title: Is UV radiation changing the toxicity of compounds to zebrafish embryos?
abstract: At ecosystems level, environmental parameters such as temperature, pH, dissolved oxygen concentration and intensity of UV radiation (UVR) have an important role on the efficiency of organisms' physiological and behavioral performances and consequently on the capacity of response to contaminants. Insignificant alterations of these parameters may compromise this response. In addition, these parameters can additionally alter chemical compounds by inducing their degradation, producing thereafter other metabolites. Understanding the combined effects of chemicals and environmental parameters is absolutely necessary for an adequate prediction of risk in aquatic environments. According to this scenario, this work aims at studying the combined toxicity of UVR and three xenobiotics: the biocide triclosan (TCS), the metal chromium (as potassium dichromate, PD) and the fungicide prochloraz (PCZ). To achieve this goal zebrafish (Danio rerio) embryos (3h post fertilization (hpf)) were exposed to several concentrations of each chemical combined with different UV intensities; mortality and eggs were recorded every 24h for the all test duration (96 h). Results showed different response patterns depending on the toxicant, stress levels and duration of exposure. The combination of UVR and TCS indicated a dose ratio deviation where synergism was observed when UVR was the dominant stressor (day 2). The combination of UVR and PD presented a dose level dependency at day 3 indicating antagonism at low stress levels, changing with time where at day 4, a dose ratio deviation showed statistically that synergism occurred at higher PD concentrations. Finally, UVR combined with PCZ indicated a dose ratio at day 3 and dose level deviation at day 4 of exposure, suggesting a synergistic response when PCZ is the dominant stressor in the combination. The obtained results in this study highlighted the importance of taking into account the possible interaction of stressors and time of exposure to better predict environmental risk.
authors.affiliation: Department of Biology & CESAM (Centre for Environmental and Marine Studies), University of Aveiro, Portugal, Campus Universitário de Santiago, 3810 Aveiro, Portugal. Electronic address: rita.almeida@ua.pt.
authors.forename: Ana Rita
authors.initials: AR
authors.lastname: Almeida
authors.affiliation: Department of Biology & CESAM (Centre for Environmental and Marine Studies), University of Aveiro, Portugal, Campus Universitário de Santiago, 3810 Aveiro, Portugal.
authors.forename: Thayres S
authors.initials: TS
authors.lastname: Andrade
authors.affiliation: University of South Bohemia in Ceske Budejovice, Faculty of Fisheries and Protection of Waters, South Bohemian Research Center of Aquaculture and Biodiversity of Hydrocenoses, Zatisi 728/II, Vodnany 389 25, Czech Republic.
authors.forename: Viktoriia
authors.initials: V
authors.lastname: Burkina
authors.affiliation: University of South Bohemia in Ceske Budejovice, Faculty of Fisheries and Protection of Waters, South Bohemian Research Center of Aquaculture and Biodiversity of Hydrocenoses, Zatisi 728/II, Vodnany 389 25, Czech Republic.
authors.forename: Ganna
authors.initials: G
authors.lastname: Fedorova
authors.affiliation: Department of Biology & CESAM (Centre for Environmental and Marine Studies), University of Aveiro, Portugal, Campus Universitário de Santiago, 3810 Aveiro, Portugal.
authors.forename: Susana
authors.initials: S
authors.lastname: Loureiro
authors.affiliation: Department of Biology & CESAM (Centre for Environmental and Marine Studies), University of Aveiro, Portugal, Campus Universitário de Santiago, 3810 Aveiro, Portugal; Programa de Pós-Graduação em Produção Vegetal, Universidade Federal do Tocantins, Campus de Gurupi, Rua Badejós, Zona Rural, Cx Postal 66, CEP 77402-970 Gurupi, TO, Brasil.
authors.forename: Amadeu M V M
authors.initials: AM
authors.lastname: Soares
authors.affiliation: Department of Biology & CESAM (Centre for Environmental and Marine Studies), University of Aveiro, Portugal, Campus Universitário de Santiago, 3810 Aveiro, Portugal.
authors.forename: Inês
authors.initials: I
authors.lastname: Domingues
mesh_terms: D000818:Animals; D000891:Anti-Infective Agents, Local / Q000633:toxicity; D004625:Embryo, Nonmammalian / Q000187:drug effects* / Q000528:radiation effects*; D005659:Fungicides, Industrial / Q000633:toxicity; D007093:Imidazoles / Q000633:toxicity*; D011192:Potassium Dichromate / Q000633:toxicity*; D014260:Triclosan / Q000633:toxicity*; D014466:Ultraviolet Rays; D014874:Water Pollutants, Chemical / Q000633:toxicity; D015027:Zebrafish
chemical_list: D000891:Anti-Infective Agents, Local; D005659:Fungicides, Industrial; D007093:Imidazoles; D014874:Water Pollutants, Chemical; D014260:Triclosan; C045362:prochloraz; D011192:Potassium Dichromate
keywords: Chromium; Combined effects; Danio rerio; Prochloraz; Triclosan; UV radiation