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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.
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   
57.
58.
Weiss J  Päpke O  Bergman A 《Ambio》2005,34(8):589-597
The main source of human exposure to persistent organic pollutants (POPs) is, in general, food. In this study, 64 butter samples from 37 countries were analyzed to assess the global contamination of polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs), biphenyls (PCBs), hexachlorobenzene (HCB), and 2,2-bis (4-chlorophenyl)-1,1,1-trichloroethane (DDT) together with its major metabolites. The objectives of the study were to assess the presence of major organohalogen contaminants in butter, to trace geographical differences, and to determine toxic equivalents (TEQs) of PCDDs/Fs and dioxin-like PCBs in butter. The highest PCDD/F concentrations were found in butter from Korea with an average of 1.4 pg TEQ g(-1) lipid weight (l.w.). from PCDD/F and an additional contribution from the non- and mono-ortho-PCBs of 0.55 pg TEQ g(-1) l.w. Belgian butter showed average levels of 0.53 and 1.2 pg TEQ g(-1) l.w. for PCDDs/Fs and PCBs, respectively, but one sample of Belgium butter had a total TEQ level as high as 4.0 pg TEQ g(-1) l.w. Three out of five butter samples from Portugal showed similarly high PCDD/F TEQ levels. The sigmaPCB levels in European butter appeared to be somewhat higher than in the samples from the rest of the world. The average contribution of CB-153 to the total PCB concentration was 22% (SD 6.4, coefficient of variation 29%). Generally, the PCBs contributed around 60% of the total TEQ value, with CB-126 contributing approximately half of this value. This shows the important TEQ contribution from dioxinlike PCBs to the total TEQs. The highest HCB levels were found in butter samples from Russia, Ukraine, Belgium, and Slovenia. Low levels of HCB in butter were generally found in the Southern Hemisphere. Butter samples from countries from Eastern Europe had elevated sigmaDDT concentrations, with a particularly high concentration in Ukraine butter, followed by some Russian samples, Brazil, and the U.S.  相似文献   
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