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1.
A time series model was fitted to the pollen concentration data collected in the Greater Cincinnati area for the Cincinnati Childhood Allergy and Air Pollution Study (CCAAPS). A traditional time series analysis and temporal variogram approach were applied to the regularly spaced databases (collected in 2003) and irregularly spaced ones (collected in 2002), respectively. The aim was to evaluate the effect of the sampling frequency on the sampling precision in terms of inverse of standard error of the overall level of mean value across time. The presence of high autocorrelation in the data was confirmed and indicated some degree of temporal redundancy in the pollen concentration data. Therefore, it was suggested that sampling frequency could be reduced from once a day to once every several days without a major loss of sampling precision of the overall mean over time. Considering the trade-offs between sampling frequency and the possibility of sampling bias increasing with larger sampling interval, we recommend that the sampling interval should take values from 3 to 5 days for the pollen monitoring program, if the goal is to track the long-term average.  相似文献   
2.
Anupgarh is the most fertile area of Rajasthan state where a variety of seasonal crops are grown. The availability of three manmade canals has enhanced the agricultural activities in this area. The farmers use huge amounts of pesticides to increase the crop productivity. Exposure of humans to these hazardous chemicals occurs directly in the fields and indirectly due to consumption of contaminated diet, or by inhalation or by dermal contact. The organochlorine pesticides are reported to be lipophilic and their presence in human milk and blood has been documented in different parts of the world. Blood and milk samples were collected from lactating women who were divided into four groups on the basis of different living standards viz residence area, dietary habits, working conditions and addiction to tobacco. The level of total organochlorine pesticides in blood ranged from 3.319mg/L—6.253mg/L while in milk samples it ranged from 3.209Mdash;4.608 mg/L. The results are in concurrence with the reports from other countries.  相似文献   
3.
A standardized method of moss exposition for assessing variations in nitrogen deposition was tested in the western part of Germany. Six pleurocarpous moss species were transplanted to two sites differing in their deposition rates but being comparable as to their climatic conditions. The mosses were exposed in standardized containers over a period of 12 months; the focus of interest was the effect of N deposition on nitrogen content and on 15N natural abundance (δ15N-values). Within the first nine months only trends could be observed. However, after one year all species tested showed significantly higher N concentrations at the highly polluted site. Besides, more negative δ15N-values possibly reflecting the higher ammonium input were detected at this site. Surprisingly, most of the plants though being kept in plastic containers without a favourable substratum did not show any conspicuous deficiency symptoms. The potential advantages of a standardized moss exposition for N monitoring purposes are discussed. It is concluded that the method presented here can yield significant results in particular if the number of testing sites is increased.  相似文献   
4.
1 INTRODUCTIONIn the past, natural resources management initiatives havefocused on large but specific sector projects such as dams,reservoirs for water supply schemes, irrigation systems,crop production, at forestation, etc. Often these projectswere treated as technical and administrative issues ratherthan as a socio-economic and political one. However, thehigh social and environmental cost of such schemes haveled to a change of paradigm since the 1980s towards small-scale community projec…  相似文献   
5.
Analysis and residue levels of forchlorfenuron (CPPU) in watermelons   总被引:2,自引:0,他引:2  
This paper describes the application of liquid chromatography-tandem mass spectrometry (LC/MS-MS) for analysis of residues of forchlorfenuron (CPPU), a new plant growth regulator, in watermelons, after a sample preparation step based on the buffered Quick, Easy, Cheap, Effective, Rugged and Safe extraction method. Analytical determinations were carried out in a triple quadrupole system fitted with an electrospray interphase operating in the positive ionisation mode (ESI+). Three simultaneous MS-MS transitions of the quasi-molecular ion m/z 248 (precursor ion) were monitored for data acquisition (248 > 129, 248 > 155, and 248 > 248), using the transition 248 > 129 for quantitation. Recovery studies on watermelons at levels of 1-200 microg/kg, performing five replicates at each level and using bracketing single-level calibration with matrix-matched standards for quantitation, gave forchlorfenuron mean recoveries ranging from 82 to 106% with relative standard deviations (RSD) lower than 18%. The limit of determination was established at 1 microg/kg. The method was applied to evaluate the persistence of forchlorfenuron residues in watermelons grown in plastic greenhouses, after applying an individual spray treatment to the flower ovary at the anthesis stage (45 mu g/flower and 60 mu g/flower for cv "Extazy" and cv "reina de corazones" watermelons, respectively). One month after treatment, 20 "Extazy" watermelon units (1.5-2 kg/unit) and 20 "Reina de corazones" watermelon units (4-5 kg/unit) were collected and analyzed individually. None of the samples contained forchlorfenuron residues higher than 1 microg/kg.  相似文献   
6.
This article develops a methodology aimed at generating a systematic social diagnosis of social and natural landscapes. The analytical process is divided into six easily replicable and causatively connected steps. The goal is two-fold: first, to present the inextricable connections between physical landscapes and the communities that occupy them. And second, to provide a fundamental tool to public policy designers that should simultaneously improve social acceptability of conservation policies and policy efficiency and effectiveness. Finally, this methodology is consciously heterogeneous from a theoretical perspective. This article puts together, in fruitful dialogue, contributions from varying places on the social theory spectrum: from political economy to poststructural theory.  相似文献   
7.
The Air Quality Index (AQI) is an index for reporting daily air quality. A study on the annual and seasonal variations of Air Quality Index over a period of 9 years (1996-2004) based on daily averaged concentration data of criteria air pollutants has been conducted for Delhi. An attempt has been made to quantify the changes in the AQI on annual and seasonal (winter, summer, monsoon and post monsoon) basis for 9 years. Measurements for the seven monitoring sites (Nizamuddin, Ashok Vihar, Shahzada Baug, Shahadara, Janakpuri, Sirifort and ITO) in Delhi were analysed and trends were also compared amongst these sites. Maximum Operator Function method was used to compute the Air Quality Index of the above areas and percentage variations in different severity class is discussed which provides in depth analysis of the trends. The best air quality was depicted by Shahzada Baug followed by Shahdara, both of these were classified as industrial areas indicating that policy measures relating to the industries in the city during past years have helped in improving the air quality. The air quality in other areas have improved slightly in the span of nine years but still remains critical indicating continued rigorous efforts in this direction. Increased traffic density seems to have resulted into the worst air quality at ITO in the city amongst all the monitoring stations. There is a shift for the worst AQI in the city from winter to summer season in a time span of these nine years. Change of season for worst AQI from Winter to Summer may also be likely due to increased photochemical reactions playing major role with change in the nature of emissions imposed due to different control measures such as CNG implementation, significant shift to LPG in domestic sector etc. calling for a detailed study, those which started after the year 2000. After the year 2000, there is a significant increase in the Nitrogen-dioxide (NO(2)) concentration at all stations. ITO which has shown continuous exponential increase in pollution levels has first time showed a declining AQI trend in the year 2004 and one of the contributing factors could have been the Delhi metro (initiated in 2002) passing through congested neighbouring areas causing traffic decongestion here. In general, the areas which are farthest from metro route viz., Siri-fort, Nizamuddin, Janakpuri etc. did not record declining AQI in 2003 onwards as happened with stations closer to Metro route such as Ashok Vihar and ITO. An attempt has been made to quantify the reasons that lead to the changes in the values of the AQI.  相似文献   
8.
宁波市饮用水源地爆发蓝藻水华时微囊藻毒素的污染分析   总被引:3,自引:1,他引:2  
通过固相萃取净化,建立了超高效液相色谱-串联四极杆质谱法测定水中微囊藻毒素MC-LR和MC-RR的方法,并用该方法监测了宁波市两个饮用水源地爆发蓝藻水华时水体中的微囊藻毒素.监测结果表明,姚江水体中的微囊藻毒素污染水平低,MC-LR和MC-RR没有被检出;梅湖水库水体中MC-RR也未被检出,采取措施后,虽MC-LR有时被检出,但最高时也低于国家标准值(1.0μg/L).  相似文献   
9.
A review of existing life cycle assessments (LCAs) on paper and cardboard waste has been undertaken. The objectives of the review were threefold. Firstly, to see whether a consistent message comes out of published LCA literature on optimum disposal or recycling solutions for this waste type. Such message has implications for current policy formulation on material recycling and disposal in the EU. Secondly, to identify key methodological issues of paper waste management LCAs, and enlighten the influence of such issues on the conclusions of the LCA studies. Thirdly, in light of the analysis made, to discuss whether it is at all valid to use the LCA methodology in its current development state to guide policy decisions on paper waste. A total of nine LCA studies containing altogether 73 scenarios were selected from a thorough, international literature search. The selected studies are LCAs including comparisons of different management options for waste paper. Despite claims of inconsistency, the LCAs reviewed illustrate the environmental benefits in recycling over incineration or landfill options, for paper and cardboard waste. This broad consensus was found despite differences in geographic location and definitions of the paper recycling/disposal systems studied. A systematic exploration of the LCA studies showed, however, important methodological pitfalls and sources of error, mainly concerning differences in the definition of the system boundaries. Fifteen key assumptions were identified that cover the three paper cycle system areas: raw materials and forestry, paper production, and disposal/recovery. It was found that the outcome of the individual LCA studies largely depended on the choices made in some of these assumptions, most specifically the ones concerning energy use and generation, and forestry.  相似文献   
10.
Surveys of water recreational activities were conducted in the Peel-Harvey estuary. Channels used by recreationists to gain information about water quality, the perception of water quality and resulting behaviour were investigated. This study showed that personal perception, local knowledge and history, absence of warnings and residency were major factors contributing to risk perception and behaviour in this recreational community. Management strategies should take this information into account to achieve maximal outcomes.  相似文献   
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