Contribution of Priority PAHs and POPs to Ah Receptor-Mediated Activities in Sediment Samples from the River Elbe Estuary, Germany

Abstract

The estuary of the River Elbe between Hamburg and the North Sea (Germany) is a sink for contaminated sediment and suspended particulate matter (SPM). One major concern is the effect of human activities on the hydrodynamics, particularly the intensive dredging activities in this area that may result in remobilization of sediment-bound pollutants. The aim of this study was to identify pollutants contributing to the toxicological risk associated with re-suspension of sediments in the Elbe Estuary by use of an effect-directed analysis that combines chemical and biological analyses in with specific fractionation techniques.Sediments were collected from sites along the Elbe Estuary and a site from a small harbor basin of the Elbe Estuary that is known to be polluted. The sixteen priority EPA-PAHs were quantified in organic extracts of sediments. In addition, dioxin equivalents of sediments were investigated by use of the 7-ethoxyresorufin O-deethylase assay with RTL-W1 cells and the Ah receptor-mediated luciferase transactivation assay with H4IIE-luc cells.Quantification of the 16 priority PAHs revealed that sediments were moderately contaminated at all of the sites in the Elbe River Estuary (<0.02–0.906 µg/g dw). Sediments contained relatively small concentrations of dioxin equivalents (Bio-TEQ) with concentrations ranging from 15.5 to 322 pg/g dw, which were significantly correlated with dioxin equivalents calculated based on toxicity reference values and concentrations of PAH. The concentration of Bio-TEQ at the reference site exceeded 200,000 pg/g dw. In a potency balance the 16 PAHs explained between 47 and 118% of the Bio-TEQ in the luciferase assay, which can be explained by the constant input of PAHs bound to SPM from the upper course of the Elbe River into its estuary. Successful identification of a significant portion of dioxin-like activity to priority PAHs in complex environmental samples such as sediments has rarely been reported.

Linking Ah receptor mediated effects of sediments and impacts on fish to key pollutants in the Yangtze Three Gorges Reservoir, China — A comprehensive perspective

“…The obtained bio-TEQ EC25 values mainly exceeded those of crude extracts measured with RTL-W1 cells from the Yangtze Estuary (39-324 pg g − 1 ) , the German Elbe River Estuary (16-322 pg g − 1 ) (Otte et al, 2013) and European Danube River (20-123 pg g − 1 ) (Keiter et al, 2008), whereas compared to the Tietê River in Brazil (n.d. -24,170 pg g −1 ) (Suares Rocha et al, 2010) and to the European Rhine River (2387-4553 pg g −1 ; 3620 and 7920 pg g − 1 ) (Schulze et al, 2014;Heimann et al, 2011, respectively) activities ranged in the lower to medium range for most of the sediments investigated there.…”

“…17%) (Keiter et al, 2008;Liu et al, 2014;Suares Rocha et al, 2010). A part of the missing activity in those studies could be explained by other persistent pollutants -like PCBs, polychlorinated dibenzodioxins (PCDDs) and -furans (PCDFs) -as isolated by multilayer fractionation (Keiter et al, 2008;Liu et al, 2014;Otte et al, 2013). However, PCBs as well as several pesticides, like atrazine, and several other compounds can be excluded as causative agents as they could not be detected in the sediment extracts of this study (Floehr et al, in press).…”

“…Phthalic acid esters (PAEs) were the other detectable main compound class, but were not regarded to be involved in the measured activity due to their inability to bind to the AhR based on their structure. While Otte et al (2013) could refer the majority of activity to priority PAHs in most of the samples from the Elbe Estuary, only a minority of the activity could be explained by PAHs in sediment studies about the Yangtze Estuary (max. 10%), the Tietê River (max.…”

Towards science-based sediment quality standards—Effects of field-collected sediments in rainbow trout (Oncorhynchus mykiss)

“…Concentrations of these 16 EPA-PAHs in the PR and ZE sediments were within the range typically found in the river Elbe. Reported values from the literature ranged from below 1.00, to a maximum of 509.40 mg kg −1 dw (Feiler et al, 2012;Otte et al, 2013).…”

Evaluation of the Ecotoxicity of Sediments from Yangtze River Estuary and Contribution of Priority PAHs to Ah Receptor-Mediated Activities

“…The bio-TEQs of the sediments from different locations were compared on the basis of the reported results regardless of the difference between the extraction methods. EROD induction potential of the sediment extracts from the Yangtze River estuary was comparable to that of the sediment extracts from River Elbe estuary [41] and Saginaw Bay [42]. The sediment extracts from the Yangtze River estuary showed higher EROD induction potential than those from Masan Bay [43], Tai Lake [44], and Yellow Sea [45].…”