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161.
In Mississippi, spent poultry litter is used as fertilizer. Nutrient and bacterial levels in litter and nutrient levels in litter-fertilized (L+) soil are known, but less is known of bacterial levels in L+ soil. This study compared contiguous L+ and non-litter-fertilized (L-) soils comprising 15 soil types on five farms in April through May 2009. Levels of pH; NO-N; and Mehlich-3-extractable (M3) and water-extractable (WE) P, Ca, K, and Cu were higher in L+ than in L- soil. Total C; total N; NH-N; and M3 and WE Na, Fe, and Zn did not differ in L+ and L- soil. Bacterial levels were higher in 0- to 5-cm than in 5- to 10-cm cores. Levels were higher in L+ than in L- soil for culturally determined heterotrophic plate counts and staphylococci and were lower for total bacteria estimated by quantitative polymerase chain reaction (qPCR) of 16S rRNA, but cultural levels of thermotolerant coliforms, , , and enterococci were not different. Cultural presence/absence (CPA) tests and qPCR for spp., spp., and spp. detected only spp., which did not differ in L+ (CPA = 77% positive samples; mean qPCR = 0.65 log genomic units [gu] g) and L- (CPA = 70% positive samples; mean qPCR = 0 log gu g) soils. Litter applications were associated with higher levels of pH, P, Cu, heterotrophic plate counts, and staphylococci. Fecal indicator and enteric pathogen levels were not affected. We conclude that, although some litter-derived nutrients and bacteria persisted between growing seasons in L+ soils, enteric pathogens did not.  相似文献   
162.
Deposition of sea salts is commonly elevated along the coast relative to inland areas, yet little is known about the effects on terrestrial ecosystem biogeochemistry. We examined the influence of NaCl concentrations on N, C, and P leaching from a coastal Oregon forest Andisol in two laboratory studies: a rapid batch extraction (approximately 1 d) and a month-long incubation using microlysimeters. In the rapid extractions, salt additions immediately mobilized significant amounts of ammonium and phosphate but not nitrate. In the month-long incubations, salt additions at concentrations in the range of coastal precipitation increased nitrate leaching from the microcosms by nearly 50% and reduced the mobility of dissolved organic carbon. Our findings suggest that coupled abiotic-biotic effects increase nitrate mobility in these soils: exchange of sodium for ammonium, then net nitrification. Changes in sea salt deposition to land and the interactions with coastal soils could alter the delivery of N and C to sensitive coastal waters.  相似文献   
163.
Soil particle size and land management practices are known to have considerable influence on carbon (C) storage in soils, but such information is lacking for silvopastoral systems in Spain. This study quantified the amounts of soil C stored at various depths to 100 cm under silvopastoral plots of radiata pine ( D. Don) and birch ( Roth) in comparison to treeless pasture in Galicia, Spain. Soils were fractionated into three size classes (<53, 53-250, and 250-2000 μm), and C stored in them and in the whole (nonfractionated) soil was determined. Overall, the C stock to 1 m ranged from 80.9 to 176.9 Mg ha in these soils. Up to 1 m depth, 78.82% of C was found in the 0- to 25-cm soil depth, with 12.9, 4.92, and 3.36% in the 25- to 50-, 50- to 75-, and 75- to 100-cm depths, respectively. Soils under birch at 0 to 25 cm stored more C in the 250- to 2000-μm size class as compared with those under radiata pine; at that depth, pasture had more C than pine silvopasture in the smaller soil fractions (<53 and 53-250 μm). In the 75- to 100-cm depth, there was significantly more storage of C in the 250- to 2000-μm fraction in both silvopastures as compared with the pasture. The higher storage of soil C in larger fraction size in lower soil depths of silvopasture suggests that planting of trees into traditional agricultural landscapes will promote longer-term storage of C in the soil.  相似文献   
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This study aimed to evaluate possible health effects associated with long-term occupational exposure to low levels of mercury vapors. Forty-six subjects exposed to mercury and 65 healthy unexposed employees were studied. The subjects were administered a questionnaire on experienced symptoms and underwent clinical examinations as well as routine biochemical tests. Atmospheric and urinary concentrations of mercury were measured, too. Environmental concentrations of mercury were estimated to be 3.97 ± 6.28 μg/m(3) and urinary concentrations of mercury in exposed and referent groups were 34.30 ± 26.77 and 10.15 ± 3.82 μg/dm(3), respectively. Additionally, symptoms such as somatic fatigue, anorexia, loss of memory, erethism, blurred vision and teeth problems were significantly more common among exposed individuals. These observations indicate that occupational exposure to mercury vapors, even at low levels, is likely to be associated with neurological and psychological symptoms.  相似文献   
167.
Selection of the appropriate site for solid waste facilities is a complex problem and requires an extensive evaluation process, because it is very difficult to develop a selection criterion that can precisely describe the preference of one location over another. Therefore selection of these sites can be viewed as a multiple criteria decision-making or multiple attributes decision-making problem. For this purpose, we propose a technique that can effectively take managerial preferences and subjective data into consideration, along with quantitative factors. The tool proposed here relies on the use of the analytical network process (ANP) and to help integrate managerial evaluations into a more quantitatively based decision tool, data envelopment analysis (DEA) is applied. In this paper, a location selection procedure is presented to construct an undesirable facility applying ANP and DEA approaches in two stages. In the first stage ANP approach is used, results of this stage are inputs for the second stage. In this stage, DEA is applied to select the best location. Finally, to illustrate the proposed framework, at "Results and discussion" section, a total of four undesirable facility locations are evaluated.  相似文献   
168.
The effectiveness of Fenton process in municipal landfill leachate treatment, as a pre- or post-treatment approach, has been demonstrated. However, no general recommendations of universal validity could be made in the term of optimized conditions affecting Fenton process. At the first stage of this study, collected leachate samples from Aradkooh site, Tehran, Iran, were investigated using one-factor-at-a-time method to find out optimum coagulation pH and flocculation time values. Subsequently, the obtained results in addition to data issued previously by the authors were employed to develop a predictive model of the true response surface, namely chemical oxygen demand (COD) removal efficiency. Finally, the main parameters of Fenton procedure, i.e. initial pH, [H(2)O(2)]/[Fe(2+)] molar ratio, Fe(2+) dosage, and coagulation pH were optimized taking advantage of the above-mentioned quadratic model. The derived second-order model included both significant linear and quadratic terms and seemed to be adequate in predicting responses (R(2)=0.9896 and prediction R(2)=0.6954). It was found that the interaction between initial pH and Fe(2+) dosage has a significant effect on COD removal. While, the optimal [H(2)O(2)]/[Fe(2+)] molar ratio was independent of ferrous ion dosage. The optimum conditions for the maximum COD removal of 50.76% for the parameters of initial pH, [H(2)O(2)]/[Fe(2+)] molar ratio, Fe(2+) dosage, and coagulation pH were found to be 5.8, 8.0, 22,500mg/L, and 8.7 respectively.  相似文献   
169.
In this study we use a cross-sectional survey to evaluate the nutritional response to the 1998 Bangladesh Flood Disaster by 15 relief agencies using standards developed by the Sphere Project. The Sphere Project is a recent attempt by agencies around the world to establish universal minimum standards for the purpose of ensuring quality and accountability in disaster response. The main outcomes measured were resources allocated to disaster relief types of relief activities and percentage of agencies meeting selected Sphere food aid and nutrition indicators. Although the process of nutritional response was measured, specific nutritional and health outcomes were not assessed. This review found that self-reported disaster and nutritional resources varied widely between implementing agencies, ranging from US $58,947 to $15,908,712. The percentage of resources these agencies allocated to food aid and nutritional response also varied, ranging from approximately 6 to 99 per cent of total resources. Agencies met between 8 and 83 per cent of the specific Sphere indicators which were assessed Areas in which performance was poor included preliminary nutritional analysis; beneficiary participation and feedback; disaster preparedness during non-emergency times; monitoring of local markets and impact assessment. Agencies were generally successful in areas of core humanitarian response, such as targeting the vulnerable (83 per cent) and monitoring and evaluating the process of disaster response (75 per cent). The results here identify both strengths and gaps in the quality of humanitarian response in developing nations such as Bangladesh. However, they also raise the question of implementing a rights-based approach to disaster response in nations without a commitment to meeting positive human rights in non-disaster times.  相似文献   
170.
It is often unclear what the role of a local jurisdiction is with regard to land use management on nearby federal properties. Yet federal lands clearly impact nearby local communities. The US Department of Energy (DOE), with over 100 sites across the United States with varying degrees of environmental contamination, may be in a very difficult position with regard to relationships with local government about land use. Yet few, if any, studies have examined DOE land use issues. This study asks: (1) In general, how do local planners feel about federal government relationships with them? (2) Do local planners feel differently about the DOE than they do about other federal agencies? (3) What reasons explain any differences observed in answer to the second question? To answer these questions, local planners were interviewed from communities adjacent to non-DOE federal properties, and their responses compared to those of planners located near DOE facilities in the same regions. Findings showed that compared to other federal agencies that own land in the same regions, the DOE is relatively poorer at actively involving local officials in land use decisions at its sites. Primary reasons are the historic legacy of a culture of secrecy, focus on mission, and especially the lack of experience, training, or mandates in local planning cooperation. Findings also suggest that this attitude is markedly stronger in areas west of the Rocky Mountains. Recommendations for improved federal–local communications include the development of a vision for local government involvement that is supported by top levels of management and filtered effectively to the site level.  相似文献   
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