Stranded cetaceans warn of high perfluoroalkyl substance pollution in the western Mediterranean Sea

Accumulation features and temporal trends (2002-2015) for legacy and emerging per- and polyfluoroalkyl substances (PFASs) in finless porpoises bycaught off Korean coasts

Legacy and emerging per- and polyfluoroalkyl substances (PFASs) were measured in livers of finless porpoises (Neophocaena asiaeorientalis; n = 167) collected in Korean waters from 2002 to 2015 to investigate their occurrence, bioaccumulation feature, temporal trends, and ecotoxicological implications. Perfulorooctane sulfonate (PFOS), perfluoroundecanoate (PFUnDA), and perfluorotridecanoate (PFTrDA) were the predominant PFASs found in the porpoises. The concentration of 6:2 chlorinated polyfluoroalkyl ether sulfonate (F-53B), an alternative to PFOS, was comparable to that of PFTrDA. Perfluorooctane sulfonamide (FOSA), a precursor of PFOS, was also detected in all the porpoises examined. All PFASs, including F-53B, accumulated to higher concentrations in immature porpoises compared with mature specimens, implying substantial maternal transfer and limited metabolizing capacity for PFASs. A significant correlation was observed between PFOS and F-53B concentrations, indicating similar bioaccumulation processes. Based on prenatal exposure and toxicity, F-53B is an emerging contaminant in marine ecosystems. Significantly increasing trends were observed in the concentrations of sulfonates, carboxylates, and F-53B between 2002/2003 and 2010, whereas the FOSA concentration significantly decreased. During 2010-2015, decreasing trends were observed in the concentrations of FOSA and sulfonates, whereas concentrations of carboxylate and F-53B increased without statistical significance, likely due to a gap for the implementation of regulatory actions between sulfonates and carboxylates. Although PFOS and PFOA were found to pose little health risk to porpoises, the combined toxicological effects of other contaminants should be considered to protect populations and to mitigate PFAS contamination in marine ecosystems.

Occurrence and pattern of legacy and emerging per- and Poly-FluoroAlkyl substances (PFAS) in eggs of loggerhead turtle Caretta caretta from western Mediterranean

Per-and Poly-FluoroAlkyl Substances (PFAS) are a class of persistent, toxic, and mobile and chemicals both from industrial sources and from the use and disposal of Consumers products containing PFAS, whose concentration in marine food webs could pose a toxicological risk for biota and humans. In 2021, unhatched eggs were sampled from 41 loggerhead turtle Caretta caretta nests from the Italian shores of the Campania Region (Southern Italy). Whole eggs were analysed for the presence of 66 legacy and emerging PFAS with Liquid Chromatography coupled to Hybrid High Resolution Mass Spectrometry. A median Σ66 Per- and Poly-FluoroAlkyl Substances value of 3.34 ng/g egg fresh weight was found; perfluoroctane sulfonate (PFOS) represented the most contributing congener (47%), followed by perfluoro-n-undecanoic acid, perfluoro-n-tridecanoic acid, perfluoro-n-decanoic acid, perfluoro-n-decanoic acid, and perfluoro-n-tetradecanoic acid, respectively. Such compounds showed a log-norm distribution, suggesting found concentrations could represent the baseline levels in the considered sampling area. Emerging ChloroPolyFluoroPolyEthers Carboxylic Acids (ClPFECAs) were found in 20 out of 41 samples in the range 0.01-1.59 ng/g. Four samples had 20-100 fold higher concentration compared to that of other samples, suggesting the presence of hot spot areas possibly related to presence of fluoropolymer-based marine litter turtles may ingest. The analysis of two paired eggs/liver samples recovered from stranded animals revealed PFAS concentration in the same order of magnitude, supporting the role of vitellogenin in their selective transfer to yolk. Significant (P = 0.0155) Kendall negative correlation coefficient of -0.2705 among PFOS content in eggs and the recorded hatching success prompts for further investigation on associated exposure assessment and related eco-toxicity risk. This work reports for the first time PFAS presence in georeferenced loggerhead turtle eggs of the Mediterranean Sea and results represent a starting point to study PFAS time-trends in this vulnerable species.

Closing the Organofluorine Mass Balance in Marine Mammals Using Suspect Screening and Machine Learning-Based Quantification

High-resolution mass spectrometry (HRMS)-based suspect and nontarget screening has identified a growing number of novel per- and polyfluoroalkyl substances (PFASs) in the environment. However, without analytical standards, the fraction of overall PFAS exposure accounted for by these suspects remains ambiguous. Fortunately, recent developments in ionization efficiency (IE) prediction using machine learning offer the possibility to quantify suspects lacking analytical standards. In the present work, a gradient boosted tree-based model for predicting log IE in negative mode was trained and then validated using 33 PFAS standards. The root-mean-square errors were 0.79 (for the entire test set) and 0.29 (for the 7 PFASs in the test set) log IE units. Thereafter, the model was applied to samples of liver from pilot whales (n = 5; East Greenland) and white beaked dolphins (n = 5, West Greenland; n = 3, Sweden) which contained a significant fraction (up to 70%) of unidentified organofluorine and 35 unquantified suspect PFASs (confidence level 2-4). IE-based quantification reduced the fraction of unidentified extractable organofluorine to 0-27%, demonstrating the utility of the method for closing the fluorine mass balance in the absence of analytical standards.

Hepatic concentrations of per- and polyfluoroalkyl substances (PFAS) in dolphins from south-east Australia: Highest reported globally

Per- and polyfluoroalkyl substances (PFAS) concentrations were investigated in hepatic tissue of four dolphin species stranded along the south-east coast of Australia between 2006 and 2021; Burrunan dolphin (Tursiops australis), common bottlenose dolphin (Tursiops truncatus), Indo-Pacific bottlenose dolphin (Tursiops aduncus), and short-beaked common dolphin (Delphinus delphis). Two Burrunan dolphin populations represented in the dataset have the highest reported global population concentrations of ∑25PFAS (Port Phillip Bay median 9750 ng/g ww, n = 3, and Gippsland Lakes median 3560 ng/g ww, n = 8), which were 50-100 times higher than the other species reported here; common bottlenose dolphin (50 ng/g ww, n = 9), Indo-Pacific bottlenose dolphin (80 ng/g ww, n = 1), and short-beaked common dolphin (61 ng/g ww, n = 12). Also included in the results is the highest reported individual ∑25PFAS (19,500 ng/g ww) and PFOS (18,700 ng/g ww) concentrations, at almost 30 % higher than any other Cetacea reported globally. Perfluorooctane sulfonate (PFOS) was above method reporting limits for all samples (range; 5.3-18,700 ng/g ww), and constituted the highest contribution to overall ∑PFAS burdens with between 47 % and 99 % of the profile across the dataset. The concentrations of PFOS exceed published tentative critical concentrations (677-775 ng/g) in 42 % of all dolphins and 90 % of the critically endangered Burrunan dolphin. This research reports for the first time novel and emerging PFASs such as 6:2 Cl-PFESA, PFMPA, PFEECH and FBSA in marine mammals of the southern hemisphere, with high detection rates across the dataset. It is the first study to show the occurrence of PFAS in the tissues of multiple species of Cetacea from the Australasian region, demonstrating high global concentrations for inshore dolphins. Finally, it provides key baseline knowledge to the potential exposure and bioaccumulation of PFAS compounds within the coastal environment of south-east Australia.

Biomagnification and temporal trends (1990-2021) of perfluoroalkyl substances in striped dolphins (Stenella coeruleoalba) from the NW Mediterranean sea

Poly- and Perfluoroalkyl Substances (PFAS) are a well-known class of pollutants which can bioaccumulate and biomagnify with a vast majority being highly persistent. This study aims to determine the biomagnification rates of PFAS in sexually mature striped dolphins and to assess temporal trends on PFAS concentrations over the past three decades (1990-2021) in the North-Western Mediterranean Sea. Thirteen and 17 of the 19 targeted PFAS were detected in the samples of the dolphins' digestive content and liver, respectively, at concentrations ranging between 43 and 1609 ng/g wet weight, and 254 and 7010 ng/g wet weight, respectively. The most abundant compounds in both types of samples were linear perfluorooctanesulfonic acid (n-PFOS) and perfluorooctanesulfonamide (FOSA), which were present in all samples, followed by perfluoroundecanoic acid (PFUnDA), perfluorotridecanoic acid (PFTrDA) and perfluorononanoic acid (PFNA). Long-chain PFAS (i.e., PFCAs C ≥ 7 and PFSAs C ≥ 6) biomagnified to a greater extent than short-chain PFAS, suggesting a potential effect on the health of striped dolphins. Environmental Quality Standards concentrations set in 2014 by the European Union were exceeded in half of the samples of digestive content, suggesting that polluted prey may pose potential health risks for striped dolphins. Concentrations of most long-chain PFAS increased from 1990 to 2004-2009, then stabilized during 2014-2021, possibly following country regulations and industrial initiatives. The current study highlights the persistent presence of banned PFAS and may contribute to future ecological risk assessments and the design of management strategies to mitigate PFAS pollution in marine ecosystems.

Identification of key features relating to the coexistence mechanisms of trace elements and per- and polyfluoroalkyl substances (PFASs) in marine mammals

Organic and inorganic substances coexist in the livers of marine mammals and may correlate with one another; however, their coexistence mechanisms and relevant key features remain largely unknown. In this study, temporal variations (2011-2021) in the concentrations of nine trace elements and 19 per- and polyfluoroalkyl substances (PFASs) in the livers of Indo-Pacific humpback dolphins (Sousa chinensis) and finless porpoises (Neophocaena phocaenoides) were investigated. Interannual Cd in dolphins increased significantly whereas Pb concentrations decreased over the past decade (p < 0.05). Interannual levels of seven and four PFASs in dolphins and porpoises decreased significantly with time (p < 0.05). By further extending the timescale to 1993-2021, the sensitivity of trace elements to annual change further increased, whereas the sensitivity of PFASs remained relatively stable. Cu levels, similar to the majority of PFASs, were negatively correlated with the body length of the studied cetaceans, which led to positive correlations of Cu with six long-chain perfluoroalkyl carboxylic acids, perfluorodecane sulfonic acid, and perfluoroethylcyclohexane sulfonic acid. The concentrations of trace elements in the cetacean liver were closely correlated with cetacean sex, species, and body length, whereas PFAS concentration was responsive to time-related features such as stranded season and year. By further employing a machine learning method, we demonstrated that body length and a time-related factor (year) played a crucial role in predicting the concentrations of certain trace elements and PFASs, respectively, particularly Cu and perfluoroheptanoic acid.

Assessment of polycyclic aromatic hydrocarbons (PAHs) in mediterranean top marine predators stranded in SE Spain

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous environmental pollutants. Although they are not bioaccumulated in vertebrates, chronic exposures might still derive on serious toxic effects. We studied concentrations of 16 reference PAHs on blubber of two dolphin species (striped dolphin, n = 34; and bottlenose dolphin, n = 8) and one marine turtle (loggerhead turtle, n = 23) from the Mediterranean waters of SE Spain, an important or potential breeding area for these and other related species. Σ16 PAHs concentrations were relatively similar between the three species, but they were in the lower range in comparison to worldwide data. Of the six PAHs detected, fluoranthene was the only high molecular weight (HMW) PAH, so low molecular weight (LMW) PAHs predominated. Naphthalene and phenanthrene were invariably those PAHs with higher detection rates as well as those with higher concentrations. In accordance with the literature, sex and length did not have significant influence on PAHs concentrations, probably due to high metabolization rates which prevent for observation of such patterns. Despite LMW PAHs are considered less toxic, we cannot dismiss toxic effects. This is the first work assessing PAHs concentrations in cetaceans and sea turtles from the SE Spain, which could serve as the baseline for future research.

Emerging and legacy contaminants in common minke whale from the Barents sea

Persistent organic pollutants (POPs), including brominated flame retardants (BFRs), perfluoroalkyl substances (PFAS) and metals, can accumulate in marine mammals and be transferred to offspring. In this study, we analyzed 64 lipophilic POPs, including four emerging BFRs, in the blubber, liver and muscle of 17 adult common minke whales (Balaenoptera acutorostrata) from the Barents Sea to investigate occurrence and tissue partitioning. In addition, the placental transfer concentration ratios of 14 PFAS and 17 metals were quantified in the muscle of nine female-fetus pairs to investigate placental transfer. Legacy lipophilic POPs were the dominating compound group in every tissue, and we observed generally lower levels compared to previous studies from 1992 to 2001. We detected the emerging BFRs hexabromobenzene (HBB) and pentabromotoluene (PBT), but in low levels compared to the legacy POPs. We detected nine PFAS, and levels of perfluorooctane sulfonate (PFOS) were higher than detected from the same population in 2011, whilst levels of Hg were comparable to 2011. Levels of lipophilic contaminants were higher in blubber compared to muscle and liver on both a wet weight and lipid adjusted basis, but tissue partitioning of the emerging BFRs could not be determined due to the high number of samples below the limit of detection. The highest muscle ΣPFAS levels were quantified in fetuses (23 ± 8.7 ng/g ww), followed by adult males (7.2 ± 2.0 ng/gg ww) and adult females (4.5 ± 1.1 ng/g ww), showing substantial placental transfer from mother to fetus. In contrast, Hg levels in the fetus were lower than the mother. Levels were under thresholds for risk of health effects in the whales. This study is the first to report occurrence and placental transfer of emerging contaminants in common minke whales from the Barents Sea, contributing valuable new data on pollutant levels in Arctic wildlife.

POPs concentrations in cetaceans stranded along the agricultural coastline of SE Spain show lower burdens of industrial pollutants in comparison to other Mediterranean cetaceans

Despite the Mediterranean Sea being one of the world's marine biodiversity hotspots, it is a hotspot of various environmental pollutants. This sea holds eight cetacean with resident populations whose numbers are considered to decline in the last decades and which are particularly susceptible to POPs bioaccumulation due to their peculiar characteristics. In this work, we studied blubber concentration of various OCPs and several PCBs and PBDEs congeners in cetaceans stranded in the northern coast of the Gulf of Vera (Region of Murcia, SE Spain) between 2011 and 2018. Most compounds and congeners were above the limit of detection in most samples, although some pesticides like endosulfan stereoisomers or endrin were never detected. DDT and its metabolites, PCBs and metoxychlor appear as the dominant compounds while PBDEs shows concentrations of lower magnitude. Striped dolphin was the species accounting for higher concentrations of most pollutants. There were differences in concentrations and profiles between species which could be partially explained by differences on diet and feeding behavior. We also observed differences based on life history parameters suggesting maternal transfer for most POPs, in accordance with other works. DDE/ ΣDDT ratio suggest no recent exposure to these pesticides. Despite showing lower concentrations than some previous works, PCB concentrations accounted for higher total TEQ than many studies. According to toxicity thresholds in the literature, we cannot guarantee the absence of health consequences on populations studied, especially for those caused by PCBs. These findings are of major importance considering the relevance of the study area in the conservation of Mediterranean cetaceans.

Spatiotemporal and life history related trends of per- and polyfluoroalkyl substances in Indo-Pacific finless porpoises from south China sea (2007-2020)

Per- and polyfluoroalkyl substances (PFASs) levels in Indo-Pacific finless porpoises (Neophocaena phocaenoides) in the Pearl River Estuary (PRE), near the most economically developed region in China, have not been characterized. We measured the hepatic concentrations of twelve PFASs, including nine perfluoroalkyl carboxylic acids (PFCAs) and three perfluoroalkane sulfonic acids (PFSAs) in the finless porpoises (n = 21) collected from the PRE between 2007 and 2020. The average level of PFSAs was more than 2-times higher than that of PFCAs. The order of six dominant PFASs was perfluorooctane sulfonate (PFOS) > perfluoroundecanoic acid (PFUdA) > perfluorodecanoic acid (PFDA) > perfluorotridecanoic acid (PFTrDA) > perfluorononanoic acid (PFNA) > perfluorododecanoic acid (PFDoDA). The levels of Hepatic PFOS of 29% samples exceeded the no observable adverse effect level (NOAEL) values. The concentration of PFASs in males was significant higher than in females. PFASs levels were significantly negatively correlated with body length in males and positively correlated in females. PFASs levels in the PRE finless porpoises were lower than in humpback dolphins possibly due to different foraging habitat toward the coast and the consumption of less fish. PFCAs levels in finless porpoises from the western PRE were higher compared to Hong Kong, possibly due to the high-intensity sources of terrestrial anthropogenic pollutants. Significant increasing spatiotemporal trends of PFSAs, PFCAs and PFASs were found in finless porpoises from 2007 to 2020, suggesting a continuously increased risk of PFASs exposure for PRE cetaceans in the last decade.

Cell cycle alterations due to perfluoroalkyl substances PFOS, PFOA, PFBS, PFBA and the new PFAS C6O4 on bottlenose dolphin (Tursiops truncatus) skin cell

Per- and polyfluoroalkyl substances (PFAS) have become ubiquitous environmental contaminants in aquatic ecosystems worldwide. Marine mammals, as top predators, are constantly exposed to several PFAS compounds that accumulate in different tissues. As a proxy to assess cytotoxicity of PFAS in the bottlenose dolphin (Tursiops truncatus), we generated a new immortalized cell line derived from skin samples of bottlenose dolphin. Using high content imaging, we assessed the effects of increasing concentrations of PFOS, PFOA, PFBS, PFBA and C6O4 on cell viability and cell cycle phases. In particular, we classified all cells based on multiple morphometric differences of the nucleus in three populations, named respectively "Normal" (nuclei in G0, S and M phase); "Large" (nuclei showing characteristics of senescence) and "Small" (nuclei with fragmentation and condensed chromatin). Combining this approach with cell cycle analysis we determined which phases of the cell cycle were influenced by PFAS. The results revealed that the presence of PFOS, PFBS and PFBA could increase the number of cells in G0+G1 phase and decrease the number of those in the S phase. Moreover, PFOS and PFBS lowered the fraction of cells in the M phase. Interestingly PFOS, PFBS and PFBA reduced the prevalence of the senescence phenotype ("large" nuclei), suggesting a potential tumorigenic effect. Besides, the presence of PFOS and PFBS correlated also with a significant decrease in the number of "small" nuclei. The C6O4 exposure did not highlighted morphometric alteration or cell cycle modification bottlenose dolphin skin cell nuclei. While the effects of PFAS on cell cycle was clear, no significant change was detected either in term of cell proliferation or of viability. This study fosters the overall knowledge on the cellular effects of perfluoroalkyl substances in marine mammals.

Brazilian overview of per- and polyfluoroalkyl substances listed as persistent organic pollutants in the stockholm convention

PFAS are a group of organic chemicals, which some presents environmental persistence, dispersion and potential toxicity. Some of them have been listed in the Stockholm Convention as persistent organic pollutants (POPs) to have its production and use restricted, namely PFOS, its salts and PFOSF and PFOA, its salts and related substances. As a Party, Brazil has to comply with the Convention provisions regarding the control of POPs. In order to develop listed PFAS inventories in the country, the Convention guidance documents were used. Stakeholders were consulted and trade data was assessed. Complementary, a review on listed PFAS occurrence in Brazil was performed. From over 1000 queries sent, only 3 answers were received. International trade data showed an import of 93.7 tonnes of PFOSF from China and export of sulfluramid-base ant bait to other developing countries. Domestic trade data showed that around 28 t per year of EtFOSA is commercialized in Brazil. The EtFOSA sold internally could lead to emissions of up to 616 t of PFOS. With domestic and foreign trade data it was possible to estimate the production of EtFOSA from 2010 to 2018 to 40 t per year. Only 10 studies reported listed PFAS occurrence in Brazilian environmental matrices. All of them reported ubiquitous occurrence of listed PFAS in the country, being PFOS the predominant in terms of occurrence and concentration. Brazil needs to develop strategies to overcome the low engagement of stakeholders and enforce control over listed PFAS foreign trade.

Evaluation of per- and poly-fluorinated alkyl substances (PFAS) in livers of bottlenose dolphins (Tursiops truncatus) found stranded along the northern Adriatic Sea

Per-and poly-fluorinated alkyl substances (PFAS) are a group of chemicals used in a wide variety of commercial products and industrial applications. These chemicals are persistent, can accumulate in humans' and animals' tissues and in the environment, representing an increasing concern due to their moderate to highly toxicity. Their global distribution, persistence and toxicity led to an urgent need to investigate bioaccumulation also in marine species. In 2013 PFAS contamination was detected in a vast area in Veneto region, mainly in Adige and Brenta rivers. In order to investigate any relevant presence of these substances in marine vertebrates constantly living in the area, PFAS were measured in hepatic tissue samples of 20 bottlenose dolphins (Tursiops truncatus) stranded along the northern Adriatic Sea coastline between 2008 and 2020. Using high performance liquid chromatography-mass spectrometry, 17 target PFAS (PFBA, PFPeA, PFHxA, PFHpA, PFOA, PFNA, PFDA, PFUnA, PFDoA, PFTrDA, PFTeDA, PFBS, PFHxS, PFOS, PFDS, PFHpS, PFPeS), were quantified in the samples. PFAS profiles were generally composed of the same five dominant PFAS (PFOS > PFUnA > PFDA ≈ PFDoA ≈ PFTrDA). The greatest PFOS concentration found was 629,73 ng/g wet weight, and PFOS accounted until 71% in the PFAS profiles. No significant differences between sexes were found, while calves showing higher mean values than adults, possibly indicating an increasing ability in the elimination of PFAS with age. Finally, a temporal analysis was carried out considering three different periods of time, but no temporal differences in concentrations were found. The results suggest that long-chain PFAS are widespread in bottlenose dolphins along the North Adriatic Sea. Furthermore, they represent a baseline to investigate the impact of PFAS on marine mammals' conservation and health. Filling an important gap in the knowledge of PFAS accumulation in bottlenose dolphins, this study highlights the relevant role of Environmental and Tissue Banks for retrospective analyses on emergent contaminants.

Per- and polyfluoroalkyl substances (PFAS), trace elements and life history parameters of mass-stranded common dolphins (Delphinus delphis) in New Zealand

Profiles of 33 PFAS analytes and 12 essential and non-essential trace elements were measured in livers of stranded common dolphins (Delphinus delphis) from New Zealand. PFAS concentrations reported were largely comparable to those measured in other marine mammal species globally and composed mostly of long-chain compounds including perfluorooctanesulfonic acid (PFOS), perfluorododecanoic acid (PFDoDA), perfluorotridecanoic acid (PFTrDA) and perfluorooctanesulfonamide (FOSA). PFAS profiles did not vary significantly by location, body condition, or life history. Notably, significant positive correlations were observed within respective PFAS and trace elements. However, only negative correlations were evident between these two contaminant types, suggesting different exposure and metabolic pathways. Age-associated concentrations were found for PFTrDA and four trace elements, i.e. silver, mercury, cadmium, selenium, indicating differences in the bioaccumulation biomagnification mechanisms. Overall, our results contribute to global understanding of accumulation of PFAS by offering first insights of PFAS exposure in cetaceans living within South Pacific Australasian waters.

Per and polyfluoroalkyl substances (PFAS) at high concentrations in neonatal Australian pinnipeds

Per and polyfluorinated substances (PFAS) exposure was investigated in Australian pinnipeds. Concentrations of 16 PFAS were measured in the livers of Australian sea lion (Neophoca cinerea), Australian fur seal (Arctocephalus pusillus doriferus) and a long-nosed Fur Seal (Arctocephalus forsteri) pup sampled between 2017 and 2020 from colonies in South Australia and Victoria. Findings reported in this study are the first documented PFAS concentrations in Australian pinnipeds. Median and observed range of values in ng/g wet weight were highest for perfluorooctane sulfonate (PFOS), perfluorooctanoic acid (PFOA) and perfluorononanoic acid (PFNA) in the liver of N. cinerea (PFOS = 7.14, 1.00-16.9; PFOA = 2.73, 0.32-11.2; PFNA = 2.96, 0.61-8.22; n = 28), A. forsteri (PFOS = 15.98, PFOA = 2.02, PFNA = 7.86; n = 1) and A. p. doriferus (PFOS = 27.4, 10.5-2119; PFOA = 0.98, 0.32-52.2; PFNA = 2.50, 0.91-44.2; n = 20). PFAS concentrations in A. p. doriferus pups were significantly greater (p < 0.05) than in N. cinerea pups for all PFAS except PFOA and were of similar magnitude to those reported in northern hemisphere marine animals. These results demonstrate exposure differences in both magnitude and PFAS profiles for N. cinerea in South Australia and A. p. doriferus in Victoria. This study reports detectable PFAS concentrations in Australian pinniped pups indicating the importance of maternal transfer of these toxicants. As N. cinerea are endangered and recent declines in pup production has been reported for A. p. doriferus at the colony sampled, investigation of potential health impacts of these toxicants on Australian pinnipeds is recommended.