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71.
The potential of passive air sampling devices (polyurethane foam disks) to assess the influence of local sources on the quality of the surrounding environment was investigated. DEZA Valasske Mezirici, a coal tar and mixed tar oils processing plant, and Spolana Neratovice, a chemical factory with the history of high production of organochlorinated pesticides (OCPs), were selected as the point sources of PAHs, and OCPs, respectively. Levels of PCBs, OCPs and PAHs were determined for all sampling sites and sampling periods. The study brought useful data about the air concentrations of POPs in the investigated regions. More important, it provided information on the transport and fate of POPs in the vicinity of local sources of contamination useful for the estimation of their influence. Very good capability of passive samplers to reflect temporal and spatial fluctuation in concentrations of persistent organic pollutants in the ambient air was confirmed which makes them applicable for monitoring on the local scale.  相似文献   
72.
The capability of passive air sampling to be employed in the evaluation of direct genotoxicity of ambient air samples was assessed. Genotoxic effects of the total extracts from the polyurethane foam filters exposed for 28 days during a regional passive air sampling campaign were investigated. Twenty sampling sites were selected in Brno city on the area of approximately 20x20 km in October and November 2004. Brno is the second largest city of the Czech Republic, highly industrialized with approximately 370,000 of permanent inhabitants. The levels of PAHs, PCBs, and chlorinated pesticides were determined in all samples. Fraction of each extract was also assayed in the bacterial genotoxicity test using Escherichia coli sulA::lacZ. Complete dose-response relationships of the air extracts were determined. The statistical analysis showed significant correlation between observed biological effects and PAHs concentrations in samples.  相似文献   
73.
This study presents a bioassay procedure, based on the root and shoot growth parameters, for the determination of the herbicide sulfosulfuron (1-(4,6 dimethoxypyrimidin-2-yl)-3-(2-ethylsulfonylimidazo[1,2-a]pyridin-3-ylsulfonil)urea) sensitivity on seven vegetal species. Plant response to sulfosulfuron was calculated with the equations fitted to the root growth data as a function of the logarithm of the herbicide concentration by non-linear regression and was used to calculate the doses for 10, 30 and 50% inhibition of root growth (EC10, EC30 and EC50). The results indicate that the phytotoxic effect of sulfosulfuron in all the species assayed followed the order: flax > maize > onion > vetch > lepidium sativum > tomato > barley. These species showed phytotoxicity at low levels of sulfosulfuron and flax appeared to be the most susceptible species to sulfosulfuron (0.001 mg/L).  相似文献   
74.
Environmental Persistence of Chemicals   总被引:1,自引:0,他引:1  
- DOI: http://dx.doi.org/10.1065/espr2006.01.008 Background The hazard criterion of persistence as it applies to chemicals in the environment is reviewed and discussed. This quantity can not be measured directly in the environment, thus it must be estimated using models that synthesise information on chemical half-lives and partitioning properties, the nature of the environment and how the chemical is released into the environment. Main Features It is suggested that the preferred criterion is the average residence time of the chemical in the environment, i.e. conceptually the sum of the life-times of all molecules (attributable only to losses by degrading reactions) divided by the number of molecules. If all chemical fate processes are first order, this persistence is independent of the quantity of chemical introduced and whether introduction is steady- or unsteady-state in nature. It is shown that in a multimedia environment persistence is affected not only by degradation kinetics, but also by mode-of-entry and partitioning. For screening level purposes a Level II equilibrium model may be adequate but a Level III model is generally preferable for estimating the average persistence. If a distribution of persistences is required a dynamic Level IV model must be used. Discussion The implications for regulating chemicals on the basis of persistence are discussed. Conclusion It is concluded that the preferred strategy is to use Level II, III, and IV models and that the use of only degradation kinetics or media-specific half-lives can be misleading and uneconomical.  相似文献   
75.
Environmental Science and Pollution Research - Arsenic (As) concentrations and deposition fluxes were measured in snow and rime at 10 mountain-top sites near the borders between the Czech Republic...  相似文献   
76.
77.
Feral pigeons are descendants of wild rock pigeons that have adapted to the urban habitat. They have partially conserved the foraging behaviour of their wild ancestors (flights to agricultural areas) but have also developed new habits. Previous studies on the foraging strategies of feral pigeons have given various results, e.g. maximum distances reached by the pigeons (measured in a straight line from the resting places) differed between 0.3–0.5 km and 18–25 km. This study focuses on the spatio-temporal activity of feral pigeons in the urban habitat. We equipped 80 free-living feral pigeons from Basel, Switzerland with GPS receivers. We found three different foraging strategies for pigeons in Basel: (1) in the streets, squares and parks near the home loft, (2) in agricultural areas surrounding the city, (3) on docks and railway lines in harbours. The maximum distance reached by a pigeon was 5.29 km. More than 32% of the pigeons remained within 0.3 km of the home lofts and only 7.5% flew distances of more than 2 km. Females covered significantly longer distances than males, preferring to fly to more abundant and predictable food sources. Temporal activity patterns showed to be influenced by sex, breeding state and season. In contrast to wild rock pigeons and to feral pigeons in other cities, pigeons in Basel showed a clear bimodal activity pattern for breeding birds only. The differences between our results and those of other studies seem to be partly method-dependent, as the GPS-technique allows to record the pigeons’ localisations continuously in contrast to other methods. Other differences might be due to different kinds of food supply in the various cities. Our study shows that feral pigeons have individual foraging strategies and are flexible enough to adapt to different urban environments.Electronic supplementary material Supplementary material is available for this article at  相似文献   
78.
To investigate copepod nauplii ingestion rates on phytoplankton, we have adapted the traditional gut fluorescence technique as it can be used with lower gut pigment concentrations. With the improved technique, laboratory experiments were performed to estimate functional responses for nauplii of Calanus helgolandicus and Centropages typicus. Nauplii were raised from eggs to copepodites and the experiments were performed with stages NIV-NV. Gut evacuation rates and ingestion rates were measured on Isochrysis galbana at different concentrations. Specific ingestion rates ranged between 0.038–0.244 μg C μg−1 nauplii C d−1 for C. typicus and 0.041–1.412 μg C μg−1 nauplii C d−1 for C. helgolandicus. Both species showed a type III functional response, reaching a saturation concentration at around 600 μgC l−1 for C. typicus and 800 μgC l−1 for C. helgolandicus. An erratum to this article can be found at  相似文献   
79.
在中东欧,人、商品、金钱与时间之间的关系发生了迅速的变化 .货币流通速度加快了,日常生活更紧张了,产品和人本身与 10年前都不同了 .耗能多的国产旧冰箱已经被效率更高(价格更高)的新冰箱所代替;老式的苏联 "拉达"和波兰 "菲亚特"已经被"欧宝"和"现代"所代替;街道和媒体充斥着广告;菜单上的国产食品越来越少 .洗碗机和衣物干燥机等先前不知道的新产品以及新包装文化代替了资源消耗少的朴素的消费行为 .  相似文献   
80.
Coeloides bostrichorum Giraud parasitoids (Hymenoptera: Braconidae) attack late larval stages of various bark beetle species breeding in spruce. Volatile compounds collected from Norway spruce (Picea abies) infested by Ips typographus L. (Coleoptera: Scolytidae) were analysed by coupled gas chromatography-mass spectrometry (GC-MS) and GC-electroantennographic detection (GC-EAD). Monoterpene hydrocarbons are the predominant volatile compounds of fresh Norway spruce, while the presence of oxygenated monoterpenes indicates damaged trees. Between one and eight EAD-active oxygenated monoterpenes were used, in amounts reflecting their natural abundance in spruce trees containing bark beetle larvae, to prepare five synthetic baits which were tested in wind tunnel bioassays. Odour samples collected from spruce logs containing the preferred host stage were attractive, while similar samples from uninfested logs failed to elicit any flight activity. However, when a four- or an eight-component synthetic bait was added to volatiles collected from uninfested spruce logs, this combination was as attractive as volatiles collected from infested spruce logs.  相似文献   
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