title: PAH toxicity at aqueous solubility in the fish embryo test with Danio rerio using passive dosing.
abstract: As part of the risk assessment process within REACh, prior to manufacturing and distribution of chemical substances their (eco)toxicological impacts have to be investigated. The fish embryo toxicity test (FET) with the zebrafish Danio rerio has gained a high significance as an in vitro alternative to animal testing in (eco)toxicology. However, for hydrophobic organic chemicals it remains a technical challenge to ensure constant freely dissolved concentration at the maximum exposure level during such biotests. Passive dosing with PDMS silicone was thus applied to control the freely dissolved concentration of ten PAHs at their saturation level in the FET. The experiments gave repeatable results, with the toxicity of the PAHs generally increasing with the maximum chemical activities of the PAHs. HPLC analysis confirmed constant exposure at the saturation level. In additional experiments, fish embryos without direct contact to the silicone surface showed similar mortalities as those exposed with direct contact to the silicone. Silicone oil overlaying the water phase as a novel passive dosing phase had no observable effects on the development of the fish embryos until hatching. This study provides further data to support the close relationship between the chemical activity and the toxicity of hydrophobic organic compounds. Passive dosing from PDMS silicone enabled reliable toxicity testing of (highly) hydrophobic substances at aqueous solubility, providing a practical way to control toxicity exactly at the maximum exposure level. This approach is therefore expected to be useful as a cost-effective initial screening of hydrophobic chemicals for potential adverse effects to freshwater vertebrates.
authors.affiliation: Department of Ecosystem Analysis, Institute for Environmental Research (Biology V), RWTH Aachen University, Worringerweg 1, D-52074 Aachen, Germany. Electronic address: seiler@bio5.rwth-aachen.de.
authors.forename: Thomas-Benjamin
authors.initials: TB
authors.lastname: Seiler
authors.affiliation: Department of Ecosystem Analysis, Institute for Environmental Research (Biology V), RWTH Aachen University, Worringerweg 1, D-52074 Aachen, Germany. Electronic address: ping@gmx.de.
authors.forename: Nina
authors.initials: N
authors.lastname: Best
authors.affiliation: Department of Environmental Science, Aarhus University, Frederiksborgvej 399, PO Box 358, 4000 Roskilde, Denmark. Electronic address: mmf@dmu.dk.
authors.forename: Margit Møller
authors.initials: MM
authors.lastname: Fernqvist
authors.affiliation: Department of Ecosystem Analysis, Institute for Environmental Research (Biology V), RWTH Aachen University, Worringerweg 1, D-52074 Aachen, Germany.
authors.forename: Hendrik
authors.initials: H
authors.lastname: Hercht
authors.affiliation: Energy and Environment Centre, Korean Institute of Science and Technology Europe Forschungsgesellschaft mbH, University of Saarland, 66123 Saarbrücken, Germany. Electronic address: k.smith@kist-europe.de.
authors.forename: Kilian E C
authors.initials: KE
authors.lastname: Smith
authors.affiliation: Aquatic Ecology and Toxicology Group, Department of Zoology, University of Heidelberg, Im Neuenheimer Feld 230, D-69120 Heidelberg, Germany. Electronic address: braunbeck@uni-hd.de.
authors.forename: Thomas
authors.initials: T
authors.lastname: Braunbeck
authors.affiliation: Department of Environmental Engineering, Technical University of Denmark, Building 115, DK - 2800 Kgs. Lyngby, Denmark. Electronic address: philm@env.dtu.dk.
authors.forename: Philipp
authors.initials: P
authors.lastname: Mayer
authors.affiliation: Department of Ecosystem Analysis, Institute for Environmental Research (Biology V), RWTH Aachen University, Worringerweg 1, D-52074 Aachen, Germany. Electronic address: henner.hollert@bio5.rwth-aachen.de.
authors.forename: Henner
authors.initials: H
authors.lastname: Hollert
mesh_terms: D000818:Animals; D004129:Dimethylpolysiloxanes / Q000737:chemistry*; D004305:Dose-Response Relationship, Drug; D054750:Ecotoxicology / Q000379:methods*; D004625:Embryo, Nonmammalian / Q000187:drug effects*; D057927:Hydrophobic and Hydrophilic Interactions; D011084:Polycyclic Aromatic Hydrocarbons / Q000737:chemistry* / Q000633:toxicity*; D012995:Solubility; D014867:Water / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000737:chemistry / Q000633:toxicity; D015027:Zebrafish / Q000196:embryology*
chemical_list: D004129:Dimethylpolysiloxanes; D011084:Polycyclic Aromatic Hydrocarbons; D014874:Water Pollutants, Chemical; D014867:Water; C013830:baysilon
keywords: Chemical activity; Danio rerio; Fish embryo toxicity; PAHs; PDMS silicone; Passive dosing