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51.
The chemical composition of persistent organic pollutants (POPs) in the environment is not uniform throughout the world, and these contaminants contain many structurally different lipophilic compounds. In a well-defined study cohort in the Slovak Republic, the POP chemicals present in the peripheral blood of exposed children were chemically analyzed. The chemical analysis data revealed that the relative concentration and profile of structurally different organic pollutants, including polychlorinated biphenyls (PCBs), 2,2′-bis(4-chlorophenyl)-1,1-dichloroethylene (p,p′-DDE), 2,2′-bis(4-chlorophenyl)-1,1,1-trichloro-ethane (p,p′-DDT), hexachlorobenzene (HCB) and β-hexachlorocyclohexane (β-HCH), may vary from individual to individual, even within the same exposure area. These chemicals can be broadly classified into two groups. The first group, the PCB congeners, primarily originated from industrial compounds and their byproducts. The second group of compounds originated from or was commonly used in the agricultural sector (e.g., DDT, HCB). The objective of this study was to examine the effects of the two POP exposure profiles on gene expression. For the study population, we selected pre-pubertal girls (mean age of 46.2 ± 1.4 months) with high POP concentrations in their blood (> 75% tile of total POP) and classified them in the high ‘PCB’ group when the total PCB concentration was significantly higher than the total concentration of other POP components and in the ‘Other Than PCB’ (OTP) group, when the total PCB concentration was significantly lower than the concentration of the other major POP constituents. A matched control group of girls (< 25% tile of total POP) was selected for comparison purpose (n = 5 per group). Our aims were to determine whether there were any common effects of high POP exposure at a toxicogenomic level and to investigate how exposure may affect physiological functions of the children in two different exposure scenarios. Global gene expression analysis using a microarray (Affymetrix Gene Chip Human genome U133 Plus 2.0 Array) platform was conducted on the total RNA of peripheral blood mononuclear cells from the girls. The results were analyzed by Partek GS, Louis, MI, which identified twelve genes (ATAD2B, BIVM, CD96, CXorf39, CYTH1 ETNK1, FAM13A, HIRA, INO80B, ODG1, RAD23B, and TSGA14) and two unidentified probe sets, as regulated differentially in both the PCB and OTP groups against the control group. The qRT-PCR method was used to validate the microarray results. The Ingenuity Pathway Analysis (IPA) software package identified the possible molecular impairments and disease risks associated with each gene set. Connective tissue disorders, genetic disorders, skeletal muscular disorders and neurological diseases were associated with the 12 common genes. The data therefore identified the potential molecular effects of POP exposure on a genomic level. This report underscores the importance of further study to validate the results in a random population and to evaluate the use of the identified genes as biomarkers for POP exposure.  相似文献   
52.
探讨了有机物特性及中间产物H2O2在催化臭氧化中的作用。结果表明,有机物在自由基链反应过程中的特性直接影响催化臭氧化的降解效率。当目标有机物是对链反应具有促进作用的甲酸时,自由基引发反应可以明显提高甲酸的臭氧化效率。当目标有机物是对自由基链反应具有抑制剂作用的乙酸时,O3和Fe2+/O3对乙酸有着相似的降解效率。以上结果表明,自由基引发反应并不是臭氧化降解效率提高的充分条件。另外,当臭氧化过程有H2O2产生时,必须考虑类Fenton反应对臭氧化效率的影响。  相似文献   
53.
用CAF涡凹气浮设备处理含油污水   总被引:5,自引:0,他引:5  
用CAF涡凹气浮设备进行含油污水处理的试验,结果表明:当进水油、CODCr平均浓度分别为40.7mg/L、883.8mg/L,平均去除率分别为86.05%,32.62%,出水可满足后续生化处理的进水要求。  相似文献   
54.
在水流量为模糊随机变量且河流中工业污水含量标准给定的条件下,以极小化污水处理费用为目标,建立了水污染控制系统问题的模糊随机机会约束规划模型。采用将模糊随机模拟、神经元网络及遗传算法相结合的混合遗传算法来求解该模型,并用算例进行了验证,结果表明该算法是有效可行的。  相似文献   
55.
随着中国城市化进程的加快,城市改造的速度也在加快,但是由于缺少科学的理论指导,城市改造往往表现为盲目的重建。天津市在城市的改造中,以生态学原理指导城市改造,注重城市景观多样性的保护和发展,成功地对部分城区进行了改造。对城市改造应遵循的生态学理念进行了阐述,并指出,生态学原理的运用是解决目前中国城市改造中存在的问题的有效途径;并结合天津市“五大道”和海河改造的实例说明生态学原理在城市改造中的应用。  相似文献   
56.
Mutagenicity of surface water in Lake Taihu was monitored by genotoxicological methods. The goal is to determine the situation concerning the contamination by mutagens, their distribution in the lake, and the potential effect on public health. In this study, the micronucleus test of Vicia faba root tip, a standard monitoring technique now in China, was carried out to make a preliminary screening of environmental mutagens in 39 representative sites of the lake. Highly significant differences in MCN permillage (average number of micronuclei per 1000 cells) and PI (pollution index) values were found among these sites. From the results, a rough distribution of the contamination could be obtained: mainly concentrated in the north-west area of the lake from several tributaries flowing into the lake. In order to provide further evidence, organic extracts from four entrances and one outlet of the five major tributaries were examined by the micronucleus test of human peripheral lymphocytes. The results were in accord with those of the micronucleus tests using Vicia faba. The tests also revealed that the intensity and mechanism of the pollutants were diverse in the different sources.  相似文献   
57.
岷江上游典型退化生态系统鸟类物种多样性的初步研究   总被引:7,自引:0,他引:7  
在岷江上游典型的退化生态系统(十里乡)、逐渐恢复的生态系统(茂县生态站,1986年开始人工恢复)和原始森林及次生高山草甸生态系统(上卡卡沟)选择样地,对其乌类物种多样性在夏秋两季进行了调查,并计算其多样性指数和均匀度指数。各多样性指数的变化有微小差异,但总体一致。综合夏秋两季,茂县生态站夏季的鸟类丰富度、多度和多样性指数值最高,十里乡秋季的鸟类丰富度、多样性指数值最低,上卡卡沟秋季的均匀度指数最高。各群落的相似性指数较低,表明各群落组成有较大差异,拟合各样地鸟类的物种-多度曲线模型,十里乡鸟类的物种-多度模型与对数级数分布拟合,茂县鸟类的物种-多度模型与对数级数分布相似,上卡卡沟鸟类的物种-多度模型与分割线段模型分布拟合,夏秋季的物种-多度模型无明显差异,仅茂县的物种-多度模型与风何级数分布拟合,并对鸟类对生态恢复的监测效应进行了探讨,认为物种-多度模型是良好的生境变化生物指示因子,图3表4参19。  相似文献   
58.
我国正在起草《土壤污染防治法》,这将为我国土壤、场地污染防治管理提供基本法律依据,并逐步建成完善的污染场地管理的法律制度体系。其中,监管体系、资金体系和责任体系是污染场地管理体系中的3大重要方面。美国、日本等发达国家和我国台湾地区在各自污染场地管理法律制度体系中,均规定了明确的监管主体,采用了多样化的监管手段,建立了可持续的污染场地专项基金,确定了明晰的责任判定和追究原则,为我国场地污染防治立法和制度设计中监管体系、资金体系和责任体系的建设提供了宝贵的借鉴。  相似文献   
59.

Resuspended sediment is an important carrier of underwater material circulation, and bed shear stress is usually considered to be closely related to sediment resuspension. To analyze the resuspension dynamics in severely eutrophic Lake Chaohu, China, three fixed stations were set up to collect wave, current, and suspended sediment concentrate (SSC) data under windy weather, and two significant sediment resuspension events were recorded. Based on the Gaussian-shaped spectrum characteristics of waves in Lake Chaohu, the wave orbital velocity was estimated by using the wave parameter method. The selection of the general wave spectrum is important for the accurate estimation of wave orbital velocity. The results of the simple linear wave method were very similar to those of the wave parameter method with a Gaussian-shaped spectrum in Lake Chaohu. The total bed shear stress combining waves and currents during the observation period was calculated, and most of it was contributed by wind-driven waves. The bed material of Lake Chaohu has silt-enriched and weak cohesive features, and an examination of critical shear stress showed that the modified Shields curve method was still applicable to Lake Chaohu. When a sediment resuspension event occurred, the vertical gradient of SSC increased significantly, and the peak SSC value depended on the peak value of bed shear stress. As a predictor, bed shear stress only showed a good linear relationship during sediment resuspension events. At other times, the prediction of SSC using bed shear stress may be biased, especially at the time after a significant sediment resuspension event.

  相似文献   
60.
研究基于阿尔山市2011年-2015年统计年鉴数据测算该市五年来人均生态足迹及生态承载力.结果表明:(1)阿尔山市2011年-2015年人均生态足迹(2.9223~4.0030 hm2·cap-1)呈现"先增后减再增"的变化趋势,以耕地占比最大;(2)人均生态承载力呈现"先减后增"的变化趋势,以林地贡献最大;(3)五年来总体表现为生态盈余,但牧草地及耕地出现生态赤字;(4)当地万元GDP生态足迹先减后增,资源利用率较低.阿尔山市目前整体社会经济发展供给大于需求,基本维持可持续发展.  相似文献   
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