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Wolz J.,RWTH Aachen | Fleig M.,Water Technology Center | Schulze T.,Helmholtz Center for Environmental Research | Maletz S.,RWTH Aachen | And 6 more authors.
Journal of Soils and Sediments

Purpose: The presented study investigated on contamination of suspended particulate matter (SPM) in rivers that was sampled long-term and with higher frequency during a flood event at the river Rhine. It was conducted to determine in vitro biological effects as well as to identify and quantify compound classes and effective contaminants. Research was part of investigation on hazards of contaminants bound to SPM to inundated sites and retention areas that are inundated during flood events. Material and methods: SPM was sampled in 2006 and more frequently in a flood event (August, 2007) at the river Rhine barrage of Iffezheim, Germany. SPM was GC-MS analyzed for hexachlorobenzene (HCB), several polychlorinated biphenyls (PCBs) as well as for polycyclic aromatic hydrocarbons (PAHs). Flood samples were fractionated applying a recently developed automated fractionation method to receive further insight into contaminant loads in flood SPM. Impacts on biological scale were assessed using in vitro biotests for xenometabolic 7-ethoxyresorufin-o-deethylase (EROD) assay as well as for mutagenic activity (Ames fluctuation assay). EROD induction was calculated as biological equivalent concentrations (bio-TEQs) and mutagenic potentials were shown as NOECs and maximum induction factors. Results and discussion: Chemical analysis gave low concentrations of PCBs (2006 and 2007) and HCB (2006). HCB concentrations increased during the flood in 2007 (maximum, 110 μg/kg SPM). Concentrations of PCBs were only initially elevated in the flood (maximum, 67 μg/kg SPM). EROD induction bio-TEQs ranged from 1,160 to 6,640 pg/g SPM in 2006 and showed maximum bio-TEQ at the peak discharge in 2007. There was no mutagenic activity with SPM of both years. Fractionation indicated highest EROD induction in PAH fractions with prioritized (EPA-) PAHs contributing to less than 1% to the fractions total bio-TEQ but also fractions containing more polar-to-polar substances were shown to contribute minor. Furthermore, more polar fractions were mutagenic active with SPM sampled after the peak of discharge (IFmax = 14.7). Conclusions: Contaminants bound to flood SPM can be hazardous to inundated retention areas. Concentrations can be assumed to be increasing correlated with discharge and, thus, with more extreme flood events. Furthermore, biological effects are elevated or first place appearing with SPM from floods. Hazards have to be expected not only from persistent and non-polar substances but alike from less persistent and more polar ones that, furthermore, are more relevant evaluating hazards to drinking water resources from public well fields. © 2010 Springer-Verlag. Source

Wolz J.,RWTH Aachen | Schulze T.,Helmholtz Center for Environmental Research | Lubcke-von Varel U.,Helmholtz Center for Environmental Research | Fleig M.,Water Technology Center | And 5 more authors.
Journal of Soils and Sediments

Purpose: This study was carried out to determine hazards of particle-bound contaminants in rivers to retention areas close to public well fields in the context of flood events. The focus was on the assessment of soil contamination at a planned retention area. Soil core samples were chemically and biologically analyzed. Samples were fractionated to identify and compare contaminant loads and biological effects of soil and flood suspended particulate matter (SPM). Material and methods: Soil cores were sampled at inundated and non-inundated sites at a planned retention area. Soil was analyzed for hexachlorobenzene (HCB), polychlorinated biphenyls (PCBs) as well as for polycyclic aromatic hydrocarbons (PAHs). The highest inducing soil sample was fractionated applying a recently developed automated fractionation method to receive further insight into contaminant loads in soil at inundated sites. Impacts on biological scale were assessed using in vitro biotests for xenometabolic activity (7-ethoxyresorufin-o-deethylase (EROD) assay) as well as for mutagenic activity (Ames fluctuation assay). EROD induction was calculated as biological equivalent concentration (bio-TEQ), and mutagenic potentials were given as no observed effect concentration (NOEC) and maximum induction factor (IFmax). Results and discussion: Soil core samples of each site induced EROD activity. However, extracts of soil sampled at a ground swale was by far the highest inducing (topsoil bio-TEQ = 41,000 pg/g). Further, chemical analysis yielded relative increases in concentration in particular: HCB (0.05 mg/kg), PCBs (0.19 mg/kg), and EPA-PAHs (39 mg/kg). Extracts of soil samples caused no mutagenic effects. PAHs caused the bulk of EROD activity (bio-TEQ = 32,000 pg/g) with ground swale topsoil fractions. Further, fractions containing moderately polar and polar substances gave elevated effects (bio-TEQ = 8,200 pg/g). Mutagenic potentials were shown with most fractions. However, highest induction was observed with fractions containing moderately polar to polar substances reflected by a NOEC ≥0.03 mg/ml and an IFmax ≤29. Conclusions: Soil contamination at floodplains is heterogeneous but may reach elevated levels with soil swales giving highest chemical concentrations and biological effects with total sample extracts and fractions. The origin of floodplain soil contamination can be evaluated using lines of evidence which may result in identification of contaminant transport path from sediment, via flood SPM to soil. Taking hazard assessment of floodplain soil forward to risk evaluation may indicate a concern which highlights the need to further investigate on hazards caused by eroded sediment in flood events to avoid conflicts of interest when planning and operating retention basins. © 2010 Springer-Verlag. Source

Wolz J.,RWTH Aachen | Brack W.,Helmholtz Center for Environmental Research | Moehlenkamp C.,German Federal Institute for Hydrology | Claus E.,German Federal Institute for Hydrology | And 3 more authors.
Science of the Total Environment

Suspended particulate matter (SPM) sampled during a flood event in the year 2004 at the rivers Neckar and Rhine (Southwest Germany) was assessed for aryl hydrocarbon receptor (AhR)-mediated activities using EROD induction in the rainbow trout liver cell line RTL-W1. All EROD inductions were normalized to the positive control TCDD and given as bio-TEQ values. Since all samples indicated elevated AhR-mediated toxicities, an effect-directed analysis (EDA) was applied to identify substances causing the effects. In three primary fractions (F1 to F3) non-polar aliphatics, non-polar aromatic substances and more polar substances were separated. Fraction F2, co-eluting with non-polar polyaromatic substances (PACs) including polycyclic aromatic hydrocarbons (PAHs) gave highest AhR-agonistic effects and, thus, were sub-fractionated into seven secondary fractions (F2-1 to F2-7). Fraction F2-1, co-eluting with PCBs and PCDD/Fs, did not cause AhR-agonist activities. F2-2 to F2-4 containing PACs of less than 16 aromatic C-atoms produced minor activities. Highest inductions were detected with fraction F2-5 to F2-7, containing substances of more than 16 aromatic C-atoms (bio-TEQs up to approximately 4500. pg/g).Concentrations and relative potencies (REPs) of priority EPA-PAHs allowed the calculation of chemical toxicity equivalent concentrations (chem-TEQ values). Based on the chem-TEQs, EPA-PAHs explained between 5 and 58% of crude extract bio-TEQs from both rivers. Whereas fractions F2-1 to F2-4 indicated no biological activities, EPA-PAHs in fraction F2-5 to F2-7 accounted for 2 to 137% of AhR-related activities. © 2010 Elsevier B.V. Source

Keiter S.,RWTH Aachen | Peddinghaus S.,RWTH Aachen | Feiler U.,German Federal Institute for Hydrology | von der Goltz B.,University of Heidelberg | And 10 more authors.
Journal of Soils and Sediments

Introduction The European Water Framework Directive aims to achieve a good ecological and chemical status in surface water of European rivers by the year 2015. Since sediments and particulate matter act as secondary sources for pollutants, applied sediment toxicology is perceived to play a major role for obtaining new knowledge that can contribute to successful attainment of the goal. However, the existing bioassays for sediment toxicity analyses do not provide sufficient data concerning bioavailability of environmental pollutants. In this regard, there is an urgent need to combine sediment contact assays with gene expression analysis to investigate mechanism-specific sediment toxicity. Purpose The aim of the novel joint research project is to develop a eukaryotic test system, which can be used to investigate the ecotoxicological effects of contaminated sediments on gene expression level (DNA-array and RT-PCR). Current ecotoxicological research customarily involves a battery of bioassays to cover different toxicological endpoints (e.g., teratogenicity, genotoxicity, mutagenicity, Ah-receptor- mediated toxicity, neurotoxicity). In contrast, methods that detect alterations in gene expression offer deeper insight by elucidating how chemical exposure and/or environmental challenge affect multiple metabolic pathways leading to these particular kinds of toxic response. Gene expression profiles reflect the way cells and organisms adapt or respond to a changing environment. Conclusion The present project aspires to increase the fundamental molecular and physiological knowledge concerning the mode of action of environmental toxicants in zebrafish (Danio rerio). By working with partners from the academic and research institutions as well as from industry and waterway regulations, the success of this basic research-driven joint project in terms of development and implementation of novel sediment toxicity methods will be realized. © 2010 Springer-Verlag. Source

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