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161.
We applied statistical methods to the data of a 5-year sampling period to characterize the features of trace elements in airborne particulate matter at the South Adriatic Coast. The analysis of surface soil samples was also performed. The data were processed by cluster analysis, enrichment factor determination and receptor rose statistics. It is shown that the principal element association consists of Fe, Mn and Ti originating from surface material resuspension. Hg and Se were shown to originate from more complex natural and anthropogenic processes. A strong emission source of Cd and Se was identified in the SSE direction.Selected article from the Regional Symposium on Chemistry and Environment Krusevac, Serbia, June 2003, organized by Dr. Branimir Jovancicevic.  相似文献   
162.
随着营养学和现代生物技术的发展,发现日粮中微量元素在一定程度上影响动物基因的表达,这种作用可以发生在转录水平,也可以发生在转录后水平,进而影响机体的整个代谢过程.综述微量元素对基因表达调控的主要机制、存在方式,并介绍铁、硒、锌、铜、铅等元素对部分基因表达的主要影响.  相似文献   
163.
The Okchon black shale in Korea provides an important example of natural geological materials containing toxic elements; the Chung-Joo, Duk-Pyung, Geum-Kwan, I-Won and Chu-Bu areas are underlain by these black shales and slates of the Guryongsan Formation. This formation is part of the Okchon Group which is found in the central part of Korea. Geochemical surveys were undertaken in these five study areas in the Okchon Zone in order to examine the level of enrichment and dispersion patterns of potentially toxic elements in rocks and soils. After appropriate preparation, samples were analysed by instrumental neutron activation analysis and inductively coupled plasma atomic emission spectrometry for a range of elements. Arsenic, Cu, Mo, V, U and Zn are highly enriched in the Okchon black shales and their mean concentrations are significantly higher than those in black slates. These elements are closely associated with one another from a geochemical viewpoint and may be enriched simultaneously. Mean concentrations of As, Mo and U in soils derived from black shales occurring in the Duk-Pyung and Chu-Bu areas are higher than the permissible level suggested by Kloke (1979), and the enrichment index decreases in the order of Duk- Pyung > Chu-Bu > Chung-Joo > Geum-Kwan = I-Won areas. Uranium-bearing minerals such as uraninite and brannerite have been identified in black shales from the Chung-Joo area by electron probe micro-analysis. Uraninite grains are closely associated with monazite and pyrite with a grain size ranging from 2m to 10m whereas brannerite grains occur as a euhedral form 50m in diameter.  相似文献   
164.
燃煤灰渣中微量元素分布规律的研究   总被引:23,自引:2,他引:23  
研究了锅炉飞灰和底灰中15种微量元素的含量和分布,探讨了煤炭燃烧后,微量元素在灰渣中的集散及其影响因素,飞灰和底灰中大多数元素高于全国土壤背景值,7种元素高于克拉克值,其余8种低于克拉克值,飞灰中多数元素的地球化学富集因子高于1,呈富集状态,而底灰中多数元素富集因子小于1,飞灰和底灰中微量元素含量与煤中微量元素含量呈线性关系,微量元素含量不仅与煤有关,还受锅炉燃烧方式等人为因素影响。  相似文献   
165.
东北、内蒙古东部地区煤炭中微量元素含量及分布规律   总被引:14,自引:0,他引:14  
研究了东北和内蒙东部各矿区煤炭中As,Ba,Be,Cb,Co,Cr,Cu,Hg,Li,Mn,Ni,Pb,Se,Sr,V,Zn,Zr的含量水平及分布规律.煤灰灰分中多数元素含量高于克拉克值、土壤背景值及植物干物质中含量,呈富集状态.相关矩阵和聚类分析表明,煤炭中微量元素含量与基质元素有密切的依存性.由于复杂的成煤过程,煤炭中微量元素呈现独特的集散规律.  相似文献   
166.
POLLUTION THREATS IN THE MEDITERRANEAN SEA: AN OVERVIEW   总被引:3,自引:0,他引:3  
This overview summarises the present knowledge on major sources of pollution, which are of concern for the Mediterranean Sea. Eutrophication, red tides, organic loads, hydrocarbon spills, heavy metal contamination and their biological effects are described on the light of the ecological characteristics of the Mediterranean. In particular special attention is paid to the "new pollution" processes; i.e. , the introduction of novel substances with biological activity that might have synergetic effects with "classical pollutants". Different compartments and marine ecosystems are considered and compared. The degree of anthropogenic impact and its apparent trends are discussed. Possible monitoring plans and remedial actions for a sustainable management of coastal zones subjected to increasing pollution are also suggested.  相似文献   
167.
Owing to its unique nutritional and immunological characteristics, human milk is the most important food source for infants. Breast milk can, however, also be a pathway of maternal excretion of toxic elements. Selected toxic elements (As, Pb, Mn,a Hg and Cd) were determined in human breast milk and blood samples obtained from 120 subjects related to an integrated steel plant environment located in central India. Samples of breast milk and blood from subjects living outside the steel plant environment were also analyzed for comparative study. Higher levels of these toxic elements were found in blood samples as compared to breast milk samples. Plant workers showed the higher presence of these metals in their breast milk and blood samples compared to the residents of the area and the subjects living outside the industrial environment, respectively. Mn, Pb and Hg have shown a higher tendency to associate with blood and breast milk than As and Cd. The order of occurrence of these metals in blood and milk samples thus found is Mn > Pb > Hg > As > Cd.  相似文献   
168.
沈阳市蔬菜生产基地重金属污染及评价   总被引:10,自引:0,他引:10  
通过对沈阳市东陵区和于洪区的蔬菜生产基地的重金属污染调查与评价 ,表明两个地区均受到Pb、Cd、Cu、Zn四种重金属不同程度的污染 ,于洪区偏于中度、重度污染 ,东陵区大部分处于轻污染级。另外 ,土壤中的重金属Cu、Pb、Cd有明显的逐年增加趋势 ,而且蔬菜大棚内土壤中的Pb、Cd含量明显高于棚外。  相似文献   
169.
本文提出将复合螯合剂(NaDDTC/8—Oxin)饱和吸附于活性碳上作为吸附材料.分离富集和ICP—AES同时测定水中痕量金属元素的方法。用ICP—AES研究了该吸附材料对某些痕量元素的吸附和解吸性能;考察了共存元素的影响。方法应用于湖水中Fe、Cu、Mn、Y和Sc的测定,检出限为ng/ml级,RSD为1.9%~4.4%,加入回收率81%~101%间,试样分析结果满意。  相似文献   
170.
洪全 《重庆环境科学》2003,25(7):37-38,58
本文以某电厂的锅炉灰渣(飞灰和底灰)为研究对象,分析了24个飞灰和24个底灰样品中Hg,As,Se,Pb,Cd,Zn,Ba,Co,Cr,Cu,Li,Ni,V,Zr等微量元素的含量水平和分布规律,结果表明:飞灰中As、Pb、Zn、Ba、Cu、V、Zr和Li的含量大于10ppm,Hg和Cd含量在1ppm以下;与原煤相比,14种元素在飞灰中的含量更高。其中Hg、As、Cu、Ni、Cr、Co、Cd、Zn和V等元素的含量分别是原煤的2倍以上;除As和Se外,其余元素在底灰中的含量高于原煤。  相似文献   
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