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The extreme persistence and environmental mobility of per- and polyfluoroalkyl substances (PFAS) make their presence ubiquitous in the marine environment. Target analysis of 20 most common PFAS revealed the presence of nine perfluoroalkyl acids at low levels in surface sediments from five Norwegian marine areas covering the vast region from the eastern North Sea in the south to the Arctic Ocean north of Svalbard in the north. After correcting for sediment characteristics, no substantial difference in the sum of the nine PFAS (Σ9PFAS) between the five areas was found. Among separate compounds, PFOS, PFOA and PFNA dominate sample composition. Only two compounds, PFOS and PFUnDA, showed a statistically significant difference for one of the areas, the levels of these compounds being somewhat higher in the southernmost area than in the other areas. This may be due to local inputs in the fjords in this area. Open-sea and coastal sediments of the North-east Atlantic outside of locations with significant local sources seem to share a common, anthropogenic “PFAS background”, which may be part of a larger, global pattern.
2024
2024
Per- and polyfluorinated substances in the Nordic Countries. Use, occurence and toxicology. TemaNord, 2013:542
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2019
In the Barents Sea, pelagic and coastal polar bears are facing various ecological challenges that may explain the difference in their pollutant levels. We measured polychlorinated biphenyls, organochlorine pesticides, polybrominated diphenyl ethers in fat, and perfluoroalkyl substances in plasma in pelagic and coastal adult female polar bears with similar body condition. We studied polar bear feeding habits with bulk stable isotope ratios of carbon and nitrogen. Nitrogen isotopes of amino acids were used to investigate their trophic position. We studied energy expenditure by estimating field metabolic rate using telemetry data. Annual home range size was determined, and spatial gradients in pollutants were explored using latitude and longitude centroid positions of polar bears. Pollutant levels were measured in harp seals from the Greenland Sea and White Sea–Barents Sea as a proxy for a West–East gradient of pollutants in polar bear prey. We showed that pelagic bears had higher pollutant loads than coastal bears because (1) they feed on a higher proportion of marine and higher trophic level prey, (2) they have higher energy requirements and higher prey consumption, (3) they forage in the marginal ice zones, and (4) they feed on prey located closer to pollutant emission sources/transport pathways.
2019
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Patterns of CO2 and radiocarbon across high northern latitudes during International Polar Year 2008.
2011
Plants rely on spectral cues present in their surroundings, generated by the constantly changing light environment, to guide their growth and reproduction. Photoreceptors mediate the capture of information by plants from the light environment over a wide range of wavelengths, but despite extensive evidence that plants respond to various light cues, only fragmentary data have been published showing patterns of diurnal, seasonal and geographical variation in the spectral composition of daylight. To illustrate patterns in spectral photon ratios, we measured time series of irradiance spectra at two distinct geographical and climatological locations, Helsinki, Finland and Gual Pahari, India. We investigated the drivers behind variation of the spectral photon ratios measured at these two locations, based on the analysis of over 400 000 recorded spectra. Differences in spectral irradiance were explained by different atmospheric factors identified through multiple regression model analysis and comparison to spectral irradiance at ground level simulated with a radiative transfer model. Local seasonal and diurnal changes in spectral photon ratios were related to solar elevation angle, atmospheric water-vapour content and total ozone column thickness and deviated from their long-term averages to an extent likely to affect plant photobiology. We suggest that future studies should investigate possible effects of varying photon ratios on terrestrial plants. Solar elevation angle especially affects the patterns of B:G and B:R ratios. Water vapour has a large effect on the R:FR photon ratio and modelled climate scenarios predict that increasing global temperatures will result in increased atmospheric water vapour. The development of proxy models, utilising available data from weather and climate models, for relevant photon ratios as a function of solar elevation angle and atmospheric factors would facilitate the interpretation of results from past, present and future field studies of plants and vegetation.
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