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1.
利用土壤元素数据2069448个,鼻咽癌死亡调查资料22560例,研究了鼻咽癌死亡率与土壤环境中61个元素质量分数的相关性。结果表明,汞、铅、硒、针、锡、钛、钽、溴、碘元素质量分数与鼻咽癌死亡率呈非常显著的正相关;铪元素质量分数与鼻咽癌死亡率呈显著的正相关;铟、镱、镥、铀、锆、铋、碲元素质量分数与鼻咽癌死亡率呈较显著的正相关。锰、钠、镁、钙、锶元素质量分数与鼻咽癌死亡率呈非常显著的负相关;钾、钡元素质量分数与鼻咽癌死亡率呈较显著的负相关。钒、铷、铯、银、铝、镓、铊、钪、钇、镧、铈、钕、钆、镝、钬、铒、铥、钼、钨、铁、砷、镉、钴、铬、铜、氟、镍、锌、锂、铍、硼、镨、钐、铕、铽、锗、锑元素质量分数与鼻咽癌死亡率无明显的相关性。  相似文献   

2.
上海市郊春节期间大气颗粒物及其组分的粒径分布   总被引:5,自引:0,他引:5  
利用电称低压冲击仪(ELPI)在线监测上海市嘉定区2009年春节前后不同粒径(50%切割粒径分别为:0.03、0.06、0.11、0.17、0.26、0.40、0.65、1.00、1.60、2.50、4.40、6.80μm)大气颗粒物的粒子数浓度变化.对比春节与非节日期间该地区大气颗粒物(<0.49、0.49—0.95、0.95—1.50、1.50—3.00、3.00—7.20、>7.20μm)中Na、Mg、Al、K、Ca、Ti、V、Cr、Mn、Fe、Co、Ni、Cu、Zn、As、Se、Pb 17种元素,F-、Cl-、NO 2-、SO24-、NO 3-、Na+、NH 4+、K+、Mg2+、Ca2+10种离子与有机碳(OC)、元素碳(EC)质量浓度的粒径分布.结果表明,春节对于大气颗粒物粒子数浓度的影响主要集中在0.11—1.60μm.如果以3.00μm为界将大气颗粒物划分成细(≤3.00μm)和粗(>3.00μm)颗粒物时,春节影响体现在细颗粒的元素为:Na、As、Pb,且主要集中于<0.49μm颗粒中;春节影响集中于大颗粒(>7.20μm)的元素为:Ni、Co;没有受到显著影响的为:Ca、V、Mn、Fe、Z...  相似文献   

3.
藻类学     
内容简介本书系统介绍了藻类植物的分类、形态、构造、生态、生理、生化、遗传等方面,对近30年来海藻生理、生态、生化、分子生物学、进化和系统发育等进展均有概括,内容全面、系统、新颖。作者简介Robert Edward Lee教授拥有丰富的职业生涯,在多个国家包括南非、伊朗以及哈佛医学院从事教学工  相似文献   

4.
李其林  黄昀  王萍  刘丰祎 《生态环境》2012,21(4):764-769
采用野外采样和室内分析,试验结果表明三峡库区土壤中重金属Cu、Zn、Pb、Cd、Fe、Cr的变异系数小于50%,重金属的含量比较稳定。稻谷(Oryza sativa)中Cu、Zn、Pb、Cd、Fe、Mn、Cr,玉米(Zea mays)中Pb、Cd、Fe、Mn、Cr和小麦(Triticum aestivum)中Cu、Pb、Cd、Fe、Mn、Cr的变异系数大于50%。土壤、稻谷、玉米、小麦中大部分重金属呈偏态分布。土壤中重金属间均为正相关,且极显著正相关性明显。稻谷、玉米、小麦中重金属间有正相关,也有负相关,但正相关明显多于负相关;稻谷、玉米、小麦中Mn同其它重金属间均有显著正相关性,协同作用明显。稻谷、玉米、小麦中Pb、Cd、Cr的样本超标率较大,污染明显,并且稻谷中Cd与土壤中Cd有直线关系。  相似文献   

5.
为向动物园预防动物疾病、保障动物健康提供科学依据,采用环境检测方法对南京红山森林动物园的鹦鹉馆、孔雀馆和袋鼠馆进行空气质量检测.结果显示,氨气(NH3)的含量,鹦鹉馆内春、夏、秋、冬分别为2.69、4.61、3.07、5.48 mg/m3,孔雀馆内分别为1.66、0.98、0.66、1.15 mg/m3,袋鼠馆内分别为1.66、2.51、1.47、2.20 mg/m3;硫化氢(H2S)的含量,鹦鹉馆内春、夏、秋、冬分别为0.015 9、0.016 3、0.017 0、0.027 3 mg/m3,孔雀馆内分别为0.029 4、0.077 6、0.050 7、0.036 1 mg/m3,袋鼠馆内分别为0.004 2、0.005 1、0.009 5、0.007 4 mg/m3;细菌总数,鹦鹉馆内春、夏、秋、冬分别为15.40×103、21.53×103、20.91×103、7.73×103cfu/m3,孔雀馆内分别为25.20×103、42.61×103、42.18×103、29.40×103cfu/m3,袋鼠馆内分别为10.70×103、19.8×103、2.86×103、4.34×103cfu/m3.动物舍空气环境中细菌菌落总数、氨气、硫化氢的浓度与温度、湿度呈正相关,与风速呈负相关.空气环境质量也受动物饲养方式、饲养的数量和饲料的质量影响.  相似文献   

6.
电子废物的不当拆解、回收活动对当地及周边环境造成的严重污染已经引起了国内外的广泛关注,但相关的调查研究目前仍比较少.以长期进行电子废物回收产业活动的典型区域--广东清远龙塘镇和石角镇为研究对象,较系统地调查、分析了电子废物不当处置对区域和流域环境介质中重金属的含量、分布和迁移的影响,并对其环境风险进行了评价.此论文是该项研究的一部分,重点调查了龙塘镇电子废物焚烧迹地中Pb、Zn、Cu、Cd、Cr、Ni等6种重金属的含量、分布和迁移及其对植物根、茎、叶组织中Pb、Zn、Cu、Cd含量的影响.结果表明:1)焚烧迹地土壤中Pb、Zn、Cu、CA、Cr、Ni的平均含量分别为1714.5、1016.7、4850.6、10.3、63.3、100.3mg·kg-1,局部区域样点检出的Cu、Pb、Cd含量分别是对照土壤的1268、179和101倍,显示电子废物焚烧迹地已经成为一个巨大的土壤重金属库,必然长期贡献于区域乃至流域土壤和水体的重金属污染.2)电子废物焚烧活动造成的重金属污染能够随空气动力及重力沉降而形成垂直以及水平迁移,其中Pb和Cd的迁移能力远大于其它重金属.3)电子废物焚烧迹地内生长的植物也受到了重金属的污染,其中Cu、Cd的污染程度较严重;桉树对Cu、铁芒箕对Pb、类芦对Cd、Zn、Cu有相对较强的富集能力.  相似文献   

7.
芜湖市区土壤重金属污染评价及来源分析   总被引:5,自引:0,他引:5  
对芜湖市区153个土壤样品中9种重金属的含量进行测定和评价,利用多元地统计方法进行污染来源分析。结果表明:芜湖市区土壤Zn、Fe、Mn、Cu、Pb、Co、Cd、Ni、Cr的平均含量分别为96.8、30600.1、466.1、35.0、29.1、16.7、1.2、26.3、78.3mg/kg;除Fe、Mn、Ni外,其他元素均高于相应土壤背景值,Zn、Cu、Pb、Co、Cd、Cr分别是背景值的1.26、1.09、1.17、1.20、6.11、1.29倍,说明这些元素出现了一定程度的积累。单因子评价结果表明Cd污染最为严重,Zn、Cu、Pb、Co和Cr为轻度污染,Fe、Mn和Ni没有污染。综合相关性、聚类及主成分分析可知,Fe和Mn为"自然源因子",不同功能区分布主要受成土母质控制;Zn、Cu、Pb和Cd为"交通及工业活动因子",Cu、Cd高值区均分布在开发区,Zn和Pb的高值区分布在镜湖区;Ni、Co和Cr为"农业活动因子",其空间变异受成土母质及农业活动等因素影响。  相似文献   

8.
为了提高能源回收效率,采用大米、土豆、生菜、瘦肉、花生油和榕树叶作为实验原料,模拟有机垃圾中普遍存在的淀粉、膳食纤维、蛋白质、脂肪和木质纤维类成分,进行厌氧发酵产氢以及对其剩余物厌氧发酵产甲烷.结果表明.在厌氧发酵产氢阶段,整个过程没有甲烷生成,大米、土豆、生菜、瘦肉、花生油和榕树叶的氢气产率分别为125、103、35、0、5和0 mL g-1(VS),能源回收效率分别为7.9%、6.8%、1.9%、0、0.1%和0.大米、土豆和生菜的氢气浓度分别为34%~59%、41%~56%和37%~70%,整个产氢阶段没有甲烷生成.在厌氧发酵产甲烷阶段,上述原料的甲烷产率分别为232、237、148、278、866和50 mL g-1(VS),生物气中甲烷含量分别为42%~70%、57%~71%、73%~77%、59%~73%、68%~80%和54%~74%.厌氧发酵联产氢气和甲烷整个过程上述原料的能源回收效率分别为56.3%、58.4%、28.8%、39.2%、81.2%和8.8%,总COD去除率分别为72.30%、81.70%、32.63%、47.59%、97.46%和11.29%.图4表5参35  相似文献   

9.
贵州喀斯特山区植物营养元素含量特征   总被引:12,自引:0,他引:12  
贵州喀斯特山区是我国乃至世界喀斯特分布面积最大的片区之一,由于其生态系统的脆弱性,加之人类活动的干扰,使得该区的植被退化较为严重。文章选择该区的12种主要植物作为研究对象,对其营养元素进行了研究。结果表明:>1000μg·g-1的元素有N、P、K、Ca、Mg、S,100~1000μg·g-1的元素有Fe、Mn、Al,10~100μg·g-1的元素有Zn、Sr,<10μg·g-1的元素为Cu、Mo,其中Mo含量最低,仅为0.17μg·g-1。这些元素中,Ca、P、K元素高于所报道的陆生植物的含量范围。元素含量特点是Ca>K>Mg型。N、P、K、Mg元素的频数分布为正态分布,Ca、Al、Fe、Mn、Cu、Zn、Sr、S元素为对数正态分布。变异系数大于100%的元素有Al、Fe、Mn、Sr,变异系数小于60%的元素有N、P、K、Ca、Mg、S、Cu,其中Ca的变异系数最小,仅为11.8%。不同生境下相同植物的营养元素含量有较大的差异,石灰土上植物的N、P、K、Ca、Mg、Al、Cu、Mo元素含量要高于黄壤上植物的。元素间的相关分析表明:P和K、P和Cu、Al和Fe、Al和Zn、Fe和Zn元素具有显著相关关系;N和P、P和Mg、K和Al、K和Cu、Ca和Sr、S和Mo元素具有一般相关关系。  相似文献   

10.
本文着重阐述了在新形势下加强高校领导班子思想政治建设,必须切实抓好党的基本理论、路线、方针、政治纪律、民主集中制、团结、群众路线、观点、廉洁自律等六个方面的教育,这样才能全面提高领导班子的整体素质和整本功能。  相似文献   

11.
Indoor and outdoor air pollution is known to contribute to increased lung cancer incidence. This study is the first to address the contribution of home heating fuel and geographical course particulate matter (PM10) concentrations to lung cancer rates in New Hampshire, USA. First, Pearson correlation analysis and geographically weighted regression were used to investigate spatial relationships between outdoor PM10 and lung cancer rates. While the aforementioned analyses did not indicate a significant contribution of PM10 to lung cancer in the state, there was a trend towards a significant association in the northern and southwestern regions of the state. Second, case-control data were used to estimate the contributions of indoor pollution and secondhand smoke to the risk of lung cancer with adjustment for confounders. Increased risk was found among those who used wood or coal to heat their homes for more than 10 winters before the age of 18, with a significant increase in risk per winter. Resulting data suggest that further investigation of the relationship between heating-related air pollution levels and lung cancer risk is needed.  相似文献   

12.
河流底泥污染及其控制与修复   总被引:3,自引:0,他引:3  
水体底泥污染是世界范围内的一个环境问题。污染物通过大气沉降、废水排放、雨水淋溶与冲刷进入水体,最后沉积到底泥中并逐渐富集,使底泥受到严重污染。在河流环境中,河床沉积底泥以推移和悬浮形式输送,很大程度上导致了上覆水和沉积底泥的相互物理作用。河流有强有力的自然环境,在河流系统中趋向有利于沉积底泥的解吸作用,从而将会影响上覆水的水质。因此,在水质管理计划中,应该将已污染的沉积底泥作为一个污染源予以考虑,沉积底泥是河流污染的一个重要方面。文章根据近年来国内外对河流底泥污染的控制、处理、修复及利用的文献资料,分析了河流底泥的污染现状及主要类型,包括重金属、NP营养物质、难降解有机物和持久性有毒污染物等,指出了目前在底泥污染修复中存在的问题。针对河流底泥污染控制与修复技术,介绍了除控制外源污染物外的物理修复、化学修复和生物修复等几种主要的修复方法和技术,分析了各种方法的利弊以及适用情况。在阐述了堆肥、建材利用、低温热解、湿地及栖息地建设、修复废弃地和建设填方等利用方式后,提出具体的控制和修复应因地制宜,综合各种恢复技术及利用方式,以达到控制及修复污染的河流底泥,恢复河流生态系统之目的。  相似文献   

13.
土肥的基础地位是不随社会性质或社会经济类型的变化而变化的,它既具重要性,又具长久性.市场经济是仍然需要土肥科技的.土肥科技的教学、科研和推广的力度必须加大,局面必须改观,且宜快不宜迟.土肥科技工作者一定要将培肥地力作为中心工作.根据广东的实际,增施有机肥是培肥地力的主要措施,因而抓秸秆还田和发展冬绿肥是我们工作的重点.  相似文献   

14.
● Adsorption of PFASs on MPs and its mechanisms are critically reviewed. ● MPs could alter the transport and transformation of PFASs in aquatic environments. ● Combined toxicity of MPs and PFASs at organismal and molecular levels is discussed. Microplastics (MPs) are recognized as vectors for the transport of organic contaminants in aquatic environments in addition to their own adverse effects on aquatic organisms. Per- and polyfluoroalkyl substances (PFASs) are widely present in aquatic environments due to their widespread applications, and thus coexist with MPs. Therefore, we focus on the interaction of MPs and PFASs and related combined toxicity in aquatic environments in this work. The adsorption of PFASs on MPs is critically reviewed, and new mechanisms such as halogen bonding, π-π interaction, cation-π interactions, and micelle formation are proposed. Moreover, the effect of MPs on the transport and transformation of PFASs in aquatic environments is discussed. Based on four typical aquatic organisms (shellfish, Daphnia, algae, and fish), the toxicity of MPs and/or PFASs at the organismal or molecular levels is also evaluated and summarized. Finally, challenges and research perspectives are proposed, and the roles of the shapes and aging process of MPs on PFAS biogeochemical processes and toxicity, especially on PFAS substitutes, are recommended for further investigation. This review provides a better understanding of the interactions and toxic effects of coexisting MPs and PFASs in aquatic environments.  相似文献   

15.
基因污染与生态环境安全   总被引:6,自引:0,他引:6  
论述了基因污染可能对生态环境安全造成的影响。转基因作物有可能污染天然物种的基因库;有可能破坏传统农作物品种的遗传多样性,加速作物种植品种的单一化及基因资源的流失;使抗除草剂作物的基因向野生或半野生植物漂移的可能性加大,有可能创造出“超级杂草”;带有病毒型转基因作物的基因重组,有可能创造出新的植物病毒,导致新的病害;BT转基因抗虫作物分泌的毒素,在食物链中传递,很难加以控制,对非目标生物造成危害,并最终破坏自然生态系统的平衡。文章还从不同角度分析了基因污染的严重性。  相似文献   

16.
Recent extinctions often resulted from humans retaliating against wildlife that threatened people's interests or were perceived to threaten current or future interests. Today's subfield of human-wildlife conflict and coexistence (HWCC) grew out of an original anthropocentric concern with such real or perceived threats and then, starting in the mid-1990s, with protecting valued species from people. Recent work in ethics and law has shifted priorities toward coexistence between people and wild animals. To spur scientific progress and more effective practice, we examined 4 widespread assumptions about HWCC that need to be tested rigorously: scientists are neutral and objective about HWCC; current participatory, consensus-based decisions provide just and fair means to overcome challenges in HWCC; wildlife threats to human interests are getting worse; and wildlife damage to human interests is additive to other sources of damage. The first 2 assumptions are clearly testable, but if they are entangled can become a wicked problem and may need debunking as myths if they cannot be disentangled. Some assumptions have seldom or never been tested and those that have been tested appear dubious, yet the use of the assumptions continues in the practice and scholarship of HWCC. We call for tests of assumptions and debunking of myths in the scholarship of HWCC. Adherence to the principles of scientific integrity and application of standards of evidence can help advance our call. We also call for practitioners and interest groups to improve the constitutive process prior to decision making about wildlife. We predict these steps will hasten scientific progress toward evidence-based interventions and improve the fairness, ethics, and legality of coexistence strategies.  相似文献   

17.
High concentrations of metals (cadmium, copper, lead, and zinc) and of lindane were measured in the sediment and in the spawn and tadpoles of Bufo bufo, Rana dalmatina, and Rana ridibunda from two Austrian locations. Residues in spawn suggest maternal transfer. Increase of the metal concentrations from spawn to advanced tadpole stage is explained by the larval microphaguous feeding habits which cause high exposition of the tadpoles to substances concentrating in sediments and suspended particles. Metal and pesticide concentrations in spawn and tadpoles are toxic to various other aquatic organisms and are furthermore considered to be potentially hazardous to the anurans themselves. The results are conform with world‐wide observations of contamination of anuran larvae with heavy metals, and prove the significance of non‐point source chemical exposure due to allochthonous toxicant input by wind load and precipitation.  相似文献   

18.
Two different methods to predict biotic integrity were tested and compared in the present paper. The first one tries to predict the fish indices of biotic integrity (IBI) at the state or regional scale based on the most similar observations to a specific target site of interest using the simple to implement k-nearest neighbors (or kNN) method. Two different distance functions were considered to find the k-nearest neighbors: the Euclidean and the Mahalanobis. The second method was applied on the same datasets and consisted of a step-wise multiple regression. The two modeling approaches yielded similar results but kNN proved to be more time-efficient and very fast computationally for the given dataset sizes, which allowed applying a leave-one-out cross validation.In an attempt to reveal the importance of scale in the prediction of IBI, regression models were constructed at the state (or regional) scale and at the more refined cluster of sampling sites scale. Clusters of sites were extracted using Kohonen's self-organizing maps (SOM) followed by k-means clustering of the SOM neurons. Cluster-level regression models, constructed after site patterning, performed better in IBI prediction than global regression models constructed without any previous site patterning. The importance of identifying groups of sites with similar environmental characteristics affecting the IBI was revealed. The combined use of site patterning and regression modeling for IBI prediction also helped identifying important variables acting at the local scale which remain latent at the global scale.  相似文献   

19.
包装材料及食品中纳米材料的检测与表征技术   总被引:1,自引:0,他引:1  
随着纳米技术的发展,纳米材料在包装行业及食品工业中得到了广泛的应用。然而,纳米材料的安全应用高度依赖于对其生物及环境效应的了解。有研究表明,纳米材料对人类健康及生态环境存在着潜在危害,这使得纳米材料的安全性成为毒理学领域的热点研究课题。同时纳米材料的安全性问题也成为纳米复合包装材料及纳米食品研究和开发的新瓶颈。在对纳米材料没有充分认识的情况下,为了消费者和生态环境的安全,必须控制包装材料及食品中纳米颗粒的种类、来源、含量及可能的释放,这就需要可靠的方法对纳米颗粒的性质和结构进行检测及表征。首先,综述了目前纳米材料在复合包装材料及食品加工中的应用,然后总结了包装材料及食品中纳米材料的检测技术及表征方法,例如显微技术、色谱分离技术、光谱与质谱技术等。由于纳米材料的理化性质参数众多,应用多种分析手段来检测和表征纳米材料成为必然。最后对目前检测技术及表征方法的不足和今后发展方向进行了探讨。  相似文献   

20.
关于蔬菜施有机肥和它与无机肥的合理配施比例,对蔬菜的产量和品质有重要影响,对土壤有机质和重金属含量也有影响。为控制施禽畜粪类有机肥对蔬菜的负面影响,探讨蔬菜的合理施用量和有机/无机肥配施比例,在不同质地的土壤上进行田间试验。结果表明,(1)施过量禽畜粪类有机肥对试验蔬菜产量和品质都会产生不良影响,小白菜(Brassica chinensis)和茄子(Eggplant)施禽畜粪超过22500kg/hm2、马铃薯(Solanum tuberosum L.)超过24000kg/hm2时,其产量不再增加,成活率下降,维生素C含量下降,多个试验均表现出有机肥用量增加而小白菜硝酸盐随之增加的典型特征;同时不论土壤的质地轻重,蔬菜重金属Pb有随禽畜粪用量增加而提高的趋势;在质地较轻的土壤上,蔬菜重金属Cd、As有随禽畜粪用量增加而提高的趋势;小白菜施禽畜粪肥超过7500kg/hm2、茄子和冬种马铃薯施禽畜粪肥超过75000kg/hm2,收获后土壤重金属含量高于对照和施无机肥的总Cr和As。(2)蔬菜单独施用有机肥的合适施用量,小白菜在较粘重的土壤上可施到22500kg/hm2,但有机肥与无机肥配合施用时有机肥用量可减量;茄子合适施用量应在22500kg/hm2左右;冬种马铃薯合适施用量应在24000kg/hm2左右。(3)蔬菜的有机/无机肥合理配比,小白菜、茄子、和冬种马铃薯施肥的有机氮与无机氮之比均为0.25∶1至0.5∶1时其产量和品质水平较佳。  相似文献   

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