Determination of perfluorinated alkyl acid concentrations in biological standard reference materials

Levels and spatial profile of per- and polyfluoroalkyl substances in edible shrimp products from Japan and neighboring countries; a potential source of dietary exposure to humans

Exposure to per- and polyfluoroalkyl substances (PFAS) is of great concern for human health because of their persistence and potentially adverse effects. Dietary intake, particularly through aquatic products, is a significant route of human exposure to PFAS. We analyzed perfluoroalkyl sulfonic acid (PFSA with carbon numbers from 6 to 8 and 10 (C６-C8, C10)) and perfluorooctanesulfonamide (FOSA), and perfluoroalkyl carboxylic acid (PFCA with carbon numbers from 6 to 15 (C6-C15)) in 30 retail packs of edible shrimps, which included seven species from eight coastal areas of Japan and neighboring countries. The most prevalent compounds were perfluorooctane sulfonate (PFOS, C8) and perfluoroundecanoic acid (PFUnDA, C11), accounting for 46 % of total PFAS. The concentrations ranged from 6.5 to 44 ng/g dry weight (dw) (equivalent to 1.5 to 10 ng/g wet weight (ww)) and varied according to species and location. For example, Alaskan pink shrimp (Pandalus eous) from the Hokuriku coast, Japan contained high levels of long-chain PFCAs (38 ng/g dw (equivalent to 8.7 ng/g ww)), while red rice prawn (Metapenaeopsis barbata) from Yamaguchi, Japan contained a high concentration of PFOS (29 ng/g dw (equivalent to 6.7 ng/g ww)). We also observed regional differences in the PFAS levels with higher concentrations of long-chain PFCAs in Japanese coastal waters than in the South China Sea. The PFAS profiles in shrimp were consistent with those in the diet and serum of Japanese consumers, suggesting that consumption of seafood such as shrimp may be an important source of exposure. The estimated daily intake of sum of all PFAS from shrimp from Japanese coastal water was 0.43 ng/kg body weight/day in average, which could reach the weekly tolerable values (4.4 ng/kg body weight /week) for the sum of the four PFSA set by the EFSA for heavy consumers. The high concentration of PFAS in shrimp warrants further investigation.

Sediment-seawater partitioning, bioaccumulation, and biomagnification of perfluorobutane sulfonamide in marine environment

Environmental occurrence of perfluorobutane sulfonamide (PFBSA) has only been recently discovered. The current knowledge regarding the occurrence and environmental behaviors of PFBSA in the marine environment is still relatively limited. In this study, PFBSA and other 37 poly- and perfluoroalkyl substances were analyzed in seawater (n = 43), sediment (n = 43), and marine fish (n = 176) samples collected from East China Sea and Antarctic Ocean. PFBSA was detected in > 90% of seawater from East China Sea and Antarctic Ocean, with the concentrations of 1.0 - 19 ng/L and < LOD-228 pg/L, respectively. The field-based mean log-transformed sediment-seawater partitioning coefficients of PFBSA were 1.6 ± 0.19 L/kg dw and 1.1 ± 0.19 L/kg dw in East China Sea and Antarctic Ocean, respectively, which are lower than that of perfluorooctanoate and perfluorooctane sulfonate. This indicates its long-range transport potential in global oceans with ocean currents. The mean log-transformed bioaccumulation factor values of PFBSA determined in the multiple species of whole-body marine fishes from East China Sea and Antarctic Ocean were 2.3 L/kg ww and 2.4 L/kg ww, respectively, which are comparable to that of perfluoroheptanoate (2.3 L/kg ww) in marine fishes from East China Sea. We did not observe an obvious biomagnification or biodilution of PFBSA along the marine food chain in East China Sea or Antarctic Ocean. This study provides the first data on the environmental behaviors of PFBSA in the marine environment.

Target and suspect per- and polyfluoroalkyl substances in fish from an AFFF-impacted waterway

A major source of toxic per- and polyfluoroalkyl substances (PFAS) is aqueous film-forming foams (AFFF) used in firefighting and training at airports and military installations, however, PFAS have many additional sources in consumer products and industrial processes. A field study was conducted on fish tissues from three reaches of the Columbia Slough, located near Portland International Airport, OR, that are affected by AFFF and other PFAS sources. Fishes including largescale sucker (Catostomus macrocheilus), goldfish (Carassius auratus), and largemouth bass (Micropterus salmoides) were collected in 2019 and 2020. Fish blood, liver, and fillet (muscle) were analyzed for target and suspect PFAS by liquid chromatography high resolution mass spectrometry (LC-HRMS). Data were analyzed for patterns by fish species, tissue type, and river reach. Thirty-three out of 50 target PFAS and additional suspect compounds were detected at least once during the study, at concentrations up to 856 ng/g. Seven carboxylic acids (PFOA, PFNA, PFDA, PFUdA, PFDoA, PFTrDA, PFTeDA), three sulfonates (PFHxS, PFOS, PFDS), three electrofluorination-based compounds (FBSA, FHxSA, FOSA), and two fluorotelomer-based compounds (8:2 FTS, 10:2 FTS) were the most frequently detected compounds in all tissue types. The C6 (PFHxS) to C10 (PFDS) homologs were detected with PFOS and FHxSA at concentrations 1-3 orders of magnitude greater than the other PFAS detected. This is the first report of Cl-PFOS, FPeSA, and FHpSA detected in fish tissue. In all fish samples, fillet concentrations of PFAS were the lowest, followed by liver, and blood concentrations of PFAS were the highest. Differences in PFAS concentrations were driven primarily by tissue types and to a lesser extent fish species, but weakly by river reach. The Oregon Health Authority modified an existing fish consumption advisory on the Columbia Slough to recommend no whole-body consumption of most fish to avoid elevated levels of PFOS in fish liver. Measured PFAS concentrations in fish tissues indicate the potential for adverse ecological effects.

Bioaccumulation and biomagnification of emerging poly- and perfluoroalkyl substances in marine organisms

Accumulating evidence has demonstrated the wide environmental presence of 6:2 chlorinated polyfluoroalkyl ether sulfonates (6:2 Cl-PFAES) and p-perfluorous nonenoxybenzene sulfonate (PFNOBS). However, data on the bioaccumulation and trophic magnification of these emerging poly- and perfluoroalkyl substances (PFASs) in subtropical marine environment is still limited. In this study, seawater (n = 17), sediment (n = 14), and marine organism (27 species; n = 177) samples were collected from East China Sea, and analyzed them for legacy and emerging PFASs. Besides perfluoroalkyl carboxylates and perfluorooctane sulfonate (PFOS), 6:2 Cl-PFAES was always among the predominant PFASs detected in seawater, sediment, and marine organism. For emerging PFASs, 6:2 Cl-PFAES (mean ± SD, 3.1 ± 0.17), 8:2 Cl-PFAES (3.3 ± 0.35), and PFNOBS (3.3 ± 0.19) had lower bioaccumulation factors (BAF) than PFOS (3.4 ± 0.22) in marine fish. In crab, PFNOBS (3.7 ± 0.33) had a lower biota-sediment accumulation factor (BSAF) than PFOS (3.9 ± 0.45). In snail, among all detected PFASs, PFNOBS (4.0 ± 0.42) had the highest mean log BSAF value. 8:2 Cl-PFAES consistently had a higher log BSAF value than 6:2 Cl-PFAES in snail and crab. Notably, these differences in BAF and BSAF are not significant. Among PFASs, 6:2 Cl-PFAES (2.3; 95 % confidence interval, CI: 1.9-2.6) displayed the highest trophic magnification factor (TMF). PFNOBS had the lowest TMF value (1.8, 95 % CI: 1.4-2.1), but which still indicates its weak biomagnification through the current marine food web. This is the first study reporting the bioaccumulation and biomagnification of PFNOBS in marine organisms, which deepens the understanding of its environmental behavior in the marine ecosystem.

PFAS and Precursor Bioaccumulation in Freshwater Recreational Fish: Implications for Fish Advisories

Per- and polyfluoroalkyl substances (PFAS) are a diverse class of fluorinated anthropogenic chemicals that include perfluoroalkyl acids (PFAA), which are widely used in modern commerce. Many products and environmental samples contain abundant precursors that can degrade into terminal PFAA associated with adverse health effects. Fish consumption is an important dietary exposure source for PFAS that bioaccumulate in food webs. However, little is known about bioaccumulation of PFAA precursors. Here, we identify and quantify PFAS in recreational fish species collected from surface waters across New Hampshire, US, using a toolbox of analytical methods. Targeted analysis of paired water and tissue samples suggests that many precursors below detection in water have a higher bioaccumulation potential than their terminal PFAA. Perfluorobutane sulfonamide (FBSA), a short-chain precursor produced by electrochemical fluorination, was detected in all fish samples analyzed for this compound. The total oxidizable precursor assay interpreted using Bayesian inference revealed fish muscle tissue contained additional, short-chain precursors in high concentration samples. Suspect screening analysis indicated these were perfluoroalkyl sulfonamide precursors with three and five perfluorinated carbons. Fish consumption advisories are primarily being developed for perfluorooctane sulfonate (PFOS), but this work reinforces the need for risk evaluations to consider additional bioaccumulative PFAS, including perfluoroalkyl sulfonamide precursors.

Novel and legacy per- and polyfluoroalkyl substances (PFAS) in freshwater sporting fish from background and firefighting foam impacted ecosystems in Eastern Canada

Emerging PFAS were recently reported at sites impacted by aqueous film-forming foams (AFFFs) and near major manufacturing centers; however, few studies have evaluated whether these can occur far from release sites. Here, newly identified PFAS were investigated in wild sporting fish from boreal freshwater ecosystems (background sites, 2013-2014 summer seasons), compared to fish impacted by a major AFFF release (summer 2013 and autumn 2014). Different freshwater wild sporting fish species (Esox lucius, Esox masquinongy, Micropterus dolomieu, Sander vitreus, Perca flavescens, and Semotilus corporalis, n = 74) were collected from 13 ecosystems (lakes, reservoirs, and rivers) across Eastern Canada. Of 29 quantitative PFAS, 15 compounds were detected in fish from background sites, including perfluorocarboxylates (C_6,8-14), perfluoroalkane sulfonates (C_6,8,10), perfluorooctane sulfonamide (FOSA), 6:2 fluorotelomer sulfonate (6:2 FTSA), 7:3 fluorotelomer carboxylic acid (7:3 FTCA), and a zwitterionic PFAS-perfluorooctane sulfonamidoalkyl betaine (PFOSB). To our knowledge, this is the first report of PFOSB in biota. It is also one of the first reports of anionic fluorotelomers (6:2 FTSA, 7:3 FTCA, 9:3 FTCA) in wildlife from background sites. Long-chain fluorotelomer sulfonamidoalkyl betaines (e.g., 8:2 and 10:2 FTAB), fluorotelomer betaines (e.g., 9:3 and 9:1:2 FTB), and fluorotelomer sulfone propanoic acids (e.g., 8:2 FT(SO₂)-PA, 10:2 FT(SO₂)-PA)) were solely prevalent (up to 97% of summed suspect PFAS) in Smallmouth Bass (M. dolomieu) from the AFFF-impacted site. Perfluorobutane sulfonamide (FBSA), perfluorohexane sulfonamide (FHxSA), 6:2 FTSA and 7:3 FTCA were detected in at least one Smallmouth Bass sample both at the AFFF-impacted and background sites. According to the estimated chronic daily intake and current tolerable daily intake suggested by national agencies, the observed PFOS levels would not pose a health risk to anglers who might consume these wild-caught fish.

Perfluoroalkyl substances in circum-ArcticRangifer: caribou and reindeer

Livers of caribou and reindeer (Rangifer tarandus) from Canada (n = 146), Greenland (n = 30), Svalbard (n = 7), and Sweden (n = 60) were analyzed for concentrations of eight perfluoroalkyl carboxylic acids and four perfluoroalkane sulfonic acids. In Canadian caribou, PFNA (range < 0.01-7.4 ng/g wet weight, ww) and PFUnDA (<0.01-5.6 ng/g ww) dominated, whereas PFOS predominated in samples from South Greenland, Svalbard, and Sweden, although the highest concentrations were found in caribou from Southwest Greenland (up to 28 ng/g ww). We found the highest median concentrations of all PFAS except PFHxS in Akia-Maniitsoq caribou (Southwest Greenland, PFOS 7.2-19 ng/g ww, median 15 ng/g ww). The highest concentrations of ΣPFAS were also found in Akia-Maniitoq caribou (101 ng/g ww) followed by the nearby Kangerlussuaq caribou (45 ng/g ww), where the largest airport in Greenland is situated, along with a former military base. Decreasing trends in concentrations were seen for PFOS in the one Canadian and three Swedish populations. Furthermore, PFNA, PFDA, PFUnDA, PFDoDA, and PFTrDA showed decreasing trends in Canada's Porcupine caribou between 2005 and 2016. In Sweden, PFHxS increased in the reindeer from Norrbotten between 2003 and 2011. The reindeer from Västerbotten had higher concentrations of PFNA and lower concentrations of PFHxS in 2010 compared to 2002. Finally, we observed higher concentrations in 2010 compared to 2002 (albeit statistically insignificant) for PFHxS in Jämtland, while PFNA, PFDA, PFUnDA, PFDoDA, and PFTrDA showed no difference at all.

Levels and profiles of perfluorinated alkyl acids in liver tissues of birds with different habitat types and trophic levels from an urbanized coastal region of South Korea

Contamination status and characteristics of perfluorinated alkyl acids (PFAAs) including perfluorinated carboxylic acids (PFCAs) and perfluorinated sulfonic acids (PFSAs) was examined using liver tissue of birds - black-tailed gulls (Larus crassirostris), domestic pigeons (Columba livia var. domestica), pacific loons (Gavia pacifica), herons (Ardea cinerea), and egrets (Egretta garzetta and Ardea alba) - with different trophic levels, habitat types and migratory behaviors from an industrialized coastal region of South Korea. A wide range of PFAAs (1.09 ng/g to 1060 ng/g; median = 52.6 ng/g) were detected in bird livers from the Korean coasts with high detection frequency. Accumulation features of PFAAs in birds indicated that primarily trophic position and secondly habitat type influence the levels and composition of PFAAs, e.g., relatively high PFAA levels and high composition of odd-numbered long carbon chain PFCAs (perfluoroundecanoic acid (PFUnDA) and perfluorotridecanoic acid (PFTriDA)) and PFOS in higher trophic and marine birds. The prevalence of long carbon chain (≥14) PFCAs likely implies a wide use of fluorotelomer-based substances in Korea. Interspecies comparison in the accumulation profile of persistent organic pollutants (including polychlorinated biphenyls (PCBs), organochlorine pesticides, polybrominated diphenylethers (PBDEs), and PFAAs) reveals relatively high load of PFAAs in inland (pigeons) and estuarine (egrets/herons) species compared to marine bird species, indicating wide use of PFAAs in the terrestrial environment.

Trends (2005-2016) of perfluoroalkyl acids in top predator fish of the Laurentian Great Lakes

This work presents the first assessment of temporal trends (2005-2016) for perfluoroalkyl acids (PFAAs) in top predator fish of the Laurentian Great Lakes except Lake Ontario, for which we provide a post-2008 update. Lake trout (Salvelinus namaycush) or walleye (Sander vitreus; Lake Erie only) collected annually from 2005 to 2016 were analyzed for 12 perfluoroalkyl carboxylic acids (PFCAs) and 4 perfluoroalkyl sulfonic acids (PFSAs) with carbon chain lengths between 4 and 16 (C4-C16). Individual analyte concentrations generally decreased in fish basin-wide between 2005 and 2016, including Lake Ontario lake trout previously found to lack declining PFAA concentrations up until 2008. Declining fish PFAA burden reflects a positive response to the industrial phase-outs of these chemicals. Notable exceptions to this general decline included most analytes in lake trout collected from Lake Superior near Keweenaw Point and C6 and C8 PFSAs and C9 PFCAs in Lake Erie lake trout and walleye, which exhibited constant or increasing concentrations in recent years. Recent increases in Lake Superior shoreline development and mobilization from increased sediment resuspension and contamination from biosolids-amended agricultural soils in the Lake Erie watershed are plausible explanations for these cases. However, data scarcity prohibits confirmation of these suspected causes. The lingering lack of declining concentrations noted in this study together with the ongoing evolution of the fluorinated chemical industry emphasize the vigilance needed to better understand how past and future emissions will affect the Great Lakes and global ecosystems.

Method Development and Validation of Per- and Polyfluoroalkyl Substances in Foods from FDA's Total Diet Study Program

Human exposure to per- and polyfluoroalkyl substances (PFAS) through the US diet has not been well-characterized. Highly consumed foods are routinely monitored through FDA's Total Diet Study program. Portions of these samples were used to develop and validate a method for PFAS in a wide variety of foods. The extraction of 16 PFAS was performed using the quick, easy, cheap, effective, rugged, and safe (QuEChERS) method and analyzed by liquid chromatography/mass spectrometry. Method optimizations are described including investigations into the QuEChERS sorbents, matrix effects, and solid-phase extraction (SPE) cartridges. The use of a custom push-through SPE cartridge showed promising results as a rapid cleanup option for food samples. Challenges in ion confirmation are discussed, and the use of enhanced product ion (EPI) full-scan MS/MS spectra is presented as a potential option for verifying false positives. The validated method was then used for the analysis of 179 total diet study samples, and positive detects for perfluorooctanesulfonic acid (PFOS) were found in two fish and one meat sample.

Uptake and Biological Effects of Perfluorooctane Sulfonate Exposure in the Adult Eastern Oyster Crassostrea virginica

Perfluorooctane sulfonate (PFOS) is a legacy contaminant that has been detected globally within the environment and throughout numerous species, including humans. Despite an international ban on its use, this unique contaminant continues to persist in organisms and their surroundings due to PFOS's inability to breakdown into nontoxic forms resulting in bioaccumulation. In this study, we analyzed the effects of a technical mixture of PFOS (linear and branched isomers) in the adult Eastern oyster, Crassostrea virginica, at 2 days and 7 days exposure. Biomarker analysis (lysosomal destabilization, lipid peroxidation, and glutathione assays) in oyster tissue along with chemical analysis (liquid chromatography tandem mass spectrometry) of PFOS in oyster tissue and water samples revealed the oysters' ability to overcome exposures without significant damage to lipid membranes or the glutathione phase II enzyme system; however, significant cellular lysosomal damage was observed. The oysters were able to eliminate up to 96% of PFOS at 0.3 mg/L and 3 mg/L exposures when allowed to depurate for 2 days in clean seawater. Chemical analysis showed the linear isomer to be the prevailing fraction of the residual PFOS contained in oyster tissue. Results provide insight into possible detrimental cellular effects of PFOS exposure in addition to offering insight into contaminant persistence in oyster tissue.

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

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.

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

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.

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

The present work examined the trophic transfer of perfluoroalkyl and polyfluoroalkyl substances (PFASs) in a typical urban river (Orge River, near Paris, France), and aimed to investigate the potential contribution of precursors to the biomagnification of perfluoroalkyl acids (PFAAs). Sixteen PFAAs, twelve of their precursors (pre-PFAAs_targeted) and two fluorinated alternatives to long-chain PFASs were analyzed in water, sediments and biota (including biofilm, invertebrates and fish). Twenty two compounds were detected in biological samples (2.0-147 ng g^-1 wet weight), perfluorooctane sulfonate (PFOS) and C₁₂-C₁₄ perfluoroalkyl carboxylates (PFCAs) being predominant while ∑pre-PFAAs_targeted contributed to 1-18% of ∑PFASs. Trophic magnification factors (TMFs) were >1 (i.e. denoting biomagnification) for C₉-C₁₄ PFCAs, C₇-C₁₀ perfluoroalkyl sulfonates (PFSAs) and several pre-PFAAs (e.g. 8 : 2 and 10 : 2 fluorotelomer sulfonates). The significant decrease in ∑pre-PFCAs/∑PFCAs concentration ratio with trophic level suggested a likely contribution of selected precursors to the biomagnification of PFCAs through biotransformation, while this was less obvious for PFOS. The total oxidizable precursor assay, applied for the first time to sediment and biota, revealed the presence of substantial proportions of extractable unknown pre-PFAAs in all samples (i.e. 15-80% of ∑PFASs upon oxidation). This proportion significantly decreased from sediments to invertebrates and fish, thereby pointing to the biotransformation of unattributed pre-PFAAs in the trophic web, which likely contributes to the biomagnification of some PFAAs (i.e. C₉-C₁₂ PFCAs and C₇-C₁₀ PFSAs).

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

The occurrence at different trophic levels of 17 poly- and perfluoroalkyl substances (PFASs), including perfluoroalkyl acids (PFAAs) and some of their precursors (e.g., perfluoroalkane sulfonamides, 6:2 fluorotelomer sulfonate (6:2 FTSA)), was investigated in riverine freshwater food webs in Southeastern France. Two fish species (Barbus barbus and Squalius cephalus) and various invertebrate taxa were collected in five rivers to assess the spatial variability of trophic magnification factors (TMFs). Particular attention was devoted to sample and data processing to minimize potential biases associated with the TMF determination. Fish were significantly more contaminated than invertebrates (ΣPFAS = 7-1811 vs. 0.9-213 ng g^-1 wet weight (ww)). Those from the Rhône River presented significantly higher levels due to high concentrations of perfluoroundecanoic acid (406 ng g^-1 ww) and perfluorotridecanoic acid (566 ng g^-1 ww) ascribed to an industrial point source. Perfluorooctane sulfonate (PFOS) was dominant at the other sites (concentration range = 3.6-134 ng g^-1 ww). Two linear regression models were compared (i.e., Kendall regression vs. Generalized Linear Mixed-Effect Model, GLMM). Results showed that TMFs calculated using the non-weighted Kendall regression were higher than those obtained using the GLMM approach. GLMM-based TMFs were consistently >1 for C₉-C₁₄ perfluorocarboxylic acids (PFCAs), PFOS and perfluorodecane sulfonate (PFDS), indicating their apparent biomagnification in the investigated food webs. Comparatively, 6:2 FTSA and N-ethylperfluorooctane sulfonamidoacetic acid (N-EtFOSAA) were less often detected and were not significantly biomagnified, probably because of metabolization. TMF estimates were generally consistent across sites although some PFASs (in particular C₉, C₁₀ and C₁₃ PFCAs) displayed higher variability, due to a unique extreme value that may have resulted from the contribution of unattributed precursor biotransformation.

Temporal variations of perfluoroalkyl substances partitioning between surface water, suspended sediment, and biota in a macrotidal estuary

A one-year monitoring study was conducted in a macrotidal estuary to assess the temporal variations and partitioning behavior of perfluoroalkyl and polyfluoroalkyl substances (PFASs). Surface water, suspended particulate matter (SPM), and invertebrates including zooplankton (copepods, mysids) and shrimps were sampled on a monthly basis in the Gironde Estuary (SW France). Environmental parameters such as suspended solid loads, salinity, and river water flow rate were highly variable at the study site. However, moderate seasonal variations were observed in terms of PFAS levels and profiles. Summed PFAS (Σ₂₂PFASs) concentrations averaged 6.5 ± 2.7 ng L^-1 in the dissolved phase and 3.0 ± 1.2 ng g^-1 dry weight in the SPM. The Σ₂₂PFASs was in the range of 1.7-13 ng g^-1 wet weight in invertebrates. C₅-C₈ perfluoroalkyl carboxylates (PFCAs) generally prevailed in the dissolved phase, while perfluorooctane sulfonate (PFOS) was dominant in the SPM and biota. Suspended sediment-water partitioning coefficients Log K_D and Log K_OC were correlated with the perfluoroalkyl chain length, as were the particle-bound fraction and bioaccumulation factors (Log BAF). Compound-specific Log BAFs varied within a limited range over the period surveyed. Biomagnification factors (mysids/copepods) were consistently >1 for PFOS, perfluorooctane sulfonamide, and long-chain PFCAs (perfluorodecanoate and perfluorododecanoate), suggesting biomagnification at the base of the estuarine food web.

Perfluorinated Alkyl Acids in Hawaiian Cetaceans and Potential Biomarkers of Effect: Peroxisome Proliferator-Activated Receptor Alpha and Cytochrome P450 4A

Perfluorinated alkyl acids (PFAAs) are persistent in marine biota and are toxic to many species, including marine mammals. We measured the concentrations of 15 PFAAs in liver and kidney samples of 16 species of stranded cetaceans from Hawai'i and other tropical North Pacific regions utilizing high performance liquid chromatography-tandem mass spectrometry (LC-MS/MS). Eleven PFAAs in liver and nine PFAAs in kidney were detected, including substantial perfluorooctanesulfonate (PFOS) and perfluoroundecanoic acid (PFUnA). Regression models indicated that phylogenetic family and age class significantly influenced concentrations of certain PFAAs. PFAAs can activate transcription factor peroxisome proliferator-activated receptor alpha (PPARα), which induces transcription of cytochrome P450 4A (CYP4A). Relative expression of PPARα and CYP4A mRNA was quantified using real-time PCR (qPCR) and CYP4A protein expression, using Western blot and then compared to PFAA concentrations in liver and kidney. Concentrations of four PFAA congeners, summation of perfluoroalkyl carboxylic acids (ΣPFCAs), and ΣPFAAs correlated significantly with PPARα mRNA expression and CYP4A protein expression in kidney, suggesting either may be biomarkers of PFAA exposure in cetaceans. This is the first study to quantify PFAAs in marine mammals from this region and the first observation of a direct relationship between PFAA exposure and PPARα and CYP4A expression in cetaceans.

Per- and polyfluoroalkyl substances (PFAS) in plasma of the West Indian manatee (Trichechus manatus)

Per- and polyfluoroalkyl substances (PFAS) are ubiquitous, synthetic anthropogenic chemicals known to infiltrate and persist in biological systems as a result of their stability and bioaccumulation potential. This study investigated 15 PFAS, including short-chain carboxylic and sulfonic acids, and their presence in a threatened herbivore, the West Indian manatee (Trichechus manatus). Seven of the 15 PFAS examined were detected in manatee plasma. Perfluorooctanesulfonic acid (PFOS) (ranging from 0.13 to 166 ng/g ww) and perfluorononanoic acid (PFNA) (ranging from 0.038 to 3.52 ng/g ww) were detected in every manatee plasma sample examined (n = 69), with differing medians across sampling sites in Florida, Crystal River (n = 39), Brevard County (n = 18), Everglades National Park (n = 8), and four samples (n = 4) from Puerto Rico. With an herbivorous diet and long life-span, the manatee provides a new perspective to monitoring PFAS contamination.

Different profiles of naturally produced and anthropogenic organohalogens in the livers of cetaceans from the Sea of Japan and the North Pacific Ocean

Levels and profiles of naturally produced halogenated bipyrroles (Br₄Cl₂-DBP and Cl₇-MBP), methoxylated tetrabromodiphenyl ethers (6-MeO-BDE47), anthropogenic perfluoroalkyl substances (PFASs) and legacy persistent organic pollutants (POPs) were investigated in the livers of 14 cetaceans from the Sea of Japan and the North Pacific Ocean. The concentrations of Br₄Cl₂-DBP (4 to 4900 ng/g-wet), Cl₇-MBP (16 to 3960 ng/g-wet) and 6-MeO-BDE47 (7 to 190 ng/g-wet) were higher in the order of killer whales > toothed whales > baleen whales. Profiles of PFASs were dominated by perfluoroundecanoic and perfluorotridecanoic acids (10 to 540 ng/g-wet), sum of which accounted for 70% of total measured PFASs. Regional difference was observed for Cl₇-MBP and PFASs, which were higher in the Sea of Japan, whereas Br₄Cl₂-DBP was in the North Pacific Ocean. Specific accumulation pattern of these natural contaminants in cetaceans around northern Japan could help compare the exposure profile of PFASs and POPs among other geographic regions.

Simultaneous determination of 21 trace perfluoroalkyl substances in fish by isotope dilution ultrahigh performance liquid chromatography tandem mass spectrometry

Perfluoroalkyl substances (PFASs) have been identified as emerging environmental contaminants. In this study, an efficient and accurate ultrahigh performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) method was developed for simultaneous determination of 21 PFASs in fish. Acetonitrile was used for sample extraction. Solid phase extraction (SPE) by WAX cartridges and then freezing at -30 °C were adopted as cleanup strategies. Strict measurements were performed to control background contamination during the whole procedure. Matrix effects were evaluated by external standard and isotope dilution mass spectrometry (IDMS) methods. IDMS can compensate the matrix effects to a large extent. The method detection limits (MDLs) ranged from 2 pg/g to 10 pg/g except for PFBA (120 pg/g). The method quantitation limits (MQLs) ranged from 5 pg/g to 30 pg/g except for PFBA (300 pg/g). The matrix spiked recoveries of three spiked levels were in the range of 79.6%-109%. The intra-day relative standard deviation (RSD) and inter-day RSD were from 0.94% to 13.9% and 0.36% to 11.2% respectively. Two fish tissue reference materials were analyzed by the developed method. The results of reference materials were within the uncertainty of the given value. The quantitative results of IDMS and standard addition (SA) - IDMS were comparable. The developed UHPLC-MS/MS method was applied for PFASs detection in 20 marine fish samples. 9 PFASs were detected in the samples with the ∑₉PFASs concentration range of 0.04 to 2.14 ng/g wet weight (ww).

Tissue-specific bioaccumulation of long-chain perfluorinated carboxylic acids and halogenated methylbipyrroles in Dall's porpoises (Phocoenoides dalli) and harbor porpoises (Phocoena phocoena) stranded in northern Japan

This study investigated accumulation of perfluoroalkyl substances (PFASs), persistent organochlorines (OCs), and naturally produced halogenated compounds (NHCs), including brominated methylbipyrroles and methoxylated bromodiphenyl ethers, in liver, blood, and blubber from Dall's porpoises (Phocoenoides dalli) and harbor porpoises (Phocoena phocoena) stranded in Hokkaido, northern Japan. Profiles of the PFASs were dominated by perfluoroundecanoic acid and perfluorotridecanoic acid, both of which accounted for 70% of the total measured PFAS concentrations in both porpoise species. The mean concentrations of the ∑PFCA were 573ng/g wet weight (ng/g-wet) in liver, 62ng/g-wet in whole blood, and 28ng/g-wet in blubber from the Dall's porpoises, and were significantly higher (p<0.05) than those in the harbor porpoises. The hepatic concentrations of perfluorooctane sulfonate (PFOS) were <14ng/g-wet, and accounted for only 3% of the total measured PFASs. The profiles of PFASs in the porpoises resembled those in fish species in this area, implying a common source of exposure to PFASs in East Asia. On the other hand, in the blubber of Dall's porpoises, NHCs were dominated by 2,3,3',4,4',5,5'-heptachloro-1'-methyl-1,2'-bipyrrole (867ng/g-wet), 5,5'-dichloro-1,1'-dimethyl-3,3',4,4'-tetrabromo-2,2'-bipyrrole (481ng/g-wet), and 6-methoxy-2,2',4,4'-tetrabromodiphenyl ether (30ng/g-wet), which were present at higher concentrations than in harbor porpoises. Factor analysis with varimax rotation revealed that factor 1 had higher eigenvectors (element in eigenvalues) for long-chain PFCAs and PFOS, which was found in the highest concentrations in the liver, whereas factor 2 was mainly associated with lipid soluble NHCs and OCs in both species. No correlations were observed between long-chain PFCAs and NHCs in the porpoises, probably because of the different sources and accumulation kinetics. Future research should assess the temporal trends and long-term effects of PFASs and NHCs in the tissues of mammals from the Asia-Pacific region.

Spatial and temporal trends of poly- and perfluoroalkyl substances in fish fillets and water collected from pool 2 of the Upper Mississippi River

In 2011, poly- and perfluoroalkyl substances (PFASs) were analyzed in surface water and fish fillet samples taken from Pool 2 of the Upper Mississippi River, a 33-mile stretch inclusive of the Minneapolis/St. Paul, Minnesota (USA) metropolitan area. Approximately 100 each of bluegill, freshwater drum, smallmouth bass, and white bass were sampled within the study area. Surface water samples were also collected from each of the 10 sampling reaches established for the study. Water and fillet samples were analyzed for perfluorinated carboxylic acids (C4-C12), perfluorinated sulfonic acids (C4, C6, and C8), and perfluorooctane sulfonamide. Perfluorooctane sulfonate (PFOS) was observed with the greatest frequency in fish fillets and ranged from 3.0 to 760 ng/g wet weight. Mean (geometric) PFOS concentrations in bluegill, freshwater drum, smallmouth bass, and white bass were 20, 28, 29, and 58 ng/g wet weight, respectively. When compared with fish data collected in 2009, a significant reduction (p < 0.05) in PFOS concentrations was noted. This finding was confirmed based on data from studies conducted in 2012 and 2013. Overall, between 2009 and 2013, PFOS concentrations decreased by 65, 76, and 50% for bluegill, freshwater drum, and white bass, respectively (44% decrease for smallmouth bass from 2009 to 2012). These declines in fish PFOS concentrations are consistent with ongoing efforts to effectively control sources of PFASs to the Mississippi River. Environ Toxicol Chem 2017;36:3138-3147. © 2017 SETAC.

Analysis of PFAAs in American alligators part 1: Concentrations in alligators harvested for consumption during South Carolina public hunts

Environmental contamination resulting from the production or release of harmful chemicals can lead to negative consequences for wildlife and human health. Perfluorinated alkyl acids (PFAAs) were historically produced as protective coatings for many household items and currently persist in the environment, wildlife, and humans. PFAAs have been linked to immune suppression, endocrine disruption, and developmental toxicity in wildlife and laboratory studies. This study examines the American alligator, Alligator mississippiensis, as an important indicator of ecosystem contamination and a potential pathway for PFAA exposure in humans. Alligator meat harvested in the 2015 South Carolina (SC) public hunt season and prepared for human consumption was collected and analyzed for PFAAs to determine meat concentrations and relationships with animal body size (total length), sex, and location of harvest. Of the 15 PFAAs analyzed, perfluorooctane sulfonate (PFOS) was found in all alligator meat samples and at the highest concentrations (median 6.73ng/g). No relationship was found between PFAA concentrations and total length or sex. Concentrations of one or all compounds varied significantly across sampling locations, with alligators harvested in the Middle Coastal hunt unit having the highest PFOS concentrations (median 16.0ng/g; p=0.0001). Alligators harvested specifically from Berkley County, SC (located in the Middle Coastal hunt unit) had the highest PFOS concentrations and the greatest number of PFAAs detected (p<0.0001). The site-specific nature of PFAA concentrations in alligator meat observed in this study suggests a source of PFAA contamination in Berkley County, SC.

Analysis of PFAAs in American alligators part 2: Potential dietary exposure of South Carolina hunters from recreationally harvested alligator meat

Exposure to perfluorinated alkyl acids (PFAAs) has been linked to many harmful health effects including reproductive disorders, developmental delays, and altered liver and kidney function. Most human exposure to environmental contaminants, including PFAAs, occurs through consumption of contaminated food or drinking water. This study uses PFAA data from meat samples collected from recreationally harvested American alligators (Alligator mississippiensis) in South Carolina to assess potential dietary exposure of hunters and their families to PFAAs. Consumption patterns were investigated using intercept surveys of 23 hunters at a wild game meat processor. An exposure scenario using the average consumption frequency, portion size, and median perfluorooctane sulfonic acid (PFOS) concentration in alligator meat from all hunt units found the daily dietary exposure to be 2.11ng/kg body weight per day for an adult human. Dietary PFOS exposure scenarios based on location of harvest suggested the highest daily exposure occurs with alligator meat from the Middle Coastal hunt unit in South Carolina. Although no samples were found to exceed the recommended threshold for no consumption of PFOS found in Minnesota state guidelines, exposure to a mixture of PFAAs found in alligator meat and site-specific exposures based on harvest location should be considered in determining an appropriate guideline for vulnerable populations potentially exposed to PFAAs through consumption of wild alligator meat.

Evidence for the Trophic Transfer of Perfluoroalkylated Substances in a Temperate Macrotidal Estuary

The present survey examines the trophodynamics of a suite of 19 perfluoroalkyl substances (PFASs) in a temperate macrotidal estuary (Gironde, SW France). Across the 147 biota samples (18 taxa) collected, perfluorooctane sulfonate (PFOS), perfluorooctane sulfonamide (FOSA), and C₈-C₁₄ perfluoroalkyl carboxylates (PFCAs) were the most-recurrent analytes. ΣPFASs ranged between 0.66-45 ng per g of wet weight of the whole body. Benthic organisms had relatively high ΣPFASs compared to demersal organisms and displayed specific composition profiles with higher relative abundances of C₈ and C₉ PFCAs. Trophic magnification factors (TMFs) were determined through the use of linear mixed effect models including censored data, thereby considering data below detection limits as well as the interspecific variability of δ¹⁵N and PFAS levels (random effects). TMFs were almost consistently >1 in the benthic food web as well as when considering all data pooled together, providing evidence for the biomagnification of several PFASs in estuarine environments. In addition, in contrast with previous observations, TMFs determined in the estuarine benthic web were found to significantly decrease with increasing chain length for C₈-C₁₄ PFCAs and C₆-C₈ perfluoroalkyl sulfonates. This suggests that PFAS chemical structure might not be necessarily predictive of TMFs, which are also influenced by the trophic web characteristics.

Environmental perfluorooctane sulfonate exposure drives T cell activation in bottlenose dolphins

Perfluoroalkyl acids (PFAAs) are highly stable compounds that have been associated with immunotoxicity in epidemiologic studies and experimental rodent models. Lengthy half-lives and resistance to environmental degradation result in bioaccumulation of PFAAs in humans and wildlife. Perfluorooctane sulfonate (PFOS), the most prevalent PFAA detected within the environment, is found at high levels in occupationally exposed humans. We have monitored the environmental exposure of dolphins in the Charleston, SC region for over 10 years and levels of PFAAs, and PFOS in particular, were significantly elevated. As dolphins may serve as large mammal sentinels to identify the impact of environmental chemical exposure on human disease, we sought to assess the effect of environmental PFAAs on the cellular immune system in highly exposed dolphins. Herein, we utilized a novel flow cytometry-based assay to examine T cell-specific responses to environmental PFAA exposure ex vivo and to exogenous PFOS exposure in vitro. Baseline PFOS concentrations were associated with significantly increased CD4⁺ and CD8⁺ T cell proliferation from a heterogeneous resident dolphin population. Further analysis demonstrated that in vitro exposure to environmentally relevant levels of PFOS promoted proinflammatory cytokine production and proliferation in a dose-dependent manner. Collectively, these findings indicate that PFOS is capable of inducing proinflammatory interferon-gamma, but not immunoregulatory interleukin-4 production in T cells, which may establish a state of chronic immune activation known to be associated with susceptibility to disease. These findings suggest that PFOS directly dysregulates the dolphin cellular immune system and has implications for health hazards. Copyright © 2017 John Wiley & Sons, Ltd.

Environmental Occurrence of Perfluoroalkyl Acids and Novel Fluorotelomer Surfactants in the Freshwater Fish Catostomus commersonii and Sediments Following Firefighting Foam Deployment at the Lac-Mégantic Railway Accident

On July 6th 2013, an unmanned train laden with almost 8 million liters of crude oil careened off the rails downtown Lac-Mégantic (Québec, Canada). In the aftermath of the derailment accident, the emergency response entailed the deployment of 33 000 L of aqueous film forming foam (AFFF) concentrate that contained proprietary fluorosurfactants. The present study examines the environmental occurrence of perfluoroalkyl acids (PFAAs) and newly identified per and polyfluoroalkyl substances (PFASs) in the benthic fish white sucker (Catostomus commersonii) and sediments from Lake Mégantic and Chaudière River. In sediments, PFAAs displayed relatively low concentrations (∑PFAAs = 0.06-0.5 ng g^-1 dw) while the sum of fluorotelomer-based PFASs was in the range < LOD-6.2 ng g^-1 dw. Notably, fluorotelomer sulfonamide betaines (8:2-FTAB and 10:2-FTAB), fluorotelomer betaines (9:3-FTB, 11:3-FTB and 9:1:2 FTB) and 6:2 fluorotelomer sulfonate (6:2-FTSA) were ubiquitously identified in the sediment samples surveyed. Levels of PFAAs remained moderate in fish muscle (e.g.

, PFOS

0.28-2.1 ng g^-1 wet-weight), with little or no differences when comparing 2013 or 2014 fish samples with 2011 archived samples. In contrast, n:2-FTSAs emerged in the immediate weeks or months that followed the accident, as did several betaine-based PFASs (8:2-FTAB, 10:2-FTAB, 9:3-FTB, 11:3-FTB, 7:1:2 FTB and 9:1:2 FTB), observed for the first time in situ. Fluorotelomer thioether amido sulfonate (10:2-FTSAS) and fluorotelomer sulfoxide amido sulfonate (10:2-FTSAS-sulfoxide) were also occasionally reported after the AFFF spill. With time, levels of betaine-based PFASs gradually decreased in fish, possibly indicating attenuation by biodegradation of the fluorine-free moiety, supported by the observation of likely metabolites such as n:3-fluorotelomer carboxylates and n:2-fluorotelomer sulfonamides.

Potential exposure routes and accumulation kinetics for poly- and perfluorinated alkyl compounds for a freshwater amphipod: Gammarus spp. (Crustacea)

Gammarids were exposed to sediments from a deposition site located on the Rhône River (France) downstream of a fluoropolymer manufacturing plant. Gammarids accumulated to various extents four long-chain perfluoroalkyl carboxylic acids (PFCAs) from C9 to C13, one sulfonate, perfluorooctane sulfonate (PFOS) and three of its precursors (the perflurooctane sulfonamide (FOSA), the N-methyl perfluorooctane sulfonamidoacetic acid (MeFOSAA), the N-ethyl perfluorooctane sulfonamidoacetic acid (EtFOSAA) and the 6:2 fluorotelomer sulfonic acid (6:2 FTSA). Whatever the compound, the steady state was not achieved after a 3-week exposure; elimination was almost complete after a 3-week depuration period for perfluorononanoic acid (PFNA), PFOS, the three precursors and the 6:2FTSA. However, this was not the case for long-chain PFCAs, whose elimination rates decreased with increasing chain length. PFAS accumulation in gammarids occurred via the trophic and respiratory pathways, in proportions varying with the carbon chain length and the terminal moiety.

Polyfluorinated substances in abiotic standard reference materials

The National Institute of Standards and Technology (NIST) has a wide range of Standard Reference Materials (SRMs) which have values assigned for legacy organic pollutants and toxic elements. Existing SRMs serve as homogenous materials that can be used for method development, method validation, and measurement for contaminants that are now of concern. NIST and multiple groups have been measuring the mass fraction of a group of emerging contaminants, polyfluorinated substances (PFASs), in a variety of SRMs. Here we report levels determined in an interlaboratory comparison of up to 23 PFASs determined in five SRMs: sediment (SRMs 1941b and 1944), house dust (SRM 2585), soil (SRM 2586), and sludge (SRM 2781). Measurements presented show an array of PFASs, with perfluorooctane sulfonate being the most frequently detected. SRMs 1941b, 1944, and 2586 had relatively low concentrations of most PFASs measured while 23 PFASs were at detectable levels in SRM 2585 and most of the PFASs measured were at detectable levels in SRM 2781. The measurements made in this study were used to add values to the Certificates of Analysis for SRMs 2585 and 2781.

Organohalogen Contaminants and Vitamins in Northern Fur Seals (Callorhinus ursinus) Collected During Subsistence Hunts in Alaska

During native subsistence hunts from 1987 to 2007, blubber and liver samples from 50 subadult male northern fur seals (Callorhinus ursinus) were collected on St. Paul Island, Alaska. Samples were analyzed for legacy persistent organic pollutants (POPs), recently phased-out/current-use POPs, and vitamins. The legacy POPs measured from blubber samples included polychlorinated biphenyl congeners, DDT (and its metabolites), chlorobenzenes, chlordanes, and mirex. Recently phased-out/current-use POPs included in the blubber analysis were the flame retardants, polybrominated diphenyl ethers, and hexabromocyclododecanes. The chemical surfactants, perfluorinated alkyl acids, and vitamins A and E were assessed in the liver samples. Overall, concentrations of legacy POPs are similar to levels seen in seal samples from other areas of the North Pacific Ocean and the Bering Sea. Statistically significant correlations were seen between compounds with similar functions (pesticides, flame retardants, vitamins). With sample collection spanning two decades, the temporal trends in the concentrations of POPs and vitamins were assessed. For these animals, the concentrations of the legacy POPs tend to decrease or stay the same with sampling year; however, the concentrations of the current-use POPs increased with sampling year. Vitamin concentrations tended to stay the same across the sampling years. With the population of northern fur seals from St. Paul Island on the decline, a detailed assessment of exposure to contaminants and the correlations with vitamins fills a critical gap for identifying potential population risk factors that might be associated with health effects.

Long-chain perfluoroalkyl carboxylic acids in Pacific cods from coastal areas in northern Japan: a major source of human dietary exposure

This study investigates perfluoroalkyl carboxylic acids (PFCAs) contamination of edible fish muscle from Japanese coastal waters. The concentrations of PFCAs with 8-14 carbon atoms (C8-C14) in Pacific cods in Hokkaido, Japan were 51 (median: pg/g-wet weight) for C8, 93 for C9, 99 for C10, 746 for C11, 416 for C12, 404 for C13, and 93 for C14. The levels of C9-C14 PFCAs in fish were strongly correlated to each other, but not to C8 and the other chlorinated persistent organic pollutants, indicating that C9-C14 PFCAs have a different emission source and/or bioaccumulation mechanism. The relative ratios between estimated PFCAs intake through fish consumption and the reported total dietary exposure of PFCAs were less than 1 for C8 to C9, but were more than 1 for C10 to C14. This result strongly suggests that fish consumption is a significant source of human dietary exposure to C10-C14 PFCAs.

Perfluorinated and polyfluorinated compounds in lake food webs from the Canadian high Arctic

Per- and polyfluorinated alkyl substances (PFASs) enter Arctic lakes through long-range atmospheric transport and local contamination, but their behavior in aquatic food webs at high latitudes is poorly understood. This study compared the concentrations of perfluorocarboxylates, perfluorosulfonates, and fluorotelomer sulfonates (FTS) in biotic and abiotic samples from six high Arctic lakes near Resolute Bay, Nunavut, Canada. Two of these lakes are known to be locally contaminated by a small airport and Arctic char (Salvelinus alpinus) from these lakes had over 100 times higher total [PFAS] when compared to fish from neighboring lakes. Perfluorononanoate (PFOA) and perfluorooctanesulfonate (PFOS) dominated in char, benthic chironomids (their main prey), and sediments, while pelagic zooplankton and water were dominated by lower chain acids and perfluorodecanesulfonate (PFDS). This study also provides the first measures of perfluoroethylcyclohexanesulfonate (PFECHS) and FTS compounds in water, sediment, juvenile char, and benthic invertebrates from lakes in the high Arctic. Negative relationships between [PFAS] and δ(15)N values (indicative of trophic position) within these food webs indicated no biomagnification. Overall, these results suggest that habitat use and local sources of contamination, but not trophic level, are important determinants of [PFAS] in biota from freshwater food webs in the Canadian Arctic.

Which coastal and marine environmental contaminants are truly emerging?

To better understand the past and present impact of contaminants of emerging concern (CECs) in coastal and marine ecosystems, archived samples were analyzed for a broad suite of analytes, including pharmaceuticals and personal care products (PPCPs), flame retardants (including PBDEs), perfluorinated compounds (PFCs), and current-use pesticides. Surface sediment, mussels (Mytilus spp.) and sediment core samples collected from the California (USA) coast were obtained from environmental specimen banks. Selected CECs were detected in recent surface sediments, with nonylphenol (4-NP), its mono- and di-ethoxylates (NP1EO and NP2EO), triclocarban, and pyrethroid insecticides in the greatest abundance. Alkylphenols, triclocarban, and triclosan were present in sediment core segments from the 1970s, as well as in Mytilus tissue collected during the 1990s. Increasing concentrations of some CECs (e.g., miconazole, triclosan) were observed in the surface layers (ca. 2007) of a sediment core, in contrast to peak concentrations of 4-NP and triclocarban corresponding to input during the 1970s, and an apparent peak input for PBDEs during the 1990s. These results suggest that chemicals sometimes referred to as "emerging" (e.g., alkylphenols, triclocarban) have been present in the aquatic environment for several decades and are decreasing in concentration, whereas others (e.g., miconazole, triclosan) are increasing.

Determination of perfluorochemicals in fish and shellfish using liquid chromatography-tandem mass spectrometry

This paper reports the validation and application of a method for determination of 10 perfluorochemicals (PFCs) in retail fish and shellfish. The analytes of interest were 7 perfluorinated carboxylates and 3 perfluorinated sulfonates. Fish and shellfish samples were digested with a basic solution of 10 mM sodium hydroxide in methanol before sonication and solid phase extraction through weak anion exchange. Analysis was performed using liquid chromatography-tandem mass spectrometry. Recoveries from spiking five different types of fish and shellfish indicate that the method performs similarly with different fish types, and recoveries were over 90% for all analytes. Forty-six retail samples, collected between 2010 and 2012, including 13 different types of fish and shellfish were analyzed for PFCs. The 13 different types included the top 10 most-consumed fish and shellfish in the United States according to data collected by the National Fisheries Institute. Two Standard Reference Materials were also analyzed. Most fish and shellfish had no detected PFCs; only 11 samples of the 46 tested had detectable concentrations of PFCs.

Perfluoroalkyl acids in the Canadian environment: multi-media assessment of current status and trends

In Canada, perfluoroalkyl acids (PFAAs) have been the focus of several monitoring programs and research and surveillance studies. Here, we integrate recent data and perform a multi-media assessment to examine the current status and ongoing trends of PFAAs in Canada. Concentrations of perfluorooctane sulfonate (PFOS), perfluorooctanoate (PFOA), and other long-chain perfluorocarboxylates (PFCAs) in air, water, sediment, fish, and birds across Canada are generally related to urbanization, with elevated concentrations observed around cities, especially in southern Ontario. PFOS levels in water, fish tissue, and bird eggs were below their respective Draft Federal Environmental Quality Guidelines, suggesting there is low potential for adverse effects to the environment/organisms examined. However, PFOS in fish and bird eggs tended to exceed guidelines for the protection of mammalian and avian consumers, suggesting a potential risk to their wildlife predators, although wildlife population health assessments are needed to determine whether negative impacts are actually occurring. Long-term temporal trends of PFOS in suspended sediment, sediment cores, Lake Trout (Salvelinus namaycush), and Herring Gull (Larus argentatus) eggs collected from Lake Ontario increased consistently from the start of data collection until the 1990s. However, after this time, the trends varied by media, with concentrations stabilizing in Lake Trout and Herring Gull eggs, and decreasing and increasing in suspended sediment and the sediment cores, respectively. For PFCAs, concentrations in suspended sediment, sediment cores, and Herring Gulls generally increased from the start of data collection until present and concentrations in Lake Trout increased until the late 1990s and subsequently stabilized. A multimedia comparison of PFAA profiles provided evidence that unexpected patterns in biota of some of the lakes were due to unique source patterns rather than internal lake processes. High concentrations of PFAAs in the leachate and air of landfill sites, in the wastewater influent/effluent, biosolids, and air at wastewater treatment plants, and in indoor air and dust highlight the waste sector and current-use products (used primarily indoors) as ongoing sources of PFAAs to the Canadian environment. The results of this study demonstrate the utility of integrating data from different media. Simultaneous evaluation of spatial and temporal trends in multiple media allows inferences that would be impossible with data on only one medium. As such, more co-ordination among monitoring sites for different media is suggested for future sampling, especially at the northern sites. We emphasize the importance of continued monitoring of multiple-media for determining future responses of environmental PFAA concentrations to voluntary and regulatory actions.

Perfluoroalkyl substances in eggs and plasma of an avian top predator, great skua (Stercorarius skua), in the North Atlantic

Temporal, biological, and environmental factors affecting accumulation of perfluoroalkyl substances (PFASs) are poorly understood in comparison with legacy lipid-soluble persistent organic pollutants. Temporal and biological comparisons of PFAS concentrations were made in great skuas (Stercorarius skua), a marine apex predator. Concentrations of 16 PFASs were quantified, including C4-C10 perfluorosulfonates (PFSAs), perfluorooctanesulfonamide (PFOSA), and C5-C14 perfluorocarboxylates (PFCAs). Concentrations of PFASs (ng/g wet wt) were significantly higher in eggs collected in Shetland in 2008 compared with 1980 for most compounds. However, the magnitude of the differences was small, with a mean increase of 3 ng/g. Levels of PFASs in great skuas were low compared with those of other seabirds in similar ecological niches; and in contrast to other contaminants measured in the same eggs, concentrations of PFASs did not correlate with trophic level. Concentrations of PFASs in adult plasma were significantly higher in males than in females for most PFASs. This suggests that maternal transfer through egg laying may be a significant mode of elimination of PFASs in female great skuas. The low concentrations of PFASs in eggs and plasma compared with other halogenated organic contaminants and other species suggest that great skuas do not bioaccumulate PFASs to the same extent as some other seabirds.

Role of chromatography in the development of Standard Reference Materials for organic analysis

The certification of chemical constituents in natural-matrix Standard Reference Materials (SRMs) at the National Institute of Standards and Technology (NIST) can require the use of two or more independent analytical methods. The independence among the methods is generally achieved by taking advantage of differences in extraction, separation, and detection selectivity. This review describes the development of the independent analytical methods approach at NIST, and its implementation in the measurement of organic constituents such as contaminants in environmental materials, nutrients and marker compounds in food and dietary supplement matrices, and health diagnostic and nutritional assessment markers in human serum. The focus of this review is the important and critical role that separation science techniques play in achieving the necessary independence of the analytical steps in the measurement of trace-level organic constituents in natural matrix SRMs.