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71.
A recently designed two-chamber-lysimeter-test-system allows the detailed investigation of degradation, transport and transfer processes of 14C-labeled substances in soil–plant–atmosphere-systems under outdoor conditions. With this test system it is feasible to distinguish between 14C-emissions from soil surfaces and 14C-emissions from plant surfaces in soil monoliths under real environmental conditions. Special soil humidity sensors allow the measurement of soil water content near to the soil surface, in 1 and 5 cm depth. The behavior of organic chemicals can be followed for a whole vegetation period and a mass balance for the applied chemical can be established. Some selected results of the herbicides isoproturon and glyphosate – using the two-chamber-lysimeter-test-system – are presented to demonstrate its applicability for the identification and quantification of the processes that govern pesticide behavior in soil–plant-systems. Mineralization of 14C-isoproturon was very different in four different soils; the mineralization capacity of the soils ranged from 2 to 60%. Leaching of isoproturon in general was very low, but depending on the soil type and environmental conditions isoproturon and its metabolites could be leached via preferential flow, especially shortly after application. For the herbicide 14C-glyphosate no accumulation of residues in the soil and no leaching of the residues to deeper soil layers could be observed after three applications. Glyphosate was rapidly degraded to AMPA in the soil. Glyphosate and AMPA were accumulated in soy bean nodules.  相似文献   
72.
Germany seems to be one of the leading nations in solid waste management, especially in the case of packaging waste; success stories about the ongoing increase in recycling strengthen this impression. However, enormous costs and questionable ecological benefits are the result of Germany's packaging ordinance and the formation of the recycling organization Duales System Deutschland (DSD). This article shows that similar progress in the reduction and recycling of packaging could have been realized without the packaging ordinance and dual system, with lower costs. This regulatory impact analysis of the German packaging ordinance covers all the effects on the different life-cycle stages of packaging, from production to recycling or disposal. The conclusion is that a fragmentary solid waste management approach – one that is based, like the German packaging ordinance, more on ideology than on facts – leads to enormous costs and questionable ecological benefits. To improve this situation, there is a need for an integrated solid waste management approach, based on evaluation of the economic, environmental, and social effects of different waste management options for the materials involved. Received: February 4, 1999 / Accepted: April 30, 1999  相似文献   
73.
74.
The herbicide atrazine is the most commonly detected pesticide in groundwater world-wide. A new microcosm test-system was used to determine the fate of 14C-atrazine in a Brazilian oxisol. 14C Ring-labelled atrazine was applied in a mixture with the commercial product Gesaprim 500 (Novartis) at a rate of 3 kg ha-1. During two months, about 1% of the initially applied amount was lost by volatilization. The mineralization of the pesticide, measured directly using 14CO2 evolved from the applied pesticide, was between 0.09% and 0.16%, whereas less than 0.2% was leached. The distribution of radioactivity in the soil profile showed that most of the radioactivity remained in the top soil down to a 3 cm depth. The radioactivity in the upper 3 cm of the column was adsorbed perferably in fulvic acid (FA) and human fractions.  相似文献   
75.
Arctic and subarctic ecosystems are experiencing substantial changes in hydrology, vegetation, permafrost conditions, and carbon cycling, in response to climatic change and other anthropogenic drivers, and these changes are likely to continue over this century. The total magnitude of these changes results from multiple interactions among these drivers. Field measurements can address the overall responses to different changing drivers, but are less capable of quantifying the interactions among them. Currently, a comprehensive assessment of the drivers of ecosystem changes, and the magnitude of their direct and indirect impacts on subarctic ecosystems, is missing. The Torneträsk area, in the Swedish subarctic, has an unrivalled history of environmental observation over 100 years, and is one of the most studied sites in the Arctic. In this study, we summarize and rank the drivers of ecosystem change in the Torneträsk area, and propose research priorities identified, by expert assessment, to improve predictions of ecosystem changes. The research priorities identified include understanding impacts on ecosystems brought on by altered frequency and intensity of winter warming events, evapotranspiration rates, rainfall, duration of snow cover and lake-ice, changed soil moisture, and droughts. This case study can help us understand the ongoing ecosystem changes occurring in the Torneträsk area, and contribute to improve predictions of future ecosystem changes at a larger scale. This understanding will provide the basis for the future mitigation and adaptation plans needed in a changing climate.Electronic supplementary materialThe online version of this article (10.1007/s13280-020-01381-1) contains supplementary material, which is available to authorized users.  相似文献   
76.
Reiner JL  Kannan K 《Chemosphere》2006,62(6):867-873
Occurrence of the polycyclic musks, 1,3,4,6,7,8-hexahydro-4,6,6,7,8,8-hexamethylcyclopenta[g]-2-benzopyran (HHCB) and 7-acetyl-1,1,3,4,4,6-hexamethyl-1,2,3,4-tetrahydronapthalene (AHTN), in wastewater influent and effluent, as well as in surface waters, has been reported. HHCB and AHTN were also reported to occur in human and wildlife tissues. The major sources for HHCB and AHTN to wastewater are thought to be consumer products such as shampoos, deodorants, laundry detergents, and household surface cleaners. However, the levels of HHCB and AHTN in consumer products are not known. For evaluation of the sources of human and environmental exposures, characterization of levels of HHCB and AHTN in consumer products is needed. In this study, we measured concentrations of HHCB (Galaxolide), AHTN (Tonalide), and HHCB-lactone (Galaxolidone) from a variety of consumer products, including perfumes, body lotions, and deodorants. Concentrations of HHCB, AHTN, and HHCB-lactone in consumer products ranged from <5 ng/g to over 4000 microg/g, <5 ng/g to 451 microg/g, and <5 ng/g to 217 microg/g, respectively. The highest concentrations were found in perfumes, body creams and lotions, and deodorants. The results suggest that a wide variety of source materials exist for HHCB and AHTN, and that these materials are used on a daily basis.  相似文献   
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