Dioxins and PCBs in solid matter from the river Elbe, its tributaries and the North Sea (longitudinal profile, 2008)

The most recent longitudinal sampling profile, taken in 2008 from the river Elbe and its tributaries Vltava (Moldau), Mulde, Spittelwasser, Saale, Bode the Stör and the North Sea near Helgoland, shows contaminations of solid matter with polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans (dioxins, PCDD/Fs) and polychlorinated biphenyls (PCBs). While the dioxin contamination is mainly located along the German part of the catchment, PCBs are more abundant in the Czech section. In some of the 43 solid samples investigated high levels of contamination were detected. Selected orientation benchmarks for dioxins and PCBs in sediments and fish are exceeded, suggesting potential hazards for organisms in the contaminated rivers and for human consumption. Elevated dioxin concentrations in the Spittelwasser-Mulde system and the Saale catchment, together with consistent dioxin congener patterns Elbe downstream of the confluence, indicate that the region of Bitterfeld-Wolfen is the predominant source of the dioxin pollution, which can be traced until far off shore in the sediments of the North Sea near Helgoland. Thermal metal, presumably Magnesium production via fused salt electrolysis during the 2nd world war is the most probable primary, historic source of the dioxin contamination. The spatial distribution of dioxins as seen in 2008 matched well with earlier campaigns in 2002, both for aquatic solids and alluvial soils, suggesting minor change of the situation since then. Also the samples from the North Sea revealed elevated levels of dioxins that display the congener pattern from the Bitterfeld-Wolfen Region. In contrast to the PCDD/Fs, PCBs are mainly present in the in the Upper Elbe in the Czech Republic. After the German border PCBs display an overall decrease. Other than PCDD/Fs, PCB emissions into the Elbe cannot be attributed to a dominant source or region. Indicator PCBs did rise more or less constantly in concentration until the German border, suggesting a variety of cumulative emission sources along the whole Czech stretch. Thus, no specific recommendation on how to decrease the PCB pressure on the River Elbe can be given on the basis of the data acquired in this study. Detailed regional scale monitoring in the Czech stretch, together with the evaluation of production statistics regarding potential PCB sources are needed here. After all the PCB toxicity in eel is exceeding that of PCDD/F up to an order of magnitude (investigations of eels taken after the flood event in August 2002). As an amendment to the chemical analyses, two Ah-receptor based bioassays (DR CALUXR and EROD), which display the dioxin–like activity of all pollutants present, were performed on a subset of the samples (blind study). For The DR CALUXR the comparison revealed a good agreement between the HRGC/HRMS results along the German stretch and the bioassay. However, along the Czech section of the Elbe the DR CALUXR displayed a 10 times higher dioxin-like activity than the chemical analyses. This suggests that the solid material in the Czech section contains additional persistent dioxin-like acting pollutants. In comparison to the DR CALUXR test, the EROD assay displayed even higher dioxin-like activities. The differences can be explained by the fact that the clean up procedure for the DR CALUXR eliminated the less persistent organic pollutants in the extract, while the EROD procedure remained sensitive to those. Regarding the risk for the aquatic food chain and the human diet, the reduction of PCBs in the River Elbe ecosystem appears crucial as indicated by the dominance of the PCB over the PCDD/Fs in toxicity equivalents detected in eel samples.JRC.H.1-Water Resource

Dioxins and Dioxin-Like PCBS in Solid Material from the River Elbe, its Tributaries and from the North Sea

A distinct PCDD/F contamination of the German Elbe sediments, originating from the Mulde catchment and in particular from the creek Spittelwasser, affects the River Elbe until the coastal waters of the North Sea. PCDD/F levels in these tributaries and in Elbe sediments downstream their confluence exceed available quality standards in relation to wildlife and human consumption, thus indicating the need for an appropriate management of contaminated sediments and alluvial soils. In addition the former magnesium production sites in the region of Bitterfeld-Wolfen need to be further investigated to assess the risk of further releases and to project adequate safeguarding measures. PCBs in the Elbe sediments instead are more abundant in the Czech Republic, again exceeding the available quality standards. In contrast to the PCDD/Fs, the spatial distribution of PCBs in the sediments is more uniform. From the data presented in this study no particular sources could be evidenced. More detailed surveys are needed to evaluate the potential for remediation measures along the Czech stretch.JRC.DDG.H.5-Rural, water and ecosystem resource

Bio/Chemical Analysis of Sediments from the Elbe River, the North Sea and from Several Tributaries

23 sediment and SPM samples from the River Elbe in GER, CZ and the North Sea, analised by the JRC via standard methods (GC, HRMS, isotope dilution) were analysed with an Ah receptor test for dioxin like activity (DR CALUX). The CALUX test results showed a good correlatio with the results from standad instrumental analysis. No false negatives were observed asnd the CALUX test overestimated dioxin like activity in those samples with a high content of the 7-marker PCBs. In so far the CALUX test appeared to be technivcall y feasible for screening purpose of dioxin like activity in terrestrial and marine sediments.JRC.DDG.H.5-Rural, water and ecosystem resource

The Impact of Groyne Fields on Downstream Particle-Bound Dioxin Concentrations in the Elbe River (Germany)

Sediment concentrations of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDDs/PCDFs) in sections of the Elbe River basin significantly exceed background concentrations and contribute to fish tissue concentrations that regularly exceed maximum allowable concentrations established by the European Commission. Multivariate statistical analyses of PCDD/PCDF congener patterns suggest that the source of this contamination is effluent from thermic processes related to the metallurgical industry (e.g. magnesium production) in the Bitterfeld-Wolfen region, which were released into the Mulde River, a tributary to the Elbe River. A minimum of 72 % of the total sediment PCDD/PCDF concentration measured in Hamburg originates in the Mulde River catchment. While the contribution of the Bitterfeld-Wolfen region to Hamburg dioxin concentrations is well understood, the role of the groynes fields in retaining particle-bound contaminants had yet to be evaluated. Of particular interest is the effect of groynes on travel time of particle-bound contaminants from Mulde River basin to Hamburg. This temporal information is crucial to evaluating the benefits of potential sediment remediation in the Mulde River. To better understand the fate and transport of cohesive sediments and associated dioxin, a hydrodynamic and cohesive sediment model for the German segment of the Elbe River was developed. Integration of modeling output with the results of recently collected (2008) sediment and suspended sediment dioxin data enabled an enhanced understanding of the dynamics of dioxin and cohesive sediment in the Elbe River basin.JRC.DDG.H.5-Rural, water and ecosystem resource

Dioxin-like activity of sediments of the Elbe River and associated flood areas

The aim of the present study was the determination of cytotoxic hazard potential and dioxin-like activity of sediments from the riverbed of the Elbe River and of associated flood plains. Of peculiar interest were industrial locations with high contamination. Settled particulate matter samples from the flood areas of the Elbe River were taken after the flood disaster of 2003. The riverbed samples originate from the river head down to the estuary mouth and were sampled in the year 2008, after the flood. Freeze-dried sediments were extracted with n-hexane:acetone (1:1, v/v) by means of pressurized liquid extraction (PLE). The Neutral red assay on cytotoxicity and the EROD (7-ethoxy-resorufin-o-deethylase) assay on dioxin-like activity were then applied with the resulting extracts using the RTL-W1 permanent cell line. Within this study the main focus was set on polychlorinated biphenyles (PCBs), polycyclic aromatic hydrocarbons (PAHs) and polychlorinated dibenzodioxins and -furanes (PCDDs/Fs), which interact with the aryl hydrocarbon receptor (AhR) and cause EROD induction. Moreover, in order to identify whether PAHs, PCDDs or PCBs cause the strongest effects in the EROD assay, a multilayer fractionation was performed. Finally, results of the bioassays were compared with available analytical data to evaluate the significance of the used in-vitro bioassays.JRC.DDG.H.5-Rural, water and ecosystem resource