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941.
The population decline of the nominate lesser black-backed gull Larus fuscus fuscus in the Gulf of Finland (northern Baltic) is caused by an exceedingly high chick mortality due to diseases. The chick diseases include degeneration in various internal organs (primarily liver), inflammations (mainly intestinal), and sepsis, the final cause of death. The hypothesis of starvation causing intestinal inflammations (leading to sepsis) was tested by attempting to reproduce lesions in apparently healthy herring gull L. argentatus chicks in captivity. The herring gull chicks were provided a similar low food-intake frequency as observed for the diseased chicks in the wild. However, empty alimentary tract per se did not induce the intestinal inflammations and therefore, inflammations seem to be innate or caused by other environmental factors in the diseased lesser black-backed chicks. They had very high concentrations of PCB in their liver; but the concentrations were not significantly higher than those of the healthy herring gull chicks, indicating a common exposure area for both species (i.e. the Baltic Sea). When compared to NOEL and LOEL values for TEQs in bird eggs our TEQ levels clearly exceed most or all of the values associated with effects. Compared with published data on fish-eating waterbirds, the DDE concentrations in the diseased lesser black-backed chicks were well above the levels previously correlated with decreased reproduction, while the residues in apparently healthy herring gulls were below those levels. The DDE/PCB ratio in lesser black-backs was significantly elevated, indicating an increased exposure to DDTs as compared with most other Baltic and circumpolar seabirds. The possible exposure areas of DDT in relation to differential migration habits of the two gull species are discussed.  相似文献   
942.
943.
Pore water was separated either with or without water extraction prior to centrifugation (7600 or 20 000 × g) in order to investigate the effects of separation procedure on the amount and properties of dissolved organic matter (DOM i.e. the material passing through a 0.45-μm filter) in three freshwater sediments. On the basis of solubility in alkaline, organic matter was concluded to compose of humic substances in two (S1 and S3) and of humin (S2) in one of the sediments. DOM in the samples was quantified by total organic carbon measurement. Specific UV-absorption (SUVA) and high performance size exclusion chromatography (HPSEC) analyses were used to characterize DOM. Sorption of pyrene was used as a measure for functionality of DOM. Both water extraction and centrifugation speed were shown to affect the properties of DOM; however, the effects were sediment dependent. Water extraction increased the amount of DOM separated from the two sediments that had humic character (S1 and S3). In most cases water extraction increased SUVA and shifted the molecular size distribution of DOM towards larger sizes. The separation procedure had also an effect on the functionality of DOM. In water extracted samples of S2 and S3 the sorption of pyrene was higher than in the corresponding samples separated without water extraction, whereas in S1 similar effect was not found. Generally, centrifugation speed had smaller effects on the properties of DOM than water extraction. The fact that the effects of separation procedure on DOM depend on the sediment characteristics complicates the comparison between samples and evaluation of functionality in field conditions.  相似文献   
944.
Polychlorinated bornanes, the main components of Toxaphene, are bioconcentrated in aquatic organisms to a high extent. However, up to this time no bioconcentration tests with individual chlorinated bornanes in aquatic organisms have been performed. Therefore, the bioconcentration factors (BCFs) of seven selected persistent chlorinated bornane congeners which are regularly found in aquatic organisms, were predicted from their n-octanol/water partition coefficients (log Kow). Furthermore, these BCF values were compared with the measured bioaccumulation factors (BAFs) in zooplankton and different fish species from the aquatic environment.  相似文献   
945.
The observed high-level burdens of organohalogens among the residents of the Faroe Islands, needs to be explained. Long-finned pilot whale (Globicephala melas) blubber and meat are known sources of environmental exposure. The present study focus on the organohalogen contamination of the fulmar (Fulmarus glacialis). The compounds quantified in fulmar muscle, fat, and egg are PCBs, DDTs, hexachlorobenzene (HCB), and polybrominated diphenyl ethers (PBDEs). The dominating pollutants are the 4,4'-DDT metabolite 4,4'-DDE and the two PCB congeners, CB-153 and CB-180, which are present in geometric mean concentrations of 7100, 4700 and 2500 ng/g lipid weight (l.w.), respectively, in adult fulmar muscle. 4,4'-DDT and HCB concentrations are approximately 250 ng/gl.w., each. Concentrations in the eggs are about 50% of the fulmar muscle levels, due to differences in lipid amounts, 4% in muscle and 10% in the eggs, the exposure contribution on a fresh weight basis is almost the same. As a result, both the egg and the adult fulmar muscle may lead to a significant exposure risk, if consumed by humans. BDE-153, the most abundant PBDE congener in fulmar muscle, with a geometric mean concentration of 6.5 ng/gl.w., is much lower than the individual PCB congeners and 4,4'-DDE concentrations. In the adult fulmar muscle, the relative PBDE congener pattern is different from that previously observed in biota, with BDE-153 and BDE-154 as the dominating congeners, rather than BDE-47. In contrast, BDE-47 is the most abundant congener in juvenile muscle and subcutaneous fat. The summation operatorPBDE concentrations are almost the same in egg, muscle (adult and juvenile) and subcutaneous fat (juvenile). For the polybrominated biphenyl (BB-153) the concentrations are considerably higher in the adult bird and egg than in the juvenile bird; this is also seen for the PCB and 4,4'-DDE concentrations. PCB concentrations found in fulmar egg and muscle are in the same range as seen in the pilot whale, i.e. 590-5700 ng/gl.w. for CB-153. Hence humans are also exposed to PCBs at a reasonable degree via intake of fulmar and/or fulmar egg and not only via pilot whale blubber.  相似文献   
946.
A method, based on XAD-8 resin sorbtion and Particle Induced X-ray Emission (PIXE), was developed for Total Organic Chlorine (TOCl) determinations. The method was applied to recipient waters of a kraft bleach plant, and the determined TOCl values compared with other parameters. The detection limit was about 10 μg/l.  相似文献   
947.
Ishaq R  Näf C  Zebühr Y  Broman D  Järnberg U 《Chemosphere》2003,50(9):1131-1150
Methodology for the determination of biologically active polychlorinated biphenyls (PCBs), non-ortho PCBs, polychlorinated naphthalenes (PCNs), polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), polycyclic aromatic hydrocarbons (PAHs) was used to investigate concentrations and patterns of certain chlorinated PAH (Cl-PAH) in source related samples using synthetic reference mixtures. Thus, in addition to the above mentioned compounds, mono-heptachlorosubstituted fluorenes, phenanthrenes/anthracenes and pyrenes/fluoranthenes (Cl-PAHs) were measured in vapour and particulate air samples from urban road tunnels, samples of settling particulate matter (SPM), and in bottom sediment samples from two point source locations (pulp and paper, and Mg-plant/Fe-Mn-smelter/chlor-alkali) and in the Baltic Sea. Concentrations in air samples followed: PAHs>PCBs>PCNs>non-ortho PCBs or Cl-PAHs>PCDD/Fs. SPM samples collected at increasing distance to the urban area of Stockholm showed: PAHs>PCBs>PCNs>PCDD/Fs>non-ortho PCBs or Cl-PAHs. For all compound groups there was a tenfold (Cl-PAHs fivefold) concentration decrease in SPM samples from highest levels in the urban water area to lowest levels at a distance of 26 km from city centre. PCB profiles of SPM showed similarities with combined profiles of Aroclor 1242 and 1254. PCN profiles of SPM showed similarities with combined profiles of Halowax 1099 and 1014. A correlation with concentration of all tested Cl-PAH and their corresponding parent PAH was found only for Cl-fluorene.  相似文献   
948.
This paper presents a digitized version of a thermodynamic sorption database, implemented as a relational database with MS Access. It is mineral-specific and can therefore be used for additive models of complex solid phases such as rocks or soils. An integrated user interface helps users to access selected mineral and sorption data, to extract internally consistent data sets for sorption modeling, and to export them in formats suitable for other modeling software. Data records comprise mineral properties, specific surface area values, surface binding sites' characteristics, sorption ligand information, and surface complexation reactions. An extensive bibliography is included, providing links not only to the above listed data, but also to background information concerning surface complexation model theories, evidence for surface species, and sorption experimental techniques.  相似文献   
949.
Linear relatinships between log bioconcentration factor (BCF) and log Kow for a variety of compounds have been reported many times in the literature. Analysis of the thermodynamics of the two partition processes has, however, shown that they are not analogous and that linear relationships can be expected to have different slopes for structurally unrelated compounds. In this study a set of literature lipid normalized BCF (BCFL) values of chlorbenzenes (CBs) for rainbow trout and polycyclic aromatic hydrocarbons (PAHs) forDaphnia was put together with literature Kow values. The slopes of the regression lines for log BCFL versus log Kow for the two groups of compounds proved to differ significantly in a statistical test using analysis of variance (ANOVA). The difference, which is of significance for estimates of BCFs in environmental modelling of these types of compounds, is explained by the differences in chemical structure of the two groups of compounds.  相似文献   
950.
Sedimentation and sulfate reduction under a mussel culture   总被引:9,自引:0,他引:9  
The sedimentation and dissimilatory sulfate reduction under a blue-mussel culture were quantified in order to gain information on the environmental impact of intense mussel farming. The sedimentation rate (3 g C·m-2·d-1) under a culture is nearly three times higher than at a nearby reference station. A build-up of sediment rich in organic material and sulfide takes place under the mussels. At 15°C the sulfate reduction rate was 30.5 mmol SO = 4 ·m-2·-1 in the upper 10 cm of the mussel sediment. The increase in sedimentation under a mussel culture and the consequent effects should be considered when establishing mussel farms.  相似文献   
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