Persistence of PFOA Pollution at a PTFE Production Site and Occurrence of Replacement PFASs in English Freshwaters Revealed by Sentinel Species, the Eurasian Otter (Lutra lutra).

Concentrations of 33 PFASs were determined in 20 Eurasian otters, sampled 2015-2019, along a transect away from a factory, which used PFOA in PTFE manufacture. Despite cessation of usage in 2012, PFOA concentrations remained high near the factory (>298 µg/kg ww <20 km from factory) and declined with increasing distance (<57 µg/kg ww >150 km away). Long-chain legacy PFASs dominated the Σ33PFAS profile, particularly PFOS, PFOA, PFDA, and PFNA. Replacement compounds, PFECHS, F-53B, PFBSA, PFBS, PFHpA, and 8:2 FTS, were detected in ≥19 otters, this being the first report of PFBSA and PFECHS in the species. Concentrations of replacement PFASs were generally lower than legacy compounds (max: 70.3 µg/kg ww and 4,640 µg/kg ww, respectively). Our study underscores the utility of otters as sentinels for evaluating mitigation success and highlights the value of continued monitoring to provide insights into the longevity of spatial associations with historic sources. Lower concentrations of replacement, than legacy, PFASs likely reflect their lower bioaccumulation potential, and more recent introduction. Continued PFAS use will inevitably lead to increased environmental and human exposure if not controlled. Further research is needed on fate, toxicity, and bioaccumulation of replacement compounds.

Anthropogenic Drivers of Variation in Concentrations of Perfluoroalkyl Substances in Otters (Lutra lutra) from England and Wales.

Per- and polyfluoroalkyl substances (PFASs) are ubiquitous environmental contaminants that have been linked to adverse health effects in wildlife and humans. Here, we report the presence of PFASs in Eurasian otters (Lutra lutra) in England and Wales and their association with anthropogenic sources. The following 15 compounds were analyzed: 10 perfluoroalkyl carboxylic acids (PFCAs), 4 perfluoroalkyl sulfonic acids (PFSAs), and perfluorooctane sulfonamide, in livers of 50 otters which died between 2007 and 2009. PFASs were detected in all otters analyzed, with 12/15 compounds detected in ≥80% of otters. Perfluorooctane sulfonate (PFOS) accounted for 75% of the ΣPFAS profile, with a maximum concentration of 6800 µg/kg wet weight (ww). Long-chain (≥C8) PFCAs accounted for 99.9% of the ΣPFCA profile, with perfluorodecanoic acid and perfluorononanoic acid having the highest maxima (369 µg/kg ww and 170 µg/kg ww, respectively). Perfluorooctanoic acid (PFOA) concentrations were negatively associated with the distance from a factory that used PFOA in polytetrafluoroethylene manufacture. Most PFAS concentrations in otters were positively associated with load entering wastewater treatment works (WWTW) and with arable land, suggesting that WWTW effluent and sewage sludge-amended soils are significant pathways of PFASs into freshwaters. Our results reveal the widespread pollution of British freshwaters with PFASs and demonstrate the utility of otters as effective sentinels for spatial variation in PFAS concentrations.

Detecting illegal cyanide fishing: Establishing the evidence base for a reliable, post-collection test.

Ornamental fish have been legally harvested since the 1930's but in the 60's, cyanide fishing was first documented. Target fish exposed to the chemical are temporarily paralysed making them easier to catch, but with high post-capture mortality and significant ecological impacts, its use is banned in most exporting countries. To differentiate illegally caught fish from those sustainably collected, efforts to develop a post-collection detection test began nearly 30 years ago. However, even the most promising approach has been questioned by other researchers as unrepeatable under different experimental conditions. In this paper we summarise the evidence-base for establishing a cyanide detection test for live fish by evaluating current approaches. We describe the key knowledge gaps which continue to limit our progress in implementing a screening programme and highlight some alternative solutions which may provide greater short to medium term opportunities to prevent the illegal practise before fish enter the supply chain.

Hexabromocyclododecanes, polybrominated diphenyl ethers, and polychlorinated biphenyls in radiometrically dated sediment cores from English lakes, ~1950-present.

This paper reports input fluxes between ~1950 and present, of polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), and hexabromocyclododecanes (HBCDs) in radiometrically-dated sediment cores from 7 English lakes. Fluxes of PCBs at all but one location prone to significant sediment resuspension peaked in the late-1960s/early-1990s, before declining thereafter. Input fluxes of HBCDs at all sites increased from first emergence in the mid-1960s. Thereafter, fluxes peaked in the late-1980s/early-2000s, before declining through to the present, except at the most urban site where HBCD fluxes are still increasing. Trends of PBDEs predominant in the Penta-BDE and Octa-BDE formulations vary between sites. While at some locations, fluxes peaked in the late-1990s/early-2000s; at others, fluxes are still increasing. This suggests the full impact of EU restrictions on these formulations has yet to be felt. Fluxes of BDE-209 have yet to peak at all except one location, suggesting little discernible environmental response to recent EU restrictions on the Deca-BDE product. Strikingly, fluxes of BDE-209 in the most recent core slices either exceed or approach peak fluxes of ΣPCBs, implying substantial UK use of Deca-BDE. Excepting HBCDs, inventories of our target contaminants correlated significantly with local population density, implying substantial urban sources.

Organophosphorus flame retardants (PFRs) and plasticisers in harbour porpoises (Phocoena phocoena) stranded or bycaught in the UK during 2012.

A suite of twenty organophosphorus flame retardant compounds have been determined in blubber and liver tissue of twenty harbour porpoises stranded or bycaught in the UK during 2012 in order to establish current levels of contamination. Fourteen of the twenty compounds were below the limits of quantification in all samples. Six could be quantified at maximum concentrations (in blubber) between 6.7 and 246µgkg(-1) wet weight. These levels do not suggest a high level of concern regarding potential impacts and do not indicate that routine monitoring in UK porpoises is warranted at this time.

Organohalogen contaminants and trace metals in North-East Atlantic porbeagle shark (Lamna nasus).

The North-East Atlantic porbeagle (Lamna nasus) population has declined dramatically over the last few decades and is currently classified as 'Critically Endangered'. As long-lived, apex predators, they may be vulnerable to bioaccumulation of contaminants. In this study organohalogen compounds and trace elements were analysed in 12 specimens caught as incidental bycatch in commercial gillnet fisheries in the Celtic Sea in 2011. Levels of organohalogen contaminants were low or undetectable (summed CB and BDE concentrations 0.04-0.85 mg kg(-1)wet weight). A notably high Cd concentration (7.2 mg kg(-1)wet weight) was observed in one mature male, whereas the range observed in the other samples was much lower (0.04-0.26 mg kg(-1)wet weight). Hg and Pb concentrations were detected only in single animals, at 0.34 and 0.08 mg kg(-1)wet weight, respectively. These contaminant levels were low in comparison to other published studies for shark species.

Alternative flame retardants, Dechlorane Plus and BDEs in the blubber of harbour porpoises (Phocoena phocoena) stranded or bycaught in the UK during 2008.

Thirty alternative flame retardant compounds and a suite of 17 brominated diphenyl ether (BDE) congeners were determined in the blubber of 21 harbour porpoises stranded or bycaught around UK coasts during 2008 using GC-MS/MS. Of the 30 compounds, 19 were not detected. Of the remaining 11 compounds, some fell below the lowest calibration level and so were recorded as less than values, but were certainly present in the blubber samples (examples include tetrabromo-p-xylene (TBX), tetrabromo-o-chlorotoluene (TBCT) and 2,3-dibromopropyl-2,4,6-tribromophenyl ether (TBP-DBPE). Concentrations were low, the highest concentration being only 35µgkg(-1) wet weight. This contrasted with those of the BDEs, summed concentrations which ranged from 54.6 to 913µgkg(-1) wet weight, although levels in porpoise blubber have been declining since 1998. Both Dechlorane Plus (DDC-CO) isomers were detected in some samples, suggesting either that this product has been used in the UK or that its presence may result from atmospheric transport from source regions. BDE183, a marker for the octa-mix PBDE product, was found at low concentrations (0.63 to 1.7µgkg(-1) wet weight) and the four nona- and deca-BDE congeners were not detected in any sample.

A review of the analysis of novel brominated flame retardants.

This review provides a summary of various analytical methodologies applied to the determination of "novel" brominated flame retardants (NBFRs) in various environmental compartments, as reported in peer reviewed literature, either in print or online, until the end of 2010. NBFRs are defined here as those brominated flame retardants (BFRs) which are either new to the market or newly/recently observed in the environment. The preparation and extraction of sediment, water, sewage sludge, soil, air and marine biota samples, the extract clean-up/fractionation and subsequent instrumental analysis of NBFRs are described and critically examined. Generally, while the instrumental analysis step mainly relies on mass-spectrometric detection specifically developed for NBFRs, and hyphenated to liquid or gas chromatography, preceding steps tend to replicate methodologies applied to the determination of traditional BFRs such as polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecane (HBCD). Shortcomings and gaps are discussed and recommendations for future development are given.

Biomagnification of anthropogenic and naturally-produced organobrominated compounds in a marine food web from Sydney Harbour, Australia.

Polybrominated diphenyl ethers (PBDEs) and naturally-produced organobrominated compounds, such as methoxylated PBDEs (MeO-PBDEs), have been scarcely studied in the Southern Hemisphere. Yet, sources of the latter group of compounds were found in Southern regions, specifically in Australia. The environmental distribution and biomagnification potential of organobrominated compounds were therefore investigated in a representative aquatic food chain (invertebrates and fish) from the Sydney Harbour, Australia. Mean PBDE concentrations ranged from 6.4ng/g lipid weight (lw) in squid to 115 ng/g lw in flounder. BDE 47 was the dominant congener, followed by BDE 100. Mean levels of MeO-PBDEs (sum of congeners 2'-MeO-BDE 68 and 6-MeO-BDE 47) were as high as 110 ng/g lw in tailor, with a slight dominance of 2'-MeO-BDE 68. Polybrominated hexahydroxanthene derivates (PBHDs), another class of naturally-produced compounds, were found at variable concentrations and ranged from 4.7 ng/g lw in fanbelly and 146ng/g lw in tailor. The tribrominated PBHD isomer dominated in the samples, except for luderick and squid. The lower levels of PBDEs found in luderick from the harbour compared to those obtained from the upper Parramatta River indicated a terrestrial (anthropogenic) origin of PBDEs, while the higher levels of MeO-PBDEs and PBHDs in the samples from the harbour confirmed the marine (natural) origin of these compounds. The highest trophic magnification factor (TMF) was found for sum PBDEs (3.9), while TMFs for sum MeO-PBDEs and sum PBHDs were 2.9 and 3.4, respectively. This suggests that biomagnification occurs in the studied aquatic food chain for anthropogenic brominated compounds, but also for the naturally-produced organobromines.

Biomagnification of naturally-produced methoxylated polybrominated diphenyl ethers (MeO-PBDEs) in harbour seals and harbour porpoises from the southern North Sea.

Harbour seals and harbour porpoises are top predator species from the North Sea, have long life spans and hence, are known to accumulate high levels of anthropogenic contaminants. To gain knowledge about the behaviour of naturally-produced compounds in these marine mammals, the biomagnification of naturally-produced methoxylated polybrominated diphenyl ethers (MeO-PBDEs) was assessed. The biomagnification of MeO-PBDEs (2'-MeO-BDE 68 and 6-MeO-BDE 47) was lower in harbour seals (all biomagnification factors (BMFs)<1) compared to the same age-gender groups of the harbour porpoises (all BMFs>1). This may indicate a better metabolic breakdown of MeO-PBDEs in harbour seals, as was previously suggested for polybrominated diphenyl ethers (PBDEs). In both predators, 6-MeO-BDE 47 had the highest concentrations (range: 45-483 ng/g lw and 2-38 ng/g lw for harbour porpoises and seals, respectively) compared to 2'-MeO-BDE 68 (range: 2-28 ng/g lw and 1-6 ng/g lw for harbour porpoises and seals, respectively). In general, the highest concentrations were found in juveniles, suggesting an increased biotransformation capacity with age or the influence of dilution by growth for both species. Here we show that naturally-produced brominated organic compounds can biomagnify and accumulate in North Sea top predators, although to a lesser extent than anthropogenic lipophilic contaminants, such as polychlorinated biphenyls (PCBs) or PBDEs.

Anthropogenic and naturally occurring organobrominated compounds in two deep-sea fish species from the Mediterranean Sea.

Polybrominated diphenyl ethers (PBDEs) were investigated in 15 composite liver samples from two deep-sea fish species, the hollowsnout grenadier (Trachyrinchus trachyrinchus, TT) and the roughsnout grenadier (Coelorhynchus coelorynchus, CC). Mean concentrations of sum tri- to hepta-BDEs were higher in CC species than in the TT species (16.9 vs. 4.5 ng/g lipid weight (lw), respectively). BDE 47 and BDE 100 were the major congeners in both species. Methoxylated PBDEs (MeO-PBDEs), reported as being naturally produced in marine environments, were also measured in all samples. Similar to those of PBDEs, mean concentrations of sum MeO-PBDEs (sum congeners 2'-MeO-BDE 68 and 6-MeO-BDE 47) were higher in the CC species (28.9 vs 6.6 ng/g lw, respectively). Interestingly, polybrominated hexahydroxanthene derivatives (PBHDs) had the highest contribution to the total load of organobromines in the deep-sea fish samples. Contraryto those of PBDEs and MeO-PBDEs, the mean concentrations of PBHDs were higher in the TT species (7040 vs. 530 ng/g lw, respectively). Furthermore, an unusual profile was seen in the TT species, for which a tetrabrominated BHD isomer was the predominant isomer (up to 98% of the sum PBHDs). This differs from the profiles of PBHDs dominated by a tribrominated BHD isomer reported until now in the literature. The mixed halogenated monoterpene (MHC-1) and 2,4,6-tribromoanisole (TBA) were detected as well, albeit at lower concentration (<5 ng/g lw), supporting the hypothesis that these two natural products are rather abundant in shallow waters.