Equilibrium sampling of polychlorinated biphenyls in River Elbe sediments – Linking bioaccumulation in fish to sediment contamination. (November 2015)

• Record Type: Journal Article
• Authors: Schäfer, Sabine; Antoni, Catherine; Möhlenkamp, Christel; Claus, Evelyn; Reifferscheid, Georg; Heininger, Peter; Mayer, Philipp
• Is Part Of: Chemosphere. Volume 138(2015)
• Page Start: 856
• Page End: 862
• Publication Date: 2015-11
• Subjects: Equilibrium sampling -- Sediment -- Bioaccumulation -- Polychlorinated biphenyl (PCB) -- River Elbe -- Freely dissolved concentration (cfree); Pollution -- Periodicals; Pollution -- Physiological effect -- Periodicals; Environmental sciences -- Periodicals; Atmospheric chemistry -- Periodicals; 551.511
• DOI: 10.1016/j.chemosphere.2015.08.032
• Languages: English
• ISSNs: 0045-6535

Abstract

Graphical abstract: Highlights: Application of equilibrium sampling in routine sediment monitoring. Freely dissolved concentrations ( c free ) of PCBs in sediments. Determining PCB concentrations in lipids at equilibrium with sediment ( c lip⇌sed ). Close link between sediment contamination and fish bioaccumulation. Cross validation of two independent monitoring programs. Abstract: Equilibrium sampling can be applied to measure freely dissolved concentrations ( c free ) of hydrophobic organic chemicals (HOCs) that are considered effective concentrations for diffusive uptake and partitioning. It can also yield concentrations in lipids at thermodynamic equilibrium with the sediment ( c lip ⇌ sed ) by multiplying concentrations in the equilibrium sampling polymer with lipid to polymer partition coefficients. We have applied silicone coated glass jars for equilibrium sampling of seven 'indicator' polychlorinated biphenyls (PCBs) in sediment samples from ten locations along the River Elbe to measure c free of PCBs and their c lip ⇌ sed . For three sites, we then related c lip ⇌ sed to lipid-normalized PCB concentrations ( c bio, lip ) that were determined independently by the German Environmental Specimen Bank in common bream, a fish species living in close contact with the sediment: (1) In all cases, c bio, lip were below c lip ⇌ sed, (2) there was proportionality between the two parameters with high R 2 values (0.92–1.00) and (3) the slopes of the linear regressions were very similar between the three stations (0.297; 0.327; 0.390). These results confirm the close link between PCB bioaccumulation and the thermodynamic potential of sediment-associated HOCs for partitioning into lipids. This novel approach gives clearer and more consistent results compared to conventional approaches that are based on total concentrations in sediment and biota-sediment accumulation factors. We propose to apply equilibrium sampling for determining bioavailability and bioaccumulation potential of HOCs, since this technique can provide a thermodynamic basis for the risk assessment and management of contaminated sediments.