Fluorine Mass Balance and Suspect Screening in Marine Mammals from the Northern Hemisphere

Abstract

There is increasing evidence that the ∼20 routinely monitored perfluoroalkyl and polyfluoroalkyl substances (PFASs) account for only a fraction of extractable organofluorine (EOF) occurring in the environment. To assess whether PFAS exposure is being underestimated in marine mammals from the Northern Hemisphere, we performed a fluorine mass balance on liver tissues from 11 different species using a combination of targeted PFAS analysis, EOF and total fluorine determination, and suspect screening. Samples were obtained from the east coast United States (US), west and east coast of Greenland, Iceland, and Sweden from 2000 to 2017. Of the 36 target PFASs, perfluorooctane sulfonate (PFOS) dominated in all but one Icelandic and three US samples, where the 7:3 fluorotelomer carboxylic acid (7:3 FTCA) was prevalent. This is the first report of 7:3 FTCA in polar bears (∼1000 ng/g, ww) and cetaceans (<6−190 ng/g, ww). In 18 out of 25 samples, EOF was not significantly greater than fluorine concentrations derived from sum target PFASs. For the remaining 7 samples (mostly from the US east coast), 30−75% of the EOF was unidentified. Suspect screening revealed an additional 37 PFASs (not included in the targeted analysis) bringing the total to 63 detected PFASs from 12 different classes. Overall, these results highlight the importance of a multiplatform approach for accurately characterizing PFAS exposure in marine mammals.

Emerging per- and polyfluoroalkyl substances (PFAS) in human milk from Sweden and China

“…35 In addition to its widespread occurrence in surface water from China, 33 Cl-PFESAs were observed in >98% of metal plating workers and high sh consumers sampled from the provinces of Shandong and Hube at concentrations up to 5040 ng mL À1 . 36 Most recently, Cl-PFESAs have been detected in marine mammal livers from Greenland 37,38 and Sweden, 38 polar bear serum from Hudson Bay and the Beaufort Sea, 39 and human milk from Hangzhou, China. 40 To shed further light on PFAS exposure in breastfed newborns, in particular to emerging PFAS, the current study investigated 20 PFAS (including the alternatives F53-B and ADONA) in human milk from residents of three Chinese cities (Shanghai, Jiaxing, and Shaoxing), sampled between 2010 and 2016.…”

Bioaccumulation, Biodistribution, Toxicology and Biomonitoring of Organofluorine Compounds in Aquatic Organisms

“…For instance, a study on molluscs from the semi-closed basin of the Bohai (China) and investigating the presence of 23 PFCs, showed differences between aquaculture sites and more restricted areas with PFOA being the more abundant component (87% of the total PFAS) showing a very high frequency of detection (i.e., percentage of samples where PFOA has been detected) of 98%, followed by PFNA, perfluorodecane sulfonic acid (PFDS) and PFOS [95]. Indeed, the most frequently detected PFCs in various tissues of aquatic organisms are long-chain PFAS such as PFOS [56,58,115,[117][118][119] and PFOA [78,83,95]. This frequency is particularly important when referred to organisms that are directly consumed by humans or by endangered species.…”

“…In this context, despite the Organization for Economic Cooperation and Development (OECD) has identified more than 4500 PFAS-related substances [57], only a few of them (<20) are regularly analysed and monitored, thus underestimating the real exposure to PFAS. For example, the percentage of unidentified organofluorine compounds may range from 30 to 90% of the total extracted fluorinated substances in wildlife animals or marine mammals [58,59]. Additionally, it is important to remark that the levels of seafood contamination due to the conservation and transformation processes increase with the market demand of such products [60] thus, considering the diffusion of PFAS in the environment, constant and extensive monitoring of PFAS contamination is required to guarantee food safety to the consumers.…”

Quantification of per‐ and polyfluoroalkyl substances with a modified total organic carbon analyzer and ion chromatography

“…CIC methods typically achieve lower detection limits by solid phase extraction (SPE) of samples prior to CIC measurements (e.g., EOF or AOF) Schultes et al, 2020;Spaan et al, 2020;von Abercron et al, 2019). Although these methods have been developed and validated separately, we conducted one experiment to demonstrate that CIC-F TOC is amenable to samples concentrated via EOF.…”

“…TOF captures all PFAS (known and unknown), precursors, and their decomposition products without selectivity, thus providing valuable PFAS measurements beyond well-investigated PFAS (e.g., PFOA and PFOS). TOF methods may be supplemented with adsorbable organofluorine (AOF) and extractable organofluorine (EOF) methods, which are commonly adopted organofluorine enrichment techniques that avoid fluoride interference and reduce detection limits (Spaan et al, 2020;von Abercron et al, 2019). In a recent investigation of Swedish surface water near PFAS point sources, unidentified EOF accounted for 45%-92% of measured organofluorine (Koch et al, 2019).…”