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501.
We tested the effects of three amendments (a biosolid compost, a sugar beet lime, and a combination of leonardite plus sugar beet lime) on trace element stabilisation and spontaneous revegetation of a trace element contaminated soil. Soil properties were analysed before and after amendment application. Spontaneous vegetation growing on the experimental plot was studied by three surveys in terms of number of taxa colonising, percentage vegetation cover and plant biomass. Macronutrients and trace element concentrations of the five most frequent species were analysed. The results showed a positive effect of the amendments both on soil chemical properties and vegetation. All amendments increased soil pH and TOC content and reduced CaCl(2)-soluble-trace element concentrations. Colonisation by wild plants was enhanced in all amended treatments. The nutritional status of the five species studied was improved in some cases, while a general reduction in trace element concentrations of the aboveground parts was observed in all treated plots. The results obtained show that natural assisted remediation has potential for success on a field scale reducing trace element entry in the food chain.  相似文献   
502.
Carp (Cyprinus carpio) and barbel (Barbus graellsii) were collected from five sites along the Ebro River. The study was designed to assess levels of persistent organic pollutants and metals bioaccumulated by fish, and some biochemical responses (cytochrome P450 system, phase II activities, and metallothioneins) against those pollutants. The highest levels of PCBs and DDTs were detected in carp from industrialised areas, which also showed high levels of mercury and cadmium in the liver, and high levels of nonylphenol in bile. Significant alterations in some biochemical markers were observed and associated to combined exposure to pollutants. The activity 7-ethoxyresorufin O-deethylase ranged from 69 pmol/min/mg protein in carp from the reference site to 415 pmol/min/mg protein in those from polluted sites. Carp from the Ebro Delta, an agricultural area, had depressed acetylcholinesterase in muscle tissue. Metallothionein concentrations were positively correlated with copper residues, but no significant differences among sampling points were observed.  相似文献   
503.
Priority organic pollutants were investigated in sediments and fish collected along the Ebro river basin (NE Spain) to evaluate their occurrence, transport and bioavailability. Sediments were collected in 18 sites and two species of fish were captured in nine sites according to the availability in each area. The sampling sites covered industrial, urban and agricultural areas. Four methods were used to detect 20 organochlorine compounds (OCs), 8 polycyclic aromatic hydrocarbons, 3 organotin compounds, 2 alkylphenols and 40 polybrominated diphenyl ethers (PBDEs) from purified extracts. The contamination pattern was site specific and no downstream increase in concentration of pollutants was observed but rather a generalized low level diffuse pollution. Target compounds were detected in sediments at 0.01 to 2331 microg/kg dry weight, and only OCs and PBDEs were accumulated in benthopelagic fish. Toxicological assessment was performed according to predicted environmental levels and revealed sites where adverse effects could occur.  相似文献   
504.
The concentrations of heavy metals (Cd, Cu, Ni, Pb, Zn and Mn) and macroelements (K, Na, Ca and Mg) were determined in green alga Enteromorpha sp. from the coastal zone of the southern Baltic including Gulf of Gdańsk and Vistula Lagoon in 2000-2003. In order to estimate the degree of accumulation of each element by the green alga, concentration and discrimination factors (CFs) with respect to seawater were calculated. The results of factor analysis (FA) and ANOVA clearly indicate geographical differences between concentrations of chemical elements. Enteromorpha sp. from Vistula Lagoon and the southern Baltic exhibited higher levels of Mn and Ni, and Na and K, respectively. Anthropogenic impact of Cu, Pb and Zn, possibly originated from municipal sewage, was identified in alga samples collected in the Gulf of Gdańsk, especially in the vicinity of Gdynia. From comparison our data with those published earlier results that Pb content in Enteromorpha sp. from the Gulf of Gdańsk decreased within 1978-2003 reflecting reducing use of leaded petrol in Baltic countries in this period. The alga Enteromorpha sp. can be used for biomonitoring surveys of metal contaminants in coastal areas of the Baltic Sea.  相似文献   
505.
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   
506.
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   
507.
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   
508.
Laboratory toxicity tests, using ciliated protozoa, are scarce and they have been carried out usually with freshwater species. In this study, we have analysed the acute cytotoxicity of Cd, Zn and Cu in five different strains of very common soil ciliate species (Colpoda steinii, Colpoda inflata and Cyrtolophosis elongata), which were isolated from very different soil samples (polluted or not with heavy metals). Soil ciliates are quite resistant to heavy metals pollution with regard to ciliates from other habitats. The toxicity sequence was Cd>Cu>Zn. Results from Cd+Zn mixtures indicated that Cd cytotoxicity decreases in the presence of low or moderate Zn concentrations. A broad heavy metal resistance level diversity exists among isolates of colpodid ciliates and it is seen to be a genetic feature rather than a habitat dependence. Bioaccumulation is seen to be the main mechanism involved in the metal resistance, except for Cu. For the first time in ciliates, a fluorescent method has been applied to detect Zn intracellular deposits. This methodology might be an useful tool for monitoring heavy metal pollution in soils.  相似文献   
509.
IntroductionThe aim of this study was to quantify and identify correlates to the amount of parent-supervised behind-the-wheel practice hours by novice teen drivers.MethodsA national survey of 945 parents of recently licensed teen drivers was conducted. Multivariate logistic regression was used to identify factors related to the number of practice hours completed.ResultsSixty-one percent of parents reported practicing 50 or more hours with their teen. Two-parent involvement was associated with more practice hours, though use of a professional driving instructor was not. Parents of teens licensed in states mandating 50 or more hours of practice driving were more likely to report at least 50 practice hours than those in states mandating 20–40 hours or in states without mandates.Impact on IndustryThe findings underscore the integral role of parents in the learning to drive process and provide further support for GDL requirements for practice hours.  相似文献   
510.
This paper presents the design and the implementation of a methodology for measuring and improving safety culture at a nuclear power plant (NPP). The study has involved the completion of a pilot project aimed at seeing how to make use of the RADAR logic (Results, Approach, Deployment, Assessment and Review) of the EFQM model as a tool for the self assessment of safety culture in a nuclear power plant. The work was aimed at finding evidence of the safety culture that was in place at the plant and at identifying both the strengths of that culture and any areas in which it could be improved. The score obtained from an analysis of those strengths and areas for improvement has made it possible to prioritise the actions to be taken. The identification of perceptions and evidence, the agreement on the strong points and areas for improvement and the quantification of the safety culture have been performed by groups comprising volunteers who work at the NPP. The advantages of this methodology are assessed in the paper.  相似文献   
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