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241.
This research explores the boundaries of a valid application of contingent valuation as a method to value environmental changes. Recent criticism from social psychologists refers to unrealistic cognitive demands upon respondents. Criticism from economists point to the problem of measuring preferences in relation to non-use values. In this research the hypothesis is tested that the CV method in valuing goods with non-use value and with a complex content of information produces less valid results than with use values and non-complex content of information. Validity is tested across goods (sample survey: N=832). Results show that scope validity is ambiguous for goods with high content of complexity. Construct validity is not guaranteed for environmental changes with non-use values: Economic factors are not significant, only attitudes are relevant. Given the importance of WTP figures in cost-benefit analysis these results are of paramount importance for the trust in contingent valuation.  相似文献   
242.
243.
Resolving CO2 and methane hydrate formation kinetics   总被引:1,自引:0,他引:1  
We analyse the kinetics of CO2 and methane hydrate formation. The characteristic formation times are associated with different steps of the formation process. Conditions for minimising these rate times are identified while maintaining a regime where CO2 hydrate is formed and methane remains predominantly gaseous. This involves a rapid pressurisation routine and accesses points well above the phase boundary in order to enable faster kinetics. Conditions for optimising rates and times, to obtain maximum CO2 uptake with respect to CH4, were identified as (1) stirring faster than 1,000 rpm, (2) rapid pressurisation to a partial pressure of around 50 bar for CO2 and (3) re-use of contaminated as opposed to fresh water.  相似文献   
244.
The increasing production of nanomaterials will in turn increase the release of nanosized byproducts to the environment. The aim of this study was to evaluate the behaviour, uptake and ecotoxicity of TiO2 byproducts in the earthworm Eisenia fetida. Worms were exposed to suspensions containing 0.1, 1 and 10 mg/L of byproducts for 24 h. Size of TiO2 byproducts showed aggregation of particles up to 700 μm with laser diffraction. Only worms exposed at 10 mg/L showed bioaccumulation of titanium (ICP-AES), increasing expression of metallothionein and superoxide dismutase mRNA (Real-time PCR) and induction of apoptotic activity (Apostain and TUNEL). TiO2 byproducts did not induce cytotoxicity on cœlomocytes, but a significant decrease of phagocytosis was observed starting from 0.1 mg/L. In conclusion, bioaccumulation of byproducts and their production of reactive oxygen species could be responsible for the alteration of the antioxidant system in worms.  相似文献   
245.
Shipping is an important source of pollution affecting both atmospheric and aquatic environments. To allow for efficient mitigation of environmental degradation, it is essential to know the extent of the impacts of shipping in relation to other sources of pollution. Here, we give a perspective on a holistic approach to studies of the environmental impacts of operational shipping through presentation of an assessment framework developed and applied on a case of shipping in the Baltic Sea. Through transfer of knowledge and concepts, previously used in assessments of air pollution, now applied to assessments of marine pollution and underwater noise, the horizon of understanding of shipping-related impacts is significantly improved. It identifies the main areas of environmental degradation caused by shipping and potential improvements through legislation and technological development. However, as the vast majority of contaminants discharged into the sea are not routinely monitored and assessed, the links between pressure of contaminants from shipping and environmental state and impacts will not be caught in the current environmental regulatory frameworks.  相似文献   
246.

Background, aim, and scope

The use of plants and associated microorganisms to remove, contain, inactivate, or degrade harmful environmental contaminants (generally termed phytoremediation) and to revitalize contaminated sites is gaining more and more attention. In this review, prerequisites for a successful remediation will be discussed. The performance of phytoremediation as an environmental remediation technology indeed depends on several factors including the extent of soil contamination, the availability and accessibility of contaminants for rhizosphere microorganisms and uptake into roots (bioavailability), and the ability of the plant and its associated microorganisms to intercept, absorb, accumulate, and/or degrade the contaminants. The main aim is to provide an overview of existing field experience in Europe concerning the use of plants and their associated microorganisms whether or not combined with amendments for the revitalization or remediation of contaminated soils and undeep groundwater. Contaminations with trace elements (except radionuclides) and organics will be considered. Because remediation with transgenic organisms is largely untested in the field, this topic is not covered in this review. Brief attention will be paid to the economical aspects, use, and processing of the biomass.

Conclusions and perspectives

It is clear that in spite of a growing public and commercial interest and the success of several pilot studies and field scale applications more fundamental research still is needed to better exploit the metabolic diversity of the plants themselves, but also to better understand the complex interactions between contaminants, soil, plant roots, and microorganisms (bacteria and mycorrhiza) in the rhizosphere. Further, more data are still needed to quantify the underlying economics, as a support for public acceptance and last but not least to convince policy makers and stakeholders (who are not very familiar with such techniques).  相似文献   
247.
The monetary valuation of ecosystem services has proved to be a powerful tool for influencing management decisions, as it can be used to quantify the relative importance of various ecosystem functions. However, these valuation methods are rarely implemented with adequate care; in particular, they do not consider spatial and temporal variations in the services offered and demanded. This paper examines the effect of heterogeneity on the valuation of cultural services offered by the Doñana natural protected area in Spain. We apply the zonal travel cost method at various spatial scales, and the individual travel cost method at various temporal scales. We conclude that economic valuation techniques must account for spatial and temporal heterogeneity if they are to provide accurate and realistic information.  相似文献   
248.
Our growing demand for meat and dairy food products is unsustainable. It is hard to imagine that this global issue can be solved solely by more efficient technologies. Lowering our meat consumption seems inescapable. Yet, the question is whether modern consumers can be considered as reliable allies to achieve this shift in meat consumption pattern. Is there not a yawning gap between our responsible intentions as citizens and our hedonic desires as consumers? We will argue that consumers can and should be considered as partners that must be involved in realizing new ways of protein consumption that contribute to a more sustainable world. In particular the large food consumer group of flexitarians offer promising opportunities for transforming our meat consumption patterns. We propose a pragmatic approach that explicitly goes beyond the standard suggestion of persuasion strategies and suggests different routes of change, coined sustainability by stealth, moderate involvement, and cultural change respectively. The recognition of more routes of change to a more plant-based diet implies that the ethical debate on meat should not only associate consumer change with rational persuasion strategies and food citizens that instantiate “strong” sustainable consumption. Such a focus narrows the debate on sustainable protein consumption and easily results in disappointment about consumers’ participation. A more wide-ranging concept of ethical consumption can leave the negative verdict behind that consumers are mainly an obstacle for sustainability and lead to a more optimistic view on modern consumers as allies and agents of change.  相似文献   
249.
Bennedsen LR  Muff J  Søgaard EG 《Chemosphere》2012,86(11):1092-1097
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250.
Participatory processes for obtaining residents' input about community impacts of proposed environmental management actions have long raised concerns about who participates in public involvement efforts and whose interests they represent. This study explored methods of broad-based involvement and the role of deliberation in social impact assessment. Interactive community forums were conducted in 27 communities to solicit public input on proposed alternatives for recovering wild salmon in the Pacific Northwest US. Individuals identified by fellow residents as most active and involved in community affairs ("AE residents") were invited to participate in deliberations about likely social impacts of proposed engineering and ecological actions such as dam removal. Judgments of these AE participants about community impacts were compared with the judgments of residents motivated to attend a forum out of personal interest, who were designated as self-selected ("SS") participants. While the magnitude of impacts rated by SS participants across all communities differed significantly from AE participants' ratings, in-depth analysis of results from two community case studies found that both AE and SS participants identified a large and diverse set of unique impacts, as well as many of the same kinds of impacts. Thus, inclusion of both kinds of residents resulted in a greater range of impacts for consideration in the environmental impact study. The case study results also found that the extent to which similar kinds of impacts are specified by AE and SS group members can differ by type of community. Study results caution against simplistic conclusions drawn from this approach to community-wide public participation. Nonetheless, the results affirm that deliberative methods for community-based impact assessment involving both AE and SS residents can provide a more complete picture of perceived impacts of proposed restoration activities.  相似文献   
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