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51.
波罗的海中的灰海豹和环斑海豹种群在60~70年代期间发生严重减少的现象。成年动物曾显示出(目前仍显示出)一系列损害现象,特别是雌性动物的生殖器官、肠、皮肤、肾、肾上腺以及颅骨(波罗的海海豹综合症)等的损害。本报告提供了1977~1996年期间在波罗的海本体和波的尼亚湾收集的76只灰海豹和29只环斑海豹肾脏光学显微病变的形态和盛行情况。血管小球的特殊变化是毛细血管壁的弥散性变厚以及毛细血管壁或被膜壁中存在大而圆的透明体。远曲小管和集合管的特殊变化包括通过多层细胞增殖使正常上皮发生病灶性置换。这些病变的盛行及程度与年龄有关,因此也就是与接触环境毒物的时间长短有关。肾损害在波罗的海灰海豹身上比在环斑海豹身上明显。在来自瑞典动物园的5只灰海豹身上也记录下了类似的发现。这些动物在其生命的大部分时间内都是以波罗的海中的鱼类为食的。在5只波罗的海灰海豹和动物园灰海豹中的其中一只身上进行了显微镜检测。主要是根据一只波罗的海灰海豹身上的发现进行电子显微镜检的结果包括肾小球毛细血管壁的肾小球膜间位以及肾单位远基部位细胞增殖中居间细胞的特征。来自苏格兰海岸的11只灰海豹和来自斯瓦尔巴群岛23只环斑海豹被作为参照物。这些参考海豹没有一只显示出有上述的特殊损害现象。作者认为,波罗的海环境中的有机氯污染是造成这些肾脏病变的一个因素。  相似文献   
52.
The preparation of 14C-labelled biphenyl, 2,5-dichlorobiphenyl, 2,4′,5-trichlorobiphenyl, 2,2′,4,5′-tetrachlorobiphenyl, 2′,3,4,4′,5-pentachlorobiphenyl, 2,2′,3,4,4′-pentachlorobiphenyl, 2,3,3′,4′,6-pentachlorobiphenyl and 2,2′,3,3′,6-pentachlorobiphenyl is described [14C]Aniline hydrogen sulfate used as a starting material was acetylated, chlorinated and deacetylated followed by coupling to benzene or an appropriate chlorobenzene to give the biphenyls labelled in the phenyl nuclei having chlorine atoms at the 4-, 2,4- or 2,3,6-positions, respectively. The structures of the labelled compounds were established by comparison with authentic samples among which 2′,3,4,4′,5- and 2,2′,3,4,4′-pentachlorobiphenyl were not earlier described.A simple method for the preparation of 2,3,6-trichloroacetanilide, unlabelled and labelled, was worked out. 2,6-Dichloroacetanilide in concentrated hydrochloric acid gave the meta substituted product when treated with chlorine.An improved thin layer chromatographic technique utilizing plates impregnated with certain tetraalkylammonium salts was used for separation of some of the labelled compounds prepared.  相似文献   
53.
Valters K  Olsson A  Asplund L  Bergman A 《Chemosphere》1999,38(9):2053-2064
Polychlorinated biphenyls (PCBs), DDT-related substances, hexachlorocyclohexane (HCH) isomers and hexachlorobenzene (HCB) were analysed in perch (Perca fluviatilis) from Latvian lakes and rivers. DDE is present in the highest concentrations in all samples; 62-170 ng/g lipid weight in perch from rural areas and 460 ng/g in perch from the Riga area. Individual dominating PCB congeners were in the range 16-45 ng/g and 200-210 ng/g, respectively. The degree of contamination of rural areas in Latvia of these organohalogen substances is in the same range as in background areas in Sweden. Riga, the major urban area in Latvia, is shown to be more polluted with PCBs than other areas in Latvia.  相似文献   
54.
P.O Darnerud     Bergman  B.O Lund  I Brandt 《Chemosphere》1989,18(9-10):1821-1827
Three 14C-labelled polychloroalkanes (C12 and C16), representing low (23% Cl by weight), medium (51%), and highly (68%) chlorinated paraffin (CP) mixtures, were presented to rainbow trout via the water. The uptake in fat-rich tissues was positively correlated to the degree of chlorination of the preparations. Notably, all preparations gave rise to a high and selective uptake of radioactivity in the olfactory organ and gills. This selective radiolabelling may reflect a general ability of these organs to enrich xenobiotics from the surrounding water. The olfactory organ may be a hitherto unforseen target for toxic environmental pollutants in fish.  相似文献   
55.
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   
56.
The distribution of tributyltin (TBT) contamination in the subtidal zone of the waters between Denmark and Sweden was investigated in relation to major international shipping lanes. Sediment and different benthic molluscs were sampled in transects along and perpendicularly to the shipping lanes in the Sound (?resund) and the Kattegat/Skagerrak region. The samples were analysed for TBT and its degradation products, dibutyltin (DBT) and monobutyltin (MBT), using GC-PFPD. In sediments, the TBT concentration ranged from <1 to 19 ng g(-1) dry weight (dw) with a strong correlation between the TBT concentration and the organic fraction in sediment (r(2)=0.90) in the samples collected in the Sound, where the highest concentrations were found. This relationship was not observed in the samples from the Kattegat because the TBT concentration in most sediment samples was below the limit of detection. In the molluscs, TBT and its degradation products were detected in all samples from the entire area with concentrations ranging from 8.1 ng g(-1) dw in Buccinum undatum to 1316 ng g(-1) dw in Nuculana pernula. The deposit-feeding bivalve N. pernula was found to have a particularly high accumulation potential for TBT. In addition, a strong correlation between TBT concentrations in sediment and N. pernula was found. Therefore this species seems to be an ideal organism for monitoring sediment contamination. The TBT concentration in N. pernula was found to decrease gradually along the shipping lanes from the Sound, through the Kattegat and into the Skagerrak.  相似文献   
57.
Within predator-prey systems behavior can heavily influence spatial dynamics, and accordingly, the theoretical study of how spatial dynamics relate to stability within these systems has a rich history. However, our understanding of these behaviors in large mammalian systems is poorly developed. To address the relationship between predator selection patterns, prey density, and prey vulnerability, we quantified selection patterns for two fine-scale behaviors of a recovering wolf (Canis lupus) population in Yellowstone National Park, Wyoming, USA. Wolf spatial data were collected between November and May from 1998-1999 until 2001-2002. Over four winters, 244 aerial locations, 522 ground-based telemetry locations, 1287 km of movement data from snow tracking, and the locations of 279 wolf kill sites were recorded. There was evidence that elk (Cervus elaphus) and bison (Bison bison) densities had a weak effect on the sites where wolves traveled and made kills. Wolf movements showed a strong selection for geothermal areas, meadows, and areas near various types of habitat edges. Proximity to edge and habitat class also had a strong influence on the locations where elk were most vulnerable to predation. There was little evidence that wolf kill sites differed from the places where wolves traveled, indicating that elk vulnerability influenced where wolves selected to travel. Our results indicate that elk are more vulnerable to wolves under certain conditions and that wolves are capable of selecting for these conditions. As such, vulnerability plays a central role in predator-prey behavioral games and can potentially impact the systems to which they relate.  相似文献   
58.
59.
The predictions of three models of 137Cs transfer in forest ecosystems (FOA, LOGNAT and FORESTLAND) were compared. The scenario for the model-model comparison consisted of an acute dry deposition of 137Cs over a coniferous forest. The model predictions were subsequently compared (model-data comparison) with values derived from experimental data measured in forests of the Bryansk region in Russia that were contaminated by the Chernobyl accident and that have similar characteristics to the forests described in the scenario. The predictions of radiocaesium levels in the litter-soil layer, berries, needles, wood, whole tree and moose made with the models were in relatively good agreement with each other (within a factor of 1.4-2.9). The best agreement was observed for berries and moose and the worst for wood. There was also good agreement between the model predictions for the same variables and the experimental data (within a factor of 1.2 3.2). In this case, the best agreement was observed for the litter-soil layer and the worst for wood and the whole tree. Overall, at least for the studied scenario and for the first 10 years after deposition, any of the models can be used if the final aim is to estimate average concentrations in different forest components. The agreement between the model predictions worsens with time and there were differences in the form of the time dependencies predicted by the models, especially for wood. This may lead to larger differences between the model predictions and the experimental data for times beyond the period for which data were available for comparison (10 years after the deposition).  相似文献   
60.
Previous studies have suggested that a segment of human disease may be attributable to environmental exposures. These may include exposure to chemicals released from a broad range of natural and man-made sources. The purpose of this study was to develop the sampling methodology and prepare a preliminary database on the presence of various organic chemicals in environmental media in two South Texas counties bordered by the Rio Grande River. A third county, located approximately 150 miles north of the Rio Grande River, was also sampled. The South Texas counties were the focus of study due to an increased incidence of anencephalic births in recent years. The environmental media that was sampled included surface water and sediment from the Rio Grande River and irrigation canals, as well as soil from adjacent cropland and pastures. Samples were collected using United States Geological Survey (USGS) quadrangle maps (7.5'; 1:24,000 scale) to identify the area of interest. At least one sampling location was established in each quadrangle. A pond sampler was used for the collection of surface water samples, while soil was collected with a stainless steel trowel. Sediment samples were collected directly in a glass jar. Solid samples were extracted in a soxhlet extractor using methylene chloride. Organic chemicals were concentrated from water samples on a Sep-Pak cartridge and the organics eluted with methanol/acetonitrile. Extracts were analyzed using GC-MS. All of the surface water samples contained aliphatic hydrocarbons and plasticizers, while soil samples contained aliphatics, plasticizers, pesticides, and industrial estrogens. Specific chemicals detected in environmental samples included atrazine and benzene dicarboxylic acid. Contaminant levels in sediments were generally higher than were detected in other media. The results demonstrate the broad variability of contaminant types and concentrations in environmental samples. Although this study presents only a very preliminary characterization of a large area of South Texas, the data indicate a number of pesticides and xenobiotic estrogens that were identified in environmental samples. Additional data providing more details of spatial and temporal distribution of contaminants as well as wildlife studies are needed.  相似文献   
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