Perfluoroalkyl Acids (PFAAs) and Selected Precursors in the Baltic Sea Environment: Do Precursors Play a Role in Food Web Accumulation of PFAAs?

Abstract

The present study examined the presence of perfluoroalkyl acids (PFAAs) and selected precursors in the Baltic Sea abiotic environment and guillemot food web, and investigated the relative importance of precursors in food web accumulation of PFAAs. Sediment, water, zooplankton, herring, sprat, and guillemot eggs were analyzed for perfluoroalkane sulfonic acids (PFSAs; C4,6,8,10) and perfluoroalkyl carboxylic acids (PFCAs; C6-15) along with six perfluoro-octane sulfonic acid (PFOS) precursors and 11 polyfluoroalkyl phosphoric acid diesters (diPAPs). FOSA, FOSAA and its methyl and ethyl derivatives (Me- and EtFOSAA), and 6:2/6:2 diPAP were detected in sediment and water. While FOSA and the three FOSAAs were detected in all biota, a total of nine diPAPs were only detected in zooplankton. Concentrations of PFOS precursors and diPAPs exceeded PFOS and PFCA concentrations, respectively, in zooplankton, but not in fish and guillemot eggs. Although PFOS precursors were present at all trophic levels, they appear to play a minor role in food web accumulation of PFOS based on PFOS precursor/PFOS ratios and PFOS and FOSA isomer patterns. The PFCA pattern in fish could not be explained by the intake pattern based on PFCAs and analyzed precursors, that is, diPAPs. Exposure to additional precursors might therefore be a dominant exposure pathway compared to direct PFCA exposure for fish.

Organic Contaminants in Zooplankton of Italian Subalpine Lakes: Patterns of Distribution and Seasonal Variations

“…Concentrations of PFAS in pelagic invertebrates in this study are higher than those that are reported in Baltic Sea [36], where the sums of PFSA and PFCA in zooplankton were only 0.11 ± 0.02 and 0.12 ± 0.01 ng g −1 ww, respectively. On the contrary, they are comparable with the concentrations that were measured in the Gironde estuary (France) [37] and in the Arctic Canadian Lakes that are not contaminated by local airport [38].…”

Investigation of the spatial variability of poly- and perfluoroalkyl substance trophic magnification in selected riverine ecosystems

“…EtFOSAA in the present case) concentration ratios were calculated for all invertebrates and whole fish samples, provided that both values were above the LOD (25/106 samples) ( (Asher et al, 2012;Gebbink et al, 2016;Munoz et al, 2017). The FOSA/OSD ratio was not related to δ 15 N at any site; however, significant differences were observed between invertebrates and fish (p-value < 0.0001).…”

“…For instance, the use of concentrations determined in whole organisms or in specific tissues (e.g., liver, muscle or plasma) can directly impact the calculated TMF values (Houde et al, 2006b). In addition, some studies suggested that the biotransformation of perfluoroalkyl acid (PFAA) precursors could bias, either positively or negatively, the assessment of PFAA biomagnification (Franklin, 2016;Gebbink et al, 2016).…”

Biomagnification of perfluoroalkyl acids (PFAAs) in the food web of an urban river: assessment of the trophic transfer of targeted and unknown precursors and implications

“…Identified PFAA precursors (pre-PFAAs) include for instance (alkyl-)perfluoroalkyl sulfonamides ((alkyl-)FASAs) [13][14][15] , (alkyl-) perfluoroalkyl sulfonamidoacetic acids ((alkyl-)FASAAs) 2 or polyfluoroalkyl phosphoric acid diesters (diPAPs) 16 . Gebbink et al, 17 proposed that precursors could play a significant role in the biomagnification of PFCAs in fish from the Baltic Sea and species-specific biotransformation of pre-PFAAs was suggested in fish from the Rhône River 18 . Additional pre-PFAAs including fluorotelomer sulfonates (FTSAs) previously detected in aquatic ecosystems 19,20 , could also contribute to the biomagnification of PFAAs, since their biotransformation can lead to the production of PFCA homologues [21][22][23] .…”