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521.
A first review on occurrence and distribution of pharmaceuticals and personal care products (PPCPs) is presented. The literature survey conducted here was initiated by the current Assessment of the Arctic Monitoring and Assessment Programme (AMAP). This first review on the occurrence and environmental profile of PPCPs in the Arctic identified the presence of 110 related substances in the Arctic environment based on the reports from scientific publications, national and regional assessments and surveys, as well as academic research studies (i.e., PhD theses). PPCP residues were reported in virtually all environmental compartments from coastal seawater to high trophic level biota. For Arctic environments, domestic and municipal wastes as well as sewage are identified as primary release sources. However, the absence of modern waste water treatment plants (WWTPs), even in larger settlements in the Arctic, is resulting in relatively high release rates for selected PPCPs into the receiving Arctic (mainly) aquatic environment. Pharmaceuticals are designed with specific biochemical functions as a part of an integrated therapeutically procedure. This biochemical effect may cause unwanted environmental toxicological effects on non-target organisms when the compound is released into the environment. In the Arctic environments, pharmaceutical residues are released into low to very low ambient temperatures mainly into aqueous environments. Low biodegradability and, thus, prolonged residence time must be expected for the majority of the pharmaceuticals entering the aquatic system. The environmental toxicological consequence of the continuous PPCP release is, thus, expected to be different in the Arctic compared to the temperate regions of the globe. Exposure risks for Arctic human populations due to consumption of contaminated local fish and invertebrates or through exposure to resistant microbial communities cannot be excluded. However, the scientific results reported and summarized here, published in 23 relevant papers and reports (see Table S1 and following references), must still be considered as indication only. Comprehensive environmental studies on the fate, environmental toxicology, and distribution profiles of pharmaceuticals applied in high volumes and released into the Nordic environment under cold Northern climate conditions should be given high priority by national and international authorities.  相似文献   
522.
我国4个大城市空气PM_(2.5)、PM_(10)污染及其化学组成   总被引:52,自引:3,他引:49  
报告了 1 995~ 1 996年在中国的广州、武汉、兰州、重庆 4大城市 8个采样点 PM2 .5 、PM2 .5~ 1 0 和 PM1 0 的监测结果。结果表明 ,1 995年 PM2 .5 年均值浓度为 57~ 1 60 μg/m3,比美国 1 997年颁布的标准值 (1 5μg/m3)高 2 .8~ 9.7倍。PM1 0 年日均值为 95~ 2 73μg/m3。除武汉市 1个对照点外 ,其余 7个监测点的 PM1 0 均超过我国空气质量二极标准 (1 0 0μg/m3)2 8%~ 1 73 % ,比美国标准 (50μg/m3)超过更多 ,说明污染是相当严重的。用 XRF分析了 PM2 .5 、PM2 .5~ 1 0 中 4 2种化学元素 ,结果表明 ,燃煤、燃油和其它工业污染的元素 As、Pb、Se、Zn、Cu、Cl、Br、S在这些颗粒物中有明显富集 ,特别是在PM2 .5 中的富集倍数达数十倍至数万倍 ,对人体健康有很大危害  相似文献   
523.
Enforcement gaps are an especially vexing problem in China due to pervasive "pro-growth" local government priorities, the weak administrative capacity of environmental agencies themselves, and relatively weak levels of societal support for a cleaner environment. This study seeks to examine this problem from the perspective of the local enforcement officials by empirically examining the relationships between these and other influences on their perceptions of enforcement effectiveness. Using samples of enforcement officials from the fast-growing cities of Chengdu, Dalian, and Guangzhou, this study finds that many of the more commonly cited problems related to regulatory enforcement were not as influential in accounting for variations in perceptions of enforcement effectiveness than the current literature might suggest. Moreover, this study also finds that the pattern of influences varies greatly across jurisdictions, with only the officials' belief in the legitimacy of the governments' policies being significant in all three samples. Strong influences on perceptions of enforcement effectiveness in two of the three samples include the environmental values of enforcement officials, their perceptions of organizational capacity for enforcement, and their assessment of government support for environmental protection. Although government support was found to be a strong predictor of enforcement effectiveness in two of the three samples, the influence of societal support had a somewhat mixed and more complicated effect. In addition, this study suggests that further improvements in enforcement effectiveness may be possible by cultivating or selecting enforcement officials with strong environmental values and beliefs in the legitimacy of the government's environmental policy to take charge of enforcement. Because it is generally accepted that local environmental protection bureaus are generally upgrading their organizational capacity for improvement as the result of increasing central government support for environmental protection and institutional restructuring, and because environmental awareness in China is growing, this study suggests that some incremental progress is likely in China's efforts to close the enforcement gap. Unfortunately, such improvements are likely to be masked by the steep trajectory of economic growth, the narrow scope of regulatory control (i.e., with scant attention paid to nonindustrial sources), and the migration of industrial pollution to rural areas.  相似文献   
524.
Emission of NOx is of primary environmental concern in the oil sands industry. Selective catalytic reduction (SCR) is one of the best NOx reduction technologies. The present study discusses the testing of a mechanistic kinetic model for the SCR of NOx to describe the kinetics of V2O5/TiO2 catalysis at atmospheric pressure and a temperature of 623 K in a monolith honeycomb reactor. The modeling results impart insight into the significance of the diffusion with reaction steps and guidance for optimal monolith design for SCR. The validated expression would predict the conversion performance of the catalysts for different values of temperature inlet and ammonia concentration. A good agreement between experimental and model results has been obtained. A heterogeneous numerical model consisting of coupled mass and momentum balance equations was solved using the finite elements method without neglecting the axial dispersion term. The operating range for the catalyst relies on the NO conversion and emission. The optimum operating range for the best performance of the reactor is discussed.  相似文献   
525.
The Scottish Raptor Monitoring Scheme (SRMS) comprises 7 partner organizations and was established in 2002 after i) the publication of the UK Government's Raptor Working Group Report that made recommendations for enhanced monitoring, ii) increased applied data needs (e.g., for site designation), and iii) concerns for the status of some species. The SRMS has 3 major objectives: i) to facilitate cooperation between parties; ii) to provide robust information on Scottish raptor populations by determining trends in numbers, range, survival, and productivity and understanding the causes of change; and iii) to maintain high and uniform standards for the collection, collation, auditing, and analysis of data and reporting of information. Data are collected for 19 species: 14 diurnal raptors, 4 owls, and 1 corvid, the Common Raven. Here we describe the development of the scheme, challenges, and achievements during its first 4 y, the nature and value of the data collected, and plans for the future.  相似文献   
526.
Aerial surveys of Caspian seals on the winter ice field in Kazakhstan territorial waters were carried out in February 2005 and 2006 to assess the annual pup production for the species and natural predation on newborn pups. Estimated pup production was 21063 in 2005 and 16905 in 2006 (including an estimated figure for pups born in Russian territory in each year). The breeding population size of approximately 20 000 females is much less than published estimates from the late 1980s. Eagles were the principal natural predators of pups. Commercial icebreaker routes passed through areas of dense pup concentrations in 2006, although not in 2005. Our findings have important implications for the development of conservation strategies for the species. Natural mortality, loss to predators, and, more important, the current hunting quota substantially exceed the recruitment of the Caspian seal population. Anthropogenic sources of mortality should be managed to avoid further declines in the species.  相似文献   
527.
Building recycling rates through the informal sector   总被引:1,自引:0,他引:1  
Many developing country cities aspire to modern waste management systems, which are associated with relatively high recycling rates of clean, source separated materials. Most already have informal sector recycling systems, which are driven solely by the revenues derived from selling recovered materials, even though they are saving the formal sector money by reducing waste quantities. There is clear potential for 'win-win' co-operation between the formal and informal sectors, as providing support to the informal sector, to build recycling rates and to address some of the social issues could reduce the overall costs of waste management for the formal sector. This paper shows that recycling rates already achieved by the informal sector can be quite high, typically in the range from 20% to 50%; often up to half of this is in the form of clean, source separated materials collected directly from households and businesses by itinerant waste buyers. Four country case studies provide a number of lessons on how this solid foundation could be used to build high recycling rates of clean materials.  相似文献   
528.
Identifying the errors that frequently result in the occurrence of rail incidents and accidents can lead to the development of appropriate prevention and/or mitigation strategies. Nineteen rail safety investigation reports were reviewed and two error identification tools, the Human factors analysis and classification system (HFACS) and the Technique for the retrospective and predictive analysis of cognitive errors (TRACEr-rail version), used as the means of identifying and classifying train driver errors associated with rail accidents/incidents in Australia. We aimed to identify the similarities and differences between the techniques in their capacity to identify and classify errors and also to determine how consistently the tools are applied. The HFACS analysis indicated that slips of attention (i.e. ‘skilled based errors’) were the most common ‘unsafe acts’ committed by drivers. The TRACEr-rail analysis indicated that most ‘train driving errors’ were ‘violations’ while most ‘train stopping errors’ were ‘errors of perception’. Both tools identified the underlying factors with the largest impact on driver error to be decreased alertness and incorrect driver expectations/assumptions about upcoming information. Overall, both tools proved useful in categorising driver errors from existing investigation reports, however, each tool appeared to neglect some important and different factors associated with error occurrence. Both tools were found to possess only moderate inter-rater reliability. It is thus recommended that the tools be modified, or a new tool be developed, for complete and consistent error classification.  相似文献   
529.
Estimates of streambed water flux are needed for the interpretation of streambed chemistry and reactions. Continuous temperature and head monitoring in stream reaches within four agricultural watersheds (Leary Weber Ditch, IN; Maple Creek, NE; DR2 Drain, WA; and Merced River, CA) allowed heat to be used as a tracer to study the temporal and spatial variability of fluxes through the streambed. Synoptic methods (seepage meter and differential discharge measurements) were compared with estimates obtained by using heat as a tracer. Water flux was estimated by modeling one-dimensional vertical flow of water and heat using the model VS2DH. Flux was influenced by physical heterogeneity of the stream channel and temporal variability in stream and ground-water levels. During most of the study period (April-December 2004), flux was upward through the streambeds. At the IN, NE, and CA sites, high-stage events resulted in rapid reversal of flow direction inducing short-term surface-water flow into the streambed. During late summer at the IN site, regional ground-water levels dropped, leading to surface-water loss to ground water that resulted in drying of the ditch. Synoptic measurements of flux generally supported the model flux estimates. Water flow through the streambed was roughly an order of magnitude larger in the humid basins (IN and NE) than in the arid basins (WA and CA). Downward flux, in response to sudden high streamflows, and seasonal variability in flux was most pronounced in the humid basins and in high conductivity zones in the streambed.  相似文献   
530.
1983—1986年测量了京津地区的臭氧浓度。发现其浓度的全年季节和日变化一般与日照强度变化一致。并且浓度有逐年增加的趋势,还发现下风方向浓度高于上风方向及夜间多次出现峰值的现象。  相似文献   
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