Gamification preferences in nutrition apps: Toward healthier diets and food choices.

Background: Unhealthy eating habits are costly and can lead to serious diseases such as obesity. Nutrition apps offer a promising approach to improving dietary behavior. Gamification elements (GEs) can motivate users to continue using nutrition apps by making them more enjoyable, which can lead to more positive behavioral changes regarding dietary choices. However, the effects of users' preferences and individual characteristics on gamified systems are not yet understood. Current calls for research suggest that personalized gamified systems might lead to user satisfaction, continuous app use, and-ultimately-long-term improvements in diet. Objective: The aim was to determine the most preferred GEs in nutrition apps and to define clusters of GEs preferences in terms of personality and socio-demographic characteristics. Methods: We surveyed 308 people to measure their preferences regarding GEs in nutrition apps and applied best-worst scaling to determine the most preferred GEs. Furthermore, we used cluster analysis to identify different user clusters and described them in terms of personality and socio-demographic characteristics. Results: We determine that GEs most favored are goals, progress bars, and coupons. We revealed three distinct user clusters in terms of personality and socio-demographic characteristics. Based on the individual factors of openness and self-perception, we find that significant differences exist between the preferences for leaderboards and coupons. Conclusion: We contribute by shedding light on differences and similarities in GE preferences relating to specific contexts and individual factors, revealing the potential for individualized nutrition apps. Our findings will benefit individuals, app designers, and public health institutions.

Alternative and legacy flame retardants in marine mammals from three northern ocean regions.

Flame retardants are globally distributed contaminants that have been linked to negative health effects in humans and wildlife. As top predators, marine mammals bioaccumulate flame retardants and other contaminants in their tissues which is one of many human-imposed factors threatening population health. While some flame retardants, such as the polybrominated diphenyl ethers (PBDE), have been banned because of known toxicity and environmental persistence, limited data exist on the presence and distribution of current-use alternative flame retardants in marine mammals from many industrialized and remote regions of the world. Therefore, this study measured 44 legacy and alternative flame retardants in nine marine mammal species from three ocean regions: the Northwest Atlantic, the Arctic, and the Baltic allowing for regional, species, age, body condition, temporal, and tissue comparisons to help understand global patterns. PBDE concentrations were 100-1000 times higher than the alternative brominated flame retardants (altBFRs) and Dechloranes. 2,2',4,5,5'-pentabromobiphenyl (BB-101) and hexabromobenzene (HBBZ) were the predominant altBFRs, while Dechlorane-602 was the predominant Dechlorane. This manuscript also reports only the second detection of hexachlorocyclopentadienyl-dibromocyclooctane (HCDBCO) in marine mammals. The NW Atlantic had the highest PBDE concentrations followed by the Baltic and Arctic which reflects greater historical use of PBDEs in North America compared to Europe and greater industrialization of North America and Baltic countries compared to the Arctic. Regional patterns for other compounds were more complicated, and there were significant interactions among species, regions, body condition and age class. Lipid-normalized PBDE concentrations in harbor seal liver and blubber were similar, but HBBZ and many Dechloranes had higher concentrations in liver, indicating factors other than lipid dynamics affect the distribution of these compounds. The health implications of contamination by this mixture of compounds are of concern and require further research.

Exposure to legacy and alternative flame retardants in two harbor seal populations and the association with blubber fatty acid profiles.

Flame retardants (FRs) are ubiquitously present in various environmental compartments due to widespread application. However, there have been few reports on the alternative FRs in harbor seals, and their relationship with fatty acid (FA) profiles have largely been overlooked. Here, we investigated the levels of legacy and alternative FRs and FA profiles in the blubber of harbor seals from the coasts of South Sweden (2009-2016) and Northeastern US (NE US) (1999-2010). We observed different proportions of mono- and poly-unsaturated FAs (MUFAs and PUFAs) between the two populations, which may reflect variations in the diet. Significantly higher concentrations of ΣPBDE were also observed in harbor seals from US compared to those from Sweden, both dominated by BDE 47. By comparison, the levels of alternative FRs, noticeably HBBZ and PBEB were much lower compared to those of PBDEs. Moreover, we found a positive correlation between BDE 99 and Σn-6/Σn-3 PUFA in harbor seals from Sweden. In addition, BDE 153 and BDE 154 were positively correlated with ΣUFA/ΣSFA in seals from Sweden and US, respectively. Our results imply the influence of diet in FA profiles and FR concentrations in top predators, as well as the importance of blubber FA characteristics in indicating FR exposure. Further investigations are required to assess the risk of exposure in these harbor seals, as well as to elucidate the underlying mechanisms associating FA profiles with FR exposure.

Occurrence and tissue-specific partitioning of alternative brominated flame retardants in northwest Atlantic harbor seal pups (Phoca vitulina vitulina).

Brominated flame retardants such as polybrominated diphenyl ethers (PBDEs) have been used for decades until evidence of negative health effects led to bans in many countries. PBDEs have since been replaced by alternative legacy compounds or newly developed chemicals. In this study, eight alternative brominated flame retardants were analyzed in blubber and liver of harbor seal pups (≤6 months) from the Northwest Atlantic collected during 2001-2010 to elucidate concentrations, patterns, contamination trends, potential maternal transfer, and tissue partitioning. All compounds were detected in liver and blubber tissues with hexabromocyclododecane (HBCD) isomers and 2-ethylhexyl 2,3,4,5-tetrabromobenzoate (TBB) predominating. Overall, α-HBCD was the dominant HBCD isomer in both tissues although the concentrations of γ-HBCD exceeded those of α-HBCD in seven pups, indicating their mothers may have had alternative dietary patterns or recent exposure to the commercial mixture. Although it was detected in less than half of the samples, to our knowledge, this is the first study to report tetrabromobisphenol A (TBBPA) concentrations in multiple tissues of a top marine predator. For the brominated components of Firemaster® flame retardants, TBB concentrations exceeded bis-(2-ethylhexyl)-tetrabromophthalate (TBPH). This pattern may result from recent exposure to commercial mixtures in which TBB exceeds TBPH 4:1 or from differences in perinatal or lactational transfer efficiency of the two compounds. Between the two tissues, lipid-normalized ß-HBCD, γ-HBCD, TBB and decabromodiphenyl ethane (DBDPE) concentrations were significantly higher in liver than blubber. This indicates that the bioaccumulation of these chemicals is not simply related to lipid dynamics but may be linked to blood proteins. This study demonstrates that harbor seal pups from this region are contaminated with alternative flame retardants passed to them via placental or lactational transfer. Given the evidence for negative health effects of these chemicals, this contamination adds additional pressure on the first year survival of these young, developing animals.

How to prevent technostress at the digital workplace: a Delphi study.

Technostress is a rising issue in the changing world of digital work. Technostress can cause severe adverse outcomes for individuals and organizations. Thus, organizations face the moral, legal, and economic responsibility to prevent employees' excessive technostress. As technostress develops over time, it is crucial to prevent it throughout the process of its emergence instead of only reacting after adverse outcomes occur. Contextualizing the Theory of Preventive Stress management to technostress, we synthesize and advance existing knowledge on inhibiting technostress. We develop a set of 24 technostress prevention measures from technostress inhibitor literature, other technostress literature, and based on qualitative and quantitative contributions from a Delphi study. Based on expert feedback, we characterize each measure and, where possible, assess its relevance in addressing specific technostressors. Our paper contributes to research by transferring the Theory of Preventive Stress Management into the context of technostress and presenting specific measures to prevent technostress. This offers a complementary view to technostress inhibitors by expanding the theoretical grounding and adding a time perspective through the implementation of primary, secondary, and tertiary prevention measures. For practice, we offer a comprehensive and applicable overview of measures organizations can implement to prevent technostress.

Spatiotemporal Trends of Legacy and Alternative Flame Retardants in Harbor Seals from the Coasts of California, the Gulf of Maine, and Sweden.

Temporal trends of polybrominated diphenyl ethers (PBDEs) have been extensively studied in various environmental compartments globally. However, despite the increasing use of alternative flame retardants following PBDE bans, the spatiotemporal trends of these replacements have rarely been studied, and the available results are often inconsistent. In the present study, we retrospectively investigated the spatiotemporal trends of PBDEs and a suite of alternative brominated FRs (aBFRs) and chlorinated FRs (i.e., dechloranes or DECs) in three harbor seal (Phoca vitulina) populations from the coasts of California, the Gulf of Maine, and southern Sweden during 1999-2016. We observed significantly decreasing trends of ΣPBDEs in all the three populations at an annual rate of 9-11%, which were predominantly driven by the declining concentrations of tetra- and penta-BDEs. The levels of ΣaBFRs decreased significantly in seals from California (mainly 1,3,5-tribromobenzene) and Sweden (mainly hexabromobenzene), while no trend was observed for those from Maine. By contrast, DECs (dominated by DEC 602) did not decrease significantly in any population. Compared with the consistent PBDE congener profiles across regions, aBFRs and DECs exhibited varying compositional profiles between regions, likely indicating region-specific sources of these alternative FR mixtures. Spatial analysis also revealed regional differences in the concentrations of PBDEs, aBFRs, and DECs in harbor seals. Our reconstructed spatiotemporal trends suggest the effective regulation of commercial penta-BDE mix in these regions and warrant further monitoring of the higher brominated BDEs and alternative FRs.

Open Search of Peptide Glycation Products from Tandem Mass Spectra.

Identification of chemically modified peptides in mass spectrometry (MS)-based glycation studies is a crucial yet challenging task. There is a need to establish a mode for matching tandem mass spectrometry (MS/MS) data, allowing for both known and unknown peptide glycation modifications. We present an open search approach that uses classic and modified peptide fragment ions. The latter are shifted by the mass delta of the modification. Both provide key structural information that can be used to assess the peptide core structure of the glycation product. We also leverage redundant neutral losses from the modification side chain, introducing a third ion class for matching referred to as characteristic fragment ions. We demonstrate that peptide glycation product MS/MS spectra contain multidimensional information and that most often, more than half of the spectral information is ignored if no attempt is made to use a multi-step matching algorithm. Compared to regular and/or modified peptide ion matching, our triple-ion strategy significantly increased the median interpretable fraction of the glycation product MS/MS spectra. For reference, we apply our approach for Amadori product characterization and identify all established diagnostic ions automatically. We further show how this method effectively applies the open search concept and allows for optimized elucidation of unknown structures by presenting two hitherto undescribed peptide glycation modifications with a delta mass of 102.0311 and 268.1768 Da. We characterize their fragmentation signature by integration with isotopically labeled glycation products, which provides high validity for non-targeted structure identification.

Hepatic Fatty Acid Profiles Associated with Exposure to Emerging and Legacy Halogenated Contaminants in Two Harbor Seal Populations across the North Atlantic.

Fatty acids (FAs) have been extensively used as indicators of foraging ecology in marine mammals, yet their association with exposure to contaminants has rarely been investigated. The present study provided the first characterization of the relationship between hepatic FA profiles and exposure to a suite of contaminants in a sentinel species─the harbor seal (Phoca vitulina)─from the Gulf of Maine and the south coast of Sweden. FA profiles differed in the two seal populations, and the levels of legacy and alternative brominated flame retardants and polyhalogenated carbazoles were significantly elevated in Maine seals. Correlations between individual FAs and multiple flame retardants (FRs) and poly- and perfluoroalkyl substances (PFASs) were found in seals from both populations. Moreover, several FR and PFAS chemicals were significantly associated with the estimated desaturating enzyme activity inferred from the FA profiles. The ratios of poly to monounsaturated FAs (∑PUFAs/∑MUFAs) and those of unsaturated to saturated FAs (∑UFAs/∑SFAs) were significantly associated with HBBZ, PFHxS, or BDE 47 in seals from Maine and Sweden, whereas ∑n - 6/∑n - 3 PUFAs was significantly associated with BDE 154 and 36-CCZ in Swedish and Maine seals, respectively. Our results suggest the lipid metabolism-disrupting potential of these contaminants in marine mammals and warrant continuous biomonitoring and risk assessment, considering the critical role of PUFAs in vital biological processes.

Molecular characterization of sequence-driven peptide glycation.

Peptide glycation is an important, yet poorly understood reaction not only found in food but also in biological systems. The enormous heterogeneity of peptides and the complexity of glycation reactions impeded large-scale analysis of peptide derived glycation products and to understand both the contributing factors and how this affects the biological activity of peptides. Analyzing time-resolved Amadori product formation, we here explored site-specific glycation for 264 peptides. Intensity profiling together with in-depth computational sequence deconvolution resolved differences in peptide glycation based on microheterogeneity and revealed particularly reactive peptide collectives. These peptides feature potentially important sequence patterns that appear in several established bio- and sensory-active peptides from independent sources, which suggests that our approach serves system-wide applicability. We generated a pattern peptide map and propose that in peptide glycation the herein identified molecular checkpoints can be used as indication of sequence reactivity.

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

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

Novel High-Throughput Assay for Polysorbate Quantification in Biopharmaceutical Products by Using the Fluorescent Dye DiI.

Polysorbates (PSs) are the most common surfactants in therapeutic protein formulations, and it is crucial to monitor their concentration along the life cycle of biopharmaceuticals. We developed a simple multi-well plate fluorescence-based assay for the rapid determination of PS20 and PS80 content in biopharmaceutical products. The method is based on the detection of the fluorescence emission intensity of the fluorescent dye 1,1'-Dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine perchlorate in the presence of PSs at concentrations below their critical micelle concentration. This method can be applied for PS content determination in protein formulations (≤100 mg/mL) without the need of a previous protein removal step. The 1,1'-Dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine perchlorate assay implemented in multi-well plate format is suitable for high-throughput concentration screening. It has a linear range from 0.00020% to 0.0025% (w/v) PS20, and the limits of detection and quantification were 0.00020% and 0.00055% (w/v), respectively. This assay is markedly more selective and shows no or lower interferences due to hydrophobic components (e.g., silicone oil) potentially present in finished products than the fluorescence micelle assay based on N-phenyl-1-naphthylamine. It also provides comparable results for the PS content in liquid chromatography with charged aerosol detection analysis with protein removal, providing a fast alternative.

Factors Influencing Polysorbate's Sensitivity Against Enzymatic Hydrolysis and Oxidative Degradation.

The aim was to compare the sensitivity of different grades of polysorbate 20 (PS20) and polysorbate 80 (PS80) against enzymatic hydrolysis and oxidative degradation in pharmaceutically relevant buffer systems. For this purpose, a fast liquid chromatography charged aerosol detection method was developed which allows to (1) differentiate between hydrolytic and oxidative PS degradation and (2) to monitor the PS decay over time. Systematic enzymatic and oxidative forced degradation studies were conducted with multicompendial PS20 and PS80, as well as all-laurate PS20 and all-oleate PS80 (with >98% oleic acid, as required by the Chinese Pharmacopoiea since 2015). No differences in the sensitivity toward enzymatic degradation were observed between multicompendial PS and high purity grade PS. However, all-laurate PS20 and all-oleate PS80 have a higher predisposition for oxidative degradation as compared to multicompendial PS20 and PS80. The buffer system used within the study played thereby a key role: histidine showed a protective effect against hydrogen peroxide-induced oxidation, whereas hydrogen peroxide oxidation of PS in acetate buffer was severe under the experimental conditions. Furthermore, ethylenediaminetetraacetic acid protected PS20 and PS80 against oxidative degradation in histidine buffer.

Methoxylated PBDEs (MeO-PBDEs), hydroxylated PBDEs (HO-PBDEs) and hydroxylated PCBs (HO-PCBs) in the liver of harbor seals from the northwest Atlantic.

Metabolites of PCBs and PBDEs are shown to influence the thyroid hormone homeostasis and therefore, could have an influence on the growth of newborn or young animals. We have investigated the occurrence of hydroxylated PCBs (HO-PCBs), hydroxylated PBDEs (HO-PBDEs), and methoxylated PBDEs (MeO-PBDEs) in the liver (48 pups; 6 adults) and blubber (4 pups; 1 adult) of harbor seals (Phoca vitulina concolor) from the northwest Atlantic. The sum of HO-PCBs in the liver ranged from 90 to 22,450 pg/g wet weight (ww) for pups and from 410 to 5290 pg/g ww for adults. Congener 4-HO-CB 107 was predominant in almost all samples regardless of age or gender, except in one adult male. Sum HO-PCB concentrations were highly correlated with the sum of precursor PCBs in the liver of harbor seals (r(2) = 0.79; p<0.0001). Concentrations of sum HO-PBDEs in the liver ranged from 70 to 1850 pg/g ww for pups and from 90 to 230 pg/g ww for adults. HO-PBDEs were also correlated with PBDEs (r(2) = 0.58; p<0.0001). Sum MeO-PBDE concentrations in the liver ranged from 20 to 1460 pg/g ww in pups and from 10 to 270 pg/g ww in adults. HO-PCBs and HO-PBDEs were not detected in the blubber. Levels of MeO-PBDEs in the blubber ranged from 1500 to 4400 pg/g ww. In all blubber samples, 6-MeO-BDE 47 was the predominant MeO-PBDE congener, followed by 2'-MeO-BDE 68 and 5-MeO-BDE 47, respectively. The presence of HO-metabolites in pup liver suggests that young harbor seals may have some, yet limited, metabolic capacity for PCBs and PBDEs, which can lead to an excessive accumulation of these chemicals in the body. Moreover, the presence of HO-PCB and HO-PBDE metabolites may pose an additional stress for young harbor seals due to their influence on the thyroid hormone system and could have consequences for the entire population.

Polychlorinated biphenyls still pose significant health risks to northwest Atlantic harbor seals.

Polychlorinated biphenyls (PCBs) have been detected at relatively high concentrations in harbor seals, apex predators in the northwest Atlantic. As part of an ongoing assessment of the effects of PCBs on population health, we analyzed tri- to deca-PCBs in the liver of 56 harbor seals (6 adult males, 50 pups) and in 11 blubber samples (4 adult males, 7 pups) and examined tissue-specific accumulation patterns, biomagnification potential, and toxic implications of current PCB concentrations. Hepatic ∑30PCB concentrations (overall mean±standard deviation: 76,860±111,800 ng/g lipid weight, lw) were higher than blubber concentrations (48,180±69,420 ng/g lw). Regional trends were suggestive of fresh PCB inputs from the industrialized, densely populated southern coast of New England versus the rural north. The lack of temporal trends confirmed that tissue concentrations of PCBs have plateaued since the early 1990s. Tissue distribution of PCBs varied significantly by age and, surprisingly by gender among the pups. Principal Component Analysis (PCA) revealed that lighter PCBs are selectively transferred from mother to pup blubber in relation to lipid solubility (log Kow), but heavier PCBs may be efficiently transferred during late lactation from mother to pup liver. Biomagnification factors (BMFs) for ∑6PCBs from prey fish to adult male seals ranged from 90 to 547 in the liver and 88 to 532 in the blubber, and suggested that molecular structure and metabolic capacity were more important influences than log Kow on the retention of PCBs. Blubber concentrations of ∑30PCBs in 87% of the pups were an order of magnitude higher than recent toxic reference values (TRVs) calculated for ∑154PCBs in nursing harbor seals, suggesting that the pups are at risk for PCB-mediated toxicity at a vulnerable stage of development. Given the recurring pattern of epizootics in these seals, the health of the population is of concern.

Persistent organic pollutants including polychlorinated and polybrominated dibenzo-p-dioxins and dibenzofurans in firefighters from Northern California.

Polychlorinated and polybrominated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs and PBDD/Fs) were measured in serum of twelve firefighters sampled after a fire event in San Francisco, California, along with polybrominated diphenyl ethers (PBDEs), polychlorinated biphenyls (PCBs), p,p'-DDE, hexachlorobenzene (HCB), perfluorinated chemicals (PFCs), bisphenol-A (BPA) and tetrabromobisphenol-A (TBBPA). TEQPCDD/F concentrations were relatively low (mean 5pgg(-1) (lipid weight), lw, range 1-11pgg(-1)lw), but concentrations of 1,2,3,4,6,7,8-HpCDD, a congener indicative of exposure during firefighting, were elevated. Tentative WHO2005-TEQs calculated for PBDD/Fs in our samples (mean 104pgg(-1)lw, range 0.2-734pgg(-1)lw) suggested that PBDD/Fs may contribute substantially to dioxin-like toxicity in individual firefighters. PBDE concentrations were elevated in firefighter serum (mean 135ngg(-1)lw, range 48-442ngg(-1)lw). PBDE-209, PBDE-47 and PBDE-153 were prevalent congeners; PBDE-209 contributed >50% of the total PBDE concentration in four individuals, implying continuous occupational exposure to deca-BDE. Perfluorooctanesulfonate (PFOS) was the dominant PFC in serum (mean 12ngml(-1) (wet weight), ww, range 3ngml(-1)ww to 59ngml(-1)ww), followed by perfluorooctanoic acid (PFOA) (mean 7ngml(-1)ww, range 2ngml(-1)ww to 12ngml(-1)ww). Concentrations of perfluorononanoic acid (PFNA) (mean 2ngml(-1)ww, range 1-4ngml(-1)ww) were higher than those reported in the high-smoke exposure group of World Trade Center fire responders, suggesting that the California firefighters were exposed to PFNA in smoke during firefighting. Given their elevated rates of cancers, these results illustrate the importance of monitoring halogenated contaminants including PBDD/Fs in firefighters.

Tissue-specific accumulation of polybrominated diphenyl ethers (PBDEs) including Deca-BDE and hexabromocyclododecanes (HBCDs) in harbor seals from the northwest Atlantic.

Polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecanes (HBCDs) are widely used flame retardants that enter coastal waters from multiple sources and biomagnify in marine food webs. PBDEs have been detected at relatively high concentrations in harbor seals, apex predators in the northwest Atlantic. Whereas tri- to hexa-BDEs readily biomagnified from prey fishes to seal blubber, Deca-BDE (BDE-209) did not biomagnify in blubber. To explore tissue-specific differences in the accumulation/biomagnification of BFRs, we analyzed tri- to Deca-BDES in liver of 56 harbor seals (6 adult males, 50 pups), and compared hepatic concentrations and biomagnification potential with those in blubber. HBCDs were analyzed in seal liver and blubber to enable similar comparisons. Hepatic ΣPBDE (tri- to Octa-BDE) concentrations (range 35-19,547ng/glipid weight, lw) were similar to blubber concentrations, while α-HBCD levels in seal liver (range 2-279ng/glw) were significantly higher than levels in blubber. Tissue distribution of PBDEs and α-HBCD varied significantly by age and, surprisingly, by gender among the pups. Biomagnification of α-HBCD from fish to seal liver and blubber was negligible to low, implying that harbor seals can metabolize this persistent isomer. Similar to the patterns in blubber, tri- through hexa-BDEs were highly biomagnified from fish to seal liver. In contrast, BDE-209 concentrations in liver were up to five times higher than those in blubber, which is consistent with observations that BDE-209 migrates to perfused tissues such as the liver in biota. Although detection frequency was low, BDE-209 levels in seal liver were up to ten times higher than those in their prey fish, suggesting that the accumulation/biomagnification of Deca-BDE in marine food webs is tissue-specific. As BDE-209 is the dominant PBDE found in marine sediments, its biomagnification in marine ecosystems is of concern.

Bioaccumulation of polybrominated diphenyl ethers and hexabromocyclododecane in the northwest Atlantic marine food web.

Seven species of teleost fishes comprising major prey of northwest Atlantic harbor seals were analyzed for polybrominated diphenyl ethers (PBDEs). PBDE concentrations in whole fish samples (n=87) were compared with those measured previously in harbor seal blubber to evaluate the transfer of PBDEs from prey to predator. Hexabromocyclododecane (HBCD) concentrations were measured in three fish species to provide an initial estimation of HBCD contamination in this ecosystem. HBCD was detected in 87% of the fish samples at concentrations ranging from 2.4 to 38.1 ng/g, lw (overall mean 17.2+/-10.2 ng/g, lw). SigmaPBDE concentrations in fish ranged from 17.9 to 94 ng/g, lw (overall mean 62+/-34 ng/g, lw). SigmaPBDE concentrations in the harbor seals were two orders of magnitude higher than levels in the fish. Biomagnification factors (BMFs) from fish to seals averaged from 17 to 76, indicating that tetra- to hexa-BDEs are highly biomagnified in this marine food web. BDE-47 was the dominant congener in all samples, suggesting exposure to the penta-BDE mixture. The presence of higher brominated congeners including BDE-209 at measurable levels in fish and seal tissue, along with the very high biomagnification of BDE-153, as well as -155, and -154, suggests recent exposure to the octa- and deca-BDE formulations in this US coastal marine food web, as well as the additional contribution of BDE-209 debromination in fish to the loading of persistent PBDEs in the seals. This is the first study to report the occurrence of BDE-209 and other higher BDEs in commercially important marine fishes from the northwest Atlantic.

Specific accumulation of perfluorochemicals in harbor seals (Phoca vitulina concolor) from the northwest Atlantic.

Concentrations of perfluorochemicals (PFCs) including perfluoroalkylsulfonates (PFSAs), and perfluoroalkylcarboxylates (PFCAs) were determined in liver of harbor seals (n=68) collected from the northwest Atlantic between 2000 and 2007. Of ten PFCs measured, perfluorooctane sulfonate (PFOS) concentrations were the highest in liver (8-1388 ng/g, ww), followed by perfluoroundecanoic acid (PFUnDA) (<1-30.7 ng/g, ww). An unusual accumulation profile of long-chain (C7-C12) PFCAs, and the predominance of PFUnDA, followed by PFNA in seal liver suggested that fluorotelomer alcohols (FTOHs) may be a major source of PFCAs in the northwest Atlantic. No gender-related differences in the concentrations of individual PFCs or total PFCs were found. Concentrations of PFOS and PFDS were higher in tissues of the pups than the adults, whereas concentrations of the PFCAs were similar between pups and adults. PFOS concentrations in the pups were 2.6-fold higher than those in the adult females, suggesting the importance of maternal transfer of PFCs. Hepatic PFOS concentrations were strongly, positively correlated with PFOSA, PFDS and individual PFCAs, indicating that harbor seals are exposed simultaneously to these compounds. Temporal comparisons of hepatic PFC concentrations showed a marginal increase of PFOS and PFCAs in the adult seals from 2000 to 2007. Unlike the spatial trend observed for polychlorinated biphenyls (PCBs), no south to north (urban-rural-remote) decreasing trend was observed for PFCs, suggesting the presence of diffuse sources of PFC contamination throughout the northwest Atlantic.

Bioaccumulation of polybrominated diphenyl ethers in harbor seals from the northwest Atlantic.

Polybrominated diphenyl ethers (PBDEs) were analyzed in blubber of harbor seals (Phoca vitulina concolor) collected between 1991 and 2005 along the northwest Atlantic. summation operatorPBDE concentrations (mono- to hexa-BDEs) detected in blubber samples (n=42) ranged from 80 to 25720 ng g(-1)lw, (overall mean 2403+/-5406 ng g(-1)lw). By age, mean summation operatorPBDE concentrations were: 3645+/-7388, 2945+/-5995, 1385+/-1265, and 326+/-193 ng g(-1)lw in pups, yearlings, adult males, and adult females, respectively. Unlike the trend for PCBs, no decreasing gradient from urban to rural/remote areas was observed for PBDEs in these samples, likely reflecting inputs from local sources. No significant temporal trend was observed for PBDEs in harbor seals between 1991 and 2005, although congener profiles shifted over time. Tetra-BDE-47 was the dominant congener, followed by BDEs-99, -100, -153, -154, and -155 in varying order, suggesting exposure to the penta-BDE product. In adult males, the hexa-BDEs contributed more to the total (22%) than BDEs-99 and -100 (14%), and concentrations of BDE-155 were elevated compared with -154. Higher BDEs were detected in a subset of seals (n=12) including hepta-BDE-183, the marker for the octa-BDE mixture, and octa-BDE-197, along with several unidentified hepta- and octa- congeners. BDE-209 was detected in seal blubber at concentrations ranging from 1.1 to 8 ng g(-1)lw, indicating that deca-BDE is bioavailable in this marine food web. This is the first study to document the accumulation of BDE-209 at measurable levels in wild harbor seals. While the PBDE patterns in blubber indicate exposure to all three BDE commercial mixtures, the data also suggest that BDE-209 debromination by seal prey fish may contribute to the loading of lower brominated congeners (hexa- to octa-BDEs) in these seals.