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201.
改善生产方法,和恰当使用投入与技术,可以以有益于环境的方式提高生产率,过去食品生产上的成功导致人均食品可得性显著增加,但它们部分地以牺牲自然资源为代价来实现.迅速提高的生产率减少了农业向新土地的扩张,从而对生物多样性、野生生物和土壤产生积极影响,负面影响包括引进大量化学农药,以及水和土壤退化.今后的关键问题并非自然资源是否足以供养未来各代人,而是是否要引进必要的政策和技术.  相似文献   
202.
Traditional ecological knowledge and local experience of resource management and the usefulness of plant species can make important contributions to attempts to understand forest ecosystems and to develop effective sustainable management strategies for them. Therefore, the utilization of tree species by local people, their perceptions of changes in the surrounding forests, and suggested solutions for associated problems, were studied in the Sissili province of southern Burkina Faso. Information was collected through a combination of participatory rural appraisals, household interviews, and observational methods. Principal component analysis was used to analyze the consumptive values of woody species and their respective parts. A total of 82 species were identified, 90% of them were used for medicinal purposes, 78% for fodder, 73% for food, 67% for house construction, and 58% for wood carving. This suggests that forests play a key role in sustaining the rural livelihood and contributing to poverty reduction. The various stakeholders perceived that vegetation clearing for cultivation of cash crops (agribusiness) was the main driver of the change in forest cover. Species reported to be declining in the area included Parkia biglobosa, Pterocarpus erinaceus, Afzelia africana, Bombax costatum, Tamarindus indica, and Diospyros mespiliformis. Thus, a concerted effort should be made to manage the remaining natural forests in the country. Appropriate management strategies should be developed jointly by the local communities and external support groups to integrate the valuable local knowledge about forest species with the stakeholders’ suggestions in order to promote sustainable management of the region’s forest ecosystems.  相似文献   
203.
The combined electrochemical oxidation-solar-light/immobilized TiO2 film process was conducted to degrade an azo dye, Reactive Black 5 (RB5). The toxicity was also monitored by the Vibrio fischeri light inhibition test. The electrochemical oxidation rapidly decolorized RB5 (55, 110 μM) with a supporting electrolyte of 2 g l−1 NaCl at current density 277 A m−2 and pH 4. However, TOC mineralization and A310 removal were low. Additionally, the treated solution showed high biotoxicity. RB5 at 110 μM significantly retarded the de-colorization efficiency by using the solar-light/immobilized TiO2 film process. The combined electrochemical oxidation-solar-light/immobilized TiO2 process effectively increased the removal of color, A310, and TOC. The toxicity was also significantly reduced after 3 h of solar irradiation. The results indicated that the low-cost combined process is a potential technique for rapid treatment of RB5.  相似文献   
204.
Environmental Geochemistry and Health - Environmental pollution is becoming one of the most important global problems. Understanding the main factors affecting accumulation of toxic trace elements...  相似文献   
205.
The recovery of Ascophyllum nodosum, and the associated benthic community, was followed after repeated trampling disturbance at different intensities, from 2005 to 2010, at its southern limit (41°41′27″N; 8°50′57″W). The cover of A. nodosum and associated organisms and the demography of A. nodosum individuals in the most disturbed areas were followed over a recovery period of 54 months. Recovery of A. nodosum assemblages was negatively affected by increasing trampling intensity. After 54 months, the highest intensity plots were still significantly different from control plots. Growth and mortality rates of A. nodosum increased shortly after disturbance but progressively recovered to levels close to control plots. The results of this study demonstrate the sensitivity of this habitat-building species to human trampling and also show its plasticity to cope with disturbance events.  相似文献   
206.
Polychlorinated biphenyls (PCBs) and organic pesticides (i.e., DDTs) were measured in long finned eels (Anguilla dieffenbachii) in 17 streams on the west coast of South Island, New Zealand. Very low levels of PCBs and low levels of ppDDE were found. The concentrations of PCBs and ppDDE were not correlated within sites indicating that different processes determined the levels of the two pollutants in New Zealand eels. The PCBs probably originate from atmospheric transport, ppDDE levels are determined by land use and are higher in agriculture areas. The low contamination level of these aquatic systems seems to be a function of a low input from both long and short-range transport as well as few local point sources. No correlation could be found between lipid content and persistent organic pollutants (POPs) concentration (as shown in previous studies) in the eels which could be explained by low and irregular intake of the pollutants.  相似文献   
207.
在<污染综合预防和控制法>的背景下,丹麦一家企业Kommunekemi帮助编写了有关更安全地处理有害废物的最有效技术的欧盟参考文献.几年前Kommunekemi面临着环境影响和职业健康与安全问题.1990年代安装了两个新的圆桶自动卸料系统(一个用于废液,一个用于固体和糊状废物).本文介绍了Kommunekemi公司内部和周围改善环境和安全条件所采用的方法.  相似文献   
208.
We identified factors that are important determinants of body burdens (breast milk levels) of polychlorinated biphenyls (PCBs), dioxins (polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs)) and polybrominated diphenyl ethers (PBDEs). PCBs, PCDD/Fs and PBDEs were analysed in breast milk from up to 325 first-time mothers in Uppsala, Sweden, who delivered between 1996 and 2006. Hierarchical clustering was used as a method for identification of groups of compounds with common sources of exposure and similar toxicokinetics. Based on correlations between levels of single compounds/congeners in breast milk, distinctly separated clusters were formed, strongly dependent on structural similarities of the organohalogen molecules. In a multiple regression model, levels of PCBs (except PCB 28), PCDD/Fs and BDE-153 were positively associated with age of the mother and weight loss after delivery and inversely associated with pre-pregnancy BMI (body mass index) and weight gain during pregnancy. Higher levels of mono-ortho PCB TEQ, non-ortho PCB TEQ and BDE-153 in milk were found among women with high physical activity. Women who were breastfed during infancy and grew up on the Baltic coast of Sweden, with high availability of contaminated fish from the Baltic sea, had higher levels of PCBs and PCDD/Fs in breast milk indicating that exposure early in life from breast milk and contaminated fish may still affect body burdens at the time of pregnancy. The importance of current consumption of fatty Baltic fish as a source of exposure was supported by the positive association with breast milk levels of mono-ortho PCB TEQ, PCDF TEQ and BDE-153. The results show that, in contrast to the lower brominated PBDE congeners, the hexa-brominated BDE-153 resembles the chlorinated compounds with regards to determinants in breast milk. This suggests that some of the PBDEs may have toxicokinetic properties and that are similar to the PCBs and PCDD/Fs. Our results show that a few simple advices to women regarding weight changes in connection with pregnancy and consumption of contaminated fatty fish during the whole lifetime may lower the levels of dioxins in breast milk by up to 60%.  相似文献   
209.
Environmental Science and Pollution Research - Agri-food supply chains (AFSCs) are one of the significant building blocks of agricultural production, and their sustainability aims are advanced by...  相似文献   
210.
Cyanides are waste products from the pyrolysis of coal and are frequent soil pollutants in cities nowadays. Prussic acid (HCN) is a fast acting, highly toxic poison, but iron-complexed cyanides in soil are far less toxic. The phytotoxicity of free CN to basket willows (Salix viminalis) was determined with the tree transpiration test. The EC10 for t=72 h is 0.76 mg KCN (0.3 mg CN) per liter, the EC50 is 4.47 mg/l. 5 mg/l KCN are ultimately lethal. Balsam poplars (Populus trichocarpa) can survive concentrations of up to 2500 mg/l ferroferricyanide (Prussian blue), although with reduced growth. Willows survived in gas work soils with up to 452 mg/kg total CN. More CN was taken up from nutrient solution than from the soil. Complexed cyanide is probably translocated into the leaves as well. Free CN was readily eliminated from Erlenmeyers with plants growing in nutrient solution. Planting appropriate vegetation might be a suitable solution for many former gas work and mining sites.  相似文献   
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