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21.
This paper examines the relation between the results of epidemiologic studies of air pollution mortality and impact indicators that can be informative for environmental policy decisions. Using models that are simple and transparent, yet contain the essential features, it is shown that (1) number of deaths is not meaningful for air pollution, whereas loss of life expectancy (LLE) is an appropriate impact indicator; (2) the usual short-term (time series) studies yield a change in daily number of deaths attributable to acute effects of pollution, without any information on the associated LLE (although some information on this has recently become available by extending the observation window of time series); and (3) long-term studies yield a change in age-specific mortality, which makes it possible to calculate the total population averaged LLE (acute and chronic effects) but not the total number of premature deaths attributable to air pollution. The latter is unobservable because one cannot distinguish whether few individuals suffer a large or many suffer a small LLE. The paper calculates the LLE from exposure to PM10, as implied by the long-term mortality studies of adults and infants; population LLE for infants turns out to be an order of magnitude smaller than for adults. The LLE implied by short-term studies is a small fraction of the total loss implied by long-term studies, even if one assumes a very high loss per death. Applied to environmental policy, taking a permanent 50-70% reduction of PM10 as a reasonable goal, one finds a corresponding increase of average life expectancy in urban areas of the European Union (EU) and the United States of approximately four months.  相似文献   
22.
Present investigation deals with the utilisation of bagasse fly ash (BFA) (generated as a waste material from bagasse fired boilers) and the use of activated carbons-commercial grade (ACC) and laboratory grade (ACL), as adsorbents for the removal of congo red (CR) from aqueous solutions. Batch studies were conducted to evaluate the adsorption capacity of BFA, ACC and ACL and the effects of initial pH (pH(0)), contact time and initial dye concentration on adsorption. The pH(0) of the dye solution strongly affected the chemistry of both the dye molecules and BFA in an aqueous solution. The effective pH(0) was 7.0 for adsorption on BFA. Kinetic studies showed that the adsorption of CR on all the adsorbents was a gradual process. Equilibrium reached in about 4h contact time. Optimum BFA, ACC and ACL dosages were found to be 1, 20 and 2 g l(-1), respectively. CR uptake by the adsorbents followed pseudo-second-order kinetics. Equilibrium isotherms for the adsorption of CR on BFA, ACC and ACL were analysed by the Freundlich, Langmuir, Redlich-Peterson, and Temkin isotherm equations. Error analysis showed that the R-P isotherm best-fits the CR adsorption isotherm data on all adsorbents. The Freundlich isotherm also shows comparable fit. Thermodynamics showed that the adsorption of CR on BFA was most favourable in comparison to activated carbons.  相似文献   
23.
Forest and agroecosystem fire management in Ghana   总被引:1,自引:0,他引:1  
The threat of wildfires to the economic potential of forestry and agriculture is one of the persistent national and international concerns. Improving and applying indigenous wildfire management (IWM) approaches is seen as one of the main hopes for mitigating and adapting to this threat to rural forest communities. Identifying the contextual causes and adaptation measures practiced by local people is essential for planning an appropriate mechanism for IWM. Yet only limited studies are available on IWM practices and most of those studies were conducted outside of this study region. To fill this gap, this study examined the wildfire mitigation and adaptation methods of forest communities in Ghana using interviews with 266 farming households. Their perceptions of the causes, cost and risk factors were also examined. The result suggests that wildfires are annual events. More than half of the wildfires reported were caused by slash-and-burn land preparation, with hunting-related fires in second place. Forest households loose about 208 Ghana cedi (US$ 231 in 2006) in value due to damaged crops and tree seedlings annually (i.e. about 50% of annual income of a Ghanaian farmer). The respondents had the operational skill and coping abilities to deal with small-scale wildfires and were supported by well-established local arrangements, community rules and silvicutural techniques. In addition, they were well informed about the basic risk factors (e.g. fuel load, climate, and presence of ignition triggers) and how these can interact to cause devastating wildfire. Therefore it is critical that policies and institutions that promote IWM initiatives build on the strong underlying community knowledge and local networks to enhance their effectiveness.  相似文献   
24.
The industrial sector is the biggest electricity consumer in Malaysia. Electric motors account for more than 45% of the electricity consumption in the industrial sector in the country. Therefore, it is very important to implement energy efficiency standards for electric motors to reduce energy consumption growth in this sector. This paper attempts to calculate the cost efficiency analysis and emission reduction by implementing energy efficiency standards for electric motor in Malaysia. The energy efficiency standards are proposed based on the efficiency of electric motors from survey data. The study examines the potential energy, economical and environmental impacts of the implementation of energy efficiency standards for electric motors in three scenarios i.e. 0.5%, 1.0% and 1.5% of standards efficiency improvement. Standards also enable consumers to reduce their electricity bill and contribute to a positive environmental impact.  相似文献   
25.
The aim of this study was to describe the impact of re-vegetation on the restoration of microbial community structure and soil microbiological properties in sand dunes that had been affected by mining activity. Soil samples were collected during the dry and rainy seasons from a chronosequence (1, 9, 21 years) of re-vegetated dunes using a single preserved dune as a reference. The composition of the fatty acid methyl esters and soil microbial properties were evaluated. The results showed that the changes in microbial community structure were related to seasonal variations: biomarkers of Gram-positive bacteria were higher than Gram-negative bacteria during the dry season, showing that this group of organisms is more tolerant to these stressful conditions. The microbial community structure in the natural dune was less affected by seasonal variation compared to the re-vegetated areas, whereas the opposite was observed for microbiological properties. Thus, in general, the proportion of saprobic fungi was higher in the natural dune, whereas Gram-negative bacteria were proportionally more common in the younger areas. Although over time the re-vegetation allows the recovery of the microbial community and the soil functions, these communities and functions are different from those found in the undisturbed areas.  相似文献   
26.
27.
Phytoestrogens are natural components of plant-based food items with beneficial health effects. The aim of the present study was to investigate the chronic effects of dietary phytoestrogens, genistein (8 mg kg(-1) day(-1)) and beta-sitosterol (50 mg kg(-1) day(-1)), on the weight regulation of the mink (Mustela vison). The parental generation was exposed from August 2002 to May-June 2003 to either beta-sitosterol or genistein, while the kits were exposed through gestation and lactation. Food consumption and body masses were monitored monthly. Plasma lipid, glucose, total protein and hormone (ghrelin, leptin, triiodothyronine and thyroxine) concentrations were measured from the parents in August 2002, January 2003 and at the end of the experiment in May-June 2003 when the kits were 21 days of age. Relative food intake was higher in the beta-sitosterol-exposed minks than in the control or genistein minks in September 2002. Plasma leptin and total protein concentrations were lower in the beta-sitosterol kits compared to the control kits. Furthermore, plasma ghrelin levels and liver phosphorylase activities of the mink kits were higher due to genistein exposure. In mink kits, exposure to both phytoestrogens reduced the plasma thyroxine concentrations. The kidney glycogen concentrations and the muscle phosphorylase activities of phytoestrogen-treated adult minks were elevated. The results of this study suggest that minks are sensitive to perinatal phytoestrogen exposure.  相似文献   
28.
This article covers partial results for research which was carried out to determine the effectiveness of municipal solid waste (MSW) recycling in Bandung metropolitan urban areas. It focuses on the results of waste flow analysis as basic information in developing better MSW management systems, especially in applying the reduce, reuse, recycle (3Rs) concept. The dependence upon final disposal sites in MSW management and the difficulties in finding disposal sites have resulted in interest in the 3Rs concept. In this research, the determination of waste compositions and the potential of recycling were evaluated based on data from interviews with householders, members of the nonhousehold sector, and recycling actors and on measurement. The informal sector activities observed were mainly from handcart crews, mobile scavengers, transfer point scavengers, final disposal scavengers, waste traders, and recycling business people at several locations in Bandung and Cimahi cities. The estimated waste recycling and composting by stakeholders has not yet achieved 10% (wet weight) of the total waste generated. As in other major cities in developing countries, the informal sectors hold an important role in the recovery of usable materials from waste. However, inorganic waste recycling activities from this sector have not even reached 8% (wet weight) of the total waste generated.  相似文献   
29.
Riparian forests (RF) growing along streams, rivers and lakes comprise more than 2% of the forest area in the Nordic countries (considering a 10 m wide zone from the water body). They have special ecological functions in the landscape. They receive water and nutrients from the upslope areas, are important habitats for biodiversity, have large soil carbon stores, but may emit more greenhouse gases (GHG) than the uplands. In this article, we present a review of the environmental services related to water protection, terrestrial biodiversity, carbon storage and greenhouse gas dynamics provided by RF in the Nordic countries. We discuss the benefits and trade-offs when leaving the RF as a buffer against the impacts from upland forest management, in particular the impacts of clear cutting. Forest buffers are effective in protecting water quality and aquatic life, and have positive effects on terrestrial biodiversity, particularly when broader than 40 m, whereas the effect on the greenhouse gas exchange is unclear.  相似文献   
30.
The paper presents a framework for the analysis of external costs of environmental burdens, namely an impact pathway analysis, often coupled with the inventory stage of life cycle assessment (LCA). The ground rule is: quantify as much as possible in terms of burdens (pollutant emissions, etc.), impacts, and their monetary equivalent, then use multi-criteria analysis (MCA) for any remaining impacts that are considered to be too uncertain or defy quantification through to monetization. Although MCA could be used directly on estimates of burdens or impacts, monetary valuation provides a mechanism for consistent weighting of impacts categories based on assessment of public preference. Further advantages of extending LCA through detailed impact assessment combined with monetary valuation are that it greatly simplifies MCA by combining a large number of different environmental impact categories, thereby avoiding an unmanageably large number of criteria, and also facilitates cost benefit analysis (CBA). The risks are noted of inappropriate use of the tools or interpretation/use of the results, and recommendations are made for improved practice. These points are illustrated with examples. The key messages are: (1) that policies should be targeted correctly to give a clear signal which source of a burden should be reduced by how much; (2) that analysts should take into account the needs of policy makers and the link between the analysis and possible policy applications; and (3) that current LCA practice gives limited guidance in both areas, largely through a lack of consideration of the relative and absolute importance of different types of impact. However, this is precisely the strength of external costs analysis, particularly when used with MCA.  相似文献   
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