珠海市新马墩村农业园区土壤重金属分布特征及风险评价

农田土壤重金属污染问题日益凸显,已成为影响生态农业发展的主要问题之一,越来越受到人们的关注。小尺度范围的农田重金属空间分布特征研究能更为有效地指导土地精准管理。本文对珠海市新马墩村农业园区土壤、灌溉水、典型农作物、主要施用化肥进行采样分析,开展了小尺度农业园区土壤重金属分布特征及风险评价研究。结果表明:研究区表层土壤Cd元素含量较高,其平均值是珠江三角洲土壤背景值0.11mg/kg的3.7倍,处于中度污染级别、强生态危害程度,与长期大量施用含镉磷肥(磷肥Cd含量均值20.5mg/kg)有关。Cu、Pb、Zn、Cr、Ni、As、Hg元素含量平均值低于土壤环境质量一级标准值,处于轻微危害程度。4个土壤剖面中8种重金属分布呈现不同特征,主要受土壤质地的不均一性、岩性不连续性影响。灌溉水样品和5种典型农作物可食部分重金属均未超标,白菜、无花果对重金属富集能力较强,青枣、火龙果、天冬富集能力较弱。因此,本研究提出园区应减少磷肥使用量,重视镉潜在生态风险,优先种植对重金属富集能力较弱的品种,以降低土壤中重金属对农产品品质的影响。     

珠江三角洲农作物Se含量特征及其影响因素

通过对珠江三角洲经济区中土壤Se含量具有代表性的4个调查区（开平齐洞、四会长布、高明坟典-新围、惠东凌坑）进行农作物、根系土、水及土壤溶液取样分析,结果表明：调查区中稻米、花生等主要农作物中Se含量普遍较高,对Se的富集能力也最强;农作物对根系土Se的6种不同相态（除强有机态）吸收呈正相关性,农作物Se含量与灌溉水中Se含量呈负相关性,而与土壤溶液中Se含量相关性不显著。     

农作物根系土对农产品安全的影响分析——以保定东部地区为例

农作物中重金属含量过高势必影响人类健康与生态安全,通过对农作物与其根系土调查,对污染元素进行生态效应评价具有重要的实际意义。本文以土壤重金属超标地区——保定东部地区的大宗农作物小麦、玉米及其根系土为研究对象,开展了元素含量测试和统计分析。结果表明:小麦、玉米样品中有富硒样品;部分小麦样品存在重金属元素超标现象,玉米样品全部不超标。农作物可食部分对元素的吸收能力为小麦玉米。通过调查农作物对不同元素的吸收能力,对土壤重金属超标地区的农产品种植具有指导作用,有利于研究区土地资源的安全利用。     

广西兴宾区农作物镉富集特征及控制因素研究

广西兴宾区是重要的商品粮基地,但该区土壤中镉(Cd)背景含量较高,通过系统采集各类农作物及对应根系土,对比不同种类作物的Cd元素含量特征、Cd元素在作物及根系土中的含量关系、Cd元素在根系土中的赋存状态对Cd元素在作物中含量的影响等,初步探明了该区农作物尤其是水稻籽实中Cd元素富集特征及受控因素。     

甘肃白银东大沟地区土壤镉地球化学特征及生态风险评价

甘肃白银是中国重要的有色金属基地，历史上不科学不合理的矿产资源开发和农业生产活动，造成白银市及其周边部分地区重金属严重超标。重金属生物有效性控制因素和生态风险预测，一直是元素生物地球化学行为研究非常关注的问题。本文调查研究了白银东大沟灌区及其周边根系土与玉米籽实污染情况，分析东大沟灌区农业集中区土壤2007年与2018年关键指标变化情况，并综合评价玉米种植区生态风险。研究区土壤中局部地段Cd含量超标，平均值17.48 mg/kg,最高值达到51.1 mg/kg,不同形态Cd含量相对大小依次为碳酸盐态>离子交换态>铁锰氧化态>腐殖酸态>强有机态>残渣态?水溶态，高pH值碱性土壤和低镉积累的耐镉型玉米品种等因素限制了土壤中Cd的生物有效性，玉米籽实超标率仅为8.8%。东大沟灌区玉米地集中种植区内存在一定的Cd污染，但已得到有效控制，制约Cd生物有效性的pH值、Corg和CaO含量一半以上点位呈现升高趋势，可确保现在和未来一段时间内仍将继续保持低风险。为更好地做好东大沟灌区内Cd含量超标区管控，建议继续选择低镉积累的耐镉型玉米品种种植，同时成熟期收获籽粒作为动物...     

南宁市郊周边农田土壤-农作物系统重金属元素迁移特征及其影响因素

通过采集南宁市郊农田中玉米、蔬菜、水稻可食部分及其根系土150组,研究重金属元素在不同土壤-农作物系统中迁移特征及其影响因素,结果表明:根系土中Hg、Cd、Cr、Cu、Ni、Pb、Zn平均含量分别为0.116、0.202、56.76、22.12、14.49、25.18和56.28 mg·kg-1。农作物对应平均含量分别为0.001 1、0.037、0.054、1.153、0.205、0.011和9.37 mg·kg-1。根系土富集因子表明Cd受到不同程度人为活动影响,Cr和Ni主要受地质背景控制;不同作物系统元素富集因子表明Pb在土壤-农作物系统中迁移能力最低,Zn迁移能力最强。Cd、Cr、Cu、Ni、Pb和Zn在土壤-水稻系统重迁移能力显著高于蔬菜和玉米。根系土中pH、CaO、有机质、Fe2O3、K2O、MgO与重金生物富集系数呈显著性负相关,但在土壤-叶类蔬菜系统中根系土中K2O、MgO与Hg生物富集系数呈显著正相关。      

贵州惠水农作物-土壤剖面重金属污染评价

为研究贵州省惠水县农作物-土壤重金属污染现状,采集农作物-根系土、土壤剖面-成土母岩样品,测定Cd、Hg、As、Pb、Cr、Cu、Ni、Zn和pH的含量,选用富集系数、健康风险评估、单因子污染指数法、地累积指数法对农作物-土壤重金属污染现状进行了评价。研究表明：（1）农作物中水稻、玉米和油菜中以Cd累积为主,其次为Pb、Cr、Hg;金钱橘无重金属超标;农作物富集系数中Cd是Pb、As、Cr的几倍至上百倍;经玉米、油菜、金钱橘摄入重金属的人体健康风险很低;水稻中Cd的THQ大于1,对人体的健康有一定的风险;（2）单因子污染指数研究结果说明根系土以Cd污染为主;Ig揭示根系土中Hg、Cd、Cr超标可能受人类活动影响较大;（3）从土壤剖面-成土母岩系统来看,As、Cd、Cu具有继承性,尤其Cd含量在成土母岩、土壤剖面、根系土、农作物中含量超标,有部分来源于成土母岩高背景值。     

海南五指山树仔菜重金属镉的生态地球化学研究

对海南省五指山市南圣镇什贺村（属全海南岛表层土壤背景下的镉非异常区）的树仔菜和红山镇什蛇田村（镉异常区）的包心菜、生菜、芥菜、茼蒿菜的根系土、植物样进行了配套采集分析。结果表明，所采集的树仔菜样品镉含量个别超标，镉的土壤环境质量大都符合国家规定的标准；但是研究区土壤中镉的有效量占比远高于其他元素，镉较其他元素更倾向于在树仔菜中富集，而且树仔菜较其他品种蔬菜更强烈地选择性吸收富集镉，更兼镉在树仔菜中的富集部位恰恰就是可食部分茎和叶，因此，树仔菜的食用安全性不容忽视。另外，土壤中的镉测试结果表明，对树仔菜的种植地要进行大比例尺的土壤详查评价工作，以精确圈定安全的种植地域，确保树仔菜的食用安全性。     

承德市富硒土壤区镉的地球化学特征及生态风险评价

硒是人体必需的生命元素,开发富硒农产品是提升人体硒摄入的安全有效途径,富硒土地资源是开发富硒农产品的基础。然而,近年来全国开展的多目标地球化学调查发现,富硒土壤中重金属元素镉通常较高,不利于富硒土地开发利用,因此,研究富硒土壤区镉的地球化学特征和生态风险状况对于富硒土地开发具有重要的指导意义。文章对承德市富硒土壤区表层土壤中主要的重金属元素镉的地球化学特征及生态风险进行评价,旨在为承德市富硒土地开发利用提供科学依据。采用“七步提取法”研究了表层土壤镉的形态特征。同时,配套分析了苹果、玉米样品中的重金属元素镉的含量,以了解其生物有效性。结果显示:承德市富硒土壤区表层土壤镉在全区均较富集,在新积土和中性粗骨土、水田中显著富集。研究区圈定了4处镉轻度污染土壤,均在表层土壤镉的高值区。表层土壤镉形态平均含量大小顺序为:水溶态 < 离子交换态 < 强有机结合态 < 腐殖酸结合态 < 铁锰氧化物结合态 < 碳酸盐结合态 < 残渣态,生态风险相对较低。表层土壤镉未对苹果和玉米样品产生影响,苹果和玉米中镉均不超标。承德市富硒土壤区表层土壤镉的生态风险较低,暂不影响承德市富硒土地开发利用。     

安徽石台仙寓地区土壤硒地球化学特征及生物效应

为探讨安徽石台仙寓地区土壤-作物系统中硒的富集及迁移特征,在该区系统采集了岩石、土壤、灌溉水、农作物及根系土样品,研究土壤硒的地球化学特征、赋存状态、主要影响因素及生物有效性等。结果显示：研究区表层土壤硒含量为0.27～15.79 mg/kg,平均值为0.87 mg/kg,显著高于安徽省土壤背景值;土壤硒含量与有机质呈显著正相关,但与pH值无相关性;不同基岩地层的硒含量差异显著,其中蓝田组、荷塘组及皮园村组碳质页岩是该区土壤硒的主要物质来源;土壤硒形态主要为腐殖酸结合态、强有机结合态和残渣态,生物可直接利用形态的硒约占3%。研究区稻谷、茶叶对硒的平均富集系数分别为0.21和0.08,采集的水稻样品全部达到富硒标准,具有良好的富硒产业开发优势。     

Enrichment of heavy metals in paddy crops irrigated by paper mill effluents near Nanjangud, Mysore District, Karnatake, India

 Extensive irrigation by the effluents released from a paper mill near Nanjangud have led to the accumulation of heavy metals in the soil and different parts of the paddy crops. In this paper, the physicochemical characteristics of paper mill effluents and the accumulation of heavy metals (Cu, Zn, Pb, Co, Cd, Cr, and Ni) in the soil and different parts (root, leaf, and seed) of the paddy crops growing in the irrigated area are described and compared with the soil and paddy crops irrigated by natural waters (unpolluted). Chemical and biological oxygen demands of wastewater were found to be 437 and 1070 ppm respectively, which are beyond the tolerance limits set by Indian standards. The total dissolved and suspended solids are 1754 and 900 ppm respectively. The concentration of heavy metals (except Zn) in the seeds is remarkably less than that in the roots and leaves of the paddy crops. The heavy metal uptake by plants shows the greatest accumulation of Cu, Cr, Co, and Pb in the roots; Cd and Ni in the leaves; and Zn in the seeds of rice. The heavy metal content of the soil and their total uptake by paddy roots has the relation: Pb>Zn>Cu>Cd and Pb>Cu>Zn>Cd. Survival of paddy crops irrigated by polluted waters indicates tolerance to toxic heavy metals. In conclusion, since in many tropical countries the common diet of people is rice, the accumulation of toxic heavy metals in rice may lead to health disorders. Received: 18 July 1995 / Accepted: 24 February 1997     

江汉平原富硒土壤来源解析及其生物富集程度研究 ——以沙洋县东北部为例

硒是人体必需的微量元素,具有重要的生物学功能。本研究测定了江汉平原沙洋县东北部土壤、大气干湿沉降、灌溉水、肥料、岩石以及大宗农作物(水稻、小麦、大豆、油菜、玉米)中硒的含量,通过土壤硒元素平面、垂向分布特征,综合运用因子分析、聚类分析、相关性分析及相关因素贡献量统计,探讨研究区富硒土壤来源,并对土壤硒生物富集程度进行分析。结果表明：研究区表层土壤硒背景值为0.25 mg/kg,略低于江汉流域背景值和中国土壤(A层)背景值。R型因子分析结果显示,F1因子为反映土壤原始背景特征的元素组合,F2因子为反映土壤成土母质基本特征的元素组合,F3、F4因子为人类活动对土壤元素分布特征影响的元素组合。表层土壤硒元素平面特征和土壤元素组合特征皆显示其具有较强的空间自相关性,受自然成因成土母质影响较大,硒高值区主要分布在汉江冲积带内。典型土壤垂直剖面则揭示了汉江冲积带中土壤高硒区存在一定的外源输入,研究区表层土壤明显受到人类活动的影响,但大气干湿沉降、灌溉水、肥料等的硒贡献量较低。农作物可食部分硒富集程度大小为：大豆>小麦>水稻>油菜>玉米,部分大豆出现了硒超富集现象。富硒农作物...     

河北邯邢铁矿区矿山环境生态地球化学评价

在河北邯邢西石门及周边铁矿区系统地采集了各类生态环境地球化学样品,包括土壤(n=242)、玉米(n=110)、地表水(n=37)、地下水(n=31)和水系沉积物(n=81)。通过对矿区各样品元素含量特征和元素富集程度的研究,利用区域地球化学基准值和地质累积指数定量评价了矿山污染扰动程度。研究表明,矿区土壤、玉米、地表水、地下水、水系沉积物中相对富集较高的与成矿作用有关的元素及主要的伴生元素,部分重金属元素超标,土壤和水系沉积物中Se、As、Cd、Cu、As、Cd、Cu、Co元素超标,玉米中F、Cr、Cd元素接近食品卫生限值,地表水和地下水部分指标浓度接近三类水质限值。研究表明,造成污染的主要来源是铁矿尾矿沙和煤矸石中的硫化物发生氧化作用,导致重金属淋滤转移,另一来源是燃煤降尘的积聚。     

广西八一锰矿区土壤和主要农作物重金属含量的研究

对广西八一锰矿废弃地土壤基本理化性质及重金属全量(浓HC l 浓HNO3 HF HC lO4消解)、有效态含量(0.1MHC l浸提)和主要农作物重金属含量(浓HNO3 HC lO4消解)进行了测定(AA S)。结果表明:土壤营养缺乏和重金属污染是本矿区生态恢复面临的主要问题。土壤中全磷和全氮含量低于正常指标,且部分C/N比值偏高,同时土壤存在严重的Cd污染,并可能受到M n污染。在锰矿恢复区种植的主要农作物中,部分样品中Pb、M n含量与全部样品的C r、Cd含量超出了植物正常含量范围。农作物的食用部分中Cd、C r、Pb含量普遍超过国家食品限量卫生标准,不宜食用。     

Characterization of heavy metal pollution in the paddy soils of Xiangyin County, Dongting lake drainage basin, central south China

The heavy metal accumulation in soils caused by industrialization has attracted broad attention. To evaluate the soil environmental quality of Xiangyin County, an important food production base in China, 99 top paddy soil samples were analyzed for total concentrations of As, Cd, Cr, Cu, Hg, Ni, Zn and Pb. Kriging interpolation was used to determine the spatial distribution of the metals. The assessment of soil environmental quality was performed according to pollution index methods. As the results showed, except for Cu, Cr and Ni, the mean concentrations of Zn, Pb, Cd, As and Hg in soils were elevated to different extents when compared with the background values. Moreover, except for Cd, contents of seven other elements in most soil samples were below the Class II criteria for Chinese environmental quality standards, which established the maximum allowable concentration of heavy metal in the farmland. Therefore, the soils were believed to be polluted mainly by Cd. All of the elements showed a similar spatial distribution pattern with low contents in the east upland area, and high contents in the middle by the west area, located close to Dongting lake. The long-term practice of using the Xiangjiang river as irrigation water was believed to be the main reason resulting in the enrichment of heavy metals in soils around Dongting lake. In addition, the evaluation results showed that about 45.8, 51.1 and 3.1?% of the study area were classified as slightly, moderately and seriously polluted with Cd, respectively. As for the other seven elements, soil environmental quality was fairly well because of their grades belonging to clean or excellent. By integration of the assessment results for individual elements, it was found that about 3.8?% of the study area was clean, 82.2?% was slightly polluted and 14.1?% was moderately polluted. On the whole, most of the study area was at safe and guarded level. However, appropriate measures still should be adopted to control the levels of heavy metals in agricultural soils. The findings obtained in this study were useful for establishing policies for protecting the local soil environments and guaranteeing the food quality as well as the people??s health.     

基于综合等级划分方法的土地质量地球化学评价——以吉林省乌拉街镇为例

采用图斑+网格化布样以及"S"型采样方法,采集表层土壤、灌溉水、大气干湿沉降物、农作物等样品677件,依据综合等级划分方法对吉林省乌拉街镇一带开展了土地质量地球化学评价,评价面积为153 km²。结果表明：评价区土地质量地球化学综合等级一等的约占全区面积的49.32%,二等占21.94%,三等占28.38%;该区玉米中重金属元素Cr,Cu,Zn,As,Cd,Hg,Pb质量分数分别为<0.87,0.91~2.60,15~27,<0.050,0.003~0.018,<0.010,<0.050 mg/kg,均符合国家标准;土壤酸碱度变化范围为4.43~8.09,平均值5.48,土壤酸化问题严重,酸性土壤占全区的78%,强酸性土壤占15%。该区综合土地质量为优良水平,对农作物种植较为适宜;但是,土壤酸化以及硼缺乏（0.35 mg/kg,处于4级水平0.2~0.5 mg/kg）问题应引起足够重视,亟待采取有效措施加以防治。     

山东省乐陵—河口地区重金属污染现状与分布迁移规律

对山东省乐陵—河口地区重金属元素的分布迁移规律进行研究,结果表明,研究区土壤以清洁型为主;污染区土壤轻度污染所占比例最大,中度及重度污染占研究区的0.57%,污染因子主要为Cd、Hg、Pb,工业废水是土壤污染的主要来源。Cd、Hg在污染区小麦秸杆中明显富集,接近或超过其根系土中的含量,在籽实中含量最低,小麦籽实中Se、Zn明显富集。土壤根系土中Cd、Hg等以稳定态分布为主,活动态的含量很低,活化迁移量少,这与区内碱性环境密切相关。     

Influence of high-fluorine environmental background on crops and human health in hot spring-type fluorosis-diseased areas

Drinking water-type fluorosis is the most harmful endemic disease in China with the largest number of sufferers. Although the implementation of the policy to alter water sources to lower fluoride level has effectively controlled the spread of this kind of endemic disease, its prevalence could not thoroughly be stopped because the high-fluoride environmental background in these endemically diseased areas could still do harm to human health through food chain. Therefore, it is necessary to conduct a more deep-going study on the drinking water-type fluorosis. To investigate the effect of high fluorine environmental background on crops and human health in the hot spring-type fluorosis-diseased areas, local water, paddy soil, rice, whole vegetables and soils around their roots were sampled for analysis. The results were compared with those of the control groups in fluorosis-free areas which are similar to the fluorosis-diseased areas both in natural background and in social background. It is indicated that rice and vegetables can accumulate water-soluble fluorine either in soils or in irrigating water, and different crops have different abilities of fixing fluorine. The contents of fluorine in different parts of vegetables in the fluorosis-diseased and fluorosis-free areas were statistically categorized. The results showed that the fluorine contents of roots, tubers, leaves and flowers of vegetables in the fluorosis-diseased areas are 3.56, 1.17, 3.07 and 3.23 mg/kg, respectively. However, comparisons showed that in the fluorosis-free areas, the fluorine contents are 2.17, 0.70, 1.91 and 2.52 mg/kg, respectively. Moreover, different parts of a crop also show significantly different fluorine fixation abilities. It is demonstrated that the fluorine contents of the strongly metabolic parts are relatively high. For example, the fluofine contents of roots, leaves and flowers of vegetables are much higher than those of stems. The fluorine fixation ability of seeds is very weak. In order to reduce the risk of human body＇s     

山东省东部地区农业生态地球化学调查及生态问题浅析

介绍了山东省东部地区农业生态地球化学调查、评价工作取得的一些基本成果和存在的生态地球化学问题。认为在表生作用或人类活动等因素影响下,表层土壤中Zn、Pb、Cu、Se、Cd、S、P、Hg、N、有机碳(OrgC)等元素或指标含量明显大于深层土壤;该区总体上地球化学环境质量优良,Ⅲ类和劣Ⅲ类土壤仅占全区总面积的0.13%,主要分布在矿集区和城镇周边,超标元素为Cd、Cr、Ni、Hg。浅层地下水大部分元素或指标处于自然低背景含量水平,部分水样的总硬度、溶解性总固体、NO2-、F-含量超标,已不适合饮用。该区存在的生态地球化学问题是:山地丘陵区土壤pH值低;沿海地带土地贫瘠;局部表层土壤重金属明显富集,已对农作物安全产生影响。认为人类活动(采金污染、城市化、工业化发展等)和自然地质背景作用是引起该研究区局部土壤重金属富集的重要原因。