Found 9884 publications. Showing page 312 of 396:
2016
Contaminants in Greenlandic food and chiral pesticides as indicators for selective uptake processes.
2014
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
2019
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.
Elsevier
2019
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2016
2009
2014
The safety of high quality drinking water supply relies on the quantities to be delivered, on the complexity of the water supply systems, and on the widespread phenomena of the contamination of water bodies. These parameters indicate the need for the development of an application that will allow the quick acquisition of data on strategic management. This is requires both the analysis of factors related to the hydraulic operation of the plants and the characteristics of water quality. The present paper aims to evaluate the use of models that predict data for water quality in a distribution system. The assessment is made in order to consider the use of the model as a support tool for the management system of a supply network and to optimize the quality of the provided service. The improvement of the control system related to the operations of disinfection, in particular, in the case of long pipelines, is absolutely mandatory in order to ensure the safety of public health and respect for the environment at high levels.
MDPI
2018
2006
The Arctic is one of the most rapidly warming regions of the Earth, with predicted temperature increases of 5–7 ∘C and the accompanying extensive retreat of Arctic glacial systems by 2100. Retreating glaciers will reveal new land surfaces for microbial colonisation, ultimately succeeding to tundra over decades to centuries. An unexplored dimension to these changes is the impact upon the emission and consumption of halogenated organic compounds (halocarbons). Halocarbons are involved in several important atmospheric processes, including ozone destruction, and despite considerable research, uncertainties remain in the natural cycles of some of these compounds. Using flux chambers, we measured halocarbon fluxes across the glacier forefield (the area between the present-day position of a glacier's ice-front and that at the last glacial maximum) of a high-Arctic glacier in Svalbard, spanning recently exposed sediments (<10 years) to approximately 1950-year-old tundra. Forefield land surfaces were found to consume methyl chloride (CH3Cl) and methyl bromide (CH3Br), with both consumption and emission of methyl iodide (CH3I) observed. Bromoform (CHBr3) and dibromomethane (CH2Br2) have rarely been measured from terrestrial sources but were here found to be emitted across the forefield. Novel measurements conducted on terrestrial cyanobacterial mats covering relatively young surfaces showed similar measured fluxes to the oldest, vegetated tundra sites for CH3Cl, CH3Br, and CH3I (which were consumed) and for CHCl3 and CHBr3 (which were emitted). Consumption rates of CH3Cl and CH3Br and emission rates of CHCl3 from tundra and cyanobacterial mat sites were within the ranges reported from older and more established Arctic tundra elsewhere. Rough calculations showed total emissions and consumptions of these gases across the Arctic were small relative to other sources and sinks due to the small surface area represented by glacier forefields. We have demonstrated that glacier forefields can consume and emit halocarbons despite their young age and low soil development, particularly when cyanobacterial mats are present.
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Constituents of organic aerosols. Workshop report, Kjeller, May 2005. ACCENT report, 7.05.
2005