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31.
An international cooperative project on distribution of ozone in the Carpathian Mountains, Central Europe was conducted from 1997 to 1999. Results of that project indicated that in large parts of the Carpathian Mountains, concentrations of ozone were elevated and potentially phytotoxic to forest vegetation. That study led to the establishment of new long-term studies on ecological changes in forests and other ecosystems caused by air pollution in the Retezat Mountains, Southern Carpathians, Romania and in the Tatra Mountains, Western Carpathians on the Polish-Slovak border. Both of these important mountain ranges have the status of national parks and are Man & the Biosphere Reserves. In the Retezat Mountains, the primary research objective was to evaluate how air pollution may affect forest health and biodiversity. The main research objective in the Tatra Mountains was to evaluate responses of natural and managed Norway spruce forests to air pollution and other stresses. Ambient concentrations of ozone (O(3)), sulfur dioxide (SO(2)), nitrogen oxides (NO(x)) as well as forest health and biodiversity changes were monitored on densely distributed research sites. Initial monitoring of pollutants indicated low levels of O(3), SO(2), and NO(x) in the Retezat Mountains, while elevated levels of O(3) and high deposition of atmospheric sulfur (S) and nitrogen (N) have characterized the Tatra Mountains. In the Retezat Mountains, air pollution seems to have little effect on forest health; however, there was concern that over a long time, even low levels of pollution may affect biodiversity of this important ecosystem. In contrast, severe decline of Norway spruce has been observed in the Tatra Mountains. Although bark beetle seems to be the immediate cause of that decline, long-term elevated levels of atmospheric N and S depositions and elevated O(3) could predispose trees to insect attacks and other stresses. European and US scientists studied pollution deposition, soil and plant chemistry, O(3)-sensitive plant species, forest insects, and genetic changes in the Retezat and Tatra Mountains. Results of these investigations are presented in a GIS format to allow for a better understanding of the changes and the recommendations for effective management in these two areas.  相似文献   
32.
The aim of our study was to establish changes in activity of important in detoxification enzyme-glutathione S-transferase (GST): in alimentary tract, fat body and Malpighian tubules of Spodoptera exigua larvae being under cadmium and zinc exposure through the first as well as the second generation. There was registered enhancement of the enzyme activity in the fat body and the Malpighian tubules caused by zinc as well as its decrease in the Malpighian tubules under cadmium action. Amounts of metals in the alimentary tract were either several times higher than in the diet ingested by larvae or than in the fat body. Metal concentration in the fat body correlated with the level of the enzyme activity (positive correlation for zinc and negative for cadmium). The effect of metal action differentiated dependently on time exposition.  相似文献   
33.
The aim of the study was to determine whether monobromobenzene (BB) and hexabromobenzene (HBB) administered repeatedly (for 28 days) to female rats resulted in disturbances of heme synthesis. 5-Aminolevulinate dehydratase (ALA-D) and 5-aminolevulinate synthase (ALA-S) activities were slightly changed and the concentration of glutathione increased. The excretion of 5-aminolevulinic acid (ALA-U) in urine after all doses of BB and HBB increased already in the first week. After BB administration, increased excretion of coproporphyrins was detected only at the highest dose. The increased excretion of coproporphyrins following the administration of HBB could be observed already at the lowest dose (15 mg/kg). The excretion of uroporphyrins increased after two higher doses (75 and 375 mg/kg) in the fourth week of exposure. HBB also caused elevation of microsomal P450 level. The data suggest porphyrogenic activity of HBB; whereas in the case of BB we cannot exclude that elevated excretion of ALA-U resulted from kidney impairment.  相似文献   
34.
A solution is proposed for proving compliance with emission targets and for emissions trading in the event of uncertainties in reported emission inventories. The solution is based on the undershooting concept, from which the mathematical conditions for both proving compliance with a risk α and calculating effective emissions for trading are derived. Based on the reported emission units, the number of permits granted is reduced in proportion to the uncertainty in the inventory. A country whose inventory has higher uncertainty is thereby allotted fewer permits than a country with the same inventory but smaller uncertainty.  相似文献   
35.
This article discusses a framework and tools for evaluating ecological resources and the effects of cleanup on hazardous waste sites, particularly those with ecological buffer lands. Environmental professionals are faced with assessing the risks of contamination to humans and ecological receptors (organisms and ecosystems) at hazardous waste sites. While exposure assessment has focused largely on human receptors, environmental managers have recently taken a broader view, recognizing the intrinsic value and aesthetic importance of ecological resources and services, and of including a range of stakeholders in remediation decisions. The assessment process involves understanding exposure pathways from source to receptor, and determining how best to interdict these pathways. Environmental characterization and exposure assessment, indicator and biomarker identification, and biomonitoring and surveillance are the major components of ecological assessments. Using the Department of Energy as a case study, this article offers a framework for ecological exposure assessment, recognizing that humans are important components of ecosystems and, like other biota, are exposed to contaminants that move through environmental media. © 2007 Wiley Periodicals, Inc.  相似文献   
36.
Energy-return-on-investment (ERI) analysis is a variation of more traditional cost-benefit analyses, a variation that is particularly important in times of diminishing fuel resources. We present a simple set of procedures for ERI analysis and apply those procedures to central New York State, where there is a proposal for a new 870 MWe coal-fired generating station. We compared the energy and dollar costs of building that facility with the costs of an alternative comprehensive regional program of insulation. The analysis showed that regional insulation was more efficient in conserving energy than the plant was in providing it by at least a factor of 4 in economic terms and by a factor of more than 15 when viewed as energy returned on energy invested.  相似文献   
37.
Because they cause burns that are difficult to heal, acids are dangerous, and steps should be taken to ensure that the human skin does not come into contact with them. For this purpose safety gloves are generally used by workers who have to handle acids. Such gloves need to be tested to ensure that they are acid resistant. Standard EN 374 (European Committee for Standardization [CEN], 1993c) specifies a method of testing the permeation of liquid chemicals, on a molecular level, through glove material, but it may be difficult to ensure the fitness of the joints of a two-compartment cell, when gloves are lined with jersey. To deal with this a simple pH-meter method to test the permeation of acid and alkali solutions through safety gloves has been developed. The permeation of H2S04, HCI, HN03, and CH3COOH through gloves made from neoprene, nitrile, and PVC was tested. This method seems to be simple and economical.  相似文献   
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