Temporal trends and pattern of polyfluoroalkyl compounds in Tawny Owl (Strix aluco) eggs from Norway, 1986-2009

Trophic fate and biomagnification of organic micropollutants from staple food to a specialized predator

The environmental burden of organic micropollutants has been shown in aquatic ecosystems, while trophic fate of many compounds in terrestrial food chains remains highly elusive. We therefore studied concentrations of 108 organic micropollutants in a common European mammal, the bank vole (Clethrionomys glareolus), and 82 of the compounds in a specialized predator, Tengmalm's owl (Aegolius funereus) relying to >90 % on voles as its prey. We studied compounds in whole voles (n = 19), pools of 4-8 bank voles (npools = 4), owl blood (n = 10) and in owl eggs (n = 10) in two regions in Sweden. For comparison, we also included previously published data on 23 PFAS (per- and polyfluoroalkyl substances) in bank vole liver (npools = 4) from the same regions. In voles, concentrations of the organic micropollutants caffeine (maxIndividual 220 ng/g ww) and DEET (N,N-diethyl-m-toluamide) (maxPool 150 ng/g ww) were 2-200 times higher in voles relative to owl blood and eggs. Conversely, concentrations of nicotine, oxazepam, salicylic acid, and tributyl citrate acetate were 1.3-440 times higher in owls. Several PFAS showed biomagnification in owls as revealed by maximum biomagnification factors (BMFs); PFNA (perfluorononanoate) BMF = 5.6, PFTeDA (perfluorotetradecanoic acid) BMF = 5.9, and PFOS (perfluorooctane sulfonate) BMF = 6.1. Concentrations of organic micropollutants, alongside calculated BMFs, and Tengmalm's owl's heavy reliance on bank vole as staple food, suggest, despite small sample size and potential spatio-temporal mismatch, accumulation of PFAS (especially PFNA, PFTeDA, and PFOS) in owls and biomagnification along the food chain. Concentrations of PFAS in owl eggs (e.g., 21 ng/g ww PFOS) highlight the likely pivotal role of maternal transfer in contaminant exposure for avian embryos. These concentrations are also of concern considering that certain predators frequently consume owl eggs, potentially leading to additional biomagnification of PFAS with yet undetermined consequences for ecosystem health.

Chemical threats for the sentinel Pygoscelis adeliae from the Ross Sea (Antarctica): Occurrence and levels of persistent organic pollutants (POPs), perfluoroalkyl substances (PFAS) and mercury within the largest marine protected area worldwide

The Ross Sea Marine Protected Area (RS-MPA) hosts endemic species that have to cope with multiple threats, including chemical contamination. Adèlie penguin is considered a good sentinel species for monitoring pollutants. Here, 23 unhatched eggs, collected from three colonies along the Ross Sea coasts, were analysed to provide updated results on legacy pollutants and establish a baseline for newer ones. Average sum of polychlorinated biphenyls (∑PCBs) at the three colonies ranged 20.9-24.3 ng/g lipid weight (lw) and included PCBs IUPAC nos. 28, 118, 153, 138, 180. PCBs were dominated by hexachlorinated congeners as previously reported. Hexachlorobenzene (HCB) and p,p'-dichlorodiphenyldichloroethylene (p,p'-DDE) ranged between 134 and 166 and 181-228 ng/g lw, respectively. Overall, ∑PCBs was exceeded by pesticides, contrary to previous studies from the Ross Sea. Sum of polybrominated diphenyl ethers (∑PBDEs) ranged between 0.90 and 1.18 ng/g lw and consisted of BDE-47 (that prevailed as expected, representing 60-80 % of the ∑PBDEs) and BDE-85. Sum of perfluoroalkyl substances (∑PFAS) ranged from 1.04 to 1.53 ng/g wet weight and comprised five long-chain perfluorinated carboxylic acids (PFCAs), perfluorooctane sulfonate (PFOS), perfluorohexane sulfonate (PFHxS) and perfluorooctanoic acid (PFOA); perfluorooctane sulfonamide (PFOSA) was also detected. The PFAS profile was dominated by PFCAs as already observed in Arctic seabirds. Mercury ranged from 0.07 to 0.15 mg/kg dry weight similarly to previous studies. Legacy pollutants confirmed their ongoing presence in Antarctic biota and their levels seemed mostly in line with the past, but with minor variations in some cases, likely due to continued input or release from past reservoirs. PFAS were reported for the first time in penguins from the Ross Sea, highlighting their ubiquity. Although further studies would be useful to increase the sample size and accordingly improve our knowledge on spatial and temporal trends, this study provides interesting data for future monitoring programs within the RS-MPA that will be crucial to test its effectiveness against human impacts.

Per- and poly-fluoroalkyl substances in Tawny Owl (Strix aluco) feathers from Trøndelag, Norway

Per- and polyfluoroalkyl substances (PFASs) are contaminants of global concern due to their ubiquitous occurrence in the environment, bioaccumulation and the adverse effects on organisms. Tawny Owls (Strix aluco) are documented to be exposed to increasing concentrations of perfluoroalkyl carboxylic acids (PFCAs), and have been suggested in literature as a key raptor monitoring species. Therefore, non-destructive biomonitoring efforts are of high interest. Thus far, the use of feathers for biomonitoring PFASs in Tawny Owls has not been investigated. In this study, 32 PFASs were analyzed in 49 Tawny Owl body feather samples collected from 2017 to 2020 in Trøndelag, Norway. There were 30 PFASs detected in at least one feather, with the sum concentrations ranging from 31 to 203 ng/g (w.w.). Perfluoroheptanoic acid (PFHpA) (median: 33 ng/g) and perfluorooctane sulfonamidoacetic acid (FOSAA) (median: 18 ng/g) were the two compounds with the highest concentrations. Perfluorooctane sulfonic acid (PFOS), which is banned for production and use in Norway since 2007, was found in all samples (median: 4.14 ng/g), indicating its high persistence. 8 PFASs were detected in at least 50 % of the samples: FOSAA (11-127 ng/g), PFHpA (<0.04-115 ng/g), perfluorobutanesulfonic acid (PFBS) (<0.28-21 ng/g), PFOS (0.23-13 ng/g), perfluorotridecanoic acid (PFTrDA) (0.24-5.15 ng/g), perfluorododecanoic acid (PFDoDA) (<0.28-4.45 ng/g), perfluoroundecanoic acid (PFUnDA) (<0.28-2.33 ng/g), and 1H,1H,2H,2H-perfluorooctanesulfonic acid (6:2 FTSA) (0.07-1.01 ng/g). No significant differences were found for the concentrations of PFASs between calendar years and locations, but a slight increase could be observed in the sum concentration of PFASs (Ʃ32PFASs) over the sampling years. As Tawny Owls are residential owls that usually do not cover great distances, their feathers can be used as a potential alternative matrix for future biomonitoring studies. To our knowledge, this is the first study on the occurrence of 32 PFASs investigated in feathers of a Tawny Owl population.

Large-scale assessment of exposure to legacy and emerging per- and polyfluoroalkyl substances in China's shorebirds

Emerging per- and polyfluoroalkyl substances (PFAS) have become more widely applied, whereas legacy PFAS such as PFOS continue to distribute ubiquitously in the environment. Large-scale assessment of wildlife exposure to both emerging and legacy PFAS plays a key role in effective biomonitoring to better discriminate regional contamination patterns and provide early warnings. Using eggs of two closely-related shorebird species collected across China during the breeding season in 2021, we constructed contrasting PFAS levels and profiles in coastal versus inland populations. The highest ∑PFAS concentrations were found in two Kentish plover (Charadrius alexandrinus) populations from the Bohai Sea, a semi-enclosed shallow bay located in northeast China. These two populations showed exceptionally high PFOA concentrations (mean: 94 and 121 ng/g wet weight; West and North Bohai Sea, respectively) dominating the overall PFAS profile (66% for both). This pattern is characteristic, compared to that of other seabird eggs worldwide. By comparison, PFAS profile in the white-faced plover (Charadrius dealbatus) population at the South China Sea coast was dominated by PFOS (46%), which showed similar levels to those at the North Bohai Sea coast (mean: 29 and 20 ng/g, respectively). PFAS concentrations of Kentish plovers from the remote Qinghai Lake were lower compared to the three coastal populations, and were dominated by PFNA (mean: 2.6 ng/g, 29%) and PFOS (mean: 2.5 ng/g, 27%). None of the eggs analyzed in the present study exceeded estimated toxicity reference values for PFOS or PFOA. Additionally, the emerging 6:2 Cl-PFESA was detected in eggs from all regions, while its concentrations were highest in the Bohai Sea populations, and short-chain PFBS was only detected in the North Bohai Sea population. Our results indicate intensive local emissions of PFOA and emerging PFAS at the Bohai Sea region, and warrant further investigation and monitoring.

The importance of population contextual data for large-scale biomonitoring using an apex predator: The Tawny Owl (Strix aluco)

Top predators are often used as sentinel species in contaminant monitoring due to their exposure and vulnerability to persistent, bioaccumulative and, in some cases, biomagnificable contaminants. Some of their ecological traits can vary in space and time, and are known to influence the contamination levels and therefore information on ecological traits should be used as contextual data for correct interpretation of large-scale contaminant spatial patterns. These traits can explain spatiotemporal variation in contaminant exposure (traits such as diet and dispersal distances) or contaminant impacts (traits such as population trend and clutch size). The aim of our research was to review the spatial variation in selected contextual parameters in the Tawny Owl (Strix aluco), a species identified by the COST Action European Raptor Biomonitoring Facility as one of the most suitable candidates for pan-European biomonitoring. A considerable variation in availability of published and unpublished contextual data across Europe was found, with diet being the most extensively studied trait. We demonstrate that the Tawny Owl is a suitable biomonitor at local scale but also that taking spatial variation of other contextual data (e.g. diet) into account is necessary. We found spatial gaps in knowledge about the species ecology and biology in Southern Europe, along with gaps in certain population parameters (e.g. population trends) in several countries. Based on our findings, we proposed a minimal recommended scheme for monitoring of population contextual data as one of the first steps towards a pan-European monitoring scheme using the Tawny Owl.

Targeted PFAS analyses and extractable organofluorine - Enhancing our understanding of the presence of unknown PFAS in Norwegian wildlife

With the current possible presence of thousands of PFAS compounds in industrial emissions, there is an increasing need to assess the impacts of PFAS regulation of conventional PFAS on one hand and the exposure to emerging and yet unknown PFAS on the other. Today's analytical methodologies using targeted approaches are not sufficient to determine the complete suite of PFAS present. To evaluate the presence of unknown PFAS, we investigated in this study the occurrence of an extended range of target PFAS in various species from the marine and terrestrial Norwegian environment, in relation to the extractable organofluorine (EOF), which yields the total amount of organofluorine. The results showed a varying presence of extractable fluorinated organics, with glaucous gull eggs, otter liver and polar bear plasma showing the highest EOF and a high abundance of PFAS as well. The targeted PFAS measurements explained 1% of the organofluorine for moose liver as the lowest and 94% for otter liver as the highest. PFCAs like trifluoroacetic acid (TFA, reported semi-quantitatively), played a major role in explaining the organic fluorine present. Emerging PFAS as the perfluoroethylcyclohexane sulfonate (PFECHS), was found in polar bear plasma in quantifiable amounts for the first time, confirming earlier detection in arctic species far removed from emission sources. To enable a complete organic fluorine mass balance in wildlife, new approaches are needed, to uncover the presence of new emerging PFAS as cyclic- or ether PFAS together with chlorinated PFAS as well as fluorinated organic pesticides and pharmaceuticals.

Advanced throughput analytical strategies for the comprehensive HRMS screening of organic micropollutants in eggs of different bird species

Raptors are ideal indicators for biomonitoring studies using wildlife in order to assess the environmental pollution in the terrestrial ecosystem, since they are placed in the highest trophic position in the food webs and their life expectancy is relatively long. In this study, 26 eggs of 4 bird species (Peregrine falcon, Eurasian curlew, Little owl and Eagle owl) collected in Germany, were investigated for the presence of persistent organic pollutants (POPs) and thousands of contaminants of emerging concern (CECs). Generic sample preparation protocols were followed for the extraction of the analytes and the purification of the extracts, and the samples were analyzed both by liquid (LC) and gas chromatography (GC) coupled to high resolution mass spectrometry (HRMS), for capturing a wide range of organic micropollutants with different physicochemical properties. State-of-the-art screening methodologies were applied in the acquired HRMS data, including wide-scope target analysis of 2448 known pollutants and suspect screening of over 65,000 environmentally relevant compounds. Overall, 58 pollutants from different chemical classes, such as plant protection products, per- and polyfluoroalkyl substances and medicinal products, as well as their transformation products, were determined through target analysis. Most of the detected compounds were lipophilic (logP>2), although the presence of (semi)polar contaminants should not be overlooked, underlying the need for holistic analytical approaches in environmental monitoring studies. p,p'-DDE, PCB 153 and PCB138, PFOS and methylparaben were the most frequently detected compounds. 50 additional substances were identified and semi-quantified through suspect screening workflows, including mainly compounds of industrial use with high production volume.

Occurrence and Temporal Trends of Benzotriazole UV Stabilizers in Mollusks (2010-2018) from the Chinese Bohai Sea Revealed by Target, Suspect, and Nontarget Screening Analysis

Benzotriazole UV stabilizers (BZT-UVs), including 2-(3,5-di-tert-amyl-2-hydroxyphenyl)benzotriazole (UV-328) that is currently under consideration for listing under the Stockholm Convention, are applied in many commodities and industrial products. However, limited information is available on the interannual variation of their environmental occurrence. In this study, an all-in-one strategy combining target, suspect, and nontarget screening analysis was established to comprehensively explore the temporal trends of BZT-UVs in mollusks collected from the Chinese Bohai Sea between 2010 and 2018. Significant residue levels of the target analytes were determined with a maximum total concentration of 6.4 × 10³ ng/g dry weight. 2-(2-Hydroxy-3-tert-butyl-5-methyl-phenyl)-5-chloro-benzotriazole (UV-326), 5-chloro-2-(3,5-di-tert-butyl-2-hydroxyphenyl)benzotriazole (UV-327), and 2-(2-hydroxy-5-methylphenyl) benzotriazole (UV-P) were the predominant analogues, and UV-328 was the most frequently detected BZT-UV with a detection frequency (DF) of 87%. Whereas five biotransformation products and six impurity-like BZT-UVs were tentatively identified, their low DFs and semi-quantified concentrations suggest that the targeted analytes were the predominant BZT-UVs in the investigated area. A gradual decrease in the total concentrations of BZT-UVs was observed, accompanied by downward trends of the abundant compounds (e.g., UV-326 and UV-P). Consequently, the relative abundance of UV-327 increased because of its consistent environmental presence. These results suggest that continuous monitoring and risk assessment of BZT-UVs other than UV-328 are of importance in China.

The impact of climate sensitive factors on the exposure to organohalogenated contaminants in an aquatic bird exploiting both marine and freshwater habitats

To assess how climate-sensitive factors may affect the exposure to organochlorines (OCs) and perfluoroalkyl substances (PFASs), we monitored concentrations in eggs of the common goldeneye (Bucephala clangula) over two decades (1999-2019) in central Norway. The goldeneye alternates between marine and freshwater habitats and is sensitive to climate variation, especially due to alterations in ice conditions which may affect feeding conditions. We assessed how biological factors such as diet (stable isotopes δ¹³C and δ¹⁵N), the onset of egg laying, and physical characteristics such as winter climate (North Atlantic Oscillation: NAO_w) influenced exposure. We predicted compounds to show different temporal trends depending on whether they were still in production (i.e. some PFASs) or have been banned (i.e. legacy OCs and some PFASs). Therefore, we controlled for potential temporal trends in all analyses. There were declining trends for α- and γ-hexachlorocyclohexane (HCH), oxychlordane, cis-chlordane, cis-nonachlor, p,p'-dichlorodiphenyltrichloroethane (p.p'-DDT) and less persistent polychlorinated biphenyl (PCB) congeners (e.g. PCB101). In contrast, the dominant compounds, such as p,p'-dichlorodiphenyldichloroethylene (p,p'-DDE) and persistent PCB congeners, were stable, whereas hexachlorobenzene (HCB) increased over time. Most OCs were positively related to δ¹⁵N, suggesting higher exposure in birds feeding at upper trophic levels. Chlordanes and HCB were positively associated with δ¹³C, indicating traces of marine input for these compounds, whereas the relationships to most PCBs were negative. Among PFASs, perfluorooctanesulfonamide (PFOSA) and perfluorohexane sulfonic acid (PFHxS) declined. Most PFASs were positively associated with δ¹³C, whereas there were no associations with δ¹⁵N. Egg laying date was positively associated to perfluoroheptanesulfonic acid (PFHpS), perfluorooctanesulfonic acid (PFOS) and perfluorooctanoic acid (PFOA), suggesting that some of the PFAS load originated from the wintering locations. Although NAOw had little impact on the exposure to organohalogenated contaminants, factors sensitive to climate change, especially diet, were associated with the exposure to OHCs in goldeneyes.

Ecosystem specific accumulation of organohalogenated compounds: A comparison between adjacent freshwater and terrestrial avian predators

Insight into processes determining the exposure of organohalogenated contaminants (OHCs) in wildlife might be gained from comparing predators in different ecosystems. This study compared two avian predator species with similar food chain lengths: the goldeneye duck (Bucephala clangula) and the tawny owl (Strix aluco) breeding in adjacent freshwater- and terrestrial ecosystems in central Norway. We measured lipophilic organochlorines (OCs) and protein-bound perfluorinated substances (PFASs) in eggs of the two species over 21 years (1999-2019). Across years, the proportional distribution of OCs (∼90% of the ΣOHC load) relative to PFASs (∼10%) was similar in the two species. Moreover, ΣOC concentrations were similar between the species, but PFAS compounds were 2-12 times higher in the goldeneyes than in tawny owls. OC-pesticides dominated in tawny owls (∼60% of ΣOC), whereas persistent polychlorinated biphenyl (PCBs) congeners were the main OC components in goldeneyes (∼70% of ΣOC). The lipid-normalized concentrations of most OC-pesticides and the less persistent PCB101 declined significantly in both species. Hexachlorobenzene (HCB), p,p'-dichlorodiphenyldichloroethylene (p,p'-DDE), and more persistent PCBs decreased in tawny owls, while they tended to increase in goldeneyes. The increase in HCB was particulary robust. Among the PFASs, contrasted temporal trends were found across the species for four out of 11 compounds: PFOS declined while most perfluorocarboxylic acids (PFCAs) increased in tawny owls. In contrast, most PFASs were stable in goldeneyes. Moreover, there was no annual covariance between the OHC exposure in the two species: i.e., high concentrations in one species in a given year did not translate into high concentrations in the other. Hence, the two avian predators in adjacent ecosystems seem to be subject to different processes determining the OHC exposure, probably related to variation in diet and climate, long-range transport of different contaminants, and emissions of pollution locally.

Temporal Trends of Organochlorine and Perfluorinated Contaminants in a Terrestrial Raptor in Northern Europe Over 34 years (1986-2019)

Fourteen legacy organochlorine (OC) contaminants and 12 perfluoroalkyl substances (PFASs) were measured in eggs of tawny owls (Strix alueco) in central Norway (1986-2019). We expected OCs to have reached stable equilibrium levels due to bans, and that recent phase-out of some PFASs would have slowed the increase of these compounds. ∑OC comprised on average approximately 92% of the measured compounds, whereas ∑PFAS accounted for approximately 8%. However, whereas the ∑OC to ∑PFAS ratio was approximately 60 in the first 5 years of the study, it was only approximately 11 in the last 5 years. Both OC pesticides and polychlorinated biphenyls (PCBs) showed substantial declines over the study period (~85%-98%): hexachlorocyclohexanes and chlordanes seemed to be levelling off, whereas p,p'-dichlorodiphenyldichloroethylene (p,p'-DDE) and hexachlororbenzene (HCB), and most PCB congeners still seemed to decline at a more or less constant rate. While the concentration of perfluorooctane sulfonic acid (PFOS), the dominating PFAS, was reduced by approximately 43%, other perfluorinated sulfonates (PFSAs) showed only minor changes. Moreover, the median concentrations of seven perfluorinated carboxylic acids (PFCAs) increased approximately five-fold over the study period. Perfluorononanoic acid and perfluoroundecanoate acid, however, seemed to be levelling off in recent years. In contrast, perfluorododecanoic acid, perfluorodecanoate acid, perfluorotridecanoic acid, and perfluorotetradecanoic acid seemed to increase more or less linearily. Finally, perfluorooctanoic acid (PFOA) was increasingly likely to be detected over the study period. Hence, most legacy OCs and PFOS have not reached a lower threshold with stable background levels, and voluntary elimination of perfluoroalkyl carboxylates still has not resulted in declining levels in tawny owls in central Norway. Environ Toxicol Chem 2022;41:1508-1519. © 2022 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.

Global performance and trends of research on per- and polyfluoroalkyl substances (PFASs) between 2001 and 2018 using bibliometric analysis

Per- and polyfluoroalkyl substances (PFASs) are widely used in food packaging, non-stick pots, and surfactants. However, their persistence in the environment, hazardous nature, and potential for bioaccumulation and long-range transport have alarmed an increasing number of scholars and research institutions. Although several literature reviews on PFASs research exist, only a few of them have considered bibliometric indices. In this study, 3,373 PFASs-related articles published between 2001 and 2018 were analyzed using a bibliometric analysis method based on the Science Citation Index (SCI) Expanded. The software tools for mapping knowledge domain (MKD) (VOSviewer and Science of Science (Sci2)) were used to analyze the performance of contributors and PFASs research topics, hotspots, and trends. Our results reveal that the number of PFASs-related articles published annually has increased significantly, with most originating from the United States (followed by those from China). The Chinese Academy of Sciences has published the most articles. A comprehensive analysis of title, keywords, and keywords plus showed that PFASs research hotspots include humans, precursors, and detection methods, with the main focuses being environmental science, toxicology, and environmental engineering. The four main research topics of PFASs were identified, and a literature review was carried out for each one. Overall, this study can supply researchers with a deeper understanding of the development of PFASs studies and provide a comprehensive data reference for researchers to further grasp the research direction in this field.

Extraction and Matrix Cleanup Method for Analyzing Novel Per- and Polyfluoroalkyl Ether Acids and Other Per- and Polyfluoroalkyl Substances in Fruits and Vegetables

Per- and polyfluoroalkyl ether acids (PFEAs) are a subclass of per- and polyfluoroalkyl substances (PFAS) that are detected with increasing frequency in environmental matrices. Diet can be an important route of PFEA exposure, but the presence of PFEAs in food is poorly understood. Extraction methods for food samples exist for traditionally studied PFAS, but their suitability for PFEAs and other novel PFAS remains unknown. In this study, an extraction and matrix cleanup method was developed to quantify 45 PFAS, including 13 PFEAs, 3 perfluoroalkane sulfonamides, and 6 fluorotelomer carboxylic acids in 10 types of fruits and vegetables. Homogenized samples were extracted with basic methanol, and resulting extracts were diluted with water and cleaned up using solid-phase extraction with weak anion-exchange cartridges. The method was validated by performing spike-recovery experiments at spike levels of 1 ng/g in all 10 matrices and 0.1 ng/g in 2 matrices. For PFAS without a corresponding isotopically labeled internal standard (IS), adopting an IS with a similar chromatographic retention time generated the most accurate recoveries. Dependent upon the matrix, recoveries of 38-44 PFAS (including 10-13 PFEAs) fell within 50-150% for samples spiked at 1 ng/g. Recoveries of 40 and 38 PFAS in blueberries and corn, respectively, fell within 50-150% for samples spiked at 0.1 ng/g. Method quantification limits (MQLs) of PFAS in pure solvents were determined as the lowest calibration level with an accuracy between 70 and 130%. To compensate for matrix effects, a matrix factor was applied on the basis of the analyte response in different matrices relative to the pure solvent. The MQLs of 45 PFAS (including 13 PFEAs) in 10 matrices ranged from 0.025 to 0.25 ng/g. Overall, this method is capable of sensitively quantifying 45 PFAS in many fruits and vegetables.

Legacy and emerging organohalogenated compounds in feathers of Eurasian eagle-owls (Bubo bubo) in Norway: Spatiotemporal variations and associations with dietary proxies (δ13C and δ15N)

The occurrence of organohalogenated compounds (OHCs) in wildlife has received considerable attention over the last decades. Among the matrices used for OHCs biomonitoring, feathers are particularly useful as they can be collected in a minimally or non-invasive manner. In this study, concentrations of various legacy OHCs -polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs) and polybrominated diphenyl ethers (PBDEs)-, as well as emerging OHCs -per- and polyfluoroalkyl substances (PFAS) and organophosphate ester flame retardants (OPEs)- were determined in feathers of 72 Eurasian eagle-owls (Bubo bubo) from Norway, with the goal of studying spatiotemporal variation using a non-invasive approach. Molted feathers were collected at nest sites from northern, central and southern Norway across four summers (2013-2016). Additionally, two museum-archived feathers from 1979 to 1989 were included. Stable carbon (δ13C) and nitrogen isotopes (δ15N) were used as dietary proxies. In total, 11 PFAS (sum range 8.25-215.90 ng g^-1), 15 PCBs (4.19-430.01 ng g^-1), 6 OCPs (1.48-220.94 ng g^-1), 5 PBDEs (0.21-5.32 ng g^-1) and 3 OPEs (4.49-222.21 ng g^-1) were quantified. While we observed large variation in the values of both stable isotopes, suggesting a diverse diet of the eagle-owls, only δ13C seemed to explain variation in PFAS concentrations. Geographic area and year were influential factors for δ15N and δ13C. Considerable spatial variation was observed in PFAS levels, with the southern area showing higher levels compared to northern and central Norway. For the rest of OHCs, we observed between-year variations; sum concentrations of PCBs, OCPs, PBDEs and OPEs reached a maximum in 2015 and 2016. Concentrations from 1979 to 1989 were within the ranges observed between 2013 and 2016. Overall, our data indicate high levels of legacy and emerging OHCs in a top predator in Norway, further highlighting the risk posed by OHCs to wildlife.

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.

Exposure assessment of PFAS-contaminated sites using avian eggs as a biomonitoring tool: A frame of reference and a case study in the Po River valley (Northern Italy)

For many years, eggs of diverse bird species have been used as monitoring tools in studies investigating perfluoroalkyl substances (PFAS) contamination, especially in marine and remote areas. Avian eggs are a suitable monitoring matrix because they are relatively easy to collect and their yolks store diverse maternally transferred PFAS. Moreover, the concentrations of PFAS detected in the eggs are a good proxy for maternal exposure and allow the assessment of the potential risk for birds. These features support the use of avian eggs as a key monitoring tool in exposure assessment of PFAS-contaminated sites. We first review the recent application of avian eggs in PFAS monitoring in environmental risk assessment schemes, highlighting strengths and limitations and suggesting which criteria should be considered when selecting a proper study species and structuring the sampling and analytical protocol. Eventually, we report findings from a field study realized in 2020 near a perfluoropolymer factory site in the upper Po plain (Northern Italy), revealing an unprecedented contamination level of PFOA and C6O4 in three species of wild passerines. In future, long-term monitoring of PFAS contamination using avian eggs should be maintained, to provide crucial information on the temporal trend of fluorochemical production and waste disposal, while facilitating early identification of emerging PFAS as well as the quantification of their biomagnification across the trophic web. Integr Environ Assess Manag 2021;17:733-745. © 2021 SETAC.

A review on contaminants of emerging concern in European raptors (2002-2020)

Raptors (birds of prey and owls) have been widely used as suitable bioindicators of environmental pollution. They occupy the highest trophic positions in their food chains and are documented to bioaccumulate high concentrations of persistent pollutants such as toxic metals and legacy persistent organic pollutants (POPs).Whereas raptors played a critical role in developing awareness of and policy for chemical pollution, they have thus far played a much smaller role in current research on contaminants of emerging concern (CECs). Given the critical knowledge obtained from monitoring 'legacy contaminants' in raptors, more information on the levels and effects of CECs on raptors is urgently needed. This study critically reviews studies on raptors from Europe reporting the occurrence of CECs with focus on the investigated species, the sampled matrices, and the bioanalytical methods applied. Based on this, we aimed to identify future needs for monitoring CECs in Europe. Perfluoroalkyl substances (PFASs), novel flame retardants (NFRs), and to a lesser extent UV-filters, neonicotinoids, chlorinated paraffins, parabens and bisphenols have been reported in European raptors. White-tailed Eagle (Haliaeetus albicilla), Peregrine falcon (Falco peregrinus) and Northern goshawk (Accipiter gentilis) were the most frequently studied raptor species. Among matrices, eggs, feathers and plasma were the most widely employed, although the potential role of the preen gland as an excretory organ for CECs has recently been proposed. This review highlights the following research priorities for pollution research on raptors in Europe: 1) studies covering all the main classes of CECs; 2) research in other European regions (mainly East Europe); 3) identification of the most suitable matrices and species for the analysis of different CECs; and 4) the application of alternative sample treatment strategies (e.g. QuEChERS or pressurized liquid extraction) is still limited and conventional solvent-extraction is the preferred choice.

Trends and Patterns of Perfluoroalkyl Substances in Blood Plasma Samples of Bald Eagle Nestlings in Wisconsin and Minnesota, USA

We analyzed concentrations and trends of perfluoroalkyl substances (PFAS) in blood plasma samples of bald eagle (Haliaeetus leucocephalus) nestlings at 6 study areas in the upper Midwest of the United States, 2006 to 2015, and long-term trends at 2 Lake Superior (USA/Canada) sites, 1995 to 2015. Nestling blood plasma concentrations of the sum of 15 PFAS analytes (∑PFAS) differed among study areas and were highest at the 3 industrialized river sites: pools 3 and 4 of the Mississippi River (pools 3 + 4; geometric mean [GM] = 754 μg/L; range = 633-2930), the Mississippi National River and Recreation Area (GM = 687 μg/L; range = 24-7371), and the lower St. Croix National Scenic Riverway (GM = 546 μg/L; range = 20-2400). Temporal trends in ∑PFAS in nestling plasma differed among study areas; concentrations decreased at pools 3 + 4, Mississippi National River and Recreation Area, and lower St. Croix National Scenic Riverway, but not at the most remote sites, the upper St. Croix River and Lake Superior. Overall, perfluorooctanesulfonate (PFOS) was the most abundant analyte at all study areas, and perfluorodecanesulfonate (PFDS) the second most abundant at industrialized river sites although not at Lake Superior; concentrations of both these analytes declined from 2006 to 2015 over the study area. In addition, nestling age significantly influenced plasma concentrations of ∑PFAS and 7 of the 12 analytes. For these analytes, concentrations increased by 1 to 2%/d as nestlings grew, indicating that age should be considered when using nestling plasma to assess PFAS. Environ Toxicol Chem 2021;40:754-766. © 2020 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.

Ecotoxicology of persistent organic pollutants in birds

Considering the explosive growth of the list of persistent organic pollutants (POPs), the scientific community is combatting increasing challenges to protect humans and wildlife from the potentially negative consequences of POPs. Herein, we characterize the main aspects and progress in the ecotoxicology of POPs in avian species since 2000. The majority of previous efforts has revealed the global occurrence of high levels of various POPs in birds. Laboratory research and epidemiological studies imply that POPs exert a broad-spectrum of side-effects on birds by interfering with their endocrine, immune and neural system, reproduction, and development, and growth. However, inconsistent results suggest that the potential effects of POP exposure on the physiological parameters in birds are multifactorial, involving a multitude of biological processes, species-specific differences, gender, age and types of compounds. Great progress has been achieved in identifying the species-specific sensitivity to dioxin-like compounds, which is attributed to different amino acid residues in the ligand-binding domain of the aryl hydrocarbon receptor. Besides the conventional concentration additivity, several studies have suggested that different classes of POPs possibly act synergistically or antagonistically based on their concentration. However, ecotoxicology information is still recorded in a scattered and inadequate manner, including lack of enough avian species, limited number of POPs investigated, and insufficient geographical representation, and thus our understanding of the effects of POPs on birds remains rudimentary, although mechanistic understanding of their mode of action is progressing. Particularly, research on what happens to wild bird populations and their ecosystems under POP stress is still unavailable. Thus, our aim is to predict and trace the effects POPs at different biological organization levels, especially from the molecular, cellular and individual levels to the population, community and ecosystem levels because of the limited and scattered information, as mentioned above.

Contrasting long term temporal trends in perfluoroalkyl substances (PFAS) in eggs of the northern gannet (Morus bassanus) from two UK colonies

We compared long-term (1977 to 2014) trends in concentrations of PFAS in eggs of the marine sentinel species, the Northern gannet (Morus bassanus), from the Irish Sea (Ailsa Craig) and the North Sea (Bass Rock). Concentrations of eight perfluorinated carboxylic acids (PFCAs) and three perfluorinated sulfonates (PFSAs) were determined and we report the first dataset on PFAS in UK seabirds before and after the PFOS ban. There were no significant differences in ∑PFAS or ∑PFSAs between both colonies. The ∑PFSAs dominated the PFAS profile (>80%); PFOS accounted for the majority of the PFSAs (98-99%). In contrast, ∑PFCAs concentrations were slightly but significantly higher in eggs from Ailsa Craig than in those from Bass Rock. The most abundant PFCAs were perfluorotridecanoate (PFTriDA) and perfluoroundecanoate (PFUnA) which, together with PFOA, comprised around 90% of the ∑PFCAs. The ∑PFSAs and ∑PFCAs had very different temporal trends. ∑PFSAs concentrations in eggs from both colonies increased significantly in the earlier part of the study but later declined significantly, demonstrating the effectiveness of the phasing out of PFOS production in the 2000s. In contrast, ∑PFCAs concentrations in eggs were constant and low in the 1970s and 1980s, suggesting minimal environmental contamination, but residues subsequently increased significantly in both colonies until the end of the study. This increase appeared driven by rises in long chain compounds, namely the odd chain numbered PFTriDA and PFUnA. PFOA, had a very different temporal trend from the other dominant acids, with an earlier rise in concentrations followed by a decline in the last 15 years in Ailsa Craig; later temporal trends in Bass Rock eggs were unclear. Although eggs from both colonies contained relatively low concentrations of PFAS, the majority had PFOS residues that exceeded a suggested Predicted No Effect Concentration and ~ 10% of the eggs exceeded a suggested Lowest-Observable-Adverse-Effect.

[Perfluoroalkyl and polyfluoroalkyl substances in eggs: analytical methods and their application as pollutant bioindicator]

Perfluoroalkyl and polyfluoroalkylated substances (PFASs) are environmentally persistent and biomagnified along food chains. They have been widely detected globally, even in the human body, and their potential toxicity has attracted great attention. Eggs are the origin of new life of ovipara and are rich in nutrients, thus they serve as one of the main protein sources for humans. Therefore, the level of pollutants in eggs can affect the reproduction of ovipara, and it is also related to human health by food intake. In recent years, poultry egg samples have been widely used in the assessment of biological and ecological pollution as a non-invasive biota matrix. At the same time, recent studies have used eggs to evaluate the developmental toxicity and associated health risks based on the pollutant levels in egg samples. In this study, the methods of sample pretreatment and instrumental detection of PFASs for egg samples are summarized. In addition, the application of eggs as a pollutants bioindicator of PFASs contamination has been discussed.

Bioaccumulation potential of bisphenols and benzophenone UV filters: A multiresidue approach in raptor tissues

Environmental exposure to bisphenols and benzophenone UV filters has received considerable attention due to the ubiquitous occurrence of these contaminants in the environment and their potential adverse health effects. The occurrence of bisphenols and benzophenone UV filters is well established in human populations, but data is scarce for wildlife, and especially for raptors (birds of prey, falcons and owls). In this study, concentrations of eight bisphenols and five benzophenone UV filters were determined in six raptor tissues, including muscle, kidney, liver, brain, preen gland (uropygial gland) and adipose. The tissue samples (n = 44) were taken from dead raptor species (1997-2011), including Eurasian sparrowhawks (Accipiter nisus, n = 2) and long-eared owls (Asio otus, n = 2), both from France, and white-tailed eagles (Haliaeetus albicilla, n = 16) from Greenland. Overall, six bisphenols and four benzophenone UV filters were found in the samples. Bisphenol A (BPA), bisphenol F (BPF), benzophenone-8 (BzP-8) and 4-hydroxybenzophenone (4-OH-BzP) were the most abundant contaminants, accounting for median concentrations of 67.5, 3.01, 27.1 and 9.70 ng/g wet weight (w.w.), respectively. The potential role of the preen gland as a major excretory organ for bisphenols and benzophenone UV filters was suggested since the median sum concentration of the two contaminant classes in the white-tailed eagle tissues showed higher bioaccumulation potential in the preen gland (5.86 ng/g w.w.) than the liver (2.92) and kidney (0.71). The concentrations of these contaminants in the tissues of the three raptor species indicated a pattern of increasing detection rates and median concentrations with an increase of the species size and their expected trophic position. To the best of our knowledge, this is the first peer-reviewed study to document multiresidues of both contaminant classes in raptor tissues.

A novel use of the leukocyte coping capacity assay to assess the immunomodulatory effects of organohalogenated contaminants in avian wildlife

Apex predators are characterized by high levels of biomagnifying organohalogenated contaminants (OHCs) which have been found to induce detrimental health effects in wildlife, such as immune system impairment. The leukocyte coping capacity (LCC) assay is a functional real-time measure of an innate immune response essential in pathogen resistance, known as the respiratory burst. The current study suggests the novel use of this tool to test whether OHCs impair the innate immune system of a sentinel top predator, the white-tailed eagle (Haliaeetus albicilla; WTE). The LCC analysis was performed in the field on WTE nestlings (n = 84) from northern Norway over two breeding seasons. Poly- and perfluoroalkyl substances (PFAS) dominated the total OHC load, surpassing the levels of legacy organochlorines. In addition, we detected significant negative correlations between concentrations of all polychlorinated biphenyls, p,p'-dichlorodiphenyldichloroethylene, perfluorohexane sulfonic acid and long-chain perfluorocarboxylic acids and the LCC of WTE nestlings. Based on our current findings reflecting a potential negative effect of both emerging and legacy OHCs on innate immune capacity, we suggest LCC to be a relevant and accessible test expanding the ecotoxicological toolbox to assess sub-lethal effects of OHCs in apex avian wildlife.

Risk to human health related to the presence of perfluoroalkyl substances in food

The European Commission asked EFSA for a scientific evaluation on the risks to human health related to the presence of perfluoroalkyl substances (PFASs) in food. Based on several similar effects in animals, toxicokinetics and observed concentrations in human blood, the CONTAM Panel decided to perform the assessment for the sum of four PFASs: PFOA, PFNA, PFHxS and PFOS. These made up half of the lower bound (LB) exposure to those PFASs with available occurrence data, the remaining contribution being primarily from PFASs with short half-lives. Equal potencies were assumed for the four PFASs included in the assessment. The mean LB exposure in adolescents and adult age groups ranged from 3 to 22, the 95th percentile from 9 to 70 ng/kg body weight (bw) per week. Toddlers and 'other children' showed a twofold higher exposure. Upper bound exposure was 4- to 49-fold higher than LB levels, but the latter were considered more reliable. 'Fish meat', 'Fruit and fruit products' and 'Eggs and egg products' contributed most to the exposure. Based on available studies in animals and humans, effects on the immune system were considered the most critical for the risk assessment. From a human study, a lowest BMDL 10 of 17.5 ng/mL for the sum of the four PFASs in serum was identified for 1-year-old children. Using PBPK modelling, this serum level of 17.5 ng/mL in children was estimated to correspond to long-term maternal exposure of 0.63 ng/kg bw per day. Since accumulation over time is important, a tolerable weekly intake (TWI) of 4.4 ng/kg bw per week was established. This TWI also protects against other potential adverse effects observed in humans. Based on the estimated LB exposure, but also reported serum levels, the CONTAM Panel concluded that parts of the European population exceed this TWI, which is of concern.

Spatiotemporal Analysis of Perfluoroalkyl Substances in White-Tailed Eagle (Haliaeetus albicilla) Nestlings from Northern Norway-A Ten-Year Study

The white-tailed eagle (Haliaeetus albicilla) in Scandinavia has suffered from impaired reproduction due to high exposure to industrial pollution between the 1960s and 1980s. While population numbers are rising again, new contaminants, such as per- and polyfluoroalkyl substances (PFAS), are increasingly found in high trophic avifauna and are of concern to potentially impact once again on population health. In the present study, we examined PFAS levels in plasma of white-tailed eagle nestlings from northern Norway over the last decade (2008-2017). While PFOA and PFNA exposure did not follow a significant time trend, PFOS and PFHxS concentrations decreased over time, and ≥C₁₁ perfluorinated carboxylic acids only seem to level off during the last four years. This may in fact be the first evidence for a change in the trend for some of these compounds. Furthermore, since several PFAS are expected to be highly present in aqueous film-forming foams used at airports, we also investigate the potential of the two main airports in the region to act as hotspots for PFAS. Our results indeed show decreasing exposure to PFOA with distance to the airports. Altogether, our results seem to show that legislation actions are effective, and continued concern for PFAS exposure of high trophic wildlife is still warranted, even in the northern environment.

Snow buntings (Plectrophenax nivealis) as bio-indicators for exposure differences to legacy and emerging persistent organic pollutants from the Arctic terrestrial environment on Svalbard

Eggs of snow buntings (Plectrophenax nivealis) were applied as a bio-indicator to examine differences in exposure to legacy persistent organic pollutants (POPs) and perflouroalkyl subtances (PFAS) from the terrestrial environment surrounding the settlements of Longyearbyen, Barentsburg and Pyramiden on Svalbard, Norway. Significantly higher concentrations of summed polychlorinated biphenyls (sumPCB7) in eggs collected from Barentsburg (2980 ng/g lipid weight (lw)) and Pyramiden (3860 ng/g lw) compared to Longyearbyen (96 ng/g lw) are attributed to local sources of PCBs within these settlements. Similar findings were observed for p,p'-dichlorodiphenyldichloroethylene (p,p'-DDE) where higher median concentrations observed in Pyramiden (173 ng/g lw) and Barentsburg (75 ng/g lw) compared to Longyearbyen (48 ng/g lw) may be influenced by guano inputs from breeding seabird populations, although other point sources cannot be ruled out. Concentrations of perfluorooctane sulphonate (PFOS) and several perfluorinated carboxylic acids (PFCAs) in snow bunting eggs were found to be statistically higher in the populated settlements of Longyearbyen and Barentsburg compared to the abandoned Pyramiden. Narrow foraging ranges of snow buntings during breeding season was useful in assessing point sources of exposure for PCBs and PFAS at particular sites with extreme differences observed between nest locations. SumPCB7 concentrations ranged from 2 μg/g ww to below detection limits between nest sites located less than a kilometer from each other in Pyramiden. Similar findings were observed in Longyearbyen, where several PFCAs ranged from 2 to 55 times higher between nest sites with similar spatial distances. These findings indicate that snow buntings can be a useful bio-indicator offering high spatial resolution for contaminant source apportionment in terrestrial environments on Svalbard.

Perfluoroalkyl substances exposure and risk of polycystic ovarian syndrome related infertility in Chinese women

Perfluoroalkyl substances (PFASs) are a family of synthetic, fluorinated organic compounds. They have been widely used in industrial applications and consumer products and widespread in the environment, wildlife and human. Experimental and epidemiologic evidence suggested that PFASs are capable of interfering with endocrine processes and have potential reproductive and developmental toxicities. Polycystic ovarian syndrome (PCOS), one of the main reasons of female infertility, is a common endocrine disorder in reproductive age women. We performed a case-control study to evaluate associations between PCOS-related infertility and PFASs concentrations in plasma. A total of 180 infertile PCOS-cases and 187 healthy controls were recruited from the Center for Reproductive Medicine of Shandong University. Blood specimens were collected at enrollment and analyzed for ten PFASs using liquid chromatography-tandem mass spectrometry. Multivariable logistic regression procedure was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for each PFAS. Perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) were the dominant PFASs in the plasma of participants, with the median concentration of 5.07 ng/mL and 4.05 ng/mL, respectively. The median levels of individual PFAS were not significantly different between PCOS-cases and controls. While adjusted for the potential confounders (age, BMI, household income, education level, employment status, age at menarche, menstrual volume), the plasma concentration of perfluorododecanoic acid (PFDoA), a 12 carbons lengths of perfluorocarboxylic acids, was associated with a significantly increased risk of PCOS-related infertility (medium vs low tertile: OR = 2.36, 95% CI: 1.12, 4.99, P = 0.02; high vs low tertile: OR = 3.04, 95% CI: 1.19, 7.67, P = 0.02), with the P trend 0.01. No significant relationship was observed between PCOS-related infertility and other PFAS analytes in the adjusted model, despite perfluoroundecanoic acid showed a negative association (P trend 0.03). The potential reproductive health effects of PFASs and the underlying mechanisms merit further investigation in the future.

Do concentrations of perfluoroalkylated acids (PFAAs) in isopods reflect concentrations in soil and songbirds? A study using a distance gradient from a fluorochemical plant

Perfluoroalkylated acids (PFAAs) are persistent chemicals that have been detected globally in the environment and in wildlife. Although it is known that PFAAs sorb to solid matrices, little is known on PFAA concentrations in soils. PFAA pollution has often been studied in aquatic invertebrates. However, this has rarely been done on terrestrial species. In the present study, we examined whether the concentrations of 15 PFAAs in isopods (Oniscidae), collected at a fluorochemical plant and in four other areas, representing a gradient in distance from the pollution source (1 km to 11 km), were related to those in the soil and in eggs of a songbird, the great tit (Parus major), collected in the same areas. Additionally, we examined the effect of physicochemical properties such as total organic carbon (TOC) and clay content on the relationship between the concentrations in soil and isopods. Finally, we examined the composition profile in the soil and isopods. Mean PFOS and PFOA concentrations of 1700 ng/g dw and 24 ng/g dw were detected in the soil at the plant. PFOS and PFPeA were the dominant PFAAs in isopods and were detected at mean concentrations of 253 and 108 ng/g ww, respectively. The great tit eggs showed elevated mean PFOS concentrations of 55,970 ng/g ww. In most cases, PFAA concentrations decreased with increasing distance from the plant. As PFAA concentrations in isopods were correlated with concentrations in the soils, isopods could serve as a bioindicator for PFAA concentrations in soils. Additionally, there were indications that isopods could also serve as a bioindicator for PFAA concentrations in eggs of great tits. However, these indications were only the case at two locations, showing the need to further monitor the possibilities of using isopods as a bioindicator for PFAA concentrations in song bird eggs. CAPSULE: Elevated PFAA concentrations in isopods reflected concentrations in songbird eggs and in soil, indicating that trophic transfer of PFAAs from soil, via isopods, to songbirds might play a role in the PFAA exposure of terrestrial songbirds.

Variation in PFAA concentrations and egg parameters throughout the egg-laying sequence in a free-living songbird (the great tit, Parus major): Implications for biomonitoring studies

Over the past decades, there has been growing scientific attention and public concern towards perfluoroalkyl acids (PFAAs), due to their widespread presence in the environment and associations with adverse effects on various organisms. Bird eggs have often been used as less-invasive biomonitoring tools for toxicological risk assessments of persistent organic pollutants, including some PFAAs. Hereby, it is typically assumed that one random egg is representative for the PFAA concentrations of the whole clutch. However, variation of PFAA concentrations within clutches due to laying sequence influences can have important implications for the egg collection strategy and may impede interpretations of the quantified concentrations. Therefore, the main objective of this paper was to study variation patterns and possible laying sequence associations with PFAA concentrations in eggs of the great tit (Parus major). Eight whole clutches (4-8 eggs) were collected at a location in the Antwerp region, situated about 11 km from a known PFAA point source. The ∑ PFAA concentrations ranged from 8.9 to 75.1 ng g^-1 ww. PFOS concentrations ranged from 6.7 to 55.1 ng g^-1 ww and this compound was the dominant contributor to the total PFAA profile (74%), followed by PFDoA (7%), PFOA (7%), PFDA (5%), PFTrA (4%) and PFNA (3%). The within-clutch variation (70.7%) of the ∑ PFAA concentrations was much larger than the among-clutch variation (29.3%) and concentrations decreased significantly for some PFAA compounds throughout the laying sequence. Nevertheless, PFAA concentrations were positively and significantly correlated between some egg pairs within the same clutch, especially between egg 1 and egg 3. For future PFAA biomonitoring studies, we recommend to consistently collect the same egg along the laying sequence, preferably the first or third egg if maximizing egg exposure metrics is the main objective.

Limited reproductive impairment in a passerine bird species exposed along a perfluoroalkyl acid (PFAA) pollution gradient

Although bird eggs have been used in biomonitoring studies on perfluoroalkyl acids (PFAAs), effects of environmental concentrations on reproduction remain largely unknown in wild birds. In the present study we examined the associations between the concentrations of 4 perfluoroalkyl sulfonic acids (PFSAs) and 11 perfluoroalkyl carboxylic acids (PFCAs) in the eggs of great tits (Parus major), collected along a distance gradient from a pollution source, and multiple reproductive parameters (including the start of egg laying, clutch size, hatching success, fledging success and total breeding success) along with egg shell thickness and body condition of the nestlings. The PFAA concentrations measured at the plant site were among the highest ever reported in wild bird eggs. PFAA concentrations decreased sharply with increasing distance (0-11 km) from the plant, but remained relatively elevated in the adjacent sites. PFAAs were grouped into principal components (PCs) to prevent collinearity. High concentrations of PFOS, PFDS, PFDoDA, PFTrDA and PFTeDA (grouped as PC1) were associated with a reduced hatching success of nests where at least one egg hatched, thinner egg shells and increased survival of the hatched chicks. High concentrations of PFDA (PC2) were associated with a reduced hatching success, especially in nests where no eggs hatched, an earlier start of egg laying and a reduction of total breeding success, mainly caused by the failure in hatching. Although the major manufacturer of PFAAs phased out the production of perfluorooctane sulfonate (PFOS), perfluorooctanoic acid (PFOA) and related products in 2002, concentrations appear to have increased since previous measurements. Surprisingly, despite the very high concentrations close to the fluorochemical plant, there was no clear evidence for reproductive impairment as the observed associations between PFAA concentrations and reproductive parameters were rather limited compared to previous studies in songbirds. These findings also suggest potential differences in sensitivity between species. CAPSULE: Despite the very high PFAA concentrations at the perfluorochemical hotspot, correlations with reproductive parameters were limited.

Perfluoroalkyl Acids (PFAAs) Concentrations and Oxidative Status in Two Generations of Great Tits Inhabiting a Contamination Hotspot

The ubiquity of perfluoroalkyl acids (PFAAs) contrasts with the limited information about their effects. We report here PFAA plasma concentrations in wild populations of great tits ( Parus major) settled at and in the vicinity of a fluorochemical plant in Antwerp (Belgium). Using two generations we obtained novel results on some poorly known issues such as differences between sexes, maternal transfer of the compounds and potential associations with the oxidative status. For five out of the 11 detected PFAAs, the concentrations were the highest ever reported in birds' plasma, which confirms that Antwerp is one of the main hotspots for PFAAs pollution. Contrary to other studies conducted in birds, we found that females presented higher mean concentrations and detection frequencies for two compounds (perfluorooctanesulfonic acid (PFOS) and perfluoroundecanoic acid (PFUnDA)) than males. Maternal transfer and the dietary intake appear to be the main route of exposure for nestlings to PFOS but not to other compounds. Finally, PFAA concentrations tended to correlate positively with protein damage in adult birds while in nestlings they positively correlated with higher activity of antioxidant enzymes (glutathione peroxidase and catalase). Experimental work is needed to confirm oxidative stress as a pathway for the pernicious effects of PFAAs.

Perfluoroalkyl substances (PFASs) and polychlorinated naphthalenes (PCNs) add to the chemical cocktail in peregrine falcon eggs

A suite of perfluoroalkyl substances (PFASs) and polychlorinated naphthalenes (PCNs) were determined in 41 peregrine falcon eggs collected in South Greenland between 1986 and 2014. Median concentrations of perfluorinated sulfonic acids (ΣPFSA) and perfluorinated carboxylic acids (ΣPFCA) were 303 ng/g dry weight (dw) (58 ng/g wet weight, ww) and 100 ng/g dw (19 ng/g ww), respectively, which was comparable to other studies. Perfluorooctane sulfonate (PFOS) accounted for 94% on average of all PFSAs, but did not show a significant time trend. Perfluorohexane sulfonate (PFHxS), perfluoroheptane sulfonate (PFHpS) and perfluorodecane sulfonate (PFDS) showed non-linear decreases over the study period, while some long-chain PFCAs increased significantly. The PCN profile was dominated by the penta-, hexa- and tetrachlorinated congeners CN-52/60, CN-66/67 and CN-42. CN-54, an indicator of combustion, accounted for 2.4% of ΣPCN on average. All PCN congeners showed a decreasing tendency, which was significant for lipid-normalized concentrations of CN-53, CN-54 and CN-63. The ΣPCN median concentration was 21 ng/g lipid weight, which is in the high end of concentrations reported for bird eggs. The PCN and PFAS concentrations add to an already high contaminant burden and a complex chemical cocktail in the peregrine falcon population in Greenland, mainly reflecting contaminant exposure during migration and winter stays in Central and South America.

Developmental Toxicity of Perfluorooctanesulfonate (PFOS) and Its Chlorinated Polyfluoroalkyl Ether Sulfonate Alternative F-53B in the Domestic Chicken

The chlorinated polyfluoroalkyl ether sulfonate F-53B is used as a mist suppressant in the Chinese electroplating industry. Because of the regulations on perfluorooctanesulfonate (PFOS), its use is expected to increase. Until now, F-53B toxicity data have been scarce and are, to our knowledge, lacking for birds. This study therefore investigated the effects of PFOS and F-53B, separately and as mixtures, on the development of the chicken ( Gallus gallus domesticus). Compounds were injected in ovo, before incubation, at 150 and 1500 ng/g egg. At embryonic day 20, a significantly lower heart rate was observed in all treated groups compared to the control group and hatchlings exposed to the high dose of F-53B had a significantly enlarged liver (8%). Embryonic survival was not affected and no significant effects on hatchling body mass or oxidative stress parameters were found. Our results suggest that these compounds likely have different toxicity thresholds for the investigated endpoints, and/or different modes of action. This study thereby underlines the potential developmental toxicity of PFOS and F-53B at environmentally relevant concentrations. Assessment of PFOS alternatives should therefore continue, preferably prior to their large scale use, as they should be ensured to be less harmful than PFOS itself.

Variation and accumulation patterns of poly- and perfluoroalkyl substances (PFAS) in European perch (Perca fluviatilis) across a gradient of pristine Swedish lakes

This study assessed variations in the concentrations of poly- and perfluoroalkyl substances (PFAS) in European perch (Perca fluviatilis) in Swedish lakes and the extent to which fish size, age and indicators of fish trophic ecology (δ¹⁵N and δ¹³C) correlate with the sum of individual PFAS concentrations (ΣPFAS). Fish muscle tissue samples (n=80) were taken from six lakes across Sweden and analysed using solid-liquid extraction followed by liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS). PFAS levels in the lakes were affected by atmospheric deposition in relatively pristine areas with no direct point source of PFAS in the catchment. PFTeDA, PFUnDA, PFTriDA, PFDoDA, PFDA, PFOS and 6:2 FTSA were detected with a frequency between 68% and 99% and were included in the statistical evaluation. ΣPFAS differed between lakes (ANOVA: F=50.6, p<0.0001): fish from lakes in southern Sweden (lake Gårdsjön, 58°03'N, 12°01'E) showed elevated levels of PFAS, with a maximum ΣPFAS of 3.4ng g^-1 wet weight (ww) (mean±SD: 0.99±0.63ng g^-1 ww), while the lowest levels were found in lake Björntjärn (0.31±0.08ng g^-1 ww) in northern Sweden (63°54'N, 18°51'E). PFOS was most abundant in perch from south-western Sweden, while other long-chain perfluorocarbons (>10 carbon atoms) were relatively more abundant in lakes in northern Sweden. Pearson correlation coefficients indicated that concentrations of PFAS in perch did not show any relation to fish size or age and were negatively correlated with trophic position of the fish (δ¹⁵N). It was also found that ΣPFAS were negatively correlated with both latitude and altitude. The PFAS data in this study represent national background concentrations in freshwater fish across Swedish lakes.

Perfluoroalkylated acids in the eggs of great tits (Parus major) near a fluorochemical plant in Flanders, Belgium

Perfluoroalkyl acids (PFAAs) are highly persistent substances which have been detected in wildlife around the world, including birds. Although bird eggs have often been used to determine and monitor PFAAs levels in the marine environment, this has rarely been done in the terrestrial environment. In the present study we examined the concentrations and composition profile of 12 PFAAs (4 perfluoroalkyl sulfonic acids (PFSAs) and 8 perfluoroalkyl carboxylic acids (PFCAs) in the eggs of great tits (Parus major) collected at a fluorochemical plant and in three other areas, representing a gradient in distance from the pollution source (from 1 to 70 km), in Antwerp, Belgium. The PFSA concentrations measured at the site of the fluorochemical plant were among the highest ever reported in eggs with median concentrations of 10380 ng/g (extrapolated), 99.3 ng/g and 47.7 ng/g for PFOS, PFHxS and PFDS respectively. Furthermore, the median concentration of 19.8 ng/g for PFOA was also among the highest ever reported in bird eggs. Although these concentrations decreased sharply with distance from the fluorochemical plant, levels found in the adjacent sites were still high compared to what has been reported in literature. Moreover, based on what is known in literature, it is likely that these concentrations may cause toxicological effects. PFOS was the dominant contributor to the PFSA and PFAAs (63.4-97.6%) profile at each site, whereas for PFCAs this was PFOA at the plant site and the nearest locations (41.0-52.8%) but PFDoA (37.7%) at the farthest location. Although there is some evidence that PFAAs concentrations close to the plant site are decreasing in comparison with earlier measurements, which may be due to the phase out of PFOS, more research is necessary to understand the extent of the toxicological effects in the vicinity of this PFAAs hotspot.

High levels of PFOS in eggs of three bird species in the neighbourhood of a fluoro-chemical plant

We studied perfluorooctane sulfonate (PFOS) levels in the eggs of three primarily invertivorous bird species sampled in 2006 near a fluoro-chemical plant: the great tit (Parus major), the northern lapwing (Vanellus vanellus) and the Mediterranean gull (Larus melanocephalus). Our study reported some of the highest PFOS levels ever measured in wildlife to date (i.e. up to 46182ng/g ww in lapwing eggs). A pronounced decrease in PFOS concentration in the Northern lapwing eggs with distance from the fluoro-chemical plant was found. A similar relationship was found for the great tit, with eggs being collected close to the fluoro-chemical plant having significantly higher PFOS levels than eggs collected 1700m further away. When comparing the PFOS levels in eggs for the three species, collected between 1700 and 5500m no significant differences were observed. In addition, when comparing PFOS levels in eggs between Northern lapwing and great tits closer to the plant (900-1700m) no significant differences were found neither. Despite the high levels found in great tit eggs, plasmatic biochemical biomarker responses did not appear to be affected.

Home produced eggs: An important pathway of human exposure to perfluorobutanoic acid (PFBA) and perfluorooctanoic acid (PFOA) around a fluorochemical industrial park in China

Dietary intake is considered to be a major pathway of human exposure to perfluoroalkyl acids (PFAAs). Chicken egg is an important contributor to the Chinese diet. In the present study, PFAAs in home produced eggs (HPEs) and commercially produced eggs (CPEs) surrounding a fluorochemical industrial park (FIP) in China were investigated. PFAAs in HPEs decreased with increasing distance from the FIP. HPEs were much more contaminated than CPEs, with PFAAs in CPEs comparable to or lower than those in HPEs from 20km away from the FIP. PFOA concentrations in HPEs were higher than the levels of PFOA in eggs from other studies reported so far. For the first time, PFBA was reported in eggs and detected in all egg samples. PFOA and PFBA were the predominant forms in HPEs, while PFOA, PFBA and PFOS dominated in CPEs. For PFOA, estimated daily intakes (EDI) were 233ng/kg·bw/day for adults and 657ng/kg·bw/day for children who consume HPEs at households about 2km away from the FIP. The EDI of PFOA for children via HPEs exceeded the reference dose value (333ng/kg·bw/day) proposed by the Environmental Working Group.

Comparison of PFASs contamination in the freshwater and terrestrial environments by analysis of eggs from osprey (Pandion haliaetus), tawny owl (Strix aluco), and common kestrel (Falco tinnunculus)

The level of PFAS (per- and polyfluorinated alkyl substances) contamination in freshwater and terrestrial Swedish environments in 2013/2014 was assessed by analyzing a range of perfluorinated alkyl acids, fluorotelomer acids, sulfonamides, sulfonamidoethanols and polyfluoralkyl phosphate diesters (diPAPs) in predator bird eggs. Stable isotopes ((13)C and (15)N) were analyzed to elucidate the dietary source. The tawny owl (Strix aluco, n=10) and common kestrel (Falco tinnunculus, n=40), two terrestrial species, and the osprey (Pandion haliaetus, n=30), a freshwater specie were included. In addition, a temporal trend (1997-2001, 2008-2009, 2013) in osprey was studied as well. The PFAS profile was dominated by perfluorooctane sulfonic acid (PFOS) in eggs from osprey and tawny owl, while for common kestrel perfluorinated carboxylic acids (∑PFCA) exceeded the level of PFOS. PFOS concentration in osprey eggs remained at the same level between 1997 and 2001 and 2013. For the long-chained PFCAs, there were a significant increase in concentrations in osprey eggs between 1997 and 2001 and 2008-2009. The levels of PFOS and PFCAs were about 10 and five times higher, respectively, in osprey compared to tawny owl and common kestrel. Evidence of direct exposure from PFCA precursor compounds to birds in both freshwater and terrestrial environment was observed. Low levels of diPAPs were detected in a few samples of osprey (<0.02-2.4ng/g) and common kestrel (<0.02-0.16ng/g) eggs, and 6:2 FTSA was detected in a majority of the osprey eggs (<6.3-52ng/g). One saturated telomer acid (7:3 FTCA), which is a transformation marker from precursor exposure, was detected in all species (<0.24-2.7ng/g). The (15)N data showed higher levels in osprey eggs compared to tawny owl and common kestrel, indicating that they feed on a 2-3 times higher trophic level. We conclude that ospreys are continuously exposed to PFAS at levels where adverse toxic effects have been observed in birds.

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.

Organohalogenated contaminants in white-tailed eagle (Haliaeetus albicilla) nestlings: An assessment of relationships to immunoglobulin levels, telomeres and oxidative stress

Biomagnifying organohalogenated compounds (OHCs) may have adverse effects on the health of birds, especially marine avian top predators that accumulate high OHC loads. Contaminants may impair the humoral immunity and also influence the antioxidant enzyme activity (i.e. oxidative stress). Moreover, physical conditions and oxidative stress during development may reduce telomere lengths, one of the main mechanisms explaining cell senescence. To examine the potential effects of environmental contaminants on physiological biomarkers of health, OHCs with different 'physicochemical' properties were related to immunoglobulin Y levels (IgY; humoral immunity), superoxide dismutase enzyme (SOD) activity in blood plasma, and telomere length (measured in red blood cells) in individual 7-8weeks old nestlings (n=35) of white-tailed eagles (Haliaeetus albicilla) in the Norwegian Sub-Arctic. Different organochlorines (OCs) and perfluoroalkylated substances (PFASs) were measured in blood plasma of nestlings, demonstrating higher concentrations of the emerging contaminants (PFASs), notably perfluorooctane sulfonate (PFOS), compared to legacy OCs. There were no relationships between the contaminant loads and plasma IgY levels. Moreover, differences between years were found for telomere lengths, but this was not related to contaminants and more likely a result of different developmental conditions. However, there were significant and negative relationships between the OC loadings and the SOD activity. This suggests that some legacy OCs challenge the antioxidant capacity in nestlings of white-tailed eagles.

Perfluoroalkyl and polyfluoroalkyl substances in consumer products

Perfluoroalkyl and polyfluoroalkyl substances (PFAS) are used in a wide range of products of all day life. Due to their toxicological potential, an emerging focus is directed towards their exposure to humans. This study investigated the PFAS load of consumer products in a broad perspective. Perfluoroalkyl sulfonic acids (C4, C6-C8, C10-PFSA), carboxylic acids (C4-C14-PFCA) and fluorotelomer alcohols (4:2, 6:2; 8:2 and 10:2 FTOH) were analysed in 115 random samples of consumer products including textiles (outdoor materials), carpets, cleaning and impregnating agents, leather samples, baking and sandwich papers, paper baking forms and ski waxes. PFCA and PFSA were analysed by HPLC-MS/MS, whereas FTOH were detected by GC/CI-MS. Consumer products such as cleaning agents or some baking and sandwich papers show low or negligible PFSA and PFCA contents. On the other hand, high PFAS levels were identified in ski waxes (up to about 2000 μg/kg PFOA), leather samples (up to about 200 μg/kg PFBA and 120 μg/kg PFBS), outdoor textiles (up to 19 μg/m(2) PFOA) and some other baking papers (up to 15 μg/m(2) PFOA). Moreover, some test samples like carpet and leather samples and outdoor materials exceeded the EU regulatory threshold value for PFOS (1 μg/m(2)). A diverse mixture of PFASs can be found in consumer products for all fields of daily use in varying concentrations. This study proves the importance of screening and monitoring of consumer products for PFAS loads and the necessity for an action to regulate the use of PFASs, especially PFOA, in consumer products.

Spatial distribution and partition of perfluoroalkyl acids (PFAAs) in rivers of the Pearl River Delta, southern China

This study investigated the occurrence of perfluoroalkyl acids (PFAAs) in surface water from 67 sampling sites along rivers of the Pearl River Delta in southern China. Sixteen PFAAs, including perfluoroalkyl carboxylic acids (PFCAs, C5-14, C16 and C18) and perfluoroalkyl sulfonic acids (PFSAs, C4, C6, C8 and C10) were determined by high performance liquid chromatography-negative electrospray ionization-tandem mass spectrometry (HPLC/ESI-MS/MS). Total PFAA concentrations (∑ PFAAs) in the surface water ranged from 1.53 to 33.5 ng·L(-1) with an average of 7.58 ng·L(-1). Perfluorobutane sulfonic acid (PFBS), perfluorooctanoic acid (PFOA), and perfluorooctane sulfonic acid (PFOS) were the three most abundant PFAAs and on average accounted for 28%, 16% and 10% of ∑ PFAAs, respectively. Higher concentrations of ∑ PFAAs were found in the samples collected from Jiangmen section of Xijiang River, Dongguan section of Dongjiang River and the Pearl River flowing the cities which had very well-developed manufacturing industries. PCA model was employed to quantitatively calculate the contributions of extracted sources. Factor 1 (72.48% of the total variance) had high loading for perfluorohexanoic acid (PFHxA), perfluoropentanoic acid (PFPeA), PFBS and PFOS. For factor 2 (10.93% of the total variance), perfluorononanoic acid (PFNA) and perfluoroundecanoic acid (PFUdA) got high loading. The sorption of PFCAs on suspended particulate matter (SPM) increased by approximately 0.1 log units for each additional CF2 moiety and that on sediment was approximately 0.8 log units lower than the SPM logKd values. In addition, the differences in the partition coefficients were influenced by the structure discrepancy of absorbents and influx of fresh river water. These data are essential for modeling the transport and environmental fate of PFAAs.

Brain region-specific perfluoroalkylated sulfonate (PFSA) and carboxylic acid (PFCA) accumulation and neurochemical biomarker responses in east Greenland polar bears (Ursus maritimus)

Perfluoroalkyl substances (PFASs) is a growing class of contaminants in the Arctic environment, and include the established perfluorinated sulfonates (PFSAs; especially perfluorooctane sulfonate (PFOS)) and carboxylic acids (PFCAs). PFSAs and PFCAs of varying chain length have been reported to bioaccumulate in lipid rich tissues of the brain among other tissues such as liver, and can reach high concentrations in top predators including the polar bear. PFCA and PFSA bioaccummulation in the brain has the potential to pose neurotoxic effects and therefore we conducted a study to investigate if variations in neurochemical transmitter systems i.e. the cholinergic, glutaminergic, dopaminergic and GABAergic, could be related to brain-specific bioaccumulation of PFASs in East Greenland polar bears. Nine brain regions from nine polar bears were analyzed for enzyme activity (monoamine oxidase (MAO), acetylcholinesterase (AChE) and glutamine synthetase (GS)) and receptor density (dopamine-2 (D2), muscarinic cholinergic (mAChR) and gamma-butyric acid type A (GABA-A)) along with PFSA and PFCA concentrations. Average brain ∑PFSA concentration was 25ng/g ww where PFOS accounted for 91%. Average ∑PFCA concentration was 88ng/g ww where PFUnDA, PFDoDA and PFTrDA combined accounted for 79%. The highest concentrations of PFASs were measured in brain stem, cerebellum and hippocampus. Correlative analyses were performed both across and within brain regions. Significant positive correlations were found between PFASs and MAO activity in occipital lobe (e.g. ∑PFCA; rp=0.83, p=0.041, n=6) and across brain regions (e.g. ∑PFCA; rp=0.47, p=0.001, ∑PFSA; rp=0.44, p>0.001; n=50). GABA-A receptor density was positively correlated with two PFASs across brain regions (PFOS; rp=0.33, p=0.02 and PFDoDA; rp=0.34, p=0.014; n=52). Significant negative correlations were found between mAChR density and PFASs in cerebellum (e.g. ∑PFCA; rp=-0.95, p=0.013, n=5) and across brain regions (e.g. ∑PFCA; rp=-0.40, p=0.003, ∑PFSA; rp=-0.37, p=0.007; n=52). AChE activity and D2 density were negatively correlated with single PFCAs in several brain regions, whereas GS activity was positively correlated with PFASs primarily in occipital lobe. Results from the present study support the hypothesis that PFAS concentrations in polar bears from East Greenland have exceeded the threshold limits for neurochemical alterations. It is not known whether the observed alterations in neurochemical signaling are currently having negative effects on neurochemistry in East Greenland polar bears. However given the importance of these systems in cognitive processes and motor function, the present results indicate an urgent need for a better understanding of neurochemical effects of PFAS exposure to wildlife.

Temporal trends of polychlorinated biphenyls, polybrominated diphenyl ethers, and perfluorinated compounds in Chinese sturgeon (Acipenser sinensis) eggs (1984-2008)

Because investigation on the temporal trends of persistent halogenated compounds (PHCs) is necessary to predict their future impacts on the environment and human health and evaluate the effectiveness of regulations on their production and usage, it is of concern to investigate annual temporal trends of PHCs in biota samples. This study examined the temporal trends of polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), and perfluorinated compounds (PFCs) in Chinese sturgeon (Acipenser sinensis) eggs over a period of 25 years (1984-2008), and 62 PCBs (19.2-1030 ng/g dw for total PCBs), 16 PBDEs (4.7-572 ng/g dw for total PBDEs), and 14 PFCs (26-46 ng/g dw for total PFCs) were detected. Although a decreasing temporal trend was observed for total PCBs with annual reduction rate of 3.4% (ρ = 0.005), a clear break point was observed around 1991, indicating their continuing emission in the 1980s in China. All major PBDEs showed increasing temporal trends, with annual change rates at 3.5-10.2% over the 25 years, but a sharp decreasing trend was observed after 2006, indicating a rapid response to the banning of PBDE usage in China in 2004. The greatest annual rate of increase was observed for BDE-28 (10.2%) followed by BDE-100 (7.7%), which would be due to metabolism input from higher brominated PBDEs. Significantly increasing temporal trends were observed for all PFCs, and the annual rates of increase were 7.9% and 5.9% for total perfluorinated carboxylic acids and perfluorooctanesulfonate (PFOS), respectively. A peak concentration for PFOS was observed in 1989, which may be related to the import history of PFCs in China. The present study is the first report of systematic temporal trends of PHCs in biota samples from China and shows that regulatory policy is needed to reduce their potential health and ecological risk in China considering the increasing temporal trends of PBDEs and PFCs.

Perfluoroalkyl substance concentrations in a terrestrial raptor: relationships to environmental conditions and individual traits

Accumulation of persistent organic pollutants (POPs) in wildlife may be influenced by the physical and biotic environment, and concentrations vary greatly among areas, seasons, and individuals. Different hypotheses about sources of variation in perfluoroalkyl substance (PFAS) concentrations were examined in eggs (n = 107) of tawny owls (Strix aluco) collected over a 24-yr period (1986-2009) in Norway. Predictor variables included the North Atlantic Oscillation (NAO), temperature, snow, food availability (vole abundance), and individual traits such as age, body condition, and clutch size. Concentrations of both perfluoro-octane sulfonate (PFOS) and perfluoroalkyl carboxylates (PFCAs) varied several fold in the population, both inter- and intra-annually. Moreover, individuals laid eggs with several times higher or lower PFAS concentrations within few years (1 yr-5 yr). After controlling for temporal trends (i.e., declining PFOS and increasing PFCA concentrations), both PFOS and PFCAs were positively associated to the winter NAO in the previous year (NAOy - 1 ), suggesting that atmospheric transport may be affecting the input of PFASs to the local ecosystem. Perfluoro-octane sulfonate was negatively related to temperature, but the pattern was complex as there was an interaction between temperature and the feeding conditions. The PFOS accumulation was highest in years with high vole abundance and low to medium temperatures. For PFCAs, there was an interaction between NAOy - 1 and feeding conditions, suggesting that strong air transport toward Norway and high consumption of voles led to a moderate increase in PFCA accumulation. The individual traits, however, had very little impact on the concentrations of PFASs in the eggs. The present study thus suggests that annual variation in environmental conditions influences the concentrations of PFASs in a terrestrial raptor such as the tawny owl.

Characterisation of perfluorooctane sulfonate (PFOS) in a terrestrial ecosystem near a fluorochemical plant in Flanders, Belgium

Bioaccumulation of perfluorooctane sulfonate (PFOS) in a restricted terrestrial food chain was investigated with the omnivorous wood mouse (Apodemus sylvaticus) on top of the studied food chain. The levels detected are very high compared with literature as a result of the presence of fluorochemical plant in the immediate vicinity of the study area. Soil, surface water, fruits of European elder and common blackberry, invertebrates, bank vole and wood mouse were collected at two sites, e.g. Blokkersdijk, adjacent to the fluorochemical plant, and Galgenweel, a reference site 2 km further away. In wood mouse, the highest PFOS concentrations were found in the liver followed by the pancreas, lungs and kidneys, with the spleen having the lowest levels. In the liver, the concentrations ranged from 787 to 22,355 ng/g ww at Blokkersdijk and these were significantly correlated with those detected in the kidneys (13.7-4,226 ng/g ww). If current results are compared to the findings of a previous study conducted in 2002 at the same sites, a significant decrease of PFOS in livers of wood mouse is observed. To the best of our knowledge, so far no studies reported levels of PFOS in terrestrial invertebrates under field conditions. At Blokkersdijk, PFOS was detected in all invertebrate species ranging from 28 to 9,000 ng/g. Soil and water were also contaminated with levels of respectively 68 ng/g and 22 ng/L. Biota-to-soil accumulation factors ranged from 0.11 to 68 for earthworms. Biomagnification factors (BMFs) of liver wood mouse/berries were as high as 302. BMFs for invertebrates were remarkably lower (up to 2).

Repeated measurements of per- and polyfluoroalkyl substances (PFASs) from 1979 to 2007 in males from Northern Norway: assessing time trends, compound correlations and relations to age/birth cohort

BACKGROUND

Longitudinal biomonitoring studies can provide unique information on how human concentrations change over time, but have so far not been conducted for per- and polyfluoroalkyl substances (PFASs) in a background exposed population.

OBJECTIVES

The objectives of this study were to determine: i) serum PFAS time trends on an individual level; ii) relative compositions and correlations between different PFASs; and iii) assess selected PFAS concentrations with respect to periodic (calendar year), age and birth cohort (APC) effects.

METHODS

Serum was sampled from the same 53 men in 1979, 1986, 1994, 2001 and 2007 in Northern Norway and analysed for 10 PFASs. APC effects were assessed by graphical and mixed effect analyses.

RESULTS

The median concentrations of perfluorooctane sulphonic acid (PFOS) and perfluorooctanoic acid (PFOA) increased five-fold from 1979 to 2001 and decreased by 26% and 23%, respectively, from 2001 to 2007. The concentrations of PFOS and PFOA peaked during 1994-2001 and 2001, respectively, whereas perfluorohexane sulphonic acid (PFHxS) increased to 2001, but did not demonstrate a decrease between 2001 and 2007. Perfluorononanoic acid (PFNA), perfluorodecanoic acid (PFDA), and perfluoroundecanoic acid (PFUnDA) displayed increasing trends throughout the entire study period (1979-2007). Although PFOS comprised dominating and stable proportions of PFAS burdens during these years, the contributions from PFOA and PFHxS were considerable. The evaluation of APC effects demonstrated that calendar year was the dominating influence on concentrations of PFOA, PFUnDA, and PFOS, although time-variant and weaker associations with age/birth cohort were indicated.

CONCLUSIONS

The concentration changes of 10 PFASs in the repeated measurements from 1979 to 2007 demonstrated divergent time trends between the different PFASs. The temporal trends of PFASs in human serum during these 30years reflect the overall trends in historic production and use, although global transport mechanisms and bioaccumulation potential of the different PFASs together with a varying extent of consumer exposure influenced the observed trends. Sampling year was the strongest descriptor of PFOA, PFUnDA and PFOS concentrations, and the calendar-year trends were apparent for all birth year quartiles. Discrepancies between the trends in this current longitudinal study and previous cross-sectional studies were observed and presumably reflect the different study designs and population characteristics.

Exposure and effects of perfluoroalkyl substances in tree swallows nesting in Minnesota and Wisconsin, USA

The exposure and effects of perfluoroalkyl substances (PFASs) were studied at eight locations in Minnesota and Wisconsin between 2007 and 2011 using tree swallows (Tachycineta bicolor). Concentrations of PFASs were quantified as were reproductive success end points. The sample egg method was used wherein an egg sample is collected, and the hatching success of the remaining eggs in the nest is assessed. The association between PFAS exposure and reproductive success was assessed by site comparisons, logistic regression analysis, and multistate modeling, a technique not previously used in this context. There was a negative association between concentrations of perfluorooctane sulfonate (PFOS) in eggs and hatching success. The concentration at which effects became evident (150-200 ng/g wet weight) was far lower than effect levels found in laboratory feeding trials or egg-injection studies of other avian species. This discrepancy was likely because behavioral effects and other extrinsic factors are not accounted for in these laboratory studies and the possibility that tree swallows are unusually sensitive to PFASs. The results from multistate modeling and simple logistic regression analyses were nearly identical. Multistate modeling provides a better method to examine possible effects of additional covariates and assessment of models using Akaike information criteria analyses. There was a credible association between PFOS concentrations in plasma and eggs, so extrapolation between these two commonly sampled tissues can be performed.