Recent changes in international commodity agreements

The contents of international commodity agreements have changed from those in which open-ended intervention mechanisms regulated the market defending a normative price to those limiting intervention so as not to obscure market forces and consequently the market price. Underlying this change is the principle to which the developed countries accorded the highest priority, namely that the interests of producing and consuming countries must balance to avoid an indiscriminate transfer of resources. On the other hand, the principles which guided agreements that set a normative price were based on the grounds that the market price determined by unequal partners was unfair and that internationally agreed developmental goals implied untied and unconditional resource transfers by means of normative, higher than market, prices. These two sets of principles were incompatible. As a result negotiations were not only difficult but inconclusive. Another reason for this outcome was that the question of the cost effectiveness of market duplicating agreements based on the principle of balanced interests was unresolved. These reasons explain why commodity agreements do not figure currently in substantive discussions on North-South cooperation and why only three commodity agreements have a functional role and even of these three, one is not in force definitively.     

Land use change and carbon exchange in the tropics: II. Estimates for the entire region

Determining the effect of tropical land use on the carbon dioxide (CO₂) content of the atmosphere requires: (a) estimates of the rates of land use change, (b) estimates of the difference between the carbon stored in forests and that stored in pastures and cultivated fields, and (c) a consideration of the fate of carbon stored in the cleared vegetation. The first article of this series analyzed land use in four tropical countries and estimated the carbon released to the atmosphere as a consequence of changes in land use. This article estimates the carbon released from the entire tropical region based on the two published studies of land use change for the tropics as a whole that distinguish between temporary and permanent land use: Seiler and Crutzen (1980) and Lanly (1982). We combine these estimates with two estimates of the difference in carbon storage between forests and fields derived from Whittaker and Likens (1975) and Brown and Lugo (1982), and the two scenarios of the fate of cleared vegetation, developed in the previous article, to produce several complete sets of data describing the necessary parameters to calculate carbon exchange. These data sets, entered into our model, produce a range of estimates of the annual release of carbon from tropical vegetation in 1980 of from 0.6 to 1.8 BMT/year, with the more likely range being 0.9–1.2 BMT/year. Our preliminary analysis suggests that the release from tropical soils due to land use change adds about an additional 0.3 BMT C/year, so that the total release is probably between 1.2 and 1.5 BMT C/year. Peng and others (1983) reported that new models of the oceanic carbon cycle can accommodate at least 1.2 BMT C/year in 1980 from forests and soils. Our results indicate that, given the uncertainties in the size of both the biotic release and oceanic uptake, the global carbon budget may be balanced if there is no significant release from nontropical ecosystems due to land use change and all mature ecosystems are in collective equilibrium with the atmosphere.     

MUNICIPAL AND INDUSTRIAL WATER SUPPLY IN CIUDAD JUAREZ,MEXICO1

Rapid industrialization and population growth in the north Mexican desert city of Ciudad Juarez are placing a serious strain on the city's municipal water resources. Water deliveries and service area have more than doubled over the past decade, and plans for additional expansion are presently being implemented. This expansion is already contributing to water table declines and salinity increases in the Mexican portion of the Heuco Bolson, the sole source of water for the city. Continued mining of the limited fresh water reserves should produce serious water supply problems in the near future. New estimates of future water consumption incorporated into a digital aquifer simulation model indicate that these problems may show up much sooner than was anticipated in previous investigations. The results of this study point to the need to accelerate the gathering of basic data on alternative water resources. The problems faced by Cd. Juarez are illustrative of the kinds of difficulties likely to confront other rapidly developing cities of the arid zone.     

Notions of environment and environmental management in Akwa Ibom State, Southeastern Nigeria

In the study of environmental degradation, there has not been sufficient attention paid to the perceptions of the local inhabitants. The importance of traditional beliefs and practices has often been overlooked. This paper looks at traditional and Christian beliefs in Akwa Ibom State in South Eastern Nigeria. Interviews, observations and focus group discussions were used to collect the data. The data analysis shows that knowledge and attitudes are somewhat linked to tradition but also influenced by Christian ideas concerning genesis. There are a number of recommendations made.     

世界主要国家城市人均用地研究及其对我国的启示

城市人均用地作为城市规划和土地利用规划的重要依据,一直受到学者和规划师的广泛重视。1991年我国颁布了人均建设用地标准,之后,这个标准成为我国核准各级城市规划的一个主要指标。经过近20 a的快速发展,这个指标是否还能反映我国城市用地的真实需求?为此,研究选择了世界上人口规模最大的80个国家的城市人均用地作为研究对象,分析了各国人均用地的差异,并用截面数据对城市用地的差异进行了分析;在此基础上,对我国城市用地的需求水平进行了估算。结果显示:不同国家城市人均用地差别很大;一个国家城市人均用地水平的高低和该国人均土地资源的丰富程度、耕地面积占土地总面积的比重及国家经济发展水平(人均GDP)有着明显的正相关;基于本文的数据,运用经验模型,研究认为2020年我国城市人均用地约为165 m2/人。     

世界主要产煤国家煤矿安全生产现状及发展趋势

通过对近20年世界煤炭产量进行统计,分析世界煤炭产量变化趋势,表明世界煤炭产量近年来呈明显增长态势,其中十大产煤国家的产量占到了世界总产量的88.7%。选择美国、印度、俄罗斯、南非、波兰和乌克兰等6个世界主要产煤国家进行煤矿安全生产状况的统计、分析和研究,总结世界主要产煤国家煤矿安全发展趋势。研究表明:20世纪70年代以来,世界各主要产煤国家的煤矿安全状况都有不同程度的改善,事故死亡人数不断降低。总体来看,世界主要产煤国家的煤矿安全生产状况发展并不均衡,发达国家好于发展中国家。发达国家通过建立和完善煤矿安全法律法规、监管监察、科技支撑和教育培训四大体系实现了煤矿安全状况的显著改善。     

发达国家工业场地拆迁过程中污染防治管理经验及启示

综述了欧美发达国家工业企业搬迁中环境管理的方法,重点介绍了德国、英国、美国在管理工业场地拆迁方面的主要法规、工作规范和危险防控规程等内容,并在此基础上总结了其管理经验。分析了我国工业场地拆迁管理面临的问题,借鉴国外经验,提出了建立工业企业拆迁场地环境管理法律法规框架、制定详细的操作流程和规范、建立工业搬迁场地信息系统等建议。     

Determination and health risk assessment of enrofloxacin,flumequine and sulfamethoxazole in imported Pangasius catfish products in Thailand

The goals of this study were to determine the levels of three antibiotics – enrofloxacin, flumequine and sulfamethoxazole – in Pangasius catfish products imported into Thailand and to assess the health risks from consumption. To extract these antibiotic residues, acetonitrile, methanol and a small amount of formic acid were used as solvents. Determination of the antibiotics after extraction steps was carried out by liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) technique. The results showed that 14 and 3 samples of Pangasius catfish products were contaminated with enrofloxacin and sulfamethoxazole, respectively. No flumequine residue was found. While the concentration levels of these antibiotics in most contaminated samples were lower than the European Union (EU) standard, one sample was found to contain sulfamethoxazole at 245.91 µg kg^?1, which was higher than the EU standard (100 µg kg^?1), indicating the likelihood that some contaminated freshwater fish products are widely distributed in Thai markets. Notably, the concentration levels of enrofloxacin in samples of Pangasius catfish with skin were higher than in non-skin products, suggesting that products with skin might retain more antibiotic residues than non-skin products. Although the hazard quotient showed that consuming imported Pangasius catfish products, based on the current consumption rate, will not adversely affect consumer health, antibiotic residues in Pangasius catfish products imported into Thailand should be continually monitored.     

Environmental Security: A Geographic Information System Analysis Approach—The Case of Kenya

Studies into the relationships between environmental factors and violence or conflicts constitute a very debated research field called environmental security. Several authors think that environmental scarcity, which is scarcity of renewable resources, can contribute to generate violence or social unrest, particularly within states scarcely endowed with technical know-how and social structures, such as developing countries. In this work, we referred to the theoretical model developed by the Environmental Change and Acute Conflict Project. Our goal was to use easily available spatial databases to map the various sources of environmental scarcity through geographic information systems, in order to locate the areas apparently most at risk of suffering negative social effects and their consequences in terms of internal security. The analysis was carried out at a subnational level and applied to the case of Kenya. A first phase of the work included a careful selection of databases relative to renewable resources. Spatial operations among these data allowed us to obtain new information on the availability of renewable resources (cropland, forests, water), on the present and foreseen demographic pressure, as well as on the social and technical ingenuity. The results made it possible to identify areas suffering from scarcity of one or more renewable resources, indicating different levels of gravity. Accounts from Kenya seem to confirm our results, reporting clashes between tribal groups over the access to scarce resources in areas that our work showed to be at high risk.