Heterocyclic aromatic compounds containing nitrogen, sulfur, or oxygen heteroatoms (NSO-HET) have been detected in air, soil,
marine, and freshwater systems. However, only few publications are available investigating NSO-HET using in vitro bioassays.
To support better characterization of environmental samples, selected NSO-HET were screened for dioxin-like activity in two
bioassays. 相似文献
Polybrominated diphenyl ethers (PBDEs) and tetrabromobisphenol A (TBBPA) are brominated flame retardants that are produced in large quantities and are commonly used in construction materials, textiles, and as polymers in electronic equipment. Environmental and human levels of PBDEs have been increasing in the past 30 years, but the toxicity of PBDEs is not fully understood. Studies on their effects are relatively limited, and show that PBDEs are neurotoxins and potential endocrine disrupters. Hydroxylated (OH) and methoxylated (MeO) PBDEs have also been reported in the adipose tissue, blood and milk of wild animals and humans. In the present study, 15 PBDE metabolites, two BDE mixtures (DE71 and DE79), and TBBPA were studied individually to determine their effects on ten steroidogenic genes, aromatase activity, and concentrations of two steroid hormones (testosterone and 17beta-estradiol) in the H295R human adrenocortical carcinoma cell line. Exposure to 0.05 microM 2'-OH-BDE-68 significantly induced the expression of CYP11A, CYP11B2, CYP17, CYP21, 3betaHSD2, 17betaHSD1, and 17betaHSD4, and the expression of StAR was induced by 6-OH-BDE-90 at the three exposure concentrations. Exposure to DE71 and DE79 resulted in dose-dependent trend towards induction, but these effects were not significant. Exposure to 0.5 microM 2-OH-BDE-123 and 2-MeO-BDE-123 resulted in significantly greater aromatase activity. However, none of the compounds affected sex hormone production at the concentrations tested. Generally, OH-BDEs had a much stronger ability to affect steroidogenic gene expression than MeO-BDEs. 相似文献
The ever increasing impact of the marine industry and transport on vulnerable sea areas puts the marine environment under exceptional pressure and calls for inspired methods for mitigating the impact of the related risks. We describe a method for preventive reduction of remote environmental risks caused by the shipping and maritime industry that are transported by surface currents and wind impact to the coasts. This method is based on characterizing systematically the damaging potential of the offshore areas in terms of potential transport to vulnerable regions of an oil spill or other pollution that has occurred in a particular area. The resulting maps of probabilities of pollution to be transported to the nearshore and the time it takes for the pollution to reach the nearshore are used to design environmentally optimized fairways for the Gulf of Finland, Baltic Proper, and south-western Baltic Sea. 相似文献
The article investigates four alternative allocation schemes for emission allowances. The investigated schemes are emission-based
allocation, production-based allocation with actor-specific emission factors, production-based allocation with benchmarking
and production-based allocation based on data on best available technology (BAT). All the examined schemes apply free allocation
based on historical activities. The allocation schemes are evaluated against the criteria for a National Allocation Plan,
listed in the Annex III of the EU ETS Directive, and regarding their conformity with the criteria put forward by the Swedish
Parliamentary Delegation on Flexible Mechanisms, The FlexMex 2 Commission.
No allocation scheme unambiguously meets all criteria. Each has its advantages and disadvantages. Emission-based allocation
schemes are most straightforward, transparent and are the easiest to implement.
Production-based allocation schemes meet more of the criteria, but are more costly to implement and require more data. Data
on BAT will not be available to the extent necessary in order to base an allocation scheme implemented for the trading starting
2005 on BAT. It is unlikely that any given allocation scheme will be perceived as fair by all concerned parties, no matter
how sophisticated it is. The overall characteristics of the studied allocation schemes are summarised in the paper. Due to
the lack of abatement cost curves, it is not possible to accurately model capital flows between the trading sectors. Data
availability will most probably limit the options available to the authorities designing the allocation schemes.
An erratum to this article is available at . 相似文献
We analyze the exploitation of an antibiotic in a market subject to open access on the part of antibiotic producers to the common pool of antibiotic efficacy. While the market equilibrium depends only on current levels of antibiotic efficacy and infection of the epidemiological system, the social optimum accounts for the dynamic externalities which relate those levels to the intertemporal use being made of the antibiotic. We show that depending on the parameters of the model, in particular the cost of production and the improvement in the recovery rate that results from antibiotic treatment, the positive steady-state level of antibiotic efficacy to which the system tends under open access can be lower or higher than the level which should prevail in the socially optimal steady state. In fact there are parameter configurations for which the steady states can be exactly the same. However, the paths leading to the steady state always differ. 相似文献
Objective: The aim of the study was to compare the safety effects of studded and unstudded winter tires based on fatal road accidents.
Methods: The data included 958 road accidents involving a passenger car or van that occurred in Finland from November to March between 1997 and 2012.
Results: Comparing the proportions of winter tire type in accidents and in general traffic showed that the overall effect of tire type on the number of accidents was not significant, although studded tires reduced fatal accidents by 10–15%. Compared to unstudded tires, studded tires reduced accidents significantly only on bald ice in 2005–2012. Drivers using unstudded tires were more experienced and their profession was more frequently related to driving. In addition, the vehicle age was lower for vehicles with unstudded tires. On the other hand, the state of repair was less pertinent for unstudded than for studded tires. These confounding factors offset their effects to some degree.
Conclusions: The risk of fatal road accidents in winter between studded and unstudded tires does not differ significantly. However, the accident risk has recently been substantially higher on bald ice for unstudded than for studded tires. The magnitude of this risk difference is difficult to determine without specific information on exposure by road surface. 相似文献
We compared soil moisture from the soil water balance model for European Water Accounting (swbEWA) with in situ observations from nine locations in three European climatic zones (continental, Mediterranean and maritime temperate), for different periods between 2003 and 2011. Despite the simplicity of the swbEWA model, the patterns of temporal changes in soil moisture content are well represented at all locations. Annual averages show that the model overestimates the soil moisture content, and that overestimations are the smallest when measurements are obtained from more than one depth. These results suggest that the relationship between simulated and observed soil moisture also depends on the number of measurements and the depth over which they are taken. In the continental climate, where snow cover and frozen soil influence soil moisture, we observe higher root mean square error values in winter months. However, in the Mediterranean and maritime temperate climates, we do not observe clear common seasonal patterns in the soil moisture profile, which makes it difficult to relate the model’s accuracy to climate. With the percentage of correctness and probability of detection measures, we tested the model performance in simulating dry versus non-dry events. The percentage of the correctly classified dry and non-dry events is higher than 84 % at all locations, whereas the probability to detect dry events is significantly lower, exceeding 50 % at only four out of nine stations. The frequency distribution of consecutive days with dry soil (CDDS) confirms the model performance: higher number of short dry periods (with less than 20 days of soil moisture near wilting point) are reproduced and observed in continental climates, whereas long dry periods (longer than 50 days) are noted in the Mediterranean climate. Overall, the statistical measures suggest that the model produces the highest accuracy in summer months at the stations in continental climates, whereas in the Mediterranean climate, the accuracy is slightly higher in the colder seasons. 相似文献
Societal and technological development during the last century has enabled Western economies to achieve a high standard of living. Yet this profusion of wealth has led to several outcomes that are undesirable and/or unsustainable. There is thus an imperative need for a fundamental and rapid transition towards more sustainable practices. While broad conceptual frameworks for managing sustainability transitions have been suggested in prior literature, these need to be further developed to suit contexts in which the overall vision is arguably clear, such as in the case of consuming animal-originated foodstuffs. In this article we introduce a novel transition management framework that is based upon the dimensions of sustainability. The suggested transition management process includes the identification of objectives and obstacles, the listing of options and their opportunities and threats as well as the evaluation of the outcomes (the Five O’s). We argue that sustainability transition management should be a process in which the identification of the relevant dimensions of sustainability and related objectives forms the foundation for strategic, tactical and operational governance activities. We illustrate the practical applicability of the framework in the case of transition towards plant-based diets. 相似文献
In Germany, plans at the local level to construct wind turbines often find support as well as rejection – often in both cases for ecological reasons. In this paper, we argue that the key to understanding local wind energy debates is to analyse the interrelations between collective identities and concepts of place. Based on the discourse theory of Laclau and Mouffe, we analyse how two completely contradictory place notions have evolved in a local dispute in a small town in Germany, and how existing political identities have been modified, realigned and superseded in the course of the conflict. Furthermore, we show how the involved discourses are characterised by strong continuities with respect to an earlier struggle over an asphalt mixing plant. 相似文献