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451.
Estimating the extent of intraspecific variation in sensitivity to contaminant exposure is important in order to explain variation in the outcome of toxicity tests and to predict the effects of chemical stress on natural populations of plants and animals. However, only few studies provide evident data concerning intraspecific variation in life-history traits caused by a differential response to chemical stress. In this study, we compared the life-history response of six laboratory strains of the midge Chironomus riparius to cadmium exposure in a full life-cycle assay. In addition, the level of genetic variation in all strains was measured at five variable microsatellite loci. Several significant differences in life-history traits among the strains were observed in controls and cadmium treatments. The extent of variation among strains was largest at moderate cadmium concentration (0.42 mg Cd/kg dw). At increased Cd concentrations all strains showed similar levels of high mortality and reduced reproductive success. All strains exhibited considerable levels of genetic impoverishment compared to field populations. Strains with low genetic variation showed reduced fitness in the controls and were more susceptible to Cd exposure. For instance, no reproductive success in the lowest Cd treatment was observed for the strain with the lowest level of genetic diversity. In contrast, this Cd concentration had no negative effects on life-history traits of more variable strains. These results confirm recent findings, that inbreeding and reduced genetic variation influence the reaction of populations towards environmental stress. In addition, we show that the level of genetic variation and inbreeding directly influences the outcome of toxicity tests and contributes to the lack of reproducibility of test results among laboratories. 相似文献
452.
Klaus Kabelitz 《生态毒理学报》1999,21(1)
志愿协议(VAs)正在作为环境政策的一种新手段出现,因为它们有超过传统政策措施的优势.具体地说,它们是经济上效率更高的.德国工业界涉及众多工业协会、大概是世界上最昂贵的1996年志愿气候保护协议,是以到2005年显著削减CO2为目标的.这项志愿协议的实施是由一个独立机构按年度监测的.从全球来说,志愿协议应当与联合实施和排放交易相互联系,从而使国际气候保护政策更加灵活和成本有效. 相似文献
453.
The synthesis of eleven environmentally relevant mono-, di- and trichlorodibenzothiophenes (2) by photochemical ring-closure of polychlorodiphenylsulfides (1) is described. All monochlorodibenzothiophenes were additionally synthesized starting with a chlorothiophenol in a three-step reaction adapted from the synthesis of methyldibenzothiophenes. 相似文献
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Pharmaceuticals and contrast media have been detected in hospital effluents, sewage treatment plants, surface water, and ground water. Only little is known about their elimination during sewage treatment and effects of possible biotransformation products against bacteria. The modified Zahn-Wellens test (ZWT, OECD 302 B) and a test simulating biological sewage treatment (modified OECD 303 A test) were used to assess the biodegradability of the widely used ionic iodinated contrast agent diatrizoic acid (diatrizoate). Effects against sewage sludge bacteria were studied in the two test systems by monitoring the biomarkers quinones, polyamines, phospholipids and adenosine triphosphate. Diatrizoate was biotransformed into 2,4,6-triiodo-3,5-diamino-benzoic acid in the ZWT. 2,4,6-Triiodo-3,5-diamino-benzoic acid was stable under the test conditions of the ZWT. Diatrizoate was not eliminated in the OECD 303 A simulation test. It was not adsorbed by the sewage sludge. No effects of the test compound or its aerobic transformation products against the bacteria present in the sewage sludge were detected using phospholipids, quinones, polyamines, and adenosine triphosphate as biomarkers. 相似文献
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Infrared spectrometry is a versatile basis to analyse greenhouse gases in the atmosphere. A multicomponent air pollution software (MAPS) was developed for retrieval of gas concentrations from radiation emission as well as absorption measurements. Concentrations of CO, CH4, N2O, and H2O as well as CO2, NO, NO2, NH3, SO2, HCl, HCHO, and the temperature of warm gases are determined on-line. The analyses of greenhouse gases in gaseous emission sources and in ambient air are performed by a mobile remote sensing system using the double-pendulum interferometer K300 of the Munich company Kayser-Threde. Passive radiation measurements are performed to retrieve CO, N2O, and H2O as well as CO2, NO, SO2, and HCl concentrations in smoke stack effluents of thermal power plants and municipal incinerators and CO and H2O as well as CO2 and NO in exhausts of aircraft engines. Open-path radiation measurements are used to determine greenhouse gas concentrations at different ambient air conditions and greenhouse gas emission rates of diffusive sources as garbage deposits, open coal mining, stock farming together with additional compounds (e.g. NH3), and from road traffic together with HCHO. Some results of measurements are shown. A future task is the verification of emission cadastres by these inspection measurements. 相似文献