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171.
The announcement of plans for exploratory oil drilling at a number of offshore sites in Belize raised concerns about the risks associated with drilling, particularly given the socio‐economic importance of the marine ecosystem. The current economic value of fisheries and marine ecotourism is estimated, along with the potential revenue from offshore oil and potential economic losses stemming from oil pollution, under various assumptions on risk and uncertainty. Marine fisheries and ecotourism are estimated to generate around US$ 183 million per year. Single‐year estimated maximum revenue is higher for oil extraction initially but quickly declines; during a 50 year (two generation) period, total discounted benefits from marine fisheries and ecotourism are estimated at US$ 5.1 billion, compared to US$ 3.2 billion from offshore oil revenue. Following a hypothetical oil spill, discounted losses in marine fisheries and ecotourism due to perception and ecological impacts are estimated at US$ 912 million, with clean‐up costs and capital losses of US$ 6.1‐10.4 billion. Considering the short extraction life of oil resources compared to fisheries and ecotourism, the difference in benefits increases substantially in favour of the latter with a longer time horizon. A recent public referendum resulted in a 98% vote against oil exploration and a subsequent annulment of oil concessions pending environmental impact assessments.  相似文献   
172.
Recent scientific research on perfluorinated surfactants (PS) revealed their ocurrence in German surface and drinking waters (Skutlarek, Exner, Färber 2006). Since several years, PS have been found in the global environment, especially in animal and human tissues. PS possess extreme persistence against microbiological and chemical degradation and are able to bioaccumulate in animals and humans (Houde et al. 2006). PS concentrations (sum of 12 components) in the Rhine river and its main tributaries were determined below 100 ng/L, but the rivers Ruhr (tributary of the Rhine) and Möhne (tributary of the Ruhr) showed remarkable high concentrations (Ruhr: up to 446 ng/L, Möhne: up to 4385 ng/L). The maximum concentration in drinking waters was 598 ng/L with the major component perfluorooctanoic acid (PFOA). The PS concentrations decreased similarly to the PS concentrations of the raw waters along the flow direction of the Ruhr river. Therefore it seems to be necessary to install legal regulations for these compounds.  相似文献   
173.
Hintergrund und Ziel Seit Juni 2007 ist in der EU die neue europ?ische Chemikalienverordnung REACH gültig. Wesentlicher Inhalt der neuen Regelung ist die Einführung eines einheitlichen Systems zur Registrierung, Bewertung, Zulassung und Beschr?nkung von Chemikalien. Die Hersteller/Importeure von Chemikalien müssen wesentliche Angaben zu den inh?renten Stoffeigenschaften vorlegen und die Bedingungen für eine sichere Verwendung der Stoffe über den gesamten Lebenszyklus nennen, d. h. für die Herstellung, Verarbeitung, Nutzung und Entsorgung der Stoffe. Damit birgt REACH das Potenzial von Schnittstellen zu produktbezogenen Regelungen, sofern bei diesen ebenfalls eine Bewertung der enthaltenen oder emittierten Chemikalien erfolgt.  相似文献   
174.
Energy efficiency in the residential housing market can play an important role in the reduction of global carbon emissions. This paper reports the first evidence on the market adoption and economic implications of energy performance certificates implemented by the European Union. The results show that adoption rates are low and declining over time, coinciding with a negative sentiment regarding the label in the popular media. Labels are clustered among smaller, post-war homes in neighborhoods with more difficult selling conditions. We also document that geographic variation in the adoption rate of energy labels is positively related to the fraction of “green” voters during the 2006 national elections. Within the sample of labeled homes, the energy label creates transparency in the energy efficiency of dwellings. Our analysis shows that consumers capitalize this information into the price of their prospective homes.  相似文献   
175.
According to the EU directive 91/414/EEC potential environmental concentrations of pesticides have to be assessed with environmental fate models. For the calculation of pesticide concentrations it is necessary to provide an application date which has to match the specific Biologische Bundesanstalt, Bundesamt, Chemische Industrie (BBCH) stage at which the pesticide shall be applied. If these application dates are not available for a specific stage, crop and country they must be estimated, which adds an additional uncertainty to the predicted concentrations. In the present study, we therefore evaluate to which extent application dates can be derived from phenological data. For this analysis phenological data, converted to BBCH stages, of two field crops provided by the German Weather Service (DWD) were analyzed. We found a linear correlation between BBCH stages and the respective appearance dates, which can be used for interpolation of appearance dates of specific BBCH stages. Remarkably, when comparing BBCH stages from Germany and the Czech Republic almost identical correlations of appearance dates and BBCH stages were found. In the next step, soil and climate data from Joint Research Centre (JRC) were analyzed together with phenological data in order to evaluate if BBCH stages can be estimated for countries with other climate or soil conditions. This analysis revealed that temperature, global radiation and evaporation were the parameters with the strongest impact. These parameters were used for estimating appearance dates of BBCH stages for other countries. Exemplarily, appearance dates for maize BBCH were calculated for Italy. Estimated and observed appearance dates showed a high concordance (on average six days difference). Finally, the political of impact a variation of a few days on calculated pesticide concentration was analyzed. Exemplarily, the pesticide fate model FOCUS PEARL was used to estimate pesticide groundwater concentrations. When calculating concentrations for application dates varying by ± two weeks, concentrations in groundwater usually varied very little. The highest variation was found for application at BBCH 30 in maize (6.6 % variation over all scenarios). These results showed that the uncertainty included in the estimation of appearance dates of BBCH stages for other countries has a relatively small effect on the results of PEARL and consequentially on the decision of the pesticide risk assessment by changing only the application date.  相似文献   
176.
In Brazil, artisanal and small-scale gold mining (ASGM) produces in the range of 6 tonnes of gold (Au) per annum, and employs approximately 200,000 people. Most of this mining activity is in the Amazon region, where miners have been extracting gold for more than 40 years. In the Tapajos River Basin, assessments indicate that around 99% of miners operate without the environmental and mining permits required by law. This is a result of a combination of unrealistic or lack of proper policies and regulations, lack of political will, lack of infra-structure to enforce the existing regulations and lack of incentives to miners to comply with legal requirements.In this article, we analyze a group of 20 laws, decrees and resolutions in Brazil, focusing on how idiosyncrasies in these regulations reveal gaps between policy and reality in ASGM areas. Artisanal miners operate in vast and remote areas and the government lacks the resources (personnel, vehicles, information and materials) to enforce the laws. Our analysis emphasizes the need for creating new government commitments and identifying priority areas where government agents can focus their efforts.There is no single solution for the environmental, health, technical and socio-economic problems associated with ASGM. However, a realistic approach should consider improving the level of education of miners, creating government programs to provide technical assistance in the field, simplifying administrative procedures and ensuring adequate measures for enforcement.  相似文献   
177.
Zusammenfassung  Um zu einer sachgerechten und nachvollziehbar quantifizierbaren Beurteilung der m?glichen Gesundheitsbelastungen des Menschen durch Schadstoffe zu gelangen, ist es von grundlegender Bedeutung dessen ?u?ere Schadstoffexposition absch?tzen zu k?nnen. Um die Durchführung derartiger Absch?tzungen zu erm?glichen, werden nutzergruppen- und expositionsszenariospezifisch orale, inhalative und dermale Aufnahmeraten für die Kontaktmedien Boden, Pflanzen aus Haus- und Schreberg?rten, Trinkwasser, Staub, Hausstaub und Innenraumluft vorgeschlagen. Diese Aufnahmeraten dienen, gemeinsam mit gemessenen oder berechneten Schadstoffkonzentrationen in den entsprechenden Kontaktmedien, zur Absch?tzung der von Menschen aufgenommenen Schadstoffdosen und erm?glichen durch einen Vergleich mit tolerierbaren Schadstoffdosen eine stoff-, nutzungs- und standortbezogene Beurteilung von Schadstoffexpositionen, auch für komplexe Nutzungen.   相似文献   
178.
When making an assessment of animal welfare, it is important to take environmental (housing) or animal-based parameters into account. An alternative approach is to focus on the behavior and appearance of the animal, without making actual measurements or quantifying this. None of these tell the whole story. In this paper, we suggest that it is possible to find common ground between these (seemingly) diametrically opposed positions and argue that this may be the way to deal with the complexity of animal welfare. The model will have to be acceptable for the different parties that will be affected by it and real benefits for the animal should result from it. This will be the basis of a practical ethical approach. All this can be condensed into a model that essentially is made up out of three basic elements: the classical welfare analysis with an existing welfare assessment tool, an assessment of the stockholder, and an implementation of the Free Choice Profiling technique. This new framework does not pretend to be a different or better animal welfare matrix; it is intended to integrate existing knowledge and to provide a practical tool to improve animal welfare. It identifies whether there are welfare problems on a farm, if present whether these problems are caused by the housing system or the stockholder, and what can be done to improve the situation.  相似文献   
179.
Magnetic field of the earth as additional zeitgeber for endogenous rhythms?   总被引:1,自引:0,他引:1  
The influence of 50% decrease and increase of the earth magnetic field on the activity of the enzymes hydroxyindole-O-methyltransferase (HIOMT) and N-acetyl-serotonintransferase (NAT) is proved in vivo and in vitro. NAT and HIOMT catalyse the melatonin biosynthesis in the pineal gland and in the retina. Our results support the hypothesis of Leask and Schulten, that molecular magnetic field sensitivity is the basis of animals' magnetic field detection.  相似文献   
180.
We used DNA microsatellites to investigate temporal and spatial patterns of local genetic differentiation and relatedness in a solitary mammal, the dusky-footed woodrat (Neotoma fuscipes). Patterns of genetic variation were measured relative to spatial clusters, or neighborhoods, of woodrats. We detected significant genetic differentiation among woodrat neighborhoods in two populations spanning multiple habitat types and densities. Estimates of θ ST among neighborhoods ranged 0.034–0.075 and were comparable to levels reported in social mammals. Genetic differentiation at such a local scale is noteworthy because it occurred in the absence of any physical barriers to gene flow, suggesting that the patterns observed are linked to the nonrandom patterns of mating and dispersal that characterize woodrat social structure. Genetic differentiation and relatedness among neighborhoods were even higher when only resident females were analyzed. These results are consistent with a pattern of female philopatry and male-biased dispersal in woodrats. Geographic distance and relatedness were inversely correlated in adult females at intermediate densities, but not at low densities. Nonetheless, matrilineal genetic structure was apparent even at low woodrat densities based on estimates of θ ST among neighborhoods of resident females that were significantly greater than zero and consistently greater than estimates including all individuals. In summary, this study demonstrates a matrilineal genetic structure in dusky-footed woodrats. In addition, our results support the idea that intermediate densities may be better at facilitating the formation of spatial kin clusters than either extreme. An erratum to this article can be found at  相似文献   
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