Uptake of hydrophobic organic compounds, including OCPs and PBDEs, and perfluoroalkyl acids (PFAAs) in fish and blue crabs of the lower Passaic River (NJ, USA)

Abstract

The bioavailability and bioaccumulation of sedimentary hydrophobic organic compounds (HOCs) is of concern at contaminated sites. Passive samplers have emerged as a promising tool to measure the bioavailability of sedimentary HOCs and possibly to estimate their bioaccumulation. We thus analyzed HOCs including organochlorine pesticides (OCPs), polybrominated diphenyl ethers (PBDEs), polychlorinated biphenyls (PCBs) and polychlorinated dibenzo-p-dioxins/furans (PCDD/Fs) in sediment, porewater and riverwater using low density polyethylene (LDPE) passive samplers, and in 11 different finfish species and blue crab from the lower Passaic River. Additionally, perfluorinated alkyl acids (PFAAs) were measured in grab water samples, sediment and fish. Best predictors of bioaccumulation in biota were either porewater concentrations (for PCBs and OCPs), or sediment organic carbon (PBDEs and PFAAs), including black carbon (OCPs, PCBs and some PCDD/F congeners) normalized concentrations. Measured lipid-based concentrations of the majority of HOCs exceeded the chemicals’ activites in porewater by at least 2-fold, suggesting dietary uptake. Trophic magnification factors were > 1 for moderately hydrophobic analytes (log K _OW = 6.5 – 8.2) with low metabolic transformation rates (< 0.01 day ⁻¹), including longer alkyl chain PFAAs. For analytes with lower (4.5 – 6.5) and higher (>8.2) K _OWs, metabolic transformation was more important in reducing trophic magnification.