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Stuttgart, Germany

Knobel M.,Eawag - Swiss Federal Institute of Aquatic Science and Technology | Busser F.J.M.,University Utrecht | Rico-Rico A.,University Utrecht | Kramer N.I.,University Utrecht | And 7 more authors.
Environmental Science and Technology | Year: 2012

The zebrafish embryo toxicity test has been proposed as an alternative for the acute fish toxicity test, which is required by various regulations for environmental risk assessment of chemicals. We investigated the reliability of the embryo test by probing organic industrial chemicals with a wide range of physicochemical properties, toxicities, and modes of toxic action. Moreover, the relevance of using measured versus nominal (intended) exposure concentrations, inclusion of sublethal endpoints, and different exposure durations for the comparability with reported fish acute toxicity was explored. Our results confirm a very strong correlation of zebrafish embryo to fish acute toxicity. When toxicity values were calculated based on measured exposure concentrations, the slope of the type II regression line was 1 and nearly passed through the origin (1 to 1 correlation). Measured concentrations also explained several apparent outliers. Neither prolonged exposure (up to 120 h) nor consideration of sublethal effects led to a reduced number of outliers. Yet, two types of compounds were less lethal to embryos than to adult fish: a neurotoxic compound acting via sodium channels (permethrin) and a compound requiring metabolic activation (allyl alcohol). © 2012 American Chemical Society. Source

Hahn S.,Fraunhofer Institute for Toxicology and Experimental Medicine | Schneider K.,Research and Advisory Institute for Hazardous Substances GmbH FoBiG | Gartiser S.,Hydrotox GmbH | Heger W.,German Federal Environmental Agency | Mangelsdorf I.,Fraunhofer Institute for Toxicology and Experimental Medicine
Environmental Health: A Global Access Science Source | Year: 2010

Background. Products containing biocides are used for a variety of purposes in the home environment. To assess potential health risks, data on products containing biocides were gathered by means of a market survey, exposures were estimated using a worst case scenario approach (screening), the hazard of the active components were evaluated, and a preliminary risk assessment was conducted. Methods. Information on biocide-containing products was collected by on-site research, by an internet inquiry as well as research into databases and lists of active substances. Twenty active substances were selected for detailed investigation. The products containing these substances were subsequently classified by range of application; typical concentrations were derived. Potential exposures were then estimated using a worst case scenario approach according to the European Commission's Technical Guidance Document on Risk Assessment. Relevant combinations of scenarios and active substances were identified. The toxicological data for these substances were compiled in substance dossiers. For estimating risks, the margins of exposure (MOEs) were determined. Results. Numerous consumer products were found to contain biocides. However, it appeared that only a limited number of biocidal active substances or groups of biocidal active substances were being used. The lowest MOEs for dermal exposure or exposure by inhalation were obtained for the following scenarios and biocides: indoor pest control using sprays, stickers or evaporators (chlorpyrifos, dichlorvos) and spraying of disinfectants as well as cleaning of surfaces with concentrates (hydrogen peroxide, formaldehyde, glutardialdehyde). The risk from aggregate exposure to individual biocides via different exposure scenarios was higher than the highest single exposure on average by a factor of three. From the 20 biocides assessed 10 had skin-sensitizing properties. The biocides isothiazolinone (mixture of 5-chloro-2-methyl-2H-isothiazolin-3-one and 2-methyl-2H-isothiazolin-3-one, CMI/MI), glutardialdehyde, formaldehyde and chloroacetamide may be present in household products in concentrations which have induced sensitization in experimental studies. Conclusions. Exposure to biocides from household products may contribute to induction of sensitization in the population. The use of biocides in consumer products should be carefully evaluated. Detailed risk assessments will become available within the framework of the EU Biocides Directive. © 2010 Hahn et al; licensee BioMed Central Ltd. Source

A concept for determining the anaerobic biodegradability of high-concentrated wastewater (HCW) by means of a semibatch-method based on DIN EN ISO 21734 is proposed. The TOC of the HCW investigated was 15000-25000 mg/L. At higher test concentrations, as intended, inhibition effects were observed. In order to avoid these, a semibatch-method was applied by dosing 1 % HCW over 5 weeks into the flasks. Hereby, the hydraulic load was similar to that of the technical digestion tower. After the last dosing the flasks were further incubated until the digestion gas production was negligible. After the anaerobic pre-treatment the HCW was precipitated and aerobically biodegraded in the Zahn-Wellens test. The anaerobic biodegradation of the HCW was 79 % based on the production of digestion gas. The magnitude was confirmed by a rough estimate of the carbon balance of the digestion tower. The concept allows a cost-effective determination of the anaerobic and aerobic degradation potential of liquid substrates during the co-fermentation. Source

Enaud E.,Catholic University of Louvain | Trovaslet M.,Catholic University of Louvain | Bruyneel F.,Catholic University of Louvain | Billottet L.,Catholic University of Louvain | And 10 more authors.
Dyes and Pigments | Year: 2010

The enzymatic synthesis of an azoanthraquinone by Perenniporia ochroleuca MUCL 41114 laccase was undertaken. The major product was purified and its structure identified by NMR, MS, IR analyses. In order to scale up the production of this azoanthraquinone named Laccase Acid Red 1, a commercial laccase from Trametes versicolor immobilised on perlite as an inexpensive carrier was used. Laccase Acid Red 1 showed lower toxicity than other commercial red dyes, was not mutagenic and displayed low ecotoxicity. In addition, its dyeing properties were assayed on polyamide and the industrial potential of the dye was demonstrated. To our knowledge, this is the first example of sulfonic azoanthraquinone production through enzymatic coupling of aromatic amine monomers. These results show promise for new, safer and environmental friendly routes to azo dye biosynthesis. © 2009 Elsevier ltd. Source

Gartiser S.,Hydrotox GmbH | Hafner C.,Hydrotox GmbH | Kronenberger-Schafer K.,Hydrotox GmbH | Happel O.,DVGW Technologiezentrum Wasser TZW | And 2 more authors.
Environmental Science and Pollution Research | Year: 2012

Many pharmaceuticals and related metabolites are not efficiently removed in sewage treatment plants and enter into surface water. There, they might be subject of drinking water abstraction and treatment by ozonation. In this study, a systematic approach for producing and effect-based testing of transformation products (TPs) during the drinking water ozonation process is proposed. For this, two pharmaceutical parent substances, three metabolites and one environmental degradation product were investigated with respect to their biodegradability and fate during drinking water ozonation. The Ames test (TA98, TA100) was used for the identification of mutagenic activity present in the solutions after testing inherent biodegradability and/or after ozonation of the samples. Suspicious results were complemented with the umu test. Due to the low substrate concentration required for ozonation, all ozonated samples were concentrated via solid phase extraction (SPE) before performing the Ames test. With the exception of piracetam, all substances were only incompletely biodegradable, suggesting the formation of stable TPs. Metformin, piracetam and guanylurea could not be removed completely by the ozonation process. We received some evidence that technical TPs are formed by ozonation of metformin and piracetam, whereas all tested metabolites were not detectable by analytical means after ozonation. In the case of guanylurea, one ozonation TP was identified by LC/MS. None of the experiments showed an increase of mutagenic effects in the Ames test. However, the SPE concentration procedure might lead to false-positive results due to the generation of mutagenic artefacts or might lead to false-negative results by missing adequate recovery efficiency. Thus, these investigations should always be accompanied by process blank controls that are carried out along the whole ozonation and SPE procedure. The study presented here is a first attempt to investigate the significance of transformation products by a systematic approach. However, the adequacy and sensitivity of the methodology need to be further investigated. The approach of combining biodegradation and ozonation with effect-based assays is a promising tool for the early detection of potential hazards from TPs as drinking water contaminants. It can support the strategy for the evaluation of substances and metabolites in drinking water. A multitude of possible factors which influence the results have to be carefully considered, among them the selectivity and sensibility of the mutagenicity test applied, the extraction method for concentrating the relevant compounds and the biocompatibility of the solvent. Therefore, the results have to be carefully interpreted, and possible false-negative and false-positive results should be considered. © 2012 Springer-Verlag. Source

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