Bioavailability of Persistent Organic Pollutants in Fish from Gunston Cove (Potomac River Watershed, Virginia)
Date
2013-08-16
Authors
Moody, Adam
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Abstract
Three classes of Persistent Organic Pollutants (POPs): Polycyclic Aromatic Hydrocarbons (PAHs), Polychlorinated Biphenyls (PCBs) and Organochlorine Pesticides (OCPs) were investigated in aquatic biota and bed sediments from an embayment-river mainstem of the Potomac River. Mean sediment concentrations ranged from 2.85 * 10^3 to 3.27 * 10^3 ng g^-1 for total-PAHs, 27.9 to 29.6 ng g-^1 for total-PCBs, 1.42 to 1.66 ng g^-1 for 4,4’-DDE and 0.65-0.66 ng g^-1 for γ-chlordane. A greater portion of high molecular weight PAHs were present in the bed sediments indicating high contribution of pyrogenically-derived PAHs. Consensus-based Threshold Effect Concentrations (TECs) have been compared to concentrations of total-PAHs, individual PAHs, total-PCBs and individual OCPs. Mean concentrations of POPs in fish tissue ranged from 5.4 to 34.3 ng g^-1 for total-PAHs, 40 to 116 ng g^-1 for total-PCBs, 14.0 to 28.9 ng g^-1 for 4,4’-DDE and <LOD to 1.8 ng g^-1 for γ-chlordane. The highest total-PCB and 4,4’-DDE concentrations were observed in White Perch (Morone americana) and Spottail Shiner (Notropis hunsonius) indicating strong correlation with their dietary consumptions. The median biota-sediment accumulation factor (BSAF) estimated in all fish species for total-PCBs was 1.88. However, some individual and co-eluting PCB congeners had median BSAFs that were substantially greater (e.g. congener numbers 44, 84, 91, 138/164, 151, 158 and 183) or lower (e.g. congener numbers 22, 56/60, 191 and 208) than the total-PCB average. Bioaccumulation for PCB congeners showed a somewhat parabolic relation with n-octanol/water partition coefficients, confirming some previous investigations. The median BSAF value for 4,4’-DDE was 9.58, higher than all other analytes of interest indicating an exceptionally high affinity to partition into aquatic biota. No clear trend was observed between apparent bioaccumulation factors and trophic level.
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Keywords
Bioaccumulation, Pesticides, PCBs, Fish, PAHs, Sediment