Fluorinated Precursor Compounds in Sediments as a Source of Perfluorinated Alkyl Acids (PFAA) to Biota.

The environmental behavior of perfluorinated alkyl acids (PFAA) and their precursors was investigated in lake Tyrifjorden, downstream a factory producing paper products coated with per- and polyfluorinated alkyl substances (PFAS). Low water concentrations (max 0.18 ng L-1 linear perfluorooctanesulfonic acid, L-PFOS) compared to biota (mean 149 µg kg-1 L-PFOS in perch livers) resulted in high bioaccumulation factors (L-PFOS BAFPerch liver: 8.05 × 105-5.14 × 106). Sediment concentrations were high, particularly for the PFOS precursor SAmPAP diester (max 1 872 µg kg-1). Biota-sediment accumulation factors (L-PFOS BSAFPerch liver: 22-559) were comparable to elsewhere, and concentrations of PFAA precursors and long chained PFAA in biota were positively correlated to the ratio of carbon isotopes (13C/12C), indicating positive correlations to dietary intake of benthic organisms. The sum fluorine from targeted analyses accounted for 54% of the extractable organic fluorine in sediment, and 9-108% in biota. This, and high trophic magnification factors (TMF, 3.7-9.3 for L-PFOS), suggests that hydrophobic precursors in sediments undergo transformation and are a main source of PFAA accumulation in top predator fish. Due to the combination of water exchange and dilution, transformation of larger hydrophobic precursors in sediments can be a source to PFAA, some of which are normally associated with uptake from water.

Bioaccumulation of Fluorotelomer Sulfonates and Perfluoroalkyl Acids in Marine Organisms Living in Aqueous Film-Forming Foam Impacted Waters.

The use of aqueous film-forming foams (AFFFs) has resulted in hot spots polluted with poly- and perfluorinated alkyl substances (PFASs). The phase out of long-chained perfluoroalkyl acids (PFAAs) from AFFFs resulted in the necessity for alternatives, and short-chained PFAAs and fluorotelomer-based surfactants have been used. Here, the distribution of PFAS contamination in the marine environment surrounding a military site in Norway was investigated. Up to 30 PFASs were analyzed in storm, leachate, and fjord water; marine sediments; marine invertebrates (snails, green shore crab, great spider crab, and edible crab); and teleost fish (Atlantic cod, European place, and Lemon sole). Perfluorooctanesulfonic acid (PFOS) was the most abundantly detected PFAS. Differences in PFAS accumulation levels were observed among species, likely reflecting different exposure routes among trophic levels and different capabilities for depuration and/or enzymatic degradation. In agreement with previous literature, almost no 6:2 fluorotelomer sulfonate (6:2 FTS) was detected in teleost fish. However, this study is one of the first to report considerable concentrations of 6:2 FTS in marine invertebrates, suggesting bioaccumulation. Biota monitoring and risk assessments of sites contaminated with fluorotelomer sulfonates (FTSs) and related compounds should not be limited to fish, but should also include invertebrates.

Paper product production identified as the main source of per- and polyfluoroalkyl substances (PFAS) in a Norwegian lake: Source and historic emission tracking.

The entirety of the sediment bed in lake Tyrifjorden, Norway, is contaminated by per- and polyfluoroalkyl substances (PFAS). A factory producing paper products and a fire station were investigated as possible sources. Fire station emissions were dominated by the eight carbon perfluoroalkyl sulfonic acid (PFSA), perfluorooctanesulfonic acid (PFOS), from aqueous film forming foams. Factory emissions contained PFOS, PFOS precursors (preFOS and SAmPAP), long chained fluorotelomer sulfonates (FTS), and perfluoroalkyl carboxylic acids (PFCA). Concentrations and profiles in sediments and biota indicated that emissions originating from the factory were the main source of pollution in the lake, while no clear indication of fire station emissions was found. Ratios of linear-to branched-PFOS increased with distance from the factory, indicating that isomer profiles can be used to trace a point source. A dated sediment core contained higher concentrations in older sediments and indicated that two different PFAS products have been used at the factory, referred to here as Scotchban and FTS mixture. Modelling, based on the sediment concentrations, indicated that 42-189 tons Scotchban, and 2.4-15.6 tons FTS mixture, were emitted. Production of paper products may be a major PFAS point source, that has generally been overlooked. It is hypothesized that paper fibres released from such facilities are important vectors for PFAS transport in the aquatic environment.