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1.
Soil-to-plant transfer factors (TF) of radiocaesium (137Cs) were determined under field condition for grassy vegetation grown in Bangladesh at contaminated land in the Atomic Energy Research Establishment (AERE) campus. TF values for rice, grass and grassy/root vegetations grown in the same type of soil were also measured under pot condition. TF values of 137Cs for grassy vegetation (2.4 x 10(-2) -4.2 x 10(-2) with an average of 3.1 x 10(-2) +/-0.005) obtained under field condition were slightly lower than the values for grass and grassy/root vegetations (2.9 x 10(-2) -6.6 x 10(-2) with an average of 4.8 x 10(-2) +/-0.01 for grass and grassy vegetations and 2.3 x 10(-2) -5.6 x 10(-2) with an average of 4.0 x 10(-2) +/-0.009 for root vegetations, respectively) obtained under pot condition. However, TF values (9.0 x 10(-3) -2.6 x 10(-2) with an average of 1.9 x 10(-2) +/-0.004) obtained for rice were about a factor of 4 lower than the values obtained for grass and grassy/root vegetations. When the properties of the AERE soils as input parameters were used in the soil-plant transfer model of Absalom, the estimated TF values (4.5 x 10(-2) -6.7 x 10(-2) with an average of 5.3 x 10(-2) +/-0.006) were consistent with the measured values obtained for grass and grassy vegetations under pot condition, however, the model overestimates the TF values for rice.  相似文献   

2.
Rice has been demonstrated to be one of the major contributors to arsenic (As) in human diets in addition to drinking water, but little is known about rice products as an additional source of As exposure. Rice products were analyzed for total As and a subset of samples were measured for arsenic speciation using high performance liquid chromatography interfaced with inductively coupled plasma-mass spectrometry (HPLC-ICP-MS). A wide range of rice products had total and inorganic arsenic levels that typified those found in rice grain including, crisped rice, puffed rice, rice crackers, rice noodles and a range of Japanese rice condiments as well as rice products targeted at the macrobiotic, vegan, lactose intolerant and gluten intolerance food market. Most As in rice products are inorganic As (75.2-90.1%). This study provides a wider appreciation of how inorganic arsenic derived from rice products enters the human diet.  相似文献   

3.
A dynamic compartment model was investigated to describe 14C accumulation in rice plants exposed to atmospheric 14C with temporally changing concentrations. In the model, rice plants were regarded to consist of three compartments: the ear and the mobile and immobile carbon pools of the shoot. Photosynthetically fixed carbon moves into the ear and the mobile carbon pool, and these two compartments release a part of this carbon into the atmosphere by respiration. Carbon accumulated in the mobile carbon pool is redistributed to the ear, while carbon transferred into the immobile carbon pool from the mobile one is accumulated there until harvest. The model was examined by cultivation experiments using the stable isotope, 13C, in which the ratios of carbon photosynthetically fixed at nine times during plant growth to the total carbon at the time of harvest were determined. The model estimates of the ratios were in relatively good agreement with the experimental observations, which implies that the newly developed compartment model is applicable to estimate properly the radiation dose to the neighboring population due to an accidental release of 14C from nuclear facilities.  相似文献   

4.
This paper presents a review of available models for radionuclide transfer to fruit with particular emphasis on the model types and the purpose for which they were developed. It is clear that the model structures that have been developed range from the simple to the complex and that the underlying data on which they are based is incomplete. The work programme of the BIOMASS Theme 3 Fruits Working Group includes model inter-comparison and model validation studies that will give an indication of the performance of the different model types discussed here. The models included in these comparative studies include several new and as yet unpublished models. In the case of fruit, there is an urgent need for data on changing radionuclide distribution in plant organs with time to increase confidence in current models.  相似文献   

5.
作为一项市场创新和政策创新,即将启动的中国全国性碳市场备受国内外关注。为保证其成功建立与平稳发展,相关经验借鉴已刻不容缓,但作为投石问路的7大试点碳市场发展层次不齐,可供参考的模式有限,因此研究全球第一大碳市场——欧盟碳排放交易体系(EU ETS)及其对中国的可参照性尤为迫切;而作为市场是否成熟的风向标,碳价规律性特征的挖掘尤为重要。前期国内外学者分别发现CER价格、原油价格、煤炭价格、天然气价格、欧洲工业指数、联合国气候变化大会、政府政策、极寒天气、暖冬天气、自然灾害、重大事件等多种因素都有可能引起EUA期货价格波动。本研究通过引入MIV-BP神经网络模型,对EU ETS二期和三期的EUA期货价格进行训练和测试,模拟了上述11个因素对EUA价格的影响,弥补了传统计量模型难以同时处理较多变量及不能整合定性与定量变量等缺点。通过对EU ETS二期1 149组和三期775组数据的挖掘,得出了各变量对EUA期货价格的影响程度。其中,二期运行阶段各变量影响程度从大到小排序为:自然灾害COPCER极寒天气Coal重大事件Brent政府政策Stock600Gas暖冬天气;三期运行阶段各变量影响程度从大到小排序为:COPStock600Coal自然灾害极寒天气重大事件政府政策BrentGasCER暖冬天气。最后,本研究对二、三期各变量对碳价影响程度的变化进行了解释,并对中国未来建立全国性碳市场提出了以下四点建议:(1)稳定碳市场参与主体预期;(2)完善核证减排抵消机制,保持政策稳定;(3)配额分配考虑区域差异;(4)建立配额应急机制。  相似文献   

6.
Environment, Development and Sustainability - Sugarcane is an industrial crop globally used for producing biofuels and bioproducts and is the only source of white sugar in Bangladesh. However,...  相似文献   

7.
Rise in temperature and annual precipitation, changes in seasonal rainfall patterns, more frequent and severe extreme weather events, and increased salinity in river water have been observed in Bangladesh in the recent years. Rising temperature will elevate total power consumption and peak power demand especially during the pre-monsoon hot summer season, reduce power plant efficiency and transformer lifetime, and increase the transmission loss. More frequent and severe extreme weather events may cause more disruption in power generation and distribution, and more damage of power infrastructure. Lower river flow in dry season may cause water scarcity in power plants and hamper the production. Increased salinity in river water due to sea level rise may lead to corrosion and leakages in power plants located in the coastal region of Bangladesh. A diversified, decentralized, and climate resilient power system can reduce negative impacts of climate change on power sector of Bangladesh. Adaptation and mitigation strategies must be incorporated in the planning and development of new power systems and the reformation of existing power systems of Bangladesh.  相似文献   

8.
The factors governing chlorine transfer from Phaeozem and Greyzem soils to various important crop species (foodstuff and forage) were determined in natural conditions in the Kiev region of Ukraine. The stable chlorine concentration ratio (CR) values were the lowest in apple (0.5+/-0.3) and strawberry (2+/-1), higher in vegetables (5+/-3), seeds (15+/-7) and reached a maximum in straw (187+/-90). The average CR values of 36Cl were estimated for the most important crops using all experimental data on 36Cl and stable chlorine transfer into plants from various soils. It was experimentally shown that boiling potatoes in water leads to an equilibrium between 36Cl specific content in the water and moisture in the cooked potato. The 36Cl processing factor (PF) for boiling various foodstuffs is equal to the ratio of water mass in the cooked foodstuff to the total water mass (in the food and the decoction). 36Cl PF for cereal flour can be estimated as 1. The 36Cl processing factor for dairy products is equal to the ratio of residual water mass in the product to initial water mass in milk. At a 36Cl specific activity in soil of 1 Bq kg-1, the estimated annual dietary 36Cl intake into human organism (adult man) is about 10 kBq. Sixty to seventy percent of the above amount will be taken in via milk and dairy products, 7-16% via meat, 14-16% via bread and bakery items and 8-12% via vegetables. The highest annual 36Cl intake, 10.7 kBq, is predicted for 1-year-old children. The expected effective doses from annual 36Cl intake are higher for younger age groups, increasing from 0.008 mSv in adults to 0.12 mSv in 1-year-old children.  相似文献   

9.
ObjectivesEuropean legislation requires reporting from Member States on acute poisoning incidents involving pesticides. However, standard rules for data collection and reporting have not yet been set out. The new categorization system presented in this paper is aimed at enabling Member States to gather comparable data and provide standard reporting on pesticide poisoning exposures.Materials and methodsEuropean Regulations providing separate official categorization of biocidal and plant protection pesticides, were used as a basis to build up a unified pesticide categorization and coding system. Data on selected pesticide exposures collected by Poison Control Centres in six EU countries were reviewed, categorized and reported according to the proposed system.ResultsThe resulting pesticide categorization system has two dimensions. The first part identifies the main category of use, i.e. biocide/plant protection pesticide/unknown, and the secondary category of use, e.g. Rodenticides, Insecticides and acaricides. The second part of the system is organized into two levels: level one identifies chemical grouping, e.g. Coumarins, Pyrethrins/pyrethroids, while level two identifies the active compound by using its Chemical Abstract Service Registry Number. The system was used to provide a unified categorization to compare exposures to plant protection and biocidal Rodenticides and Pyrethrins/pyrethroids Insecticides and acaricides identified by six EU member states.ConclusionThe developed pesticide categorization system was successfully applied to data extracted from different databases and was able to make the required information comparable. The data reported filling in common templates containing a pre-ordinate list of active compounds categorized according the proposed system, highlighted different capabilities in data collection and recording, showing that some of the collaborating centres were not able to distinguish between main categories of pesticide products or provide information on active compounds. The results indicate that a special effort should be dedicated to support detailed data recording at national level. Providing common tools to systematically report to the EU Commission hazardous exposures to pesticides, as well as to other selected categories of products, could allow for data comparability between Member States and greatly improve post marketing surveillance and alerting systems in Europe.  相似文献   

10.
欧洲有关国家关于执行欧盟废旧电子电气指令的措施   总被引:2,自引:1,他引:1  
随着全球高科技工业的迅猛发展、人类消费水平的不断提高和消费结构的变化,电子废弃物快速增长,并造成日益严重的环境污染问题,因此引起了全球各国高度关注并制定了相关环境管理对策。2003年2月13日,欧盟公布了《废旧电子电气设备指令》(简称WEEE指令)和《限制某些有害物质在电子电气设备中使用指令》(简称ROHs指令)。欧盟各国实践表明,欧盟成员在欧盟指令公布之前已经制定了关于收集和适当处理电子电气废物的规定,这些规定基本上与欧盟新指令有着相同的内涵。因此,欧盟成员政府并不需要为了满足欧盟指令的新要求而对目前国内的电子电气处理体制做太大的修改,故可以预期欧盟各国执行欧盟关于废旧电子电气设备指令过程中将不会导致过多问题产生,并且执行成本相对较小。  相似文献   

11.
Arsenic (As), cited as the most hazardous substance by the U.S. Agency for Toxic Substance and Disease Registry (ATSDR, 2005), is an ubiquitous metalloid which when ingested for prolonged periods cause extensive health effects leading to ultimate untimely death. Plants and microbes can help mitigate soil and groundwater As problem since they have evolved elaborate detoxification machineries against this toxic metalloid as a result of their coexistence with this since the origin of life on earth. Utilization of the phytoremediation and bioremediation potential of the plants and microbes, respectively, is now regarded as two innovative tools that encompass biology, geology, biotechnology and allied sciences with cutting edge applications for sustainable mitigation of As epidemic. Discovery of As hyperaccumulating plants that uptake and concentrate large amounts of this toxic metalloid in their shoots or roots offered new hope to As phytoremediation, solar power based nature's own green remediation. This review focuses on how phytoremediation and bioremediation can be merged together to form an integrated phytobial remediation which could synergistically achieve the goal of large scale removal of As from soil, sediment and groundwater and overcome the drawbacks of the either processes alone. The review also points to the feasibility of the introduction of transgenic plants and microbes that bring new hope for more efficient treatment of As. The review identifies one critical research gap on the importance of remediation of As contaminated groundwater not only for drinking purpose but also for irrigation purpose and stresses that more research should be conducted on the use of constructed wetland, one of the most suitable areas of application of phytobial remediation. Finally the review has narrowed down on different phytoinvestigation and phytodisposal methods, which constitute the most essential and the most difficult part of pilot scale and field scale applications of phytoremediation programs.  相似文献   

12.
This paper compares predictions of the foodchain model SPADE with experimental data for the transfer of (134)Cs and (85)Sr to strawberry plants following acute foliar and soil contamination. The transfer pathways considered in this exercise included direct deposition to fruit, leaf-to-fruit, soil-to-leaf and soil-to-fruit transfers. Following foliar contamination, the difference between predicted and measured radionuclide activity values varied between a factor of 0.5-10 for fruit and 4.5-7 for leaf. Following soil contamination, the difference between predicted and measured values varied between a factor of 3-74 for fruit and 32-44 for leaf. In all cases the difference between measured and predicted values was smaller for (85)Sr than (134)Cs. Measured and predicted activities were higher for leaf than fruit. Both measured and predicted (134)Cs concentrations in fruit and leaf are higher when deposition occurs at ripening than at anthesis. These results confirm the need for more data on fruit, even for Cs and Sr, to support models in predicting the transfer of radionuclides to fruit crops. Ongoing research projects funded by the UK Food Standards Agency aim to provide some data on radionuclide transfer to herbaceous, shrub and tree fruits, which will help improve radiological assessment models in order to provide better protection for consumers.  相似文献   

13.
Environment, Development and Sustainability - In order to solve regional ecological inequity in carbon emissions, building a balanced ecological compensation mechanism is paramountly important....  相似文献   

14.
15.
The objective of this paper was to develop a mechanistic-based framework to explicitly incorporate the factors controlling the bioavailability, toxicodynamics and mode of action to enhance predictive ability of arsenic (As) toxicity to protect the health of farmed tilapia Oreochromis mossambicus. We linked the biotic ligand model and damage assessment model to develop a toxicokinetic model for elucidating the site-specific temporal changes of As bioavailability and to characterize how the fish regulate the metal toxicity. We built a bioavailability-mode of action-based growth toxicity model by linking a bioenergetic growth model and damage assessment model to predict how the As affects on the tilapia growth in the entire life span in site-specific field ecosystems. Here we show that the proposed model well describes the water-chemistry-dependent toxicokinetics and toxicodynamics variations of As to tilapia. We selected two local tilapia farms with different water chemistries located at southwestern Taiwan coast region to implement the proposed algorithm to predict the risk of As exposure. Results indicate that the growth toxicity of O. mossambicus in Taihsi is more sensitive than that in Peimen. We found that the effect of ion competition on the As bioavailability and their ecotoxicological effects on tilapia are more obvious in Taihsi comparing with that in Peimen. We suggested that the proposed bioavailability- and mode of action-based framework can be used to capture the biological response and regulation of tilapia to As exposures. It is applicable for a site-specific and long-term ecotoxicological risk assessment.  相似文献   

16.
Past arsenic exposure was found associated with increased incidence of type 2 diabetes. However, the mechanisms remain unclear. Metabolic syndrome has been shown as a strong predictor for diabetes occurrence. We aimed at examining the association of inorganic arsenic exposure and the prevalence of metabolic syndrome. The authors recruited 660 age and gender stratified random population of residents in central Taiwan during 2002-2003. They received home interviews and health examinations at local health care units, where blood and hair specimens were collected. Hair arsenic (H-As) concentrations were determined by inductively coupled plasma-mass spectrometry. Metabolic syndrome was defined as the presence of three or more of the following risk factors: elevated levels of blood pressure, plasma glucose, and triglycerides, also the body mass index, and reduced high-density lipoprotein. Prevalence of metabolic syndrome increased from the 2nd tertile (0.034 ug/g) of H-As levels (odds ratio=2.54, 95% confidence interval: 1.20-5.39, p=0.015) after the adjustment for age, gender, occupation and life styles including cigarette smoking. We further found linear relation between H-As concentrations and increased levels of plasma glucose and lipids, and blood pressures. This first report may help identify modifiable factors associated with diabetogenesis and cardiovascular disease progression and thus be worth following for community health.  相似文献   

17.
The characteristics of arsenic-contaminated groundwater and the potential risks from the groundwater were investigated. Arsenic contamination in groundwater was found in four villages (Vinh Tru, Bo De, Hoa Hau, Nhan Dao) in Ha Nam province in northern Vietnam. Since the groundwater had been used as one of the main drinking water sources in these regions, groundwater and hair samples were collected in the villages. The concentrations of arsenic in the three villages (Vinh Tru, Bo De, Hoa Hau) significantly exceeded the Vietnamese drinking water standard for arsenic (10 microg/L) with average concentrations of 348, 211, and 325 microg/L, respectively. According to the results of the arsenic speciation testing, the predominant arsenic species in the groundwater existed as arsenite [As(III)]. Elevated concentrations of iron, manganese, and ammonium were also found in the groundwater. Although more than 90% of the arsenic was removed by sand filtration systems used in this region, arsenic concentrations of most treated groundwater were still higher than the drinking water standard. A significant positive correlation was found between the arsenic concentrations in the treated groundwater and in female human hair. The risk assessment for arsenic through drinking water pathways shows both potential chronic and carcinogenic risks to the local community. More than 40% of the people consuming treated groundwater are at chronic risk for arsenic exposure.  相似文献   

18.
Toasting friends and family with realgar wines and painting children's foreheads and limbs with the leftover realgar/alcohol slurries is an important customary ritual during the Dragon Boat Festival (DBF); a Chinese national holiday and ancient feast day celebrated throughout Asia. Realgar is an arsenic sulfide mineral, and source of highly toxic inorganic arsenic. Despite the long history of realgar use during the DBF, associated risk to human health by arsenic ingestion or percutaneous adsorption is unknown. To address this urine samples were collected from a cohort of volunteers who were partaking in the DBF festivities. The total concentration of arsenic in the wine consumed was 70 mg L?1 with all the arsenic found to be inorganic. Total arsenic concentrations in adult urine reached a maximum of ca. 550 μg L?1 (mean 220.2 μg L?1) after 16 h post-ingestion of realgar wine, while face painting caused arsenic levels in children's urine to soar to 100 μg L?1 (mean 85.3 μg L?1) 40 h after the initial paint application. The average concentration of inorganic arsenic in the urine of realgar wine drinkers on average doubled 16 h after drinking, although this was not permanent and levels subsided after 28 h. As would be expected in young children, the proportions of organic arsenic in the urine remained high throughout the 88-h monitoring period. However, even when arsenic concentrations in the urine peaked at 40 h after paint application, concentrations in the urine only declined slightly thereafter, suggesting pronounced longer term dermal accumulation and penetration of arsenic. Drinking wines blended with realgar or using realgar based paints on children does result in the significant absorption of arsenic and therefore presents a potentially serious and currently unquantified health risk.  相似文献   

19.
Although fruit is an important component of the diet, the extent to which it contributes to radiological exposure remains unclear, partially as a consequence of uncertainties in models and data used to assess transfer of radionuclides in the food chain. A Fruits Working Group operated as part of the IAEA BIOMASS (BIOsphere Modelling and ASSessment) programme from 1997 to 2000, with the aim of improving the robustness of the models that are used for radiological assessment. The Group completed a number of modelling and experimental activities including: (i) a review of experimental, field and modelling information on the transfer of radionuclides to fruit; (ii) discussion of recently completed or ongoing experimental studies; (iii) development of a database on the transfer of radionuclides to fruit; (iv) development of a conceptual model for fruit and (v) two model intercomparison studies and a model validation study. The Group achieved significant advances in understanding the processes involved in transfer of radionuclides to fruit. The work demonstrated that further experimental and modelling studies are required to ensure that the current generation of models can be applied to a wide range of scenarios.  相似文献   

20.
This paper aims to identify how targeted asset transfers help to build adaptive capacity and adaptive actions of the urban extreme poor to climate change phenomena. This paper explores the theoretical debates of community-based adaptation approach and failure of such approach to address urban extreme poor. The empirical evidence of these theoretical debates will be drawn from two informal settlements of Dhaka city, where a targeted asset transfer project has been implementing since 2009. This paper explains that urban extreme poor usually work as unskilled labour and lack different livelihood capitals; and climate change is an increasingly important influence exacerbating an already vulnerable livelihood context. There is growing recognition in the literature that poor urban people and communities are adapting to climate change in physical and behavioural terms. But, in the case of urban extreme poor these adaptation approaches are delivering short-term survival strategies disregarding the notion of wellbeing in the medium to long-term perspectives. It is also evident that community level initiatives structurally reproduce the exclusion of the urban extreme poor. However, poverty literatures acknowledge that poverty-centred approaches could help to reduce vulnerability. As urban extreme poor are significantly more resource constrained, it is reasonable to assert that targeted asset transfers could be a poverty-centred adaptation approach in a changing climate. Targeted asset transfers approaches are the outcomes of recent social protection revolution that especially consider accumulation of physical, financial, human, and social capital in order to build adaptive capacity of the urban extreme poor. This adaptive capacity of the extreme poor may facilitate adjustments in assets, livelihoods, behaviours, and technologies in order to reduce future climate vulnerability. In this context, this paper seeks to answer whether targeted asset transfer approaches can be considered as effective poverty-centred adaptation approaches for the urban extreme poor or not.  相似文献   

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