title: The oxidized state of the nanocomposite Carbo-Iron® causes no adverse effects on growth, survival and differential gene expression in zebrafish.
abstract: For degradation of halogenated chemicals in groundwater Carbo-Iron®, a composite of activated carbon and nano-sized Fe(0), was developed (Mackenzie et al., 2012). Potential effects of this nanocomposite on fish were assessed. Beyond the contaminated zone Fe(0) can be expected to have oxidized and Carbo-Iron was used in its oxidized form in ecotoxicological tests. Potential effects of Carbo Iron in zebrafish (Danio rerio) were investigated using a 48 h embryo toxicity test under static conditions, a 96 h acute test with adult fish under semi-static conditions and a 34 d fish early life stage test (FELST) in a flow-through system. Particle diameters in test suspensions were determined via dynamic light scattering (DLS) and ranged from 266 to 497 nm. Particle concentrations were measured weekly in samples from the FELST using a method based on the count rate in DLS. Additionally, uptake of particles into test organisms was investigated using microscopic methods. Furthermore, effects of Carbo-Iron on gene expression were investigated by microarray analysis in zebrafish embryos. In all tests performed, no significant lethal effects were observed. Furthermore, Carbo-Iron had no significant influence on weight and length of fish as determined in the FELST. In the embryo test and the early life stage test, growth of fungi on the chorion was observed at Carbo-Iron concentrations between 6.3 and 25mg/L. Fungal growth did not affect survival, hatching success and growth. In the embryo test, no passage of Carbo-Iron particles into the perivitelline space or the embryo was observed. In juvenile and adult fish, Carbo-Iron was detected in the gut at the end of exposure. In juvenile fish exposed to Carbo-Iron for 29 d and subsequently kept for 5d in control water, Carbo-Iron was no longer detectable in the gut. Global gene expression in zebrafish embryos was not significantly influenced by Carbo-Iron.
authors.affiliation: ECT Oekotoxikologie GmbH, Böttgerstrasse 2-14, 65439 Flörsheim, Germany. Electronic address: m.weil@ect.de.
authors.forename: Mirco
authors.initials: M
authors.lastname: Weil
authors.affiliation: Fraunhofer Institute for Ceramic Technologies and Systems, Winterbergstrasse 28, 01277 Dresden, Germany. Electronic address: tmeiss@gmx.net.
authors.forename: Tobias
authors.initials: T
authors.lastname: Meißner
authors.affiliation: Helmholtz Centre for Environmental Research - UFZ, Dept. of Bioanalytical Ecotoxicology, Permoser Strasse 15, 04318 Leipzig, Germany. Electronic address: wibke.busch@ufz.de.
authors.forename: Wibke
authors.initials: W
authors.lastname: Busch
authors.affiliation: Centre for Translational Bone, Joint and Soft Tissue Research, Technical University Dresden, Fetscherstrasse 74, 01307 Dresden, Germany. Electronic address: armin.springer@tu-dresden.de.
authors.forename: Armin
authors.initials: A
authors.lastname: Springer
authors.affiliation: Helmholtz Centre for Environmental Research - UFZ, Dept. of Bioanalytical Ecotoxicology, Permoser Strasse 15, 04318 Leipzig, Germany. Electronic address: dana.kuehnel@ufz.de.
authors.forename: Dana
authors.initials: D
authors.lastname: Kühnel
authors.affiliation: Institute for Environmental Sciences, University of Koblenz-Landau, Fortstrasse 7, 76829 Landau, Germany. Electronic address: schulz@uni-landau.de.
authors.forename: Ralf
authors.initials: R
authors.lastname: Schulz
authors.affiliation: ECT Oekotoxikologie GmbH, Böttgerstrasse 2-14, 65439 Flörsheim, Germany. Electronic address: k-duis@ect.de.
authors.forename: Karen
authors.initials: K
authors.lastname: Duis
mesh_terms: D000818:Animals; D002606:Charcoal / Q000633:toxicity; D004625:Embryo, Nonmammalian; D015870:Gene Expression / Q000187:drug effects; D007501:Iron / Q000633:toxicity; D053761:Nanocomposites / Q000633:toxicity*; D018675:Toxicity Tests; D014874:Water Pollutants, Chemical / Q000633:toxicity*; D015027:Zebrafish
chemical_list: D014874:Water Pollutants, Chemical; D002606:Charcoal; D007501:Iron
keywords: Excretion; Fish toxicity; Groundwater remediation; Iron-based nanocomposite; Uptake