Fate of polychlorinated biphenyls in a contaminated lake ecosystem: Combining equilibrium passive sampling of sediment and water with total concentration measurements of biota

Abstract

Equilibrium sampling devices can be applied to study and monitor the exposure and fate of hydrophobic organic chemicals on a thermodynamic basis. They can be used to determine freely dissolved concentrations and chemical activity ratios and to predict equilibrium partitioning concentrations of hydrophobic organic chemicals in biota lipids. The authors' aim was to assess the equilibrium status of polychlorinated biphenyls (PCBs) in a contaminated lake ecosystem and along its discharge course using equilibrium sampling devices for measurements in sediment and water and by also analyzing biota. The authors used equilibrium sampling devices (silicone rubber and polyethylene [PE]) to determine freely dissolved concentrations and chemical activities of PCBs in the water column and sediment porewater and calculated for both phases the corresponding equilibrium concentrations and chemical activities in model lipids. Overall, the studied ecosystem appeared to be in disequilibrium for the studied phases: sediment, water, and biota. Chemical activities of PCBs were higher in sediment than in water, which implies that the sediment functioned as a partitioning source of PCBs and that net diffusion occurred from the sediment to the water column. Measured lipid‐normalized PCB concentrations in biota were generally below equilibrium lipid concentrations relative to the sediment (CLip⇌Sed) or water (CLip⇌W), indicating that PCB levels in the organisms were below the maximum partitioning levels. The present study shows the application versatility of equilibrium sampling devices in the field and facilitates a thermodynamic understanding of exposure and fate of PCBs in a contaminated lake and its discharge course. Environ Toxicol Chem 2015;34:2463–2474. © 2015 SETAC

Determining equilibrium partition coefficients between lipid/protein and polydimethylsiloxane for highly hydrophobic organic contaminants using preloaded disks

“…Jahnke et al (2012) also found that Clipid,partition of PCBs were about five times higher than Clipid,biota in fish from Baltic Sea. Moreover, Clipid,partition of PCBs were higher than Clipid,biota in mussels and fish (Jahnke et al, 2014b, Mäenpää et al, 2015b, Schäfer et al, 2015, but hexachlorobenzene was approaching equilibrium (Jahnke et al, 2014a). Overall, Clipid,partition were generally higher than Clipid,biota, implying accumulation of HOCs in most field-collected organisms didn't achieve equilibrium.…”

Applications for Passive Sampling of Hydrophobic Organic Contaminants in Water—A Review

“…Monitoring alongside biota Sediments and overlying waters PCBs SR and LDPE deployed in various lake and river sediments and overlying waters alongside biota to monitor the concentration of a range of HOCs and assess the bioaccumulation prediction capacity of each device for biota at a range of trophic levels. [229,309] River waters PAHs; PCBs; pesticides SR deployed in rivers alongside resident macroinvertebrates and attached to captured fish (flathead catfish) to measure water concentrations and exposure of biota through chemical analysis of PSD extracts and biota tissues for a range of HOCs.…”

Transferring mixtures of chemicals from sediment to a bioassay using silicone-based passive sampling and dosing

“…Jars coated with a silicone polymer on the inner vertical walls have been used for passive sampling of PAHs in soils 36 and hexachlorobenzene and PCBs in sediment. 18,19,37 Coating of 180 mL amber glass jars was done as described by Reichenberg et al, 36 with slight modications. Jars were rolling horizontally and a (Dow Corning® 1-2577) polymer-pentane solution was added to the jars.…”

“…The jars were rinsed with Milli-Q water, wiped and dried thoroughly with lint-free tissues. 37 The chemicals in the polymer were extracted with 3 mL solvent by rolling the jars horizontally for 30 min. 18 We used a 1 : 1 mixture of acetone:n-hexane for extracting HOCs from the polymer inside the jars, instead of n-hexane only as previously used by Jahnke et al (where 3-7 Cl PCBs were targeted 18 ), since we aimed to capture a wider range of chemicals.…”