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1.
Summary The effects of pollution at population level are considered in relation to demographic characteristics and overall to the birthrate. The direct and indirect effects of pollution on community structure is discussed. The influence of pollution may vary according to the food-chain structure; (as a consequence, the hazard ceteris paribus will be greater in freshwater communities than in marine ones). Relations between diversity and stability are discussed. In addition, the advantages and difficulties in using diversity and biotic indices for monitoring polluted water are taken into account.  相似文献   

2.
J C Sherlock 《Experientia》1984,40(2):152-156
Information on the sources of cadmium in food are presented and the effects of raised environmental levels of cadmium on the concentration of cadmium in plant based foods, fish and shellfish, meat and offals, and dairy produce are discussed. Information is also presented on normal dietary intakes of cadmium and how these intakes may be elevated by environmental pollution or atypical dietary habits. The estimation of dietary intakes of cadmium using data about extreme intakes of specific foods is described.  相似文献   

3.
Summary Information on the sources of cadmium in food are presented and the effects of raised environmental levels of cadmium on the concentration of cadmium in plant based foods, fish and shellfish, meat and offals, and dairy produce are discussed. Information is also presented on normal dietary intakes of cadmium and how these intakes may be elevated by environmental pollution or atypical dietary habits. The estimation of dietary intakes of cadmium using data about extreme intakes of specific foods is described.The author wishes to thank the Ministry of Agriculture, Fisheries and Food for permission to publish this paper.  相似文献   

4.
液压油液的温升与污染是制约液压系统可靠性与液压元件寿命的关键。为了减小因油箱的设计缺陷而引起的油液污染速度快,温升高的问题,对EBZ230掘进机泵站闭式油箱进行改进设计。通过样机的应用与实验证明了这种新型的油箱系统能更有效地降低油液的污染速度与等级、更平稳更快速地冷却油液,对提高整机液压系统可靠性与稳定性有非常积极的意义。该油箱结构亦可应用于有着相似要求的液压设备中,具有较高的推广价值。  相似文献   

5.
以四川省南部县李子口小流域为研究对象,采用主成分分析方法,通过SPSS15.0软件对水质进行了定量评价,并结合综合污染损害指数对水质作出定性评价。结果表明:该流域水质污染高峰主要集中在6~10月份,11月份开始出现下降趋势,次年4月份开始出现升高状态,结合第一、二、三主分所反映的信息量,7月份主要为磷污染,5、7、8月份主要是有机物污染,而氮污染则集中在10月份。最后根据评价结果分析农业面源污染的影响。  相似文献   

6.
等离子体环保技术的研究进展   总被引:1,自引:0,他引:1  
等离子体环保技术随当今世界环境问题的日益严峻而得到迅速发展,本文简述了利用等离子体进行污染控制的基本过程,介绍了应用于处理环境污染的各种等离子体技术及特点,重点考察了国内外应用等离子体技术降解有害污染物和降解废弃物并回收高附加值产物的研究,展望了其进入商业运行的前景。  相似文献   

7.
Pore-forming toxins   总被引:3,自引:0,他引:3  
Pore-forming toxins are widely distributed proteins which form lesions in biological membranes. In this review, bacterial pore-forming toxins are treated as a paradigm and discussed in terms of the structural principles on which they work. Then, a large family of bacterial toxins, the cholesterol-binding toxins, are analyzed in depth to provide an overview of the processes involved in pore formation. The ways in which the cholesterol-binding toxins (cholesterol-dependent cytolysins) interact with membranes and form pores, the structure of the monomeric soluble and oligomeric pore-forming states, and the effects of the toxin on membrane structure are discussed. By surveying the range of work which has been done on cholesterol-binding toxins, a working model is elaborated which reconciles two current, apparently diametrically opposed, models for their mechanism. Received 7 September 2001; received after revision 12 November 2001; accepted 5 December 2001  相似文献   

8.
The objective of this study is to discuss the potential impact of a global warming on various aspects of human health. Changes in heat-related mortality are estimated for four countries: the United States, Canada, the People's Republic of China and Egypt. In addition, the potential confounding impact of increased air pollution is considered. Finally, a framework to analyze two vector-borne diseases, onchocerciasis and malaria, which may spread if temperatures increase, is discussed. Our findings suggest that heat-related mortality is estimated to rise significantly in all four countries if the earth warms, with the greatest impacts in China and Egypt. The most sensitive areas are those with intense but irregular heat waves. In the United States, air pollution does not appear to impact daily mortality significantly when severe weather is present, although it seems to have a slight influence when weather conditions are not stressful.  相似文献   

9.
元数据在信息系统的建设中占有重要地位,也是目前的研究重点。三峡工程生态与环境信息系统的数据源涵盖了几乎生态与环境的所有方面,如污染、水环境、陆生生态、水生生态等。基本对业务元数据和技术元数据的合理组织,我们成功地构建了该信息系统。本文首先介绍了业务性元数据和技术性元数据的概念并解释了抽取这些元数据的过程和方法,同时说明了如何来创建业务模型和数据模型,以及如何有效地将上述模型集成起来。最后,对业务性元数据的使用效果和不足之处作了讨论和评价。  相似文献   

10.
重金属和多环芳烃是土壤环境中的重要污染物,其复合污染土壤的修复已成为环境科学研究的热点问题。植物修复技术是目前修复土壤复合污染重要方法之一,但植物本身修复能力有限,需借助化学、微生物、基因工程等手段对其修复效果进行强化。本文对国内外近几年来植物修复重金属-多环芳烃复合污染强化措施研究成果进行综述,并重点讨论了植物根际生长促进菌及菌根在强化修复中的应用,在此基础上对未来该领域需要深入研究的科学问题进行了阐述。  相似文献   

11.
The atmosphere is part of the environment with which the human organism is permanently confronted. Epidemiological research investigates the occurrence of effects on morbidity and mortality due to heat, cold, air pollution and changes in the weather. Concentrating on aspects of the environment relevant for medical questions, three major complexes of effects can be discriminated: the complex conditions of heat exchange, the direct biological effects of solar radiation, and air pollution. Biometeorological knowledge can serve to assess the atmospheric environment, and can also be of help in the field of preventive planning, to conserve and develop the climate as a natural resource with regard to man's health, well-being and performance.  相似文献   

12.
酸雨对植物影响的研究进展   总被引:21,自引:0,他引:21  
本文综述了当前从种群和群落自然生态系统水平上、个体水平上、细胞水平上、生理生化水平上对酸雨对植物的影响研究,指出在分子遗传水平上研究酸雨生态效应及机理还有待进一步完善和发展。  相似文献   

13.
The outbreak of COVID-19 raised numerous questions on the interactions between the occurrence of new infections, the environment, climate and health. The European Union requested the H2020 HERA project which aims at setting priorities in research on environment, climate and health, to identify relevant research needs regarding Covid-19. The emergence and spread of SARS-CoV-2 appears to be related to urbanization, habitat destruction, live animal trade, intensive livestock farming and global travel. The contribution of climate and air pollution requires additional studies. Importantly, the severity of COVID-19 depends on the interactions between the viral infection, ageing and chronic diseases such as metabolic, respiratory and cardiovascular diseases and obesity which are themselves influenced by environmental stressors. The mechanisms of these interactions deserve additional scrutiny. Both the pandemic and the social response to the disease have elicited an array of behavioural and societal changes that may remain long after the pandemic and that may have long term health effects including on mental health. Recovery plans are currently being discussed or implemented and the environmental and health impacts of those plans are not clearly foreseen. Clearly, COVID-19 will have a long-lasting impact on the environmental health field and will open new research perspectives and policy needs.  相似文献   

14.
The outbreak of COVID-19 raised numerous questions on the interactions between the occurrence of new infections, the environment, climate and health. The European Union requested the H2020 HERA project which aims at setting priorities in research on environment, climate and health, to identify relevant research needs regarding Covid-19. The emergence and spread of SARS-CoV-2 appears to be related to urbanization, habitat destruction, live animal trade, intensive livestock farming and global travel. The contribution of climate and air pollution requires additional studies. Importantly, the severity of COVID-19 depends on the interactions between the viral infection, ageing and chronic diseases such as metabolic, respiratory and cardiovascular diseases and obesity which are themselves influenced by environmental stressors. The mechanisms of these interactions deserve additional scrutiny. Both the pandemic and the social response to the disease have elicited an array of behavioural and societal changes that may remain long after the pandemic and that may have long term health effects including on mental health. Recovery plans are currently being discussed or implemented and the environmental and health impacts of those plans are not clearly foreseen. Clearly, COVID-19 will have a long-lasting impact on the environmental health field and will open new research perspectives and policy needs.  相似文献   

15.
This article deals with the part of urban climatology which is of particular relevance to human beings. Presented first is a summary of all human biometeorologically effective complexes, as well as other factors which are relevant to urban planning and which depend on atmospheric conditions in urban structures in a direct or indirect manner. Later, methods for human biometeorologically significant assessment of thermal and air pollution components of the urban climate are discussed in detail, because these components can be strongly influenced by urban planning. The application of these methods is illustrated by some results of appropriate investigations in urban areas.  相似文献   

16.
The ultrastructure of blood capillaries and venules are studied in rat skin. After i.v. injection of histamine the luminal surface of the endothelial cells show protrusions of variable size. Numerous gaps have been found in the capillary wall, specially in the venules. These alterations are not observed in the animals that were treated with calcium dobesilate before the administration of histamine. In these cases the capillary structure are indistinguishable of the controls. The possible effects of the histamine and calcium dobesilate on the cell coat and cell junctions of the endothelial capillary cells are discussed.  相似文献   

17.
硼的生物效应及健康影响研究进展   总被引:13,自引:0,他引:13  
硼是动物所必需的一种微量元素,硼缺乏和硼过量都会产生不利的影响。通过动物试验,硼污染问题已经开始引起人们的重视。美国已将硼列入环境雌激素重点研究化学品之一。已有的三项针对硼作业人群的生殖健康影响研究结果不一致。有的研究表明缺硼或硼污染对人体健康均有害。本文对近30年来有关硼的生物效应及其对人体健康影响的研究进展进行了总结,并对今后研究方向提出了建议。  相似文献   

18.
环渤海地区环境污染问题演化及其对策   总被引:2,自引:0,他引:2  
环渤海地区是我国经济增长的第三极。随着该地区工农业生产的迅速发展和新型产业的崛起,其环境污染问题日益突出。本文从环渤海地区水体污染、大气污染和土壤环境污染三个角度,对该地区环境污染问题的演化进行了宏观意义上的分析和预测,并据此提出了解决该地区环境污染问题的对策措施。  相似文献   

19.
Air pollution has received more attention from many countries and scientists due to its high threat to human health. However, air pollution prediction remains a challenging task because of its nonstationarity, randomness, and nonlinearity. In this research, a novel hybrid system is successfully developed for PM2.5 concentration prediction and its application in health effects and economic loss assessment. First, an efficient data mining method is adopted to capture and extract the primary characteristic of PM2.5 dataset and alleviate the noises' adverse effects. Second, Harris hawks optimization algorithm is introduced to tune the extreme learning machine model with high prediction accuracy, then the optimized extreme learning machine can be established to obtain the forecasting values of PM2.5 series. Next, PM2.5-related health effects and economic costs was estimated based on the predicted PM2.5 values, the related health effects, and environmental value assessment methods. Several experiments are designed using three daily PM2.5 datasets from Beijing, Tianjin, and Shijiazhuang. Lastly, the corresponding experimental results showed that this proposed system can not only provide early warning information for environmental management, assist in the formulation of effective measures to reduce air pollutant emissions, and prevent health problems but also help for further research and application in different fields, such as health issues due to PM2.5 pollutant.  相似文献   

20.
结构系统模态参数识别方法研究进展   总被引:5,自引:0,他引:5  
对结构系统模态参数识别方法近十几年来的最新研究成果进行了综述和总结。分析了模态参数识别方法的发展趋势,并对其中的典型研究成果进行简要的介绍。最后指出非线性时变结构系统识别方法的研究具有非常重要的理论意义。  相似文献   

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