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1.
Some important naturally occurring α- and β-radionuclides in drinking water samples collected in Italy were determined and the radiological quality evaluated. The mean activity concentrations (mBq L−1) of the radionuclides in the water samples were almost in the order: 26 ± 36 (234U) > 21 ± 30 (238U) > 8.9 ± 15 (226Ra) > 4.8 ± 6.3 (228Ra) > 4.0 ± 4.1 (210Pb) > 3.2 ± 3.7 (210Po) > 2.7 ± 1.2 (212Pb) > 1.4 ± 1.8 (224Ra) > 1.1 ± 1.3 (235U) > 0.26 ± 0.39 (228Th) > 0.0023 ± 0.0009 (230Th) > 0.0013 ± 0.0006 (232Th). The mean estimated dose (μSv yr−1) to an adult from the water intake was in this order: 2.8 ± 3.3 (210Po) > 2.4 ± 3.2 (228Ra) > 2.1 ± 2.1 (210Pb) > 1.8 ± 3.1 (226Ra) > 0.94 ± 1.30 (234U) > 0.70 ± 0.98 (238U) > 0.069 ± 0.087 (224Ra) > 0.036 ± 0.044 (235U) > 0.014 ± 0.021 (228Th) > 0.012 ± 0.005 (212Pb) > 0.00035 ± 0.00029 (230Th) > 0.00022 ± 0.00009 (232Th). It is obvious that 210Po, 228Ra, 210Pb and 226Ra are the most important dose contributors in the drinking water intake. As far as the seventeen brands of analysed drinking water were concerned, the committed effective doses were in the range of 2.81–38.5 μSv yr−1, all well below the reference level of the committed effective dose (100 μSv yr−1) recommended by the WHO. These data throw some light on the scale of the radiological impact on the public from some naturally occurring radionuclides in drinking water, and can also serve as a comparison for the dose contribution from artificial radionuclides released to the environment as a result of human practices. Based on the radionuclide composition in the analysed waters, comment was made on the new screening level for gross α activity in guidelines for drinking-water quality recommended by the WHO, 2004.  相似文献   

2.
Sand-dust storms are the result of the integrated influences of climate, geography, society and human factors. A theoretical framework is built to explain the coherence of population growth, agriculture change and environmental degradation. On the basis of the analysis of the causes of the sand-dust storm in terms of human factors, a discussion will be given to show that these factors are internally consistent with the theoretical framework. After that, it will look at China's Agenda 21 and try to find relevant measures to reduce such large sand-dust storms happening in Northwest China and eventually make this area develop sustainably.  相似文献   

3.
Climate skepticism in the UK media has not been a major focus of recent research. This paper aims to help fill the gap by looking at the incidence of skeptical voices in UK newspapers across three periods: 2007, 2009/2010, and 2010/2011. After analyzing more than 3200 articles, it finds that skeptical voices increased their presence markedly across all newspapers and all types of articles in the second period, and maintained a significant presence in many in the third. Uncontested skeptical voices were particularly prevalent in opinion pieces and editorials in right-leaning newspapers in the second. It also finds that skeptical voices or opinions were more likely to be included in pieces written by in-house non-specialist columnists than by environment editors or correspondents. The negative implications of the results for public understanding and the quality of public debate are then explored.  相似文献   

4.
The objective of this study was to provide operational probability density functions (PDFs) for distribution coefficients (Kds) in freshwater, representing the partition of radionuclides between the particulate and the dissolved phases respectively. Accordingly, the Kd variability should be considered in uncertainty analysis of transport and risk assessment models. The construction of PDFs for 8 elements (Ag, Am, Co, Cs, I, Mn, Pu and Sr) was established according to the procedure already tested in Durrieu et al. [2006. A weighted bootstrap method for the determination of probability density functions of freshwater distribution coefficients (Kds) of Co, Cs, Sr and I radioisotopes. Chemosphere 65 (8), 1308–1320]: (i) construction of a comprehensive database where Kds values obtained under various environments and parametric conditions were collected; (ii) scoring procedure to account for the ‘quality’ of each datapoint (according to several criteria such as the presentation of data (e.g. raw data vs mean with or without replicates), contact time, pH, solid-to-liquid ratio, expert judgement) in the construction of the PDF; (iii) weighted bootstrapping procedure to build the PDFs, in order to give more importance to the most relevant datapoints. Two types of PDFs were constructed: (i) non-conditional, usable when no knowledge about the site of concern is available; (ii) conditional PDFs corresponding to a limited range of parameters such as pH or contact time; conditional PDFs can thus be used when some parametric information is known on the site under study. For 7 other radionuclides (Ba, Be, Ce, Ra, Ru, Sb and Th), a simplified procedure was adopted because of the scarcity of data: only non-conditional PDFs were built, without incorporating a scoring procedure.  相似文献   

5.
This study examines domestic media’s coverage of foreign wildfires from a climate change perspective. It explores Swedish newspapers’ coverage of wildfires in Australia, the Mediterranean region, and the USA during a three-year period (February 2013–March 2016), focusing on how and to what extent climate change is viewed as an underlying cause. A central result is that climate change is mentioned far more often in the case of Australian wildfires than of fires in the other two regions. Another finding is that the climate change issue became more prominent after a severe domestic wildfire in 2014. These observations are also examined qualitatively through a combined frame and discourse study where the importance of foreign news values, the use of foreign sources, cultural proximity/distance, and domestication procedures are analysed. In conclusion, foreign, domestic, and cultural factors in climate change reporting in relation to extreme events are further discussed.  相似文献   

6.
Contaminant input into the environment can affect the biochemical responses of exposed organisms. Activity of conjugation enzymes, such as glutathione S-transferase (GST) has been proposed as a biomarker of susceptibility to the presence of potentially damaging xenobiotics. The aim of the present study was to evaluate the activity of total and Pi-class GST in the hepatopancreas of pink-shrimp Farfantepenaeus brasiliensis. The shrimp were caught at a single site at Concei??o Lagoon and transplanted to another site (Canto da Lagoa - CA) in the same lagoon, and to the laboratory (LAB), where they were kept for 15 days. This experiment was carried out in winter 2003 and in summer 2004. Shrimp were sampled before the exposure, at a zero time (t0), and after 15-days at CA site and LAB. The activity of total GST and Pi-isoform were analyzed using CDNB and ethacrynic acid (EA) as substrates, respectively. Shrimp caught in winter showed higher levels of Pi-class GST than those caught in summer, for both t0 and CA groups. Moreover, differences in the activity of this GST isoform between groups were observed only in winter, where the animals from t0 and CA groups presented higher activity when compared to those kept in the laboratory. This difference could be associated either to changes in the contaminant input or to other water quality parameters in this ecosystem. The elevated GST Pi activity observed in the shrimp of both t0 and CA groups sampled in winter could be related to salinity, since it was higher in winter than in summer. We could also suggest a possible association of this finding to a seasonal metabolic variation in this penaeid. If that is the case, one should take into account these alterations when considering the use of this GST isoform as biomarker in F. brasiliensis in environmental monitoring programs.  相似文献   

7.
This paper set forth the goals of implementing sustainable development strategy in Shandong Province guided by the view of scientific development of being people oriented, comprehensive, coordinated and sustainable. Based on the target of sustainable development strategy in Shandong province this paper discusses the main tasks in the sustainable development strategy Countermeasures for sustainable development strategy in Shandong province are put forward.  相似文献   

8.
The vertical distribution of the 236U/238U isotopic ratio was investigated in soil samples from three different locations on La Palma (one of the seven Canary Islands, Spain). Additionally the 240Pu/239Pu atomic ratio, as it is a well establish tool for the source identification, was determined. The radiochemical procedure consisted of a U separation step by extraction chromatography using UTEVA® Resin (Eichrom Technologies, Inc.). Afterwards Pu was separated from Th and Np by anion exchange using Dowex 1x2 (Dow Chemical Co.). Furthermore a new chemical procedure with tandem columns to separate Pu and U from the matrix was tested. For the determination of the uranium and plutonium isotopes by alpha spectrometry thin sources were prepared by microprecipitation techniques. Additionally these fractions separated from the soil samples were measured by Accelerator Mass Spectrometry (AMS) to get information on the isotopic ratios 236U/238U, 240Pu/239Pu and 236U/239Pu, respectively. The 236U concentrations [atoms/g] in each surface layer (∼2 cm) were surprisingly high compared to deeper layers where values around two orders of magnitude smaller were found. Since the isotopic ratio 240Pu/239Pu indicated a global fallout signature we assume the same origin as the probable source for 236U. Our measured 236U/239Pu value of around 0.2 is within the expected range for this contamination source.  相似文献   

9.
Undoubtedly, climate change is one of the greatest problems facing today’s world. Despite this, traditional research has ignored the market response to, and accountability for, climate change reporting in developing countries. Hence, this study critically examines climate change reporting practices in the most affected countries in the world, with specific reference to Bangladesh. In the study, 32 semi-structured interviews and 71 annual reports are evaluated. Using legitimacy theory, the study contributes to building an understanding of companies’ attitude toward stakeholder accountability regarding climate change. The study finds that Bangladeshi companies are reporting climate change information on an average of 2.23 %. More specifically, the study demonstrates that large companies are reporting on more climate change issues than others because of their legitimized positions in the market. Again, a lack of regulation and a culture of low social accountability among the companies contribute to a very low level of disclosure on climate change. Surprisingly, multinationals are not providing satisfactory disclosure. The study has policy implications in developing countries for both local policy makers (the government) and international policy makers (the Intergovernmental Panel on Climate Change, the European Union, the World Bank, the UN Environment Programme, the International Energy Agency and the World Economic Forum) as to how to engage local companies so that they become more socially accountable to climate change reporting.  相似文献   

10.
The aim of the study was to compare radon concentrations in neighbouring hospital buildings which were constructed in different years during the period 1963-2000 and are located in areas with similar radon potential. The value of arithmetic mean (AM) radon concentration in soil gas amounted to 14,464 Bq m(-3). In a hospital built 40 years ago, the AM radon concentration in the cellar was 38.4+/-36.7 Bq m(-3) and on higher levels it was 17.1+/-10.3 Bq m(-3). In a hospital built 16 years ago, these values equaled 45.5+/-47.2 Bq m(-3) and 20.4+/-12.5 Bq m(-3), respectively. In the newest hospital, built three years ago, radon concentration (AM) in a cellar was 32.3+/-27.4 Bq m(-3) and the respective value on higher levels amounted to 20.4+/-12.6 Bq m(-3). When comparing radon concentrations in the cellars, no statistically significant differences were found. Similarly, no statistically significant differences were observed between radon concentrations measured on higher levels in investigated hospital buildings.  相似文献   

11.
中国荒漠化灾害评估及其经济价值核算   总被引:24,自引:0,他引:24  
本文对我国荒漠化的现状和危害进行了系统分析。运用货币估值方法对最新公布的荒漠化和水土流失监测数据进行计算,得出我国荒漠化危害的直接经济损失约642亿元/年,平均每天损失1.76亿元;其中几种主要荒漠化类型造成的经济损失分别为:水力侵蚀400亿元,风力侵蚀36亿元,盐渍化及有机质丢失造成的损失约186亿元;据估算每年因沙尘暴造成的经济损失超过13亿元,荒漠化及其衍生危害造成的间接经济损失约2889亿元/年。  相似文献   

12.
Cropland ecosystem not only provides people with grains, vegetables, fibers, etc., but also plays an important role in air regulation, soil and water conservation, environmental decontamination, etc. Furthermore, cropland ecosystem has negative effects on our environment, such as soil and water pollution, because of the use of fertilizers and pesticides. So far, there are a few research findings about Chinese farmland's ecological functions, but only a part of ecological functions is discussed in this article. At present, an integrated research is needed in order to get a comprehensive understanding of cropland ecosystem. This article gives a primary result of ecological functions and their monetary values in Chinese cropland ecosystem. The results showed that the total monetary value of ecological functions provided by Chinese cropland ecosystem was 1912.18 billion yuan RMB in 2003 (present price in 2003); the positive value was 2233.41 billion yuan RMB and negative was −321.23 yuan billion RMB. The value per hectare was 18960.60 yuan RMB/hm2, of which the value of crop products was 14788.70 yan RMB/hm2 and others were 4171.90 yuan RMB/hm2. The ecological functions in the farmland vary with regions. The values ranged from 8.68 to 505.08 billion yuan RMB, and HHHR and MLRYR were higher than those of the other ecological zones. The values per hectare ranged from 515.90 to 3498.43 yuan RMB/hm2, and SC and MLRYR were higher.  相似文献   

13.
Thailand plays an important role in the international trade of food and agricultural products, which is in alignment with its national strategy of serving as the “kitchen of the world.” When looking at its agricultural promotion and export policies, the country only counts the value gains from exports while neglecting environmental externalities related to plantation practices. The purpose of this study was to perform a trade-off analysis between consumptive water, land, and fertilizer use together with the economic values of major crops for export and consumption in the country. The results show that to gain income from agricultural exports, the country has exploited various natural resources. The area used to harvest rice, sugarcane, cassava, and rubber adds up to approximately 15.3 million ha: 7.2 million ha of which is for domestic consumption and 8.1 ha for export. To produce Thailand’s agricultural exports, total water use is estimated to be 49.8–67.5 billion m3 per year (61–65 %), while the amount used to produce crops for domestic consumption is 26.5–43.7 billion m3 per year (35–39 %). Meanwhile, 1,056–1,826 thousand tons (54 %) of fertilizer was used on crops for domestic consumption, and 1,222–1,370 thousand tons (46 %) of fertilizer was used on export crops. The best crop choice for export in terms of its export value, land use, fertilizer use, and water consumption is rubber. The worst crop choices for export are rice and cassava. More sustainable agricultural practices are needed to effect improvements such as increased yields and reduced fertilizer and water use.  相似文献   

14.
基于CVM的荆州市稻田生态系统的景观休闲旅游价值评价   总被引:2,自引:0,他引:2  
采用条件价值评估法(Contingent Valuation Method,CVM)调查了荆州市居民对稻田生态系统景观休闲旅游功能的认知程度和支付意愿,对受访者的社会经济特征与支付意愿进行了相关性分析,并对荆州市稻田景观休闲旅游功能的价值进行了货币化评估。结果表明,居民对稻田景观休闲旅游功能的认知程度很低,对其十分了解的仅占3.5%,并且更侧重于旅游这一目的,达到61.1%。同时,78.7%的受访者认为稻田景观休闲旅游是赋有乡愁情感的。对影响受访者支付意愿的诸多因素进行相关性分析显示,稻田景观休闲旅游功能的支付意愿与受访者的文化程度(P=0.000)和月收入(P=0.004)呈极显著正相关。运用Logistic回归分析得出,文化程度对支付意愿的敏感性较大。按人均支付意愿计算,荆州市稻田生态系统景观休闲旅游的总价值约为4.43亿元  相似文献   

15.
将模糊综合评价和pead生长曲线法引入到流域水污染防治的效益分析当中,建立了流域水污染防治的生态效益分析方法。以云南省寻甸县牛栏江小流域水污染综合防治规划为例,采用模糊数学法对水污染造成的水资源价值损失进行了估算,采用曲线法对水污染综合防治的生态价值进行分析,得刭水资源价值和生态价值分别为2730.3万元/年和491.45万元/年。最后将所有经济效益和费用贴现,计算效费比为3.68。分析结果可知,牛栏江小流域水污染综合防治具有良好的环境效益、经济效益和社会效益。  相似文献   

16.
Over the last few decades, Mediterranean coastal areas have experienced profound land-use changes due mainly to urban sprawl and reforestation at the expense of former traditional agrarian mosaics and natural resources, such as beach areas or freshwaters streams. These changes have had severe negative consequences on the biodiversity and ecological state (i.e. function) of the territory. The overall objective of this study was to evaluate the economic impacts of these consequences on ecosystem services (ES). By reconstructing the landscape of El Maresme County (Barcelona Province, Spain) for three historical points in time (1850, 1954 and 2010), we were able to assess how these land-use changes have affected the total ecosystem value (TEV) by estimating the ES non-market and market values provided by each land-use through market prices and benefit transfer methods. Results show an important decrease in the value of TEV since the 1950s (23.6 million Euros per year) due to urban sprawl. Despite the major changes occurring between the 1850s and 1950s, non-market values did not alter very much due to the type of agricultural practices. Our results show the necessity to take into account the value of non-market ES when designing land planning policies, and especially those concerning beaches and coastal systems to fully integrate the contribution on natural systems into decision-making processes.  相似文献   

17.
This paper discusses the economic potential in terms of income changes that may result from conversion to low-external-input agriculture (LEIA) organic farming in a Kenya’s catchment area. A spreadsheet model applying the gross margin and net present value analysis was developed to estimate economic returns to labour and land of alternative smallholder cropping systems in the East Mau Catchment. The income and costs over a 10-year horizon associated with current cropping practices of a typical farm household cultivating 1.12 hectares of maize–bean intercrop, Irish potato, carrots, tomatoes, cabbages and kales mix were characterized based on field work conducted in 2008–2010. An “average” smallholder LEIA organic farm was simulated based on the conventional one, and its income discounted. A comparison was then made of the two farm types. Results indicate annual net present value returns to cropped land average Ksh 21,878/ha ($ 267/ha) and Kshs 22,561/ha (€ 275/ha) in 2010 values for conventional and prototype LEIA organic farming systems, respectively. Net returns are particularly sensitive to crop yields and price and cost of fertilizers and seeds. Further efforts should be made to provide an economic analysis of other LEIA organic farming practices such as composting, double digging and agroforestry in terms of additional labour costs resultant. The model can be extended to build more scenarios on the role of price premiums. Additionally, further research should be done to exploit the socio-demographic factors affecting the adoption of low-external-input systems.  相似文献   

18.
秦岭自然保护区群保护成本计量研究   总被引:5,自引:0,他引:5  
秦岭自然保护区群在我国生物多样性保护方面发挥了重要作用,学术界一直缺乏保护成本计量的研究。本研究在界定秦岭自然保护区群成本的概念及分析其内涵的基础上,综合运用专家咨询法及文献参考方法,建立了秦岭自然保护区群保护成本计量指标体系,利用市场价值法、等效替代法以及机会成本法等方法,对秦岭自然保护区群保护生物多样性的投入进行了成本计量及分析。结果表明:秦岭自然保护区群在保护生物多样性投入方面,总货币量约29.72亿元人民币,其中直接保护成本为2.59亿元;间接保护成本为2.00亿元;与周边区域密切相关的机会成本为25.13亿元。其中,机会成本的计量模型多样化,在学术界存在较多争议,但是,最终每种模型都能反映出机会成本的内涵的货币量,可以表达出我国政府为建立秦岭自然保护区群而付出的无形代价。  相似文献   

19.
洞庭湖区生态服务价值变化区域差异研究   总被引:5,自引:1,他引:4  
为了定量分析和比较区域生态服务功能及其价值变化,运用中国生态系统服务价值当量因子表和洞庭湖流域单位面积农田生态系统提供的食物生产服务的经济价值,以及分析20世纪70年代末、80年代末和90年代末的TM遥感影像所得到的土地利用情况,对洞庭湖区17个县市不同年代的生态服务价值及其20年间的变化进行了估算和比较。采用变异系数来测度区域之间的差异,并初步分析了各县市生态服务价值变化差异的原因。结果表明:洞庭湖区土地利用变化明显,生态服务价值总量达到了934亿元,但区域变异系数较大,各县市之间差异明显;湖区各县市20年生态服务价值变化差异较大,变异系数为108.27%。其中变化最大的是华容县,超过了2.0亿元,最小的是津市,仅为0.12亿元。  相似文献   

20.
风景区游憩价值的评估对景区经营管理及开发保护等工作具有重要意义。本文基于笔者对条件价值法的创新,通过问卷设计和抽样调查,对凤阳山保护区游憩价值进行评估,计算出其2010年的总游憩价值2 031万元人民币。此项研究丰富了我国的环境价值评估理论研究和应用实践。  相似文献   

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