Found 9976 publications. Showing page 123 of 400:
Mindre luftforurensning gir rimeligere vedlikehold av fasader og materialer
Norges forskningsråd
2018
Environmental contaminants are found throughout Arctic marine ecosystems, and their presence in seabirds has been
associated with toxicological responses. However, there are few studies of genotoxicity in Arctic avian wildlife. The purpose of
the present study was to quantify deoxyribonucleic acid (DNA) damage in lymphocytes of selected seabird species and to
examine whether accumulation of organohalogen contaminants (SOHCs) affects DNA damage. Blood was sampled from
common eider (Somateria mollissima), black guillemot (Cepphus grylle), black-legged kittiwake (Rissa tridactyla), glaucous gull
(Larus hyperboreus), arctic skua (Stercorarius parasiticus), and great skua (Stercorarius skua) in Kongsfjorden, Svalbard (Norway).
Contaminant concentrations found in the 6 species differed, presumably because of foraging ecology and biomagnification.
Despite large differences in contaminant concentrations, ranging from SOHCs 3.3 ng/g wet weight in the common eider to
SOHCs 895 ng/g wet weight in the great skua, there was no strong difference among the species in baseline DNA damage or
sensitivity to a genotoxic stressor (hydrogen peroxide). Baseline levels of DNA damage were low, with median values ranging
from 1.7% in the common eider to 8.6% in the great skua. There were no associations between DNA damage and contaminants
in the investigated species, suggesting that contaminant concentrations in Kongsfjorden are too low to evoke genotoxic effects,
or possibly that lymphocytes are resistant to strand breakage. Clearly, genotoxicity is a topic for future studies of Arctic seabirds
Arctic; Seabirds; Genotoxicity; Comet Assay; Persistent organic pollutants; Perfluoroalkyl substances
Pergamon Press
2018
In contrast to previous studies that have tended to focus on the influence of the total Arctic sea-ice cover on the East Asian summer tripole rainfall pattern, the present study identifies the Barents Sea as the key region where the June sea-ice variability exerts the most significant impacts on the East Asian August tripole rainfall pattern, and explores the teleconnection mechanisms involved. The results reveal that a reduction in June sea ice excites anomalous upward air motion due to strong near-surface thermal forcing, which further triggers a meridional overturning wave-like pattern extending to midlatitudes. Anomalous downward motion therefore forms over the Caspian Sea, which in turn induces zonally oriented overturning circulation along the subtropical jet stream, exhibiting the east–west Rossby wave train known as the Silk Road pattern. It is suggested that the Bonin high, a subtropical anticyclone predominant near South Korea, shows a significant anomaly due to the eastward extension of the Silk Road pattern to East Asia. As a possible descending branch of the Hadley cell, the Bonin high anomaly ultimately triggers a meridional overturning, establishing the Pacific–Japan pattern. This in turn induces an anomalous anticyclone and cyclone pair over East Asia, and a tripole vertical convection anomaly meridionally oriented over East Asia. Consequently, a tripole rainfall anomaly pattern is observed over East Asia. Results from numerical experiments using version 5 of the Community Atmosphere Model support the interpretation of this chain of events.
Science Press
2018
2018
Unleaded gasoline as a significant source of Pb emissions in the Subarctic
After the phasing out of leaded gasoline, Pb emissions to the atmosphere dramatically decreased, and other sources became more significant. The contribution of unleaded gasoline has not been sufficiently recognized; therefore, we evaluated the impact of Pb from unleaded gasoline in a relatively pristine area in Subarctic NE Norway. The influence of different endmembers (Ni slag and concentrate from the Nikel smelter in Russia, PM10 filters, and traffic) on the overall Pb emissions was determined using various environmental samples (snow, lichens, and topsoils) and Pb isotope tracing. We found a strong relationship between Pb in snow and the Ni smelter. However, lichen samples and most of the topsoils were contaminated by Pb originating from the current use of unleaded gasoline originating from Russia. Historical leaded and recent unleaded gasoline are fully distinguishable using Pb isotopes, as unleaded gasoline is characterized by a low radiogenic composition (206Pb/207Pb = 1.098 and 208Pb/206Pb = 2.060) and remains an unneglectable source of Pb in the region.
Elsevier
2018
Uptake and effects of 2, 4, 6 - trinitrotoluene (TNT) in juvenile Atlantic salmon (Salmo salar)
Elsevier
2018
2018
Water column distribution of mercury species in permanently stratified aqueous environments
Biogeochemical structures of three permanently stratified waterbodies were studied: a sea water basin (the Black Sea), an estuary (Hunnbunn fjord), and a freshwater lake (Nordbytjernet), with focus on the distributions of methylmercury (MeHg) and total mercury (THg). THg concentrations were similar in the sea water basin (0.2–1.8 ng/L) and the freshwater lake (0.8–1.2 ng/L), but significantly higher in the estuary (0.6–9.4 ng/L). An increase in the MeHg concentration and MeHg/THg ratio were found in the redox zone in all three basins, indicating bacterial production of MeHg in the aqueous phase. In the lake and estuary, the maximum MeHg concentration and MeHg/THg ratio were found in samples located closest to the bottom sediments, likely due to the formation of MeHg in surface sediments and subsequent diffusion to the overlying waters.
Springer
2018
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2017
2017
2017