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61.
The aim of this work was to evaluate the use of Monte Carlo-based calibrations for in situ gamma-ray spectrometry. We have performed in situ measurements at five different sites in Sweden using HPGe detectors to determine ground deposition activity levels of 137Cs from the 1986 Chernobyl accident. Monte Carlo-calculated efficiency calibration factors were compared with corresponding values calculated using a more traditional semi-empirical method. In addition, results for the activity ground deposition were also compared with activity densities found in soil samples. In order to facilitate meaningful comparisons between the different types of results, the combined standard uncertainty of in situ measurements was assessed for both calibration methods. Good agreement, both between the two calibration methods, and between in situ measurements and soil samples, was found at all five sites. Uncertainties in in situ measurements for the given measurement conditions, about 20 years after the fallout occurred, were found to be in the range 15–20% (with a coverage factor k = 1, i.e. with a confidence interval of about 68%).  相似文献   
62.
We compared the efficiency of some commercially available products and methods used for remediation of mould-contaminated building materials. Samples of gypsum board and pinewood were artificially contaminated with toxin-producing isolates of Stachybotrys chartarum and Aspergillus versicolor, respectively, then, ten different remediation treatments were applied according to the manufacturers' instructions. Microbial and chemical analyses of the infested materials were carried out both immediately before and after treatment, after six weeks of drying at room temperature, and after another six weeks of remoistening. The aim of the study was to determine whether the investigated methods could inhibit the mould growth and destroy some selected mycotoxins produced by the moulds. None of the decontamination methods tested could completely eliminate viable moulds. Some methods, especially boron based chemicals, ammonium based chemicals, and oxidation reduced the contents of mycotoxins produced by S. chartarum (satratoxin G and H, verrucarol), whereas the one which uses an ammonium based chemical reduced the amount of sterigmatocystin produced by A. versicolor with statistical significance. No remediation treatment eliminated all the toxins from the damaged materials. These results emphasize the importance to work preventively with moisture safety throughout the construction processes and management to prevent mould growth on building materials.  相似文献   
63.
This paper contributes to the current discussion on whether ‘soft’ regulation actually influences policy outcomes by examining the effects of national policy instruments on municipal climate and energy planning. Sweden has experienced shifts in the incentive context over the last decades complementing soft planning regulations with stringent conditions for getting national economic support to local energy and climate action. We hypothesize that when soft regulations are surrounded by detailed conditions for getting state support, there will be higher degrees of local institutionalization of climate and energy strategies. The importance of economic support as part of national policy is confirmed by evidence from local energy and climate strategies and from interviews with local decision-makers. We also find that specific municipal features such as earlier municipal engagement in national support programs and relevant inter-municipal networks function as drivers for the institutionalization of local action.  相似文献   
64.
Oil spills occur commonly, and chemical compounds originating from oil spills are widespread in the aquatic environment. In order to monitor effects of a bunker oil spill on the aquatic environment, biomarker responses were measured in eelpout (Zoarces viviparus) sampled along a gradient in Göteborg harbor where the oil spill occurred and at a reference site, 2 weeks after the oil spill. Eelpout were also exposed to the bunker oil in a laboratory study to validate field data. The results show that eelpout from the Göteborg harbor are influenced by contaminants, especially polycyclic aromatic hydrocarbons (PAHs), also during “normal” conditions. The bunker oil spill strongly enhanced the biomarker responses. Results show elevated ethoxyresorufin-O-deethylase (EROD) activities in all exposed sites, but, closest to the oil spill, the EROD activity was partly inhibited, possibly by PAHs. Elevated DNA adduct levels were also observed after the bunker oil spill. Chemical analyses of bile revealed high concentrations of PAH metabolites in the eelpout exposed to the oil, and the same PAH metabolite profile was evident both in eelpout sampled in the harbor and in the eelpout exposed to the bunker oil in the laboratory study.  相似文献   
65.
To implement policies about sustainable landscapes and rural development necessitates social learning about states and trends of sustainability indicators, norms that define sustainability, and adaptive multi-level governance. We evaluate the extent to which social learning at multiple governance levels for sustainable landscapes occur in 18 local development initiatives in the network of Sustainable Bergslagen in Sweden. We mapped activities over time, and interviewed key actors in the network about social learning. While activities resulted in exchange of experiences and some local solutions, a major challenge was to secure systematic social learning and make new knowledge explicit at multiple levels. None of the development initiatives used a systematic approach to secure social learning, and sustainability assessments were not made systematically. We discuss how social learning can be improved, and how a learning network of development initiatives could be realized.  相似文献   
66.
This special issue of AMBIO presents a new approach to sustainability science that goes beyond interdisciplinary research. Using coupled natural and human systems, or landscapes, as multiple case studies in Europe’s East and West knowledge production and learning toward transdisciplinary research was applied in Sweden, countries in Central and Eastern Europe, and Russia. First, the research group Forest-Landscape-Society summarizes the research program (2005–2012) behind this special issue of AMBIO and its development to participate in transdisciplinary research. Second, stakeholders at multiple levels provide their views on the new approach presented and reported.  相似文献   
67.
Muramic acid (MA) is a unique amino sugar that is a constituent of the peptidoglycan (PG) present in prokaryotic cell walls. MA can serve as a marker for quantifying bacterial load, e.g. in indoor environments, by using gas chromatography-tandem mass spectrometry (GC-MS-MS). We demonstrated recently that the methyl ester O-methyl acetate (MMA) derivative can be used to detect MA in house dust by ion-trap GC-MS-MS. However, since the MMA derivative is not formed from free MA quantification was not optimal. Here we report 1) significant improvements in sample preparation of the MMA derivative and 2) an evaluation of the performance of derivative, using for comparison the alditol acetate derivative, the gold standard in quantitative trace analysis of MA in complex matrices. The MMA derivative was analysed using an MS instrument with internal ionization and the alditol acetate derivative was analysed using an instrument with external ionization. 13C-labelled cyanobacteria, containing MA in their PG, were used as the internal standard. A linear relationship was found between the two methods in studies on 27 parallel samples of airborne dust from school classes collected on filters. Although the analytical sensitivity of the MMA derivatives was somewhat slightly lower than of the alditol acetate derivative, this may be due to differences in yield of derivative, sample clean-up efficiency, or different performance of the GC columns or MS instruments. However preparation of the MMA derivative is quick and compatible with preparation of methyl esters of 3-hydroxy fatty acids (used as markers of Gram negative endotoxin) allowing the levels of both markers to be determined in the same dust sample. In conclusion, the MMA procedure can be used to determine MA in environmental samples with good reproducibility provided the concentration of the 13C-labelled MA internal standard in the cyanobacteria is first determined with an alternative method.  相似文献   
68.
This paper presents a methodological approach for the study of volatile organic compounds (VOCs) in air, emitted during storage of municipal solid waste in bales. Determination of VOCs was based on sampling with adsorbent tubes followed by automated analysis using on-line work-up with a thermal desorption unit directly connected to a gas chromatograph-mass spectrometer. Using calculation algorithms and multidimensional statistical analysis of large amounts of data collected, the information was compressed and visualized. The approach was applied to initial measurements of emissions of VOCs from 24 bales composed of municipal solid waste, each bale stored in a wooden box. These bales were produced using the two types of baling equipment available, resulting in cylindrical or rectangular bales, with different densities. Hundreds of different VOCs emitted from these bales sorted out into groups with different chemical structure. Differences in VOC concentrations in air were found between wastes stored in cylindrical or rectangular bales. For instance, it was found that the concentration of VOCs (relative to the concentration of toluene), in the first experiment after storing, for cylindrical bales with six layers of LDPE was 115 +/- 10 microg m(-3), while for rectangular bales it was only 64 +/- 8 microg m(-3). The procedure used for data interpretation suggested different degradation mechanisms in different types of bales. The use of multiple data interfaces, multidimensional statistics and automated chemical analysis methods are likely to be more and more common for waste companies and waste research in the near future. This is due to the interdisciplinary nature of the subject that relies heavily on various areas of science and information technology.  相似文献   
69.
70.
This paper focuses on the volatile organic compound emissions from baled municipal solid waste (MSW). The analytical methodology was based on sampling with adsorbent tubes once a month during seven occasions within a time period of 1 year. Automated analyses were carried out on-line work-up with thermal desorption directly connected to a gas chromatograph-mass spectrometer. The effect of different baling techniques, cylindrical and rectangular baling was compared. It was found that cylindrically baled MSW emitted larger concentration of esters than their rectangular counter parts. Conversely, aromatic compounds emissions dominated in rectangularly baled MSW. This indicates that different degradation mechanisms operate in the waste bales. Cylindrical and rectangular bales are generally wrapped with six layers of 250 microm thick low density polyethylene (LDPE). It was observed that by wrapping an extra six layers of LDPE film onto the bales, the emissions from cylindrical bales increased while emissions from the rectangular counterpart decreased. Over time, the volatile organic compound emissions from cylindrical bales decreased two orders of magnitudes from 96.2 +/- 20.8 microg m(-3) in September 2003 to 0.80 +/- 0.07 microg m(-3) in July 2004. The rectangular bales exhibited an almost identical relative emission reduction from 54.4 +/- 4.3 microg m(-3) in September 2003 to 0.46 +/- 0.02 microg m(-3) in July 2004. Future work will concentrate on full-scale storages, taking into account waste type, storage size, temperature development and the different baling techniques among other variables.  相似文献   
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