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21.
A procedure for the quantification of the PCB marker congeners 28, 52, 101, 138, 153, 180 in plastic waste form the recycling of cables in the range of content between 0.1 mgkg(-1) and 20 mgkg(-1) was validated. Representative reference materials for laboratory analyses were produced using granulates from different recycling processes. The method development included aspects of grinding, sieving, homogenising as well as the comparison of extraction methods and chromatographic conditions. The validated procedure foresees grinding of the technical sample to an upper particle size limit of 0.50mm followed by extraction with an unpolar solvent such as n-hexane and gas chromatographic determination. LOD and LOQ for individual congeners ranged between 0.01 mgkg(-1) and 0.08 mgkg(-1). Electron capture detection (ECD) and mass selective detection (MS) were equivalent if chromatographic conditions were appropriately selected. The application of MS was advantageous in presence of significant amounts of interfering components which have been found in some cables. Three reference materials containing the marker congeners in the range of 0.1 mgkg(-1)-5 mgkg(-1) were submitted to a final validation intercomparison with 23 selected field laboratories using the developed method. Relative reproducibility standard deviations varied between 15% and 33%.  相似文献   
22.
The potential of passive air sampling devices (polyurethane foam disks) to assess the influence of local sources on the quality of the surrounding environment was investigated. DEZA Valasske Mezirici, a coal tar and mixed tar oils processing plant, and Spolana Neratovice, a chemical factory with the history of high production of organochlorinated pesticides (OCPs), were selected as the point sources of PAHs, and OCPs, respectively. Levels of PCBs, OCPs and PAHs were determined for all sampling sites and sampling periods. The study brought useful data about the air concentrations of POPs in the investigated regions. More important, it provided information on the transport and fate of POPs in the vicinity of local sources of contamination useful for the estimation of their influence. Very good capability of passive samplers to reflect temporal and spatial fluctuation in concentrations of persistent organic pollutants in the ambient air was confirmed which makes them applicable for monitoring on the local scale.  相似文献   
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Exhaust fumes of paraffin, beeswax and stearin candles without any further paint or decorative element were analysed for the toxicological important substance classes of PCDD/PCDF, PAH and short chain aldehydes. The candle waxes and wicks were investigated for chlorinated dioxins, furans and some known precursors. Toxicological risk assessment shows that emissions of the investigated candles are much lower than all administrative limitation values — even under “worst case conditions”. Thus, they do not produce a toxicological risk for human health.  相似文献   
25.
Die Ergebnisse der Untersuchung von Wasserproben aus dem Einflu?ereich der Rüstungsaltlast „Dethlinger Teich“ bei Munster/Niedersachsen werden dargestellt und bewertet. Von mehr als 50 untersuchten spezifischen Substanzen wurden Arsenkampfstoffe als Hauptkontaminanten erkannt. Im Rahmen der Gef?hrdungsabsch?tzung wird hier erstmals eine Analysenmethode zur Unterscheidung zwischen anorganisch und organisch gebundenem Arsen vorgestellt. Groundwater analyses in the area of the former munitions depository (World War II) „Dethlinger Teich“ near Munster/Niedersachsen were evaluated. Results from 50 different chemical substances showed that arsenic compounds are the main contaminating chemicals. A new method has been developed to distinguish between morganically- and organically bound compounds. This differentiation is required for risk assessment and evaluation. Also, the relationship of chemical structure and physiological effects in organo arsenic compounds is described.  相似文献   
26.
BACKGROUND, AIM AND SCOPE: With respect to the enormous increase of chemical production in the last decades and the tens of thousands of individual chemicals on the market, the permanent improvement of chemical management is a permanent target to achieve the goals of sustainable consumption and production set by the WSSD in Johannesburg 2002. MAIN FEATURES: Several approaches exist to describe sustainability of chemistry. However, commonly agreed criteria are still missing. There is no doubt that products of modern chemistry help to achieve important goals of sustainability and that significant improvements have occurred regarding direct releases from production sites, but several facts demonstrate that chemistry is far from being sustainable. Still too many chemicals exhibit hazardous characteristics and pose a risk to health and environment. Too many resources are needed to produce chemicals and finished products. RESULTS AND CONCLUSION: Therefore, a strategy for sustainability of chemistry should be developed which comprises the following main elements: 1. Sustainable chemicals: sustainable chemical management includes a regulatory framework which makes no difference between new and existing chemicals, contains efficient information flow through the supply chain which allows users to handle chemicals safely and offers an authorisation procedure and/or an efficient restriction procedure for substances of high concern. This regulatory scheme should promote the development of inherently safe chemicals. 2. Sustainable chemical production: Sustainable chemical production needs the development and implementation of emerging alternative techniques like selective catalysis, biotechnology in order to release less CO2 and less toxic by-products, to save energy and to achieve higher yields. Information exchange on best available techniques (BAT) and best environmental practices (BEP) may help to promote changes towards more sustainability. 3. Sustainable products: An integrated product policy which provides a framework for sustainable products promotes the development of products with a long-term use phase, low resource demand in production and use, low emission of hazardous substances and properties suitable for reuse and recycling. This may be promoted by eco-labelling, chemical leasing concepts and extended information measures to enhance the demand of consumers and various actors in the supply chain for sustainable products. RECOMMENDATION AND PERSPECTIVE: Important tools for the promotion of sustainable chemistry are the abolition of barriers for innovation in legislation and within the chemical industry, more transparency for all users of chemical products, a new focus on sustainability in education and research, and a new way of thinking in terms of sustainability.  相似文献   
27.
Following the recent discovery of rodent pollination in the Pagoda lily, Whiteheadia bifolia (Hyacinthaceae) in South Africa, now the Cape rock elephant-shrew, Elephantulus edwardii (Macroscelidea, Afrotheria) is reported as an additional pollinator. Elephant-shrews, live-trapped near W. bifolia plants, were released in two terraria, containing the plants. The animals licked nectar with their long and slender tongues while being dusted with pollen and touching the stigmas of the flowers with their long and flexible noses. The captured elephant-shrews had W. bifolia pollen in their faeces, likely as a result of grooming their fur as they visited the flowers without eating or destroying them. The animals mostly preferred nectar over other food. This is the first record of pollination and nectar consumption in the primarily insectivorous E. edwardii, contributing to the very sparse knowledge about the behaviour of this unique clade of African mammals, as well as pollination by small mammals.  相似文献   
28.
The global dimensions of climate change necessitate a response that takes national differences – social, economic, geographic, and cultural – into account. Action-oriented education has a key role to play in advancing citizen engagement in a culture of sustainability. This paper describes research conducted with one such education programme, Youth Leading Environmental Change (YLEC), which operates in six countries and engages university-aged youth in discussion and practice related to global sustainability, systems thinking, and environmental justice. YLEC aims to advance four key competencies; this paper focuses on the goal of action competence, which involves acquiring knowledge, reflecting on experience in the context of one’s values, envisioning alternative futures, and acting individually and collectively to advance those alternatives. The present article examines the impacts of YLEC on environmental action competence in two of the countries involved in this research: Uganda and Germany. In-depth interviews were conducted with participants in both countries to examine the development of action competence during and after the programme. Findings suggest that outcomes differed in each country, reflective of participants’ different lived experiences. YLEC effectively built on the conditions faced in each country to accompany youth to a higher level of awareness and action. These findings have implications for environmental education programmes striving to work with multiple nations and diverse participants.  相似文献   
29.
For precautinary environmental protection the Environmental Specimen Bank (ESB) has been successfully established as a permanent environmental surveillance tool in Germany. The presented monitoring results on chlorinated hydrocarbons (CHC) show very clearly the effects of political decisions and can be used for the identification of pollutant sources. The CHC burden of breams (Abramis brama) from five German rivers (Elbe, Rhein, Saar, Mulde, Saale) gives an current overview of the pollution situation of different limnic ecosystems in Germany. A calculation model about the distribution of organic pollutants between different tissues offers the possibility to predict concentrations in liver and muscle of breams. Legislative emission restrictions have led to a significant decrease of dioxin levels in herring gull (Larus argentatus) eggs between 1988–1996.  相似文献   
30.
The model polyurethane foam and model compact polyurethane material were prepared and then decomposed by means of natural oils. Castor oil and fish oil based polyol were used in this study. Optimal conditions for the polyurethane decomposition were found. Temperature 250 °C was necessary for efficient polyurethane decomposition by castor oil whereas 200 °C is sufficient in the case of fish oil based polyol. Prepared products have hydroxyl number in the range of 95–168 mg KOH g−1. During the polyurethane decomposition no cleavage of double bonds in the fatty acid chains of castor oil and fish oil based polyol was observed.  相似文献   
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