Fant 10466 publikasjoner. Viser side 86 av 419:
2017
2017
This study investigated relationships between organohalogen compound (OHC) exposure, feeding habits, and pathogen exposure in a recovering population of Atlantic walruses (Odobenus rosmarus rosmarus) from the Svalbard Archipelago, Norway. Various samples were collected from 39 free-living, apparently healthy, adult male walruses immobilised at three sampling locations during the summers of 2014 and 2015. Concentrations of lipophilic compounds (polychlorinated biphenyls, organochlorine pesticides and polybrominated diphenyl ethers) were analysed in blubber samples, and concentrations of perfluoroalkylated substances (PFASs) were determined in plasma samples. Stable isotopes of carbon and nitrogen were measured in seven tissue types and surveys for three infectious pathogens were conducted. Despite an overall decline in lipophilic compound concentrations since this population was last studied (2006), the contaminant pattern was similar, including extremely large inter-individual variation. Stable isotope ratios of carbon and nitrogen showed that the variation in OHC concentrations could not be explained by some walruses consuming higher trophic level diets, since all animals were found to feed at a similar trophic level. Antibodies against the bacteria Brucella spp. and the parasite Toxoplasma gondii were detected in 26% and 15% of the walruses, respectively. Given the absence of seal-predation, T. gondii exposure likely took place via the consumption of contaminated bivalves. The source of exposure to Brucella spp. in walruses is still unknown. Parapoxvirus DNA was detected in a single individual, representing the first documented evidence of parapoxvirus in wild walruses. Antibody prevalence was not related to contaminant exposure. Despite this, dynamic relationships between diet composition, contaminant bioaccumulation and pathogen exposure warrant continuing attention given the likelihood of climate change induced habitat and food web changes, and consequently OHC exposure, for Svalbard walruses in the coming decades.
2019
Contaminants in Atlantic walruses Part 2: Relationships with endocrine and immune systems
Marine mammals in the Barents Sea region have among the highest levels of contaminants recorded in the Arctic and the Atlantic walrus (<i>Odobenus rosmarus rosmarus</i>) is one of the most contaminated species within this region. We therefore investigated the relationships bewteen blubber concentrations of lipophilic persistent organic pollutants (POPs) and plasma concentrations of perfluoroalkyl substances (PFASs) and markers of endocrine and immune functions in adult male Atlantic walruses (n = 38) from Svalbard, Norway. To do so, we assessed plasma concentrations of five forms of thyroid hormones and transcript levels of genes related to the endocrine and immune systems as endpoints; transcript levels of seven genes in blubber and 23 genes in blood cells were studied. Results indicated that plasma total thyroxine (TT4) concentrations decreased with increasing blubber concentrations of lipophilic POPs. Blood cell transcript levels of genes involved in the function of T and B cells (FC like receptors 2 and 5, cytotoxic T-lymphocyte associated protein 4 and protein tyrosine phosphatase non-receptor type 22) were increased with plasma PFAS concentrations. These results suggest that changes in thyroid and immune systems in adult male walruses are linked to current levels of contaminant exposure.
2019
Contaminants in fish from Etnefjord, Norway. NILU OR
1,2,5,6,9,10-hexabromocyclododecane (HBCDD) is one of the most frequently used brominated flame retardants (BFR) and is considered as an emerging environmental pollutant. Recently, high levels of HBCDD were reported in five different fish species from Etnefjord, which is a branch of the Hardangerfjord at the southwest coast of Norway. This report raised some serious concerns and the Norwegian Climate and Pollution Agency (Klif) therefore initiated a survey of HBCDD in cod and flounder from Etnefjorden in order to confirm the findings. In addition to HBCDD, the levels of other environmental pollutants were analyzed in the fish, namely polybrominated diphenyl ethers (PBDEs), polychlorinated biphenyls (PCBs), hexachlorocyclohexane (HCH), dichlorodiphenyltrichloroethane (DDT), mercury (Mg), lead (Pb), cadmium (Cd) and arsenic (As). The fish muscle filet and livers were prepared and analyzed using recognized and previously published methods. The levels of HBCDD in the fish were low, representing expected background concentrations. HBCDD was only detected in the cod livers with concentrations ranging 0.3-5.7 ng/g wet weight, corresponding to 1.3-8.2 ng/g on a lipid weight basis. Previously, it was reported a level of 30 000 ng/g lipid weight in cod filet, which is, as far as we know, the highest HBCDD concentration ever reported in cod. Our study could, therefore, not confirm the recent findings that showed high HBCDD concentrations in fish from the Etnefjord area. Also, the levels of the other pollutants were low. For example, the concentrations of DDT, PCB, HCH and Hg can, according to Klifs system for classification of environmental state, be regarded as background levels (class 1, slightly/negligible polluted). In conclusion, there are no recons to believe that cod and flounder in Etnefjorden is exposed to considerable amount of environmental pollutants, neither of HBCDD nor other contaminants. Only further analysis of sediments from the inner site of the fjord can, however, positively reveal a possible HBCDD source.
2011
Contaminants in Greenlandic food and chiral pesticides as indicators for selective uptake processes.
2014
2016
2003
2020
2020
2016
2017
2024
Content and migration of chemical additives from plastic products
NILU has, on behalf of the Norwegian Environment Agency, performed chemical analyses of a selection of additives in plastic products. The goal was to identify content and migration of the chemical additives in and from the products to air and surfaces of the products at room temperature. The plastic products covered extension cord, sockets, flooring, wall papers, upholstery, PC-mouse and PCs. Targeted chemicals were organophosphorous flame retardants (OPFRs), brominated flame retardants (BFRs) including TBBPA, and chlorinated substances. TPHP (triphenyl phosphate) was detected in most sample types, but the highest concentrations were found for TBEP (tris(2-butoxyethyl)phosphate. The highest number of compounds were detected in the PC-mouses and high levels were also found in the surface wipes on PC-mouses. None of the targeted compounds were detected in the air samples.
NILU
2022
Contextual recommendation modeling in eCoaching with machine learning, X-AI, and semantic ontology
Physical activities can be divided into indoor and outdoor activities. While outdoor activities offer enjoyable fitness opportunities, they are often limited by weather conditions. Unfavorable weather conditions such as cold, rain, fog, or snow can significantly reduce physical activity levels, posing risks such as heat stress, dehydration, or cold-related injuries. To address these challenges, we have developed the concept of an automated eCoaching system that provides personalized activity recommendations based on real-time weather data. Our system uses an algorithm to annotate, process, and classify the collected data, generating tailored suggestions for indoor or outdoor exercise. This information is semantically represented using an Ontology framework. We have conducted a comprehensive study by collecting weather data for 18 months from thirteen cities in southern Norway. Furthermore, we have developed rules to determine the appropriate activity types corresponding to different weather conditions. The classification performance of the system has been rigorously evaluated using metrics such as accuracy, precision, recall, F1 score, and Matthews correlation coefficient (MCC). Remarkably, the decision tree classifier achieved an accuracy of 99.1%. To increase interpretability, we used local model-independent interpretable explanations (LIME) to explain individual predictions. The consistency of the Ontology model has been verified using inference, providing a reliable semantic representation and efficient rule-based recommendation modeling. In addition, we have developed various test cases of the system to evaluate eCoaching recommendations under different weather scenarios. This approach provides users with accurate and contextually relevant guidance, promoting continuous physical activity regardless of external weather conditions.
2026
2015
2009
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2009
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2015
2015
Contribution of agriculture to air quality problems in cities and in rural areas in Europe. ETC/ACM Technical Paper, 2013/10
2013