTP Virovitica increased mortality and abnormality rate. Heart rate, spontaneous movements and pigmentation formation were also markedly affected. Biochemical markers confirmed the presence of MXR inhibitors in all tested wastewater samples, indicating the increase of pollutant accumulation in the cell/organism. Also, a tendency of DNA damage decrease measured with Comet assay was evident in wastewater samples downstream from WWTP although control levels were not reached in any environmental sample. Histopathological analysis showed that exposure to tested samples resulted in impaired muscle organization, notochord malformation and retardation in eye and brain development at embryos 48 hpf. Furthermore, semi-quantitative histopathology assessment indicated increased percentage of embryo defects in river water sampled several kilometers downstream from the WWTP, confirming toxic potential of WWTP effluents. Extension of the zebrafish embryotoxicity test (ZET) with biochemical and histopathological biomarkers could serve as a guiding principle in biomonitoring of wastewater contamination.
authors.affiliation: Laboratory for Biotechnology in Aquaculture, Division of Materials Chemistry, Ruđer Bošković Institute, Bijenička Cesta 54, Zagreb, Croatia.
authors.forename: Sanja
authors.initials: S
authors.lastname: Babić
authors.affiliation: Laboratory for Biotechnology in Aquaculture, Division of Materials Chemistry, Ruđer Bošković Institute, Bijenička Cesta 54, Zagreb, Croatia.
authors.forename: Josip
authors.initials: J
authors.lastname: Barišić
authors.affiliation: Division of Zoology, Department of Biology, Faculty of Science, University of Zagreb, Rooseveltov trg 6, Zagreb, Croatia.
authors.forename: Hrvoje
authors.initials: H
authors.lastname: Višić
authors.affiliation: PathCon Laboratories EU, Prilaz Ivana Visina 1-3, Zagreb, Croatia.
authors.forename: Roberta
authors.initials: R
authors.lastname: Sauerborn Klobučar
authors.affiliation: Laboratory for Biotechnology in Aquaculture, Division of Materials Chemistry, Ruđer Bošković Institute, Bijenička Cesta 54, Zagreb, Croatia.
authors.forename: Natalija
authors.initials: N
authors.lastname: Topić Popović
authors.affiliation: Laboratory for Biotechnology in Aquaculture, Division of Materials Chemistry, Ruđer Bošković Institute, Bijenička Cesta 54, Zagreb, Croatia.
authors.forename: Ivančica
authors.initials: I
authors.lastname: Strunjak-Perović
authors.affiliation: Laboratory for Biotechnology in Aquaculture, Division of Materials Chemistry, Ruđer Bošković Institute, Bijenička Cesta 54, Zagreb, Croatia.
authors.forename: Rozelindra
authors.initials: R
authors.lastname: Čož-Rakovac
authors.affiliation: Division of Zoology, Department of Biology, Faculty of Science, University of Zagreb, Rooseveltov trg 6, Zagreb, Croatia. Electronic address: goran.klobucar@biol.pmf.hr.
authors.forename: Göran
authors.initials: G
authors.lastname: Klobučar
mesh_terms: D000818:Animals; D004784:Environmental Monitoring; D012722:Sewage; D062065:Wastewater / Q000737:chemistry; D014874:Water Pollutants, Chemical; D015027:Zebrafish
chemical_list: D012722:Sewage; D062065:Wastewater; D014874:Water Pollutants, Chemical
keywords: ABC transport proteins; Comet assay; Histopathology; Wastewater; Zebrafish embryo test