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1.
Two hundred and fifty-seven urine samples collected from school children living in the Manzini region, Swaziland, were analysed for lead (Pb), using a graphite furnace atomic absorption spectrometer. The mean urine lead concentration for the urban schools ranged from 0.038–0.040 gml–1, while that for the rural schools ranged from 0.017–0.022 gml–1. The observed range shown by the urban schools was above the normal (for healthy humans) urine lead concentration of 0.035 gml–1. However, the mean urine lead concentration for the rural schools was found to be lower than this value. The mean urine lead concentration for the urban schools was significantly higher than that of the rural schools. The differences in the mean urine lead concentrations for boys and girls from both urban and rural schools were found not to be significant, despite the higher values shown by the girls. The difference in lead concentrations between urban and rural schools in Manzini was thought to be due to the traffic density within the urban area.  相似文献   

2.
The evolution of sustainability   总被引:1,自引:0,他引:1  
Six separate but related strains of thought have emerged prominently since 1950 in discussions of such phenomena as the interrelationships among rates of population growth, resource use, and pressure on the environment. They are the ecological/carrying capacity root, the resources/environment root, the biosphere root, the critique of technology root, the no growth/slow growth root, and the ecodevelopment root.Each of these strains of thought was fully developed before the word sustainable itself was used. Many of the roots are based on fundamentally opposing assessments of the future of mankind. Many of the roots, such as the ecology/carrying capacity root, are based on physical concepts, and they exclude normative values. Others, such as the ecodevelopment root, include such values as equity, broad participation in governance, and decentralized government.When the word sustainability was first used in 1972 in the context of man's future, in a British book,Blueprint for Survival, normative concepts were prominent. This continued to be the case when the word was first used in 1974 in the United States to justify a no growth economy.Sustainability was first used in a United Nations document in 1978. Normative concepts, encapsulated in the term ecodevelopment, were prominent in the United Nations publications.After about 1978, the term sustainability began to be used not only in technological articles and reports but also in policy documents culminating in the use of the term in the report of the summit meeting of the Group of Seven in 1989.The roots of the term sustainability are so deeply embedded in fundamentally different concepts, each of which has valid claims to validity, that a search for a single definition seems futile. The existence of multiple meaning is tolerable if each analyst describes clearly what he means by sustainability.  相似文献   

3.
US civil defense planning for nuclear attack since 1974 has emphasized the doctrine of crisis relocation. Under this doctrine, some 150 million people would evacuate from urban areas and other probable targets to rural host communities. The population of the latter would stay put to assist the relocatees. Local communities would be responsible for the welfare of up to ten times their normal population for an indefinite period of time.This study examined certain implications of crisis relocation for the town of Greenfield, Massachusetts, USA, a typical host community. Various assumptions were articulated regarding the timing of events, the season of year, weather, and social behavior. Assumptions were favorable to the success of crisis relocation. Nevertheless, Greenfield would face impossible burdens in attempting to provide fallout protection, water, food, medical care, and civil order. Additional pressures would arise from adjoining communities which are functionally dependent upon Greenfield for normal goods and services, but which would receive their own allotment of relocatees. Crisis relocation is not taken seriously in Greenfield and virtually no preparations have been made to implement it.  相似文献   

4.
Southeastern Utah is a region of world-renowned red-rock sandstone formations, large tracts of federal public land, rural communities centered on agriculture and extractive industries, and is often at the epicenter of environmental protection efforts in the western United States. Environmental groups have proposed formal Wilderness designations for much of the regions public land—proposals that have been actively fought by rural community leaders who do not want large areas locked-up from traditional livelihood and recreational uses. The debate over wilderness designation in the region has been characterized in the media as one that is particularly contentious and polarizing. A survey of southeastern Utah residents was conducted in order to better understand this conflict. The survey focused on attitudes toward wilderness designation and management. We found that residents of southeastern Utah have negative attitudes towards the designation and management of Wilderness Study Areas. We propose that these attitudes should be carefully considered and engaged in future policy and management decisions. We suggest that negative opinions expressed by residents of southeastern Utah are not directed primarily at the concept of environmental protection but rather at the strong perception that these programs and initiatives have been carried out in a heavy-handed manner and dominated by outside influences that have overwhelmed local voices.  相似文献   

5.
Naturalness In Biological Conservation   总被引:1,自引:0,他引:1  
Conservation scientists are arguing whether naturalness provides a reasonable imperative for conservation. To clarify this debate and the interpretation of the term natural, I analyze three management strategies – ecosystem preservation, ecosystem restoration, and ecosystem engineering – with respect to the naturalness of their outcomes. This analysis consists in two parts. First, the ambiguous term natural is defined in a variety of ways, including (1) naturalness as that which is part of nature, (2) naturalness as a contrast to artifactuality, (3) naturalness as an historical independence from human actions, and (4) naturalness as possession of certain properties. After that, I analyze the different conceptions with respect to their implications for the three management strategies. The main conclusion is that there exists no single conception of naturalness that could distinguish between the outcomes of the three management methods. Therefore, as long as the outcomes of the different methods are regarded as being of a different value in conservation, we should either abandon the idea of naturalness as the guiding concept in conservation or use the term natural only in the ways that take both its historical and feature dependent meanings into consideration.  相似文献   

6.
Conclusion As a final thought, I want to conclude with the cliche that a problem recognized is half solved. Certainly, I cannot be accused of laying out a solution to solving the major fisheries management problems, but it is hoped that the problems managers face are now clearer. The complexity of fisheries assystems to be managed is clear to even the most casual observer. The second point, a broad theory of fisheries management, should provide a framework to categorize all of the disjointed activities that we associate with management of our fisheries resources.  相似文献   

7.
This study compares community-based managed forests under different purposes of management, namely, state-driven conservation or community-designed utilization in two villages located in the Sopsai watershed, Nan Province, northern Thailand. The forest health under different intensity of uses is assessed in association with the collective behaviors and long-term purposes embedded in village social–cultural context. The study found no significant differences in forest succession and proportion in diameter at 1.3 m (dbh) class and height-class distribution of the forest under different use intensity. The forest for utilization also showed higher density and basal area of the local preferred species than the conservation forest. In the utilization forest, we also found a higher number of multipurpose and preferred species than in the conservation forest, which actually responded to the needs of the community in the long term to have more wood products (both firewood and timbers). The community-based forest management (CBFM) for utilization can also lead to natural regeneration and biodiversity similar to conservation forests. Through CBFM, forest resources can be managed to maintain the healthy condition under different intensities and respond to both community needs and external expectation. The findings also emphasize the importance of recognizing community needs and management objectives in watershed restoration and improving the productivity of forests under collective management.  相似文献   

8.
Scholarly critics such as Wendell Berry, as well as the popular media, frequently refer to problems associated with agriculture as the agricultural crisis or the farm crisis. Despite the identification of a problem or problems as symptomatic of this crisis, scant attention is paid to why the situation is a social crisis as opposed to a problem, tragedy, trend, or simple change in the structure of agriculture. This paper analyzes the use of social crisis as applied to the state of modern agriculture and, by extension, other crises such as those in legitimation and morality. It concludes that, although important social values associated with farming as a way of life may be in danger of being lost, the crisis we may be facing with respect to agriculture is more properly understood as a sociopolitical crisis that has broader implications than simply the loss of farms or traditional farming values. Indeed, what is in danger of being lost is our ability to affect a secure and sustainable political-economic system.  相似文献   

9.
Floodplain forests are flood-dependent ecosystems. They rely on well-timed, periodic floods for the provision of regeneration sites and on tapered flood recession curves for the successful establishment of seedlings. These overbank flood events are described as regeneration flows. Once floodplain forest trees are established, in order to grow they also require adequate, although variable, river stage levels or maintenance flows throughout the year. Regeneration flows are often synonymous with flood flows and only occur periodically. There is a disparity between this need for varied interannual flows over the decadal time frame and the usual annual cycle of flow management currently used by most river management agencies. Maintenance flows are often closer to established minimum flows and much easier to provide by current operational practices.A number of environmental flow methodologies, developed in North America, Australia, and South Africa are described in this review. They include the needs of the floodplain environment in the management and allocation of river flows. In North America, these methodologies have been put into practice in a number of river basins specifically to restore floodplain forest ecosystems. In Australia and South Africa, a series of related holistic approaches have been developed that include the needs of floodplain ecosystems as well as in-channel ecosystems. In most European countries, restoration of floodplain forests takes place at a few localized restoration sites, more often as part of a flood-defense scheme and usually not coordinated with flow allocation decisions throughout the river basin. The potential to apply existing environmental flow methodologies to the management of European floodplain forests is discussed.  相似文献   

10.
Applications of Artificial Intelligence, particularly Expert Systems, are rapidly increasing. This science promises to give computer-based systems the capability of reasoning and decision making in near human-like fashion. Whether used for farm management or intelligent machine control, Expert Systems will find many agricultural applications. Much of the development and distribution of such systems will probably take place in the public sector, particularly the Cooperative Extension Service. A major nontechnical factor affecting the development and extensive use of Expert Systems is the legal issue of products, liability, and negligence. The legal issues surrounding Expert Systems have not yet been fully tested and defined by the courts. Developers and users of Expert Systems must consider these factors for each particular application.  相似文献   

11.
Summary Effective communication concerning environmental issues can take a variety of forms. The following essay is offered as a metalogue, a piece of writing in which the writing itself illustrates the principles developed in the writing.International readers will be helped if they know that Jack Armstrong and Sergeant Preston are heroes of moralizing (and often jingoistic) radio dramas popular among children in the United States during the War years and that the Tom Mix Holster Set and the A-bomb Ring were premiums offered to children in boxes of cold cereal in the period after the War. These trivia illustrate the kinds of societal messages directed toward the generation of Americans who presumably will be running the country during the 1980s.The authors are a professor of Psychology and Ethology and a graduate student in International Development. Both attended Harvard University in the late 1950s and the University of California, Berkeley, in the early 1960s. Their autobiographical reflections have something to say about the motivation underlying the environmental movement and where these motivations are likely to lead in the near future.  相似文献   

12.
The spatial pattern of ecosystem function can affect ecosystem conservation. Ecosystem functions are often heterogeneous spatially due to physical and biological factors. We can influence ecosystem functions by changing the spatial patterns of the physical and biological elements of an ecosystem and regulating their combinations. The variation–position effect highlights a phenomenon resulting from the spatial pattern of ecosystem function. The effect shows that the identical variation of a factor may produce different effects on the overall situation when this variation occurs in a different spatial position. In a watershed of the Yangtze River, water retention is a primary ecosystem function. The variation–position effect for water retention capacity occurs in the watershed because of the spatial heterogeneity in vegetation, soil, and slope. The change of vegetation that occurs in a complex can affect the overall situation of water retention, and the effect can be different due to the change occurring in the position holding different vegetation-soil-slope complex. To improve the ecosystem in the watershed and to meet the social needs for the ecosystem function of water retention, a strategy called ecosystem function and spatial pattern-based forest extension was proposed to conserve forests. The implementation of the strategy enables the watershed to attain the maximum effective increase in water retention capacity.  相似文献   

13.
Soil loss and surface runoff patterns over a four-year period (1997–2000) were studied in erosion plots from three hillslopes under different vegetative covers (Rosmarinus officinalis, Triticum aestivum and natural-spontaneous vegetation) in Lanjaron (Alpujarras) on the south flank of the Sierra Nevada of southeast Spain. The erosion plots were located on the hillslopes at 35.5% incline, at 1,480 m in altitude and with 41.8 m2 (21 m×1.9 m) in area. The vegetative covers were tested for effectiveness in controlling the surface runoff and soil loss production. The highest runoff and erosion values, ranging from 114.1 to 1.7 mmyr–1 and from 14,564.3 to 6.6 kgha–1yr–1, respectively, over the entire study period, were measured under the Triticum aestivum. In the Rosmarinus officinalis, runoff ranged from 7.9 to 1.3 mmyr–1 and erosion from 156.4 to 2.3 kgha–1yr–1, while on the hillslope under natural-spontaneous vegetation, runoff ranged from 4.4 to 0.9 mmyr–1 and erosion from 322.3 to 2.2 kgha–1yr–1. According to the results the vegetative covers of Rosmarinus officinalis and natural-spontaneous vegetation reduced the soil losses by 99 and 98%, with respect to the Triticum aestivum, and the runoff losses by 94 and 96%, respectively. Also, the Rosmarinus officinalis and natural-spontaneous plants influenced infiltration by intercepting much of the rainfall water respect to the Triticum aestivum. Monitoring allowed more direct linkages to be made between management practices and their impacts on runoff and soil erosion, thereby enabling to identify problems and take appropriate preventive measures to improve the management practices.  相似文献   

14.
Professor Kathryn George's Use and Abuse Revisited does not contain an accurate assessment of my On Vegetarianism, Morality, and Science: A Counter Reply. I show that she has misrepresented my moral and empirical argumentation.  相似文献   

15.
Kathryn Paxton George has recently argued that vegetarianism cannot be a moral obligation for most human beings, even if Tom Regan is correct in arguing that humans and certain nonhuman animals are equally inherently valuable. She holds that Regan's liberty principle permits humans to kill and eat innocent others who have a right to life, provided that doing so prevents humans from being made worse off. George maintains that obstaining from meat and dairy products would in fact make most humans worse off. I argue that Regan's liberty principle either contradicts his equal rights view or does not permit the slaughter of another for food. I show that a different view recognizing the moral rights of nonhumans but according them less value than normal adult humans, the unequal rights view, would permit such action if human survival or health depended upon it. However, it would also permit the slaughter of innocent humans in the same circumstances. Finally, I argue that current nutritional research does not support George's contention that most humans would suffer if they ceased eating other animals and their products.  相似文献   

16.
A three-tiered structure of land-use and environmental management is here proposed for Australia. The structure is based on the idea that environment means the environment of people, and that environmental problems arise when a change in the interaction between people and their environment leads to conflicts about the use of land and resources. The heterogeneity of society means that a range of human aspirations and value systems must be satisfied by environmental managers. Existing methods of environmental management fail to achieve these objectives, due to inadequate perception of environmental problems by decision-makers, and the inability of currently available impact assessment techniques to resolve human conflicts associated with the use of land and resources. The main work of planning and managing land use and the environment would be carried out by regional authorities, supported by federal and state policy. Examples are given of moves towards regional administration in England and Wales, Western Australia, Australia and New Zealand. Community participation in the decision-making process is essential and can be achieved by electoral representation to the authoritative bodies and through procedures that ensure informed public comment on planning proposals.  相似文献   

17.
Increased efforts to analyze the human dimensions of anglers are necessary to improve freshwater fisheries management. This paper is a comparative analysis of urban and rural anglers living in a metropolis, based on n = 1061 anglers responding to a mail survey in the German capital of Berlin. More than two thirds of the anglers (71%) had spent most (>50%) of their effort outside the city borders of Berlin and thus were categorized as rural anglers. Compared to the rural anglers, urban anglers (50% of total effort spent inside the city) were younger and less educated. Urban anglers were more avid and committed, less mobile, and more frequently fished from boats and during weekdays. Rural anglers were more experienced, fished for longer times per trip, fished more often at weekends and on holidays, were more often members of angling clubs, and more frequently caught higher valued fish species. The achievement and fish quantity aspects of the angling experience were more important for urban than for rural anglers. Concerning management options, urban anglers more frequently suggested constraining other stakeholders and reducing regulations, whereas rural anglers more often proposed improving physical access to angling sites. Future urban fishing programs should offer ease of access, connection to public transportation, moderate prices, and diverse piscivorous fish stocks. In contrast to rural fisheries, the provision of high ecological and aesthetical quality of the angling waters can be regarded as of minor importance in urban fisheries. Rural fisheries managers need to consider the needs of stakeholders living in Berlin to minimize impacts on the less degraded rural water bodies and potential user conflicts with resident anglers. Ecosystem-based management approaches should guide rural fisheries policy.  相似文献   

18.
The interrelationship of society and environment is addressed here through the study of a remote fishing village of 750 people. An interdisciplinary study evaluated demographic, economic, and social aspects of the community, and simulation modeling was used to integrate these societal characteristics with environmental factors.The population of the village had grown gradually until the 1960's, when a decline began. Out-migration correlated with declining fish harvests and with increased communications with urban centers. Fishing had provided the greatest economic opportunity, followed by logging. A survey was conducted to investigate the costs and revenues of village fishermen. Diversification characterized the local fleet, and analysis showed that rates of return on investment in the current year were equal between vessel types.The variable levels and rate parameters of the demographic, economic, and social components of the model were specified through static and time series data. Sensitivity analysis to assess the effects of uncertainty, and validation tests against known historical changes were also conducted. Forecast scenarios identified the development options under several levels of fish abundance and investment. The weight given to ecological versus economic resource management registered disproportionate effects due to the interaction between investment and migration rates and resource stochasticity. This finding argues against a golden mean rule for evaluating policy trade-offs and argues for the importance of using a dynamic, socio-ecological perspective in designing development policies for rural communities.  相似文献   

19.
Arsenic levels in seawater, microplankton (diatoms and dinoflagellates), shrimp (Penaeus semisulcatus), mollusc (Cerithium scabridum) and five types of fish (Maid, Nakroor, Nuwaiby, Suboor and Sheim) in five sampling stations (I–V) off the Kuwait coast were determined during the years 1995 to 1999. The maximum mean concentration of arsenic was observed in the order; the five fish (0.50–0.78 g g–1)> mollusc (0.26 g g–1)> shrimp (0.23 g g–1)> particulate matter (0.03 g g–1)> water and phytoplankton (0.02 g g–1) from all the sites of the Kuwait coast. Station II possessed the maximum arsenic levels. In comparison with the arsenic levels in other parts of the globe, low arsenic levels were observed in most of the marine organisms off the Kuwait Coast. However, an increasing trend in arsenic concentrations was anticipated due to rapid local industrialization and on account of recent spills of arsenic compounds.  相似文献   

20.
On the basis of the cross-section and time-series data of the Lower Mekong Basin (LMB)—including large sections of Thailand, Lao PDR, Vietnam, and Cambodia, we find little evidence in support of the environmental Kuznets curve (EKC) hypothesis. Instead, our regressions support the general views that water pollution had been positively related to income level and that, as a result of the end of the Cold War era, it had been significantly reduced in the 1990s vis-à-vis the 1980s. In most circumstances, water resources were more seriously polluted in the transnational border areas than in the other areas. Specifically, the estimated coefficients on the political boundary dummies show that political influence on transnational water pollution was more significant in areas near the international border along which the river runs (denoted by BORDER2) than in places near the international border across which the river runs (denoted by BORDER1). The estimated coefficients on the ASEAN dummy present some information about the positive role of the Association for Southeast Asian Nations (ASEAN) membership in the reduction of transnational water pollution. Finally, the country-specific dummies are found to present conflicting information about the transnational differences of water pollution, although Thailand is found to have the least water pollution in the LMB.  相似文献   

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