A Multimethodological Approach for the Sustainable Management of Perifluvial Wetlands of the Po River (Italy)

/ Marginal aquatic systems (wetlands) of the Po River (Italy) have become the target of a renewed interest because of their value for recreation, natural reserves, and deposits of sand. To preserve these sites, wise management must be the objective of local administrations. In this paper a strategy for the sustainable use of 11 wetlands is presented. It uses simple economic analysis and multiple criteria techniques and provides suggestions to promote sustainability in terms of conservation of natural resources, economic self-sufficiency, and minimization of potential conflicts about the use of the wetlands. In the understanding that sustainability is framed in a long-term perspective, stability analysis is also considered and performed by means of loop analysis, a qualitative technique. Conditions for stability are then discussed about management opportunities.     

PROFILE: Tourism Contribution to Agro-Ecosystems Conservation: The Case of Lesbos Island, Greece

The objective of this study was to investigate the impact of tourism activities on olive tree cultivation and the human population of the island of Lesbos. The presence or absence of tourism is related with the maintenance or abandonment of olive tree cultivation and population changes for each community. A spatial segregation of the island is evident, related to tourist development, olive tree cultivation, and population change. The results of the study demonstrate that in communities where tourism plays an important role olive tree cultivation is preserved and the population is stable. The preservation of the agro-ecosystem is assured while the olive groves remain productive. Simultaneously, the landscape, which provides specific attractions for tourism, is not altered.     

An evaluation of three empirical air-to-leaf models for polychlorinated dibenzo-p-dioxins and dibenzofurans

Three empirical air-to-leaf models for estimating grass concentrations of polychlorinated dibenzo-p-dioxins and dibenzofurans (abbreviated dioxins and furans) from air concentrations of these compounds are described and tested against two field data sets. All are empirical in that they are founded on simplistic bioconcentration and related approaches which rely on field data for their parameterization. One of the models, identified as the EPA Model, partitions the total air concentration into vapor and particle phases, and separately models the impact of both. A second model addresses only the vapor phase; grass concentrations are modeled as a function of vapor deposition. For the third model, it is assumed that the grass plants "scavenge" a fixed volume of air of dioxins, and hence grass concentrations are modeled as a simple product of total air concentration and a constant scavenging coefficient. Field data from two sites, a rural and an industrial site in the United Kingdom, included concurrent measurements of dioxins in air and field grass, and dioxin and furan depositions, for one 6-week sampling period. Principal findings include: (1) the EPA Model underpredicted grass concentrations at the rural field site by a factor of 2, while the Scavenging Model underpredicted grass concentrations by a factor of 3.8, and the Vapor Deposition Model significantly underpredicted grass concentrations (by a factor greater than 10), (2) the presence of high soil concentrations for some of the dioxins and furans at the industrial site appears to have caused higher grass concentrations and confounded the air-to-plant modeling exercise, (3) the Scavenging Model could be calibrated to the data set; however, a key premise of this model that vapor and particle phase dioxins equally impact the plants, is not supported by the field data, (4) measured depositions are highly correlated to but systematically lower than modeled depositions, which could be due to modeling assumptions or a systematic measurement bias.     

Formation and long-term fate of non-extractable residues in outdoor lysimeter studies

Long-term outdoor lysimeter studies using (14)C-labelled compounds allow the quantification of the 'non-extractable residue fraction'. More than 20 lysimeter studies under realistic environmental conditions showed that more than 80% of residual carbon of the molecule is retained in the topsoil layer even after several years. Generally, 50-90% of this residual radiocarbon is regarded as 'soil bound residue'. Microbial biomass is present in large quantities in topsoil and continuously influences chemical and biochemical alteration of pesticide molecules that may interact directly with the total soil organic matter. Labelling techniques using radioactive isotopes like (14)C have been used to characterize these residues in the humus matrix. Our studies have been directed to the investigation of extractability and/or bioavailability of these residues in long-term investigations.     

A new sensitive test based on yeast cells for studying environmental pollution

Different tests based on yeast cells were developed for determination of mutagenic/carcinogenic action; however, they all showed lower sensitivity compared to bacterial tests, the main reason for this being the limited permeability of yeast cells. We found that general permeability of Saccharomyces cerevisiae cells can be increased by mutation and on this basis we developed a more sensitive test. The aim of this study was to prove the applicability of our test, called D7ts1, in environmental studies. Soil, water and air samples were taken during 1998 from regions in Bulgaria with declared low, average or high pollution levels and investigated for presence of mutagenic/carcinogenic activities in the bacterial test of Ames, the yeast D7 test of Zimmermann and our new D7ts1 test. Results obtained evidenced the following conclusions: (1) the usage of D7ts1 test instead of D7 test permits a clearer measurement of positive samples and detects mutagenic/carcinogenic activities undetectable by D7 test; (2) all samples with positive Ames test were positive in the D7ts1 test; however, some samples, clearly positive in the D7ts1, were negative in the Ames test; therefore, the simultaneous usage of D7ts1 and Ames tests in environmental studies is advantageous because it detects dangers for the human health activities to which bacterial cells do not respond; and (3) regions in Bulgaria declared clean were found to be polluted; particularly troubled are the whole-year positive data in the three tests for air samples from a 'clean' region.     

Carbon disulfide at a Chinese viscose factory external and internal exposure assessment

This article presents the results of carbon disulfide exposure measurements in a Chinese viscose rayon factory. The objectives of the study were to identify the external exposure levels at a large factory and to investigate the 2-thiothiazolidine-4-carboxylic acid (TTCA) concentrations in the urine of the subjects who were exposed to carbon disulfide in the working place atmosphere. The metabolism of carbon disulfide in the exposed subjects was also studied in order to demonstrate the best points in time for the internal exposure sampling. The measurement of the amount of personal exposure to carbon disulfide in the air of the workplace was performed by GC-FPD; the presence of TTCA in the workers urine was analyzed by use of a modified HPLC method. The kinetics of TTCA excretion was studied by analyses at different time-points both during and after exposure to carbon disulfide in the subjects. A total of 155 personal samples were obtained. The carbon disulfide concentration in the staple viscose hall was 13.72 +/- 1.12 mg m-3 in terms of the geometric mean +/- geometric standard deviation, and was 20.05 +/- 1.33 mg m-3 in the filament spinning hall. The TTCA values in the subjects who worked in the staple spinning hall were 1.18 +/- 0.43 mg g-1 creatinine and 1.07 +/- 0.38 mg g-1 creatinine for subjects working in the filament spinning hall. The best time for TTCA sampling is at the end of the working shift, the TTCA excretion was stable for a period of 4-12 h after exposure of the subjects to the carbon disulfide. It might be that the Chinese have different anthropometric characteristics; a sampling bias may therefore appear among different races.     

Matching response to context in complex political emergencies: 'relief', 'development', 'peace-building' or something in-between?

There is an ongoing debate over the value and pitfalls of the policy and practice of 'linking relief and development' or 'developmental relief' in aid responses to complex political emergencies (CPEs). Driven by concerns about relief creating dependence, sometimes doing harm and failing to address root causes of emergencies despite its high cost, pursuit of both relief and development has become a dominant paradigm among international aid agencies in CPEs as in 'natural' disasters. In CPEs a third objective of 'peace-building' has emerged, along with the logic that development can itself help prevent or resolve conflict and sustain peace. However, this broadening of relief objectives in ongoing CPEs has recently been criticised on a number of counts, central concerns being that it leads to a dilution of commitment to core humanitarian principles and is overly optimistic. This paper addresses these issues in the light of two of the CPEs studied by the COPE project: Eritrea and Somalia/Somaliland. It is argued that the debate has so far suffered from lack of clarity about what we mean by 'relief', 'development' and, for that matter, 'rehabilitation' and 'peace-building'. The wide spectrum of possible aid outcomes does not divide neatly into these categories. The relief-development divide is not always as clear-cut, technically or politically, as the critics claim. Moreover such distinctions, constructed from the point of view of aid programmers, are often of little relevance to the concerns of intended beneficiaries. Second, there has been insufficient attention to context: rather than attempting to generalise within and across CPE cases, a more productive approach would be to examine more closely the conditions under which forms of aid other than basic life support can fruitfully be pursued. This leads to consideration of collective agency capacity to respond effectively to diverse needs in different and changing circumstances.     

Cyclone mitigation, resource allocation and post-disaster reconstruction in south India: lessons from two decades of research

This paper opens with a history of development and disaster-prevention strategies in a cyclone-prone area of the east coast of India and traces the evolution in the area of British and Indian governments' programmes and policy over a century. Research over the last 20 years has shown, however, that the programmes and policies have failed to balance economic growth with safety. Resources intended for the benefit of all have been diverted by alliances of powerful people to a small minority, and recent developments have reduced the physical protection of the area. The result is that increasing numbers of people are vulnerable to the effects of cyclones and floods. The findings suggest that the best way to reduce vulnerability is to improve the socio-economic standing of the most vulnerable and for this to happen these people must have an assured income based on assets that will enable them to acquire social and economic credit-worthiness within the local economy. This paper presents evidence that suggests that non-governmental organisation (NGO)-supported co-operatives are the best way to achieve this through self-help and self-employment schemes. It also suggests that NGOs should be encouraged to take up environmentally and ecologically beneficial activities involving the poorest groups in the communities, in this way combining sustained self-employment with environmental protection.     

Review of ozone and temperature lidar validations performed within the framework of the Network for the Detection of Stratospheric Change

The use of assimilation tools for satellite validation requires true estimates of the accuracy of the reference data. Since its inception, the Network for Detection of Stratospheric Change (NDSC) has provided systematic lidar measurements of ozone and temperature at several places around the world that are well adapted for satellite validations. Regular exercises have been organised to ensure the data quality at each individual site. These exercises can be separated into three categories: large scale intercomparisons using multiple instruments, including a mobile lidar; using satellite observations as a geographic transfer standards to compare measurements at different sites; and comparative investigations of the analysis software. NDSC is a research network, so each system has its own history, design, and analysis, and has participated differently in validation campaigns. There are still some technological differences that may explain different accuracies. However, the comparison campaigns performed over the last decade have always proved to be very helpful in improving the measurements. To date, more efforts have been devoted to characterising ozone measurements than to temperature observations. The synthesis of the published works shows that the network can potentially be considered as homogeneous within +/-2% between 20-35 km for ozone and +/-1 K between 35-60 km for temperature. Outside this altitude range, larger biases are reported and more efforts are required. In the lower stratosphere, Raman channels seem to improve comparisons but such capabilities were not systematically compared. At the top of the profiles, more investigations on analysis methodologies are still probably needed. SAGE II and GOMOS appear to be excellent tools for future ozone lidar validations but need to be better coordinated and take more advantage of assimilation tools. Also, temperature validations face major difficulties caused by atmospheric tides and therefore require intercomparisons with the mobile systems, at all sites.     

荷兰政府的可持续采购思路

在 1 997年中期荷兰政府公布的《环境与经济政策文件》中 ,在为期 5年内为一项鼓励性计划拨款 1 0 0 0万荷兰盾 ,以提高环境在政府机构采购和签合同时的重要性 .这是给市场一个明确的信号 :应当重视环境 .这个“可持续采购计划”的目标有三个 :◆为其它人树立榜样 ;◆实现即时环境效益 ;◆通过创造 /增加对那些给环境带来较小负担的产品的需求 ,和通过刺激“绿色”产品革新 ,对市场施加影响 .为了实现这些目标 ,该计划的宗旨是通过中央政府 ( 1 3个部 )、1 2个荷兰省、5 72个市和 68个负责水管理的水局 ,刺激和便利自愿协调的可持续采购 .这…