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211.
The European Water Framework Directive (WFD) requires the definition of near-natural reference conditions to determine the extent of water bodies' deviation from "good ecological status" caused by stress gradients. However, the classification of ecological quality depends on the assessment method applied and the stressor concerned. While assessment methods that are generally applicable would be favourable, many European countries employ the locally developed water quality metrics that assess the impact of organic pollution (including eutrophication) and the associated decrease in dissolved oxygen. These indices do not specifically address stress from organic toxicants, such as pesticides. The aim of this study was to examine the performance of presently used assessment methods to identify reference conditions of non-contaminated streams in five selected European river basins, covering the geographical region from Spain to Finland, as a crucial prerequisite to indicate toxic gradients. The analysis comprised the Belgium biotic index (BBI), the biological monitoring working party (BMWP) scoring system and the revised German saprobic index. For comparison, we included an adaptation of the recently developed SPEAR index. In two previous field studies, this metric highly correlated with measured pesticide gradients. In this study, SPEAR was the only indicator that was generally applicable to all monitoring data and capable of determining "high ecological status" of reference conditions in all basins. Thus, based upon previous and own results, the authors suggest the species at risk (SPEAR) index to be potentially useful as a European-wide index to address deviations from "good ecological status" due to organic toxicants and recommend it for consideration in integrated water-resource evaluations under the WFD.  相似文献   
212.
The main objective of the MADAM project (Mangrove Dynamics and Management) is to generate the scientific basis enabling the sustainable stewardship of the resources of the Caeté mangrove estuary in Northeast Brazil in the sense of integrated coastal (zone) management. To achieve this, it is necessary to acquire in-depth knowledge of natural processes as well as of the relevant institutional, cultural, economic, social and political dynamics. Causal linkages within the ecosystem, as well as between ecosystem, economy and society, are analysed and explained via dynamic and trophic modelling. Scenario construction is intended to forecast the effects of acute or chronic interference on utilized resources, and to answer wider, management-related questions (e.g. restoration of destroyed areas, utilization potential for aquaculture). This paper describes the project strategy as developed and modified in the context of research results from the initial 2-yr project phase. It is argued that a continuous discussion process is essential to assess the validity of the strategies formulated at the beginning of a medium-time project, particularly if the project is of interdisciplinary nature.  相似文献   
213.
The Norwegian National Committee for Research Ethics inScience and Technology (NENT), collaborating with The NorwegianFisherman's Association and The Research Council of Norway,started in 1999 a project aiming at an ethical assessment of Norwegian fisheries for the year 2020. The project was to preparethe ground for ethical debate in and of the fishery sector inview of pending important decisions on long term strategies. Thispaper has its focus on the method used for achieving these aims,rather than the substantive results concerning the fisheries. Amethod was developed for this purpose, called the ethicalscenario process. This included the construction of scenarios forthe future of Norwegian fisheries, using an ethical matrix for evaluating strategies, and organizing a ``value workshop' whereparticipants from different stakeholder groups came together todo ethical evaluations. The positive achievements and theshortcomings of this method are discussed in this paper. The useof an ethical matrix was meant to combine a participatory approachwith insights from theoretical ethics. The project revealedinherent tensions between these two objectives. Possible ways ofdealing with this tension are indicated, but in general a goodgrasp of the socio-political context might be the best guardianagainst the possible pitfalls involved in such an approach.  相似文献   
214.
The need to involve refugees in their own reproductive health (RH) services has long been recognised, but there is a lack of published examples describing how this can be achieved collaboratively between refugee initiatives, UNHCR, bilateral development organisations and international relief agencies. This paper outlines the work, outputs and lessons learnt of the Reproductive Health Group (RHG), an organisation of Liberian and Sierra Leonean refugee midwives and laywomen providing RH services to fellow refugees in Guinea's Forest Region between 1996 and 2000. Working as part of the Guinean health system, RHG midwives and community facilitators helped make the RH services in their region the most effective in Guinea at the time. Looking at RHG's achievements, the challenges it faced and partly overcame, it is argued that refugee organisations can plan and implement RH services for refugees where UNHCR and its international partners ensure that they receive funding and technical assistance.  相似文献   
215.
Effective and efficient information dissemination is crucial for a successful management of coasts and beaches. Almost all coastal management activities use Internet portals to provide electronic accessibility of data and information. In this respect, we have analyzed web tracking data and costs to investigate the effectiveness and efficiency of two coastal management web portals. Indicators for the visiting quality, the volume and characteristics of the information flow and the associated costs were combined. The results show that mainly professional users were attracted by the two investigated online coastal management information offers. Furthermore, the coastal management contents were mainly relevant on regional scale. The results indicate that it is not enough to provide various information, instead it further needs also efforts to disseminate this information to a broader public. Specific preparation and presentation of information for the target groups would lead to an active dissemination process. The investigation of the costs shows that an increasing efficiency of information dissemination via the Internet goes together with the long term use of the information infrastructure. Therefore large coastal management web portals need runtimes of several years. The applied method combined and simplified actual used web analytic methods to allow valuable insights into the information dissemination of coastal management web portals. In this way the method can be used to help coastal decision makers or other practitioners to screen their web presence in the background of information supply and demand for all visitor groups they want to reach.  相似文献   
216.
In this study, a 3D urban groundwater model is presented which serves for calculation of multispecies contaminant transport in the subsurface on the regional scale. The total model consists of two submodels, the groundwater flow and reactive transport model, and is validated against field data. The model equations are solved applying finite element method. A sensitivity analysis is carried out to perform parameter identification of flow, transport and reaction processes. Coming from the latter, stochastic variation of flow, transport, and reaction input parameters and Monte Carlo simulation are used in calculating probabilities of pollutant occurrence in the domain. These probabilities could be part of determining future spots of contamination and their measure of damages. Application and validation is exemplarily shown for a contaminated site in Braunschweig (Germany), where a vast plume of chlorinated ethenes pollutes the groundwater. With respect to field application, the methods used for modelling reveal feasible and helpful tools to assess natural attenuation (MNA) and the risk that might be reduced by remediation actions.  相似文献   
217.
Passive sampling is a powerful method for continuous pollution monitoring, but calibration experiments are still needed to generate sampling rates in order to estimate water concentrations for polar compounds. We calibrated the Chemcatcher device with an uncovered SDB-XC Empore disk as receiving phase for 12 polar and semi-polar pesticides in aquatic environments in flow-through tank experiments at two water flow velocities (0.135 m/s and 0.4 m/s). In the 14-day period of exposure the uptake of test substances in the sampler remained linear, and all derived sampling rates R(s) were in the range of 0.1 to 0.5 L/day. By additionally monitoring the release of two preloaded polar pesticides from the SDB-XC disks over time, very high variation in release kinetics was found, which calls into question the applicability of performance reference compounds. Our study expands the applicability of the Chemcatcher for monitoring trace concentrations of pesticides with frequent occurrence in water.  相似文献   
218.
Atmospheric radioactivity is monitored for the verification of the Comprehensive Nuclear-Test-Ban Treaty, with xenon isotopes 131mXe, 133Xe, 133mXe and 135Xe serving as important indicators of nuclear explosions. The treaty-relevant interpretation of atmospheric concentrations of radioxenon is enhanced by quantifying radioxenon emissions released from civilian facilities. This paper presents the first global radioxenon emission inventory for nuclear power plants, based on North American and European emission reports for the years 1995–2005. Estimations were made for all power plant sites for which emission data were unavailable. According to this inventory, a total of 1.3 PBq of radioxenon isotopes are released by nuclear power plants as continuous or pulsed emissions in a generic year.  相似文献   
219.
In order to investigate benzo(a)pyrene (B(a)P) concentrations in ambient air in Europe and the respective deposition fields an expanded version of the Community Multiscale Air Quality (CMAQ) Modelling system has been used to simulate these fields for the years 2000 and 2001. Significant differences exist between different regions in Europe and between winter and summer concentrations. Modelled B(a)P concentrations are highest in Central Europe, South Ukraine and around Moscow. Wet deposition shows mainly the same regional distribution as the concentrations. Simulated concentrations and depositions are compared to measurements at selected sites of the EMEP network and of the German Federal Environmental Agencies. The measurements are on average underestimated by 50%. The temporal evolution and the regional distribution of B(a)P are captured by the model. In the approach presented here, particle bound B(a)P undergoes degradation by reactions with ozone. In order to assess the importance of the degradation process the results are compared to a model run where no degradation of particle bound B(a)P is considered. It was found that the inclusion of heterogeneous reactions of B(a)P with ozone results in a reduction of the modelled air concentration by approx. a factor of 5.  相似文献   
220.
Singapore has many environmental accomplishments to its credit. Accessible data on air quality indicates that all criteria pollutants satisfy both U.S. Environmental Protection Agency (EPA) and World Health Organization (WHO) air quality standards and guidelines, respectively. The exception is PM2.5 (particles with an aerodynamic diameter ≤2.5 μm), which is not currently considered a criteria pollutant in Singapore but may potentially be the major local air pollution problem and cause for health concern. Levels of other airborne pollutants as well as their physical and chemical processes associated with local formation, transformation, dispersion, and deposition are not known. According to available emission inventories, Singapore's contribution to the total atmospheric pollution and carbon budget at the regional and global scales is small. Emissions per unit gross domestic product (GDP) are low compared with other countries, although Singapore's per-capita GDP and per-capita emissions are among the highest in the world. Some information is available on health effects, but the impacts on the ecosystem and the complex interactions of air pollution and climate change at a regional level are also unknown. This article reviews existing available information on atmospheric pollution and greenhouse gas emissions and proposes a multipollutant approach to greenhouse gas mitigation and local air quality. Singapore, by reducing its per-capita emissions, increasing the availability of information (e.g., through regularly publishing hourly and/or daily PM2.5 concentrations) and developing a research agenda in this area, would likely be seen to be a model of a high-density, livable, and sustainable city in Southeast Asia and other tropical regions worldwide.

Implications Singapore is widely recognized for its environmental achievements and often cited as a model of a high-density, livable, and sustainable city. This article reviews available information with the aim to provide a reference for future scientific research of strategic relevance for Singapore's air quality and greenhouse gas mitigation management under a multipollutant framework. However, the limited publicly accessible data and little scientific information prevent a comprehensive assessment of the local air quality and greenhouse gas emissions. Singapore's dynamic economy and strong profile in advanced science and technological innovation have the potential to enhance the research agenda in this area, which is not yet well developed in tropical cities.  相似文献   
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