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101.
222Rn, 226Ra, 228Ra and U were determined in a total of 552 groundwater samples collected throughout Fujian Province of China. The geometric mean concentrations of 222Rn, 226Ra, 228Ra and total U in the groundwater were 147.8 kBq m-3, 12.7 Bq m-3, 30.2 Bq m-3 and 0.54 microgram kg-1, respectively. High groundwater 222Rn was explained by the predominantly granitic rock aquifers in Fujian. A lifetime risk of 1.7 x 10(-3) was estimated for the ingestion of groundwater 222Rn. High ratios of 228Ra to 226Ra contents (geometric mean of 2.4) and their disproportion suggest that 228Ra should also be measured in the assessment of population doses from drinking water in the regions of high rock or soil 232Th. No significant correlation between the 222Rn concentrations in groundwater and air was found. 相似文献
102.
Bossew P Ditto M Falkner T Henrich E Kienzl K Rappelsberger U 《Journal of environmental radioactivity》2001,55(2):187-194
Austria ranks among the countries that have been most strongly affected by the Chernobyl fallout. The mean contamination with 137Cs is 21.0 kBq/m2, of which 18.7 kBq/m2 is due to the Chernobyl accident, whereas global fallout contributes 2.3 kBq/m2. Maximum values of total 137Cs contamination are nearly 200 kBq/m2. Total deposition of Chernobyl 137Cs on Austrian territory is 1.6 PBq or a fraction of around 2% of the 137Cs released from the reactor. 2115 measurements were used to draw the Austrian "caesium map". The geographical pattern of fallout distribution shows regional differences of contamination as high as 1:100. 相似文献
103.
T A Przylibski 《Journal of environmental radioactivity》2001,57(2):87-103
This paper describes the occurrence of radon and its daughter products in the accessible workings, partially open to the public, in the former arsenic and gold mine in Zloty Stok. The geology of the area and the characteristics of the workings provide the background for explanation of the genesis of radon and its daughter products and of the spatial and temporal variations in their concentrations. The results demonstrate that well-ventilated areas along the tourist route have the lowest values of all the measured parameters and that temporal variations of these parameters are irregular. The highest concentration values for radon (up to 18.50kBq/m3) and its daughter products (up to 14.49kBq/m3) have been recorded in the workings with obstructed natural ventilation. These are the areas where seasonal oscillations in the concentrations of these isotopes have been registered, with the maxima in summer and the minima in winter. These sections of the workings are inaccessible to the casual visitor. Radon is supplied to the workings from the side walls and its concentration is influenced, most of all, by ventilation and the degree of rock fissuring. The reason is the uniform and not very high content of 226Ra in the rocks where the galleries were excavated. Only locally, in the workings of the Gertruda adit lying outside the tourist route, do open fault zones have significant influence on enhanced concentrations of radon and its daughter products. These fault zones constitute effective routes of radon migration to the workings. In spite of this, it must be stated that neither guides nor tourists are exposed to excessive concentrations of radon or its daughter products in the tourist route area. However, the extension of the route to other workings will require the introduction of forced ventilation in order to lower theconcentration of radon and its daughter products. reserved. 相似文献
104.
The Lagoon Olho d'Água in Pernambuco State, Northeast Brazil has received increasing environmental concern due to significant stress from pollution in the catchment. The existing environmental problems are the result of great pressure from a broad range of human activities, especially in the last 10 years. Serious pollution exists mainly from some industrial and urban activities, which increased intensively after the eighties. There is a strong social and economical pressure for housing and construction near the lagoon, due to the available land nearby beaches and estuarine zone, and recently by growing tourism activities. Uncontrolled land use by low-income communities and the pressure for construction by developers have led to landfilling and to deterioration of water quality in the lagoon catchment. Improvement of the environmental conditions in the catchment needs integrated measures. Guidelines and some specific actions involving several institutions have been established and refer to sanitation and urban infrastructure as the main priorities. A main target is the construction of low-cost sewage system with smaller and decentralised treatment plants. 相似文献
105.
Management of an Agroecosystem 总被引:4,自引:0,他引:4
Agroecosystems (AESs) are autotrophic ecosystems managed by man. The goal of the management is to obtain the maximum possible amount of high-quality agricultural products while preserving agricultural resources, primarily the soils and biodiversity. The main components of the management of AES structures and functions, including primary and secondary biological production, the ratio between the energy flows in the plant–man and plant–livestock–man food chains, the efficiency of energy transfer in the plant–livestock link, and conservation of agricultural resources, are considered. 相似文献
106.
107.
Thi Binh Minh Nguyen A.T.M. Nurul Amin 《Environment, Development and Sustainability》2002,4(3):279-297
In recent years flows of foreign direct investment (FDI) to developing countries have rapidly been increasing. It is now an important contributor to the national economy and urban growth in scores of developing countries. Rapid urbanization in these countries is leading to many problems in the cities. Existing urban infrastructure and municipal services have been unable to cope with the increased demand arising from growing population and rapid economic growth. Consequently, the environment in these cities has deteriorated alarmingly. This paper assesses the role of FDI in urban environmental management (UEM) by analyzing the linkages between them for Hanoi City in Vietnam. The paper's analysis and findings are presented under three main themes: one, FDI, employment and income; two, FDI and environmental degradation; and three, potential of utilizing FDI for the provision of urban environmental infrastructure and services (UEI&S) in order to improve the urban environment. Both primary and secondary source data have been used. Policy implications of the research findings are drawn from the perspective of sustainable development. 相似文献
108.
The mobility of radiostrontium within the Arctic environment and surrounding area has been studied by analysing the mobility of 90Sr in river catchments that are within Finland. The environmental mobility of 90Sr deposited by both nuclear weapons testing and the Chernobyl accident has been investigated in five Finnish river catchments. Different models assessing the time-dependent mobility of 90Sr have been evaluated. No significant differences were found between the mobility of 90Sr from nuclear weapons tests and from the Chernobyl accident. Model parameters obtained by fitting to the measurements of the deposition and runoff rates of the nuclear weapons test fallout gave predictions which were consistent with the mid- and long-term contamination by the Chernobyl fallout. A comparison of 90Sr with 137Cs showed that they had similar mobility on deposition but, as time passed, the relative mobility of 90Sr increased with respect to 137Cs over a period of 5-8 years. Once the relative migration of 90Sr with respect to 137Cs reached equilibrium, its runoff rate was, on average, approximately an order of magnitude greater than 137Cs. 相似文献
109.
Kirchner TB Webb JL Webb SB Arimoto R Schoep DA Stewart BD 《Journal of environmental radioactivity》2002,60(3):275-291
Concentrations of radionuclides were measured in soils from a grid of locations surrounding the US Department of Energy Waste Isolation Pilot Plant (WIPP) in southeastern New Mexico and from a grid on a reference site approximately 20 km southeast of the WIPP site. Each of the two grids has 16 sampling locations (grid nodes) systematically distributed within an area of 16.580 ha. Sampling was conducted prior to the arrival of the first waste shipment at WIPP. Thus, the 137Cs and 23,240Pu in the soil are expected to have been deposited as global fallout, although the Gnome Site, 8.8 km southwest of the WIPP, is also a potential source of 239,240Pu and fission products. The reference grid has significantly higher concentrations of fallout and natural radionuclides than the WIPP grid. Up to 80% of the total variability in radionuclide concentrations across the two grids is attributable to differences between grid nodes. Differences between replicates within a location account for 44-50% of the variability in concentrations of the uranium isotopes, but only 11-17% of the variability in the concentrations of the other radionuclides. Samples having similar abundance of radionuclides were spatially aggregated across the terrain. The activity concentrations of the radionuclides were strongly correlated with the concentrations of Al and Pb, and with the percentages of sand, silt and clay in the soil. Normalizing radionuclide concentrations to the concentration of Al or percent fine particles can help adjust for differences in soil textures among samples and facilitate the detection of gradients or temporal changes in soil concentrations. 相似文献
110.
Salonen RO Pennanen AS Vahteristo M Korkeila P Alm S Randell JT 《Environment international》2008,34(1):51-57
Poor indoor air quality and epidemic carbon monoxide (CO) and nitrogen dioxide (NO(2)) poisonings due to exhaust emissions from ice resurfacers have been continuously reported from enclosed ice arenas for over 30 years. The health risks in users of Finnish ice arenas were analysed in three ways: (1) evaluation of four cases of epidemic CO poisonings, (2) modelling the association between NO(2) exposure and respiratory symptoms among junior ice hockey players, and (3) estimation of the number of arena users at risk of breathing poor quality air due to non-compliance of ice arenas with recommended abatement measures. The common causes for the CO poisonings involving over 300 subjects were large emissions from propane-fuelled ice resurfacer, small arena volume, negligible ventilation, and very recent opening of the arena. Rhinitis (prevalence 18.3%) and cough (13.7%) during or after training or game were significantly associated with the estimated personal NO(2) exposure of young hockey players (n=793) to average concentrations ranging from 21 to 1176 microg/m(3) in their home arena. During a 6-year follow-up of an intensive information campaign the portion of electric resurfacers increased from 9% to 27%, and that of emission control technology on propane-fuelled resurfacers increased from 13% to 84%. The portion of inadequately ventilated arenas decreased from 34% to 25%. However, 48% of the investigated Finnish ice arenas (n=125) did not fully comply with the non-regulatory recommendations. Consequently, 20000 daily users of ice arenas were estimated to remain in 2001 at risk of breathing poor quality air. Modern small and inadequately ventilated ice arenas pose their users (mostly children and young adults) at risk of breathing poor quality air and suffering from acute adverse health effects. Governmental regulations are needed worldwide to ensure safe sports in enclosed ice arenas. 相似文献