Transport of Legacy Perfluoroalkyl Substances and the Replacement Compound HFPO-DA through the Atlantic Gateway to the Arctic Ocean—Is the Arctic a Sink or a Source?

Abstract

The spatial distribution of 29 per- and polyfluoroalkyl substances (PFASs) in seawater was investigated along a sampling transect from Europe to the Arctic and two transects within Fram Strait, located between Greenland and Svalbard, in the summer of 2018. Hexafluoropropylene oxide-dimer acid (HFPO-DA), a replacement compound for perfluorooctanoic acid (PFOA), was detected in Arctic seawater for the first time. This provides evidence for its long-range transport to remote areas. The total PFAS concentration was significantly enriched in the cold, low-salinity surface water exiting the Arctic compared to warmer, higher-salinity water from the North Atlantic entering the Arctic (260 ± 20 pg/L versus 190 ± 10 pg/L). The higher ratio of perfluoroheptanoic acid (PFHpA) to perfluorononanoic acid (PFNA) in outflowing water from the Arctic suggests a higher contribution of atmospheric sources compared to ocean circulation. An east–west cross section of the Fram Strait, which included seven depth profiles, revealed higher PFAS concentrations in the surface water layer than in intermediate waters and a negligible intrusion into deep waters (>1000 m). Mass transport estimates indicated a net inflow of PFASs with ≥8 perfluorinated carbons via the boundary currents and a net outflow of shorter-chain homologues. We hypothesize that this reflects higher contributions from atmospheric sources to the Arctic outflow and a higher retention of the long-chain compounds in melting snow and ice.

PAHs in the North Atlantic Ocean and the Arctic Ocean: Spatial Distribution and Water Mass Transport

“…We found that with the increase of PAH molecular weight, the net mass flux to the Arctic Ocean increased. Previous studies reveal similar trends for PFAS, as a net outflow for shorter‐chain PFASs and HCHs, while a net inflow for the PFASs with ≥eight perfluorinated carbons or high‐molecule‐weighted PCBs (Joerss et al., 2020; Y. Ma et al., 2018).…”

Legacy and Emerging Per- and Polyfluoroalkyl Substances: Analytical Techniques, Environmental Fate, and Health Effects

“…The concentration gradient of HFPO-DA in ocean water decreased with increasing distance from the European coastline, suggesting that emissions from European waters are likely the primary source of this compound. However, mass transport profiles for other PFAS suggested that long-range atmospheric deposition contributes significantly to legacy PFAS in Arctic outflow [75]. This study demonstrated for the first time the long-range transport of HFPO-DA to remote regions.…”

“…Compared with levels near FPPs, environmental concentrations of emerging PFAS distant from direct emission sources remain relatively low, indicating emissions from fluorochemical manufacturing are primarily responsible for the presence of these compounds in the environment. Still, the detection of emerging alternatives such as HFPO-DA [75] in remote regions suggests that despite relatively limited production history, many of these alternatives are, or have the potential to become, global contaminants.…”

“…In addition, one congener was detected in a soil sample from New Hampshire, US (roughly along the same sampling transect), but further investigation is needed to confirm whether this was released from the same FPP [27]. In another recent study, Joerss et al investigated the distribution of HFPO-DA and numerous legacy PFAS in ocean water samples collected between the European coastline and the Fram Strait, located south of the Arctic Ocean [75]. The concentration gradient of HFPO-DA in ocean water decreased with increasing distance from the European coastline, suggesting that emissions from European waters are likely the primary source of this compound.…”

Rapid Determination of Per- and Polyfluoroalkyl Substances (PFAS) in Harbour Porpoise Liver Tissue by HybridSPE®–UPLC®–MS/MS

“…Currently, PFAS are detected in trace concentrations worldwide in biological and environmental matrices, even at remote and pristine locations [ 7 , 8 , 9 ]. To date, several bioanalytical methods are available for the determination of PFAS in a variety of biological matrices, and liquid chromatography–tandem mass spectrometry (LC-MS/MS) is currently the main instrumental technique applied for their analysis, achieving low limits of detection that can reach the picogram range [ 10 ].…”