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1.
The implementation of sustainable development may seem a simple concept when written on paper. However to carry-out long term actions put forward by the Agenda 21 (AG21) at the local level represents one of the main challenges as municipal governments in general do not have the capacity to effectively implement the process. Regional environmental assessment (REA) has shown to be effective in supporting decision-making not only to correct environmental problems due to past unsustainable social-economic developments but also help local governments to implement sustainable actions. However this requires long-term investments of AG21 plans and projects. The allocation of regular and consistent financial resources is one of the main ingredients for the sustainable development process. But traditional plans and projects financed by national and/or international funds may not be sustainable in the long-term because they become dependent on external funding. Research demonstrate that innovative economic instruments such as ecotaxes represent a feasible alternative to sponsor local sustainability because taxes are collected permanently by the government and could be invested in continuous actions. Ecotaxes experiences have provided important reference to structure a municipal incentive model (MIM) to sponsor AG21’s environmental plans and projects on a long-term (permanent) basis. However sustainable development cannot be solely through economic investments. A comprehensive municipal environmental management scheme (MEMS) has been established to support the incentive model. The scheme seeks not only to improve local institutional framework but also incentive continuous participation of local stakeholders at all levels of society. Participatory events and the provision of incentives (educational and financial) are key to motivate society to protect the environment and support actively the sustainable development process as emphasised in the RIO-92 Conference.  相似文献   
2.
The Chillán River in Central Chile plays a fundamental role in local society, as a source of irrigation and drinking water, and as a sink for urban wastewater. In order to characterize the spatial and temporal variability of surface water quality in the watershed, a Water Quality Index (WQI) was calculated from nine physicochemical parameters, periodically measured at 18 sampling sites (January–November 2000). The results indicated a good water quality in the upper and middle parts of the watershed. Downstream of the City of Chillán, water quality conditions were critical during the dry season, mainly due to the effects of the urban wastewater discharge. On the basis of the results from a Principal Component Analysis (PCA), modifications were introduced into the original WQI to reduce the costs associated with its implementation. WQIDIR2 and WQIDIR, which are both based on a laboratory analysis (Chemical Oxygen Demand) and three (pH, temperature and conductivity), respectively, four field measurements (pH, temperature, conductivity and Dissolved Oxygen), adequately reproduce the most important spatial and temporal variations observed with the original index. They are proposed as useful tools for monitoring global water quality trends in this and other, similar agricultural watersheds in the Chilean Central Valley. Possibilities and limitations for the application of the used methodology to watersheds in other parts of the world are discussed.  相似文献   
3.
This paper reports the development of a simple and accurate on-line procedure for preconcentration and determination of dissolved iron in waters and biological materials using unloaded polyether-type polyurethane foam as solid extractor. In the developed flow injection system, the analyte was preconcentrated from acidic aqueous medium as iron-thiocyanate complex with post-elution with ascorbic acid solution and spectrophotometric measurement with 1,10-phenanthroline as colorimetric reagent. In order to improve the performance of the system several chemical and flow variables were investigated as well as the effect caused by the presence of possible interferents. The method was validated by the analysis of two certified reference materials. Application of the methodology was carried out by the determination of dissolved iron content in eight natural water samples with different characteristics. The results were compared with those obtained by electrothermal atomic absorption spectrometry (ETAAS) and no statistical difference was observed. The detection limit was 0.75 microgram l-1 and the RSD was 1.2% for 2 min preconcentration time. At this condition, a productivity of 20 samples h-1 was achieved. Increasing the preconcentration time up to 3 min, a detection limit of 0.45 microgram l-1, an RSD of 1.5% and an analytical throughput of 15 h-1 were verified.  相似文献   
4.
This article presents and discusses SO2 (ppbv) concentration measurements combined with meteorological data (mainly wind speed and direction) for a five-year campaign (1996 to 2000), in a site near an oil refinery plant close to the city of La Plata and surroundings (aprox. 740.000 inh.), considered one of the six most affected cities by air pollution in the country. Since there is no monitoring network in the area, the obtained results should be considered as medium term accumulated data that enables to determine trends by analyzing together gas concentrations and meteorological parameters. Preliminary characterization of the behaviour of the predominant winds of the region in relation with potential atmospheric gas pollutants from seasonal wind roses is possible to carry out from the data. These results are complemented with monthly averaged SO2 measurements. In particular, for year 2000, pollutant roses were determined which enable predictions about contamination emission sources. As a general result we can state that there is a clear increase in annual SO2 concentration and that the selected site should be considered as a key site for future survey monitoring network deployment. Annual SO2 average concentration and prevailing seasonal winds determined in this work, together with the potential health impact of SO2 reveals the need for a comprehensive and systematic study involving particulate matter an other basic pollutant gases.  相似文献   
5.
The sampling of carpeted surfaces to test for lead contamination primarily focuses upon vacuum techniques. Vacuum sampling techniques, however, require time-consuming, expensive laboratory analysis of the dusts obtained and are unable to determine total lead load on the carpet. X-ray fluorescence (XRF) analysis is an on-site, inexpensive, non-destructive, quick technique for predicting metals levels in a variety of media, such as water, soil, filter paper and painted surfaces. A 1992 study of the feasibility of XRF to analyze for lead and soil loadings on carpeted surfaces indicated that XRF can detect lead at a low enough level to warrant further study. This paper expands this earlier study and developes lead and soil loading calibration curves for three different carpet types based upon XRF lead L-beta peak areas and XRF iron and barium K-alpha peak and background areas. Results indicate that variation in the data can be reduced through modifications of the XRF analysis technique, thus reducing the statistically determined detection level, and that carpet type does affect the calibration. Detection levels of approximately 70 mg/m2 for lead and 5 g/m2 for soil were obtained. Overall, good agreement was found between results of this study and the earlier one. XRF shows excellent potential for quantitative analysis of lead on carpeted surfaces.  相似文献   
6.
7.
HLA typing of amniotic fluid cells has been used for the prenatal diagnosis of the HLA linked diseases congenital adrenal hyperplasia (21-OH-deficiency (21-OH-def) type) and complement C4 deficiency and it has also been used for the prenatal de termination of paternity. There are, however, technical difficulties in this test associated with the weak expression of some B locus antigens on amniotic fluid cells, and theoretical difficulties related to associations between particular HLA antigens and the 21-OH-def allele. Since certain HLA-B locus antigens are found in significantly increased frequencies among patients with 21-OH-def, there is a relatively high incidence of HLA-B homozygosity among the patients and over 40 percent of the parents of these patients share one or more HLA-B locus antigens. Results of some prenatal HLA typing tests may thus be difficult to interpret, and supplementary tests should be used whenever possible. HLA typing of amniotic cells is, however, the only available procedure for prenatal diagnosis of C4 deficiency and it is the best available procedure for prenatal determination of paternity. A modification of our original procedure allows HLA typing to be performed with increased numbers of HLA typing sera, and sera with optimum reactivity for amniotic fluid cells have now been selected for the definition of most of the more commonly expressed HLA antigens. Although amniotic fluid cells do not express DR antigens, amniotic fluid cells can be typed for the HLA-linked marker glyoxalase I (GLO) and this may be the informative for prenatal diagnosis in some cases.  相似文献   
8.
The resistance of mainly gram-negative bacteria against antibiotics is discussed with respect to new discoveries on the permeability barrier of the outer membrane. Proteins originally characterized as virus receptors have been found to be involved in the translocation of certain substrates across the membrane. Antibiotics can reach their target by the same “pores”.  相似文献   
9.
Call centre workplaces are in many ways a challenge to occupational health and safety. The occupation itself can be described as an IT information technology-supported, communication-intensive form of work with often unusual working hours and a high rate of part-time employment. Data on the employee turnover as well as absenteeism related to occupational disability is quite contradictory. Occupational safety and its proponents still have to find new ways into the corporate structures and cultures of this relatively new and rapidly growing branch of industry. In a 2-year research and development project, using a holistic approach and under consideration of all the relevant disciplines, call centre workplaces were studied, and organisational measures were developed and field tested by putting them into practice. Practical help was developed for a sustainable strategy for successful and healthy work in call centres.  相似文献   
10.
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