上海市小羽藓属植物重金属含量及其与环境的关系

应用原子吸收法对上海市13个样点的小羽藓植物体及相应土壤样品中的Cu、Pb、Cd、Zn、Cr 5种重金属元素含量进行了测定.通过对植物体内含量的聚类分析,将13个样点按重金属污染程度的轻重分为3个组：1)污染严重点,包括桂林公园、复兴公园、光启公园3个样点,均位于市区交通繁忙地带,其小羽藓体内重金属含量分别为：Cu 35.25～50.36 mg·kg^-1、Pb 55.50～65.00 mg·kg^-1、Cd 1.68～2.30 mg·kg^-1、Zn 829.63～1140.13 mg·kg^-1、Cr 7.41～16.41 mg·kg^-1;2)污染点,包括长风公园、古钟园、中山公园、和平公园、上海师范大学徐汇校区5个样点,均位于市区近郊,小羽藓体内重金属含量分别为：Cu 18.51～62.50 mg·kg^-1、Pb 14.38～34.25 mg·kg^-1、Cd 0.81～1.40 mg·kg^-1、Zn 354.25～671.75 mg·kg^-1、Cr 3.62～25.08 mg·kg^-1;3)相对清洁点,包括佘山、大观园、罗泾、植物园、崇明东平国家森林公园5个样点,位于上海市远郊,小羽藓体内重金属含量分别为：Cu 11.13～16.41 mg·kg^-1、Pb 4.63～27.25 mg·kg^-1、Cd 0.93～1.28 mg·kg^-1、Zn 489.25～1 086.75 mg·kg^-1、Cr 1.53～7.62 mg·kg^-1.结果表明,小羽藓属苔藓植物可作为监测上海地区环境重金属污染的良好指示植物.苔藓植物体内重金属含量水平与土壤重金属含量存在一定的相关性,而且也受其他因素的影响.     

集约化养殖禽畜粪中主要化学物质调查

对广东省集约化养殖场61个禽畜粪样本进行调查的结果表明,鸡粪和猪粪的总N、P、K含量均明显高于传统养殖,鸡、猪和鸽粪的P/N比高于一般作物的P/N比;3种禽畜粪总盐分含量分别为49.0、20.6和60.3 g·kg^-1,盐分组成以K和Na的硫酸盐和氯化物为主;鸡粪Cu、Zn和As的平均含量分别为107.5、366.6和21.6 mg·kg^-1;猪粪分别为765.1、1128.0和89.3 mg·kg^-1;鸽粪分别为56.1、210.9和2.9 mg·kg^-1.这3种禽畜粪的Pb、Cd和Cr含量均很低,在未检出至12.0 mg·kg^-1之间.按不同肥料重金属限量标准,鸡粪和猪粪重金属超标以Cu、Zn和As为主,其中Zn的超标最为普遍.     

异丙甲草胺及其高效体对我国南方潮土微生物的影响Ⅰ-过氧化氢酶

研究了0、5、20和100 mg·kg^-1浓度的异丙甲草胺及其高效体对土壤过氧化氢酶活性的影响.结果表明,不同浓度的异丙甲草胺处理对过氧化氢酶活性的影响不同,20 mg·kg^-1处理的土壤过氧化氢酶受到激活的程度最大,且一直处于激活状态,5 mg·kg^-1处理的土壤过氧化氢酶在前期受到抑制,后期则100 mg·kg^-1处理的土壤过氧化氢酶受激活较强.不同浓度的金都尔对供试土壤过氧化氢酶活性的影响表现为先激活、后抑制、再激活,并且后期100 mg·kg^-1处理的激活程度最大;5 mg·kg^-1和100 mg·kg^-1处理的异丙甲草胺对供试土壤生态环境的影响和危害可能大于金都尔,但20 mg·kg^-1处理则表现出例外.     

氯离子和乙二胺四乙酸对镉的植物有效性的影响

通过水培试验,向营养液中添加不同浓度的Cl^-或乙二胺四乙酸（EDTA）,研究了离子的配合作用对水稻及油菜吸收镉的影响.结果表明,随着营养液中Cl^-或EDTA浓度的增加,水稻和油菜地上部与根中镉的浓度降低.Cl^-浓度的增加抑制了水稻对镉的吸收,地上部与根部的镉含量分别从212.2和345.1 mg·kg^-1降低到34.1和209.1 mg·kg^-1.EDTA的添加抑制了水稻及油菜对镉的吸收,水稻地上部与根部的镉含量分别从212.2和345.2 mg·kg^-1降低到50.0和4.2 mg·kg^-1;油菜地上部与根部的镉含量分别从86.7和149.2 mg·kg^-1降低到22.2和12.3 mg·kg^-1.在营养液培养条件下,Cl^-或EDTA与镉的配合作用降低了植物对镉的吸收,与Cl^-相比,EDTA的抑制作用更明显.     

红壤丘陵景观单元土壤有机碳和微生物生物量碳含量特征

为了探讨我国亚热带红壤丘陵区不同利用方式下土壤有机碳(SOC)和土壤微生物生物量碳(SMB-C)含量的特征,在湖南省桃源县选取典型样区,通过密集取样,分析了红壤丘陵景观单元内水田、旱地、林地、果园4种典型利用方式下表层土壤(0～20 cm)SOC和SMB-C含量.结果表明,典型红壤丘陵景观单元中SOC含量高低的顺序为水田(16.0 g·kg^-1)＞旱地(11.2 g·kg^-1) ＞果园(9.5 g·kg^-1)＞林地(8.4 g·kg^-1),SMB-C含量则为水田(830 mg·kg^-1)＞旱地(361 mg·kg^-1)＞林地(200 mg·kg^-1)＞果园(186 mg·kg^-1),且在不同利用方式下SOC与SMB-C均呈极显著正相关(P＜0.01),说明本研究区内各土地利用类型的土壤SMB-C含量变化可以敏感地指示SOC的动态.研究结果还表明,将我国亚热带红壤丘陵林地开垦为果园或耕地后,表层土壤 SOC含量不可能降低.     

施用坡缕石对黄绵土中尿素氮的挥发和淋溶损失的影响

通过室内模拟试验,采用吸收法和土柱淋溶法研究了施用坡缕石对黄绵土中尿素氮的挥发和淋溶的影响.结果表明：施用坡缕石+尿素处理能降低尿素氨挥发高峰期的挥发速率,比单施尿素处理的氨挥发损失减少了13.6%～15.0%.坡缕石施用量为0.3和0.6 g·kg^-1时,降低了NH₄⁺-N和NO₃^--N的淋溶速率,无机氮淋溶损失比单施尿素处理分别减少13.7%和13.6%;而坡缕石施用量为0.9 g·kg^-1时,加快了NH₄⁺-N和NO₃^--N的淋溶速率,无机氮淋溶损失比单施尿素处理增加了6.1%.施用低量（0.3 g·kg^-1）坡缕石+尿素处理土壤的NH₄⁺-N含量比单施尿素处理提高了0.20 mg·kg^-1,而施用高量（0.9 g·kg^-1）坡缕石+尿素处理土壤的NH₄⁺-N含量比单施尿素处理降低了0.42 mg·kg^-1;施用坡缕石+尿素处理土壤的NO₃^--N含量比单施尿素处理增加1.24～2.52 mg·kg^-1.表明施用坡缕石能减少土壤中尿素氨的挥发损失,在一定用量范围内能降低NH₄⁺-N和NO₃^--N的淋失,提高土壤NH₄⁺-N和NO₃^--N含量.     

异丙甲草胺及其高效体对潮土微生物的影响Ⅱ.土壤呼吸

研究了0、5、20和100 mg·kg^-1浓度的异丙甲草胺及其高效体金都尔对土壤微生物呼吸的影响.结果表明,5 mg·kg^-1异丙甲草胺对土壤呼吸的激活程度大于同浓度的金都尔,后期异丙甲草胺起抑制作用,而金都尔则一直处于激发和恢复状态;20 mg·kg^-1金都尔对土壤呼吸的影响不大,而异丙甲草胺具有激发作用;100 mg·kg^-1异丙甲草胺对土壤呼吸的激活程度大于同浓度的金都尔,后期二者的抑制程度大致相同;异丙甲草胺或金都尔的浓度越大,对土壤呼吸强度的激活越显著.DMRT法检验表明,在初期各处理与对照间的呼吸强度都存在显著差异,后期则差异不显著.20和100 mg·kg^-1异丙甲草胺对土壤微生物的危害大于同浓度的金都尔.异丙甲草胺和金都尔为低毒或无实际危害的农药,对土壤微生物的危害较小.     

印度芥菜-苜蓿间作对镉胁迫的生态响应

采用温室盆栽试验,研究了重金属镉（Cd）胁迫对印度芥菜和苜蓿间作下的土壤-植物系统的影响,同时对苜蓿的Cd饲用安全进行了评估.结果表明：在土壤Cd含量为0.37～20.37 mg·kg^-1范围内,与单作印度芥菜和苜蓿相比,间作使印度芥菜生物量降低了0.4%～11.8%,而使苜蓿生物量提高了55.3%~70.0%.土壤有效Cd主要受土壤全量Cd和种植植物种类的影响,种植方式对其影响不大.在土壤Cd含量为5.37 mg·kg^-1时,间作印度芥菜地上部Cd含量较单作提高了14.5%,而间作苜蓿地上部Cd含量较单作降低了57.1%;此时,单作和间作苜蓿地上部Cd含量分别为0.21和0.09 mg·kg^-1,均未超过饲料卫生限定标准(0.5 mg·kg^-1).在土壤Cd含量为10.37～20.37 mg·kg^-1范围内,虽然单作和间作苜蓿Cd含量均超过饲料卫生限定标准,但间作种植方式仍然使苜蓿地上部Cd含量较单作降低了2.8%～48.3%,印度芥菜地上部Cd含量也较单作降低了1.1%～48.6%.不论单作还是间作印度芥菜的Cd转运系数都远高于苜蓿.     

不同作物与玉米间作对玉米吸收积累镉的影响

采用盆栽技术,研究了7种间作作物对玉米吸收积累镉(Cd)的影响.结果表明,多数间作作物对玉米生物量没有明显影响,只有扁豆对玉米生长有较明显的抑制作用,使玉米生物量降至对照的67.8 %.间作豆科作物大幅提高玉米的Cd积累总量,其中鹰嘴豆的作用最为明显,使玉米对Cd的累积量增加1倍以上.7种间作植物对Cd也有不同水平的吸收,其中,油菜与籽粒苋可在地上部大量积累Cd（油菜地上部Cd浓度达53.9 mg·kg^-1,籽粒苋达51.0 mg·kg^-1),且籽粒苋根的Cd含量高达91.8 mg·kg^-1 (土壤Cd为3 mg·kg^-1).间作植物与玉米对Cd的吸收具有不同的交互作用特征,豆科作物在自身较少吸收Cd的条件下,显著提高了玉米对Cd的积累;籽粒苋在自身大量累积Cd的同时,一定程度上抑制了与其间作的玉米的Cd累积量;油菜地上部分吸收较多的Cd,但降低了玉米地上部分Cd含量.研究表明,如果将玉米作为大生物量的Cd污染修复植物来应用,可将其与豆科植物间作,以提高Cd清除效率;籽粒苋与油菜具有大量积累Cd的能力,可作为Cd污染土壤的修复植物.     

山东寿光农业利用方式对土壤砷累积的影响

对山东省寿光市不同农业利用方式下土壤砷的累积状况进行了调查.结果表明,寿光市农田土壤砷平均含量为9.63 mg·kg^-1,最高值为15.15 mg·kg^-1,以山东省当地的土壤背景值（9.3 mg·kg^-1）为基准,有53.1%的样本出现了砷富集现象.所调查地区土壤砷含量的空间分布为西、东、北部较高,中部居中,南部最低.不同农业利用方式下土壤砷含量呈现出明显差异,按由高到低顺序排列为小麦/玉米地＞棉花地＞设施菜地＞露天菜地,分析呈现这种规律的原因发现,土壤砷含量的差异除了受当地土壤砷背景值影响外,还不同程度地受农业活动的影响.随着设施菜地种植年限的增加,土壤砷含量呈增加趋势.猪粪和鸡粪中的砷可能是设施菜地土壤砷累积的重要来源,施用豆肥可在一定程度上减少土壤砷的累积.     

惠州市3座供水水库沉积物重金属污染特征

为了解惠州市供水水库沉积物重金属(Cr、Cu、Zn、Cd、Pb和Hg)污染状况和垂直分布特征,于2008年5月在惠州市3座具代表性的水库湖泊区采集柱状沉积物样品,运用ICPMS法检测沉积物中重金属含量,并采用地积累指数法(Igen)和潜在生态风险指数法(RI)进行污染评价,同时运用主成分分析(PCA)对沉积物中重金属的可能来源进行分析.结果表明:3座水库沉积物重金属含量随沉积深度的变化差异明显,一些重金属含量的垂直变化不明显,而另一些垂直变化明显(降低或升高),但各种重金属在不同水库沉积物中呈现特有的垂直分布特征.根据地积累指数可知,3座水库中沉积物主要以Zn和Pb污染最为严重,达到轻度至强度污染(含量分别为Zn:49.98 ～ 640.29 mg·kg-1;Pb:21.94～300.66 mg· kg-1),同时沉积物中部或底部受到轻度的Cu污染(含量为16.85 ～45.46 mg·kg-1),基本未受Cr、Cd和Hg污染.据6种重金属潜在生态风险系数[Er(i)]及潜在生态风险指数(RI)可知,3座水库沉积物的重金属潜在风险均处于较低水平.据PCA分析和相关资料可知,矿山开采与冶炼、城市化和农林业快速发展等人类活动影响了3座水库沉积物重金属的分布特征和污染.其中,Zn主要来源于矿产开采与冶炼;除矿产开采与冶炼导致沙田水库Pb污染外,机动车尾气排放和生活垃圾等是3座水库沉积物Pb污染的主要途径;Cu污染主要来源于农业和林业污染.     

Assessment of potentially toxic heavy metals and health risk in water,sediments, and different fish species of River Kabul,Pakistan

Contamination of freshwater bodies and consequently freshwater fish with toxic heavy metals is a serious environmental issue. The trophic transfer of potentially toxic heavy metals in the human food chains, especially in fish has important implications for human health. The present research study was designed to assess the concentrations of the heavy metals Cr, Ni, Cd, and Pb in the water, sediments, and different freshwater fish species of River Kabul, Pakistan. The heavy metals were quantified in the samples with Atomic Absorption Spectrophotometer. Heavy metal contamination in fish muscles was characterized in terms of metal pollution index and biota-sediments accumulation factor, while human health risk was assessed through calculation of estimated weekly intake. The average concentrations of Cr, Ni, Cd, and Pb in muscle samples of the analyzed fish species at different sampling sites of the river ranged from 12.3 to 33.0, 33.2 to 109.2, 0.98 to 1.5, and 13.9 to 29.6 mg kg^?1 wet weight, respectively. Based on the current study data, consumption of the analyzed freshwater fish species from River Kabul was generally safe in terms of potential risk from Cd and Pb but the observed Ni accumulation may pose a potential health risk to regular/excessive fish consumers.     

铜尾矿区土壤与凤丹植株重金属富集研究

对安徽铜陵铜尾矿区凤丹种植地的土壤和凤丹中重金属污染状况进行了研究,结果表明,尾矿库区种植地极端贫瘠,有机质含量仅1．1～3．4g·kg^-1,而土壤Cu、Cd、Pb、Zn含量皆高于对照土壤,其中Cu含量达587．43～1176．44mg·kg^-1,Cd含量达3．08～5．16mg·kg^-1,约达国家土壤二级标准的10倍,凤丹各部位的Cu、CA和Pb含量均超过了药用植物的限量标准,尤其是根皮部位Cu含量达31．50～64．00mg·kg^-1,Cd含量达0．98～1．45mg·kg^-1,超出标准1．6～3．6倍,表明种植地和凤丹都受到严重污染．凤丹不同部位中的Zn、Cd、Pb和Cu分别以茎、叶、叶和根皮中的含量最高．凤丹对Cd、Zn的富集比Cu和Pb高,但在根皮中的富集系数均较小。     

广西锰矿恢复区食用农作物重金属污染评价

对广西平乐、荔浦两锰矿恢复区种植的食用农作物进行了调查和重金属含量分析.结果表明:两锰矿区农作物Zn、Pb、Cr、Cu和Cd的含量范围分别在1.18~20.46、0.52~16.16、0.33~6.62、0.01~6.24和0.01~2.76mg.kg-1之间.其中,豆类作物中的重金属含量最高,其次是薯类.单因子污染指数评价表明,农作物基本未受Zn、Cu污染,但受Pb、Cd和Cr污染严重,以Pb污染最重,受污染率达100%,Cr和Cd受污染率分别为96.9%和75.0%;从综合污染指数来看,农作物受污染率达100%,其中,重、中、轻污染分别占87.5%、9.4%和3.1%.表明在锰矿废弃地直接种植食用农作物存在较大风险,应重新考虑其恢复利用模式.     

Distribution and risk assessment of heavy metals in river surface sediments of middle reach of Xijiang River basin,China

Xijiang River is the main surface water source in Guangxi province, South China. This study was carried out to investigate the distribution and potential ecological risks of seven heavy metals (Cu, Pb, Zn, As, Cd, Ni, and Cr) in surface sediments in Xijiang River basin. The results illustrated that the average concentrations of Zn, Pb, Cd, Cu, As, Ni, and Cr were 483.9, 207.5, 13.35, 23.50, 312.1, 28.75, and 50.62 mg/kg, respectively. Among them, Zn, Pb, Cd, and As were the major heave metals with concentration exceeding Class 3 threshold value of Chinese national standard. The result also showed samples with high ecological risk were mainly located in the upstream of Xijiang River basin as Diaojiang River, Hongshui River, Jincheng River, and Dahuan River. Based on the pollution risk assessment, the area manifested composite pollution of heavy metals in the sediments, signifying As, Pb, and Cd as the dominant heavy metals, and there were high ecological risk in sediments for these metals. According to correlation matrix and factor analysis (FA), the seven heavy metals were divided into three types/classes, Cd, as and Zn attributed by anthropogenic sources, natural sources corresponds for Ni and Cr while both natural and anthropogenic sources were attributed to Cu.     

湖南省主要水系底泥重金属污染特征及其生态风险评价

为全面了解湖南省主要水系底泥中重金属含量及其潜在生态风险,在湖南省内的湘、资、沅、澧以及洞庭湖5个主要水系共采集了75个位点的底泥样品,分析了重金属元素含量和来源分布特征,并采用地累积指数法、内梅罗指数法和潜在生态风险指数法对其污染程度和潜在生态风险进行评价。结果表明,As、Cd、Cr、Cu、Mn、Pb和Zn的平均含量分别为32.87、7.59、78.09、70.69、1182.60、85.64 mg/kg和482.44 mg/kg。湘江和洞庭湖的污染相对严重,底泥中重金属含量明显高于资江、沅江和澧水;相关性分析表明多种重金属具有相同污染来源;地累积指数评价结果显示,湖南省主要水系底泥中Cd为重污染水平,Zn为中度污染,Cu、Mn和Pb均为轻度污染,而As和Cr污染程度为清洁;内梅罗指数法评价结果表明,除Cr为轻度污染外,湖南省主要水系底泥中其他6种重金属污染均为重污染级别;潜在生态风险评价结果显示,湖南省总体潜在生态风险属于中等级别,各水系潜在生态风险大小顺序为洞庭湖>资江>湘江>澧水>沅江,重金属Cd的潜在生态风险级别为很强,其他重金属元素都属于轻微级别。     

Heavy Metal Pollution Characteristics of Surface Sediments in Different Aquatic Ecosystems in Eastern China: A Comprehensive Understanding

Aquatic ecosystems in eastern China are suffering threats from heavy metal pollution because of rapid economic development and urbanization. Heavy metals in surface sediments were determined in five different aquatic ecosystems (river, reservoir, estuary, lake, and wetland ecosystems). The average Cd, Cr, Cu, Ni, Pb, and Zn concentrations were 0.716, 118, 37.3, 32.7, 56.6, and 204 mg/kg, respectively, and the higher concentrations were mainly found in sediment samples from river ecosystems. Cd was the most anthropogenically enriched pollutant, followed by Zn and Pb, indicated by enrichment factors >1.5. According to consensus-based sediment quality guidelines, potential ecological risk indices, and risk assessment codes, all five types of aquatic ecosystems were found to be polluted with heavy metals, and the most polluted ecosystems were mainly rivers. Cd was the most serious pollutant in all five aquatic ecosystems, and it was mainly found in the exchangeable fraction (about 30% of the total Cd concentration, on average). The results indicate that heavy metal contamination, especially of Cd, in aquatic ecosystems in eastern China should be taken into account in the development of management strategies for protecting the aquatic environment.     

Assessment of Heavy Metal Pollution in Water and Sediments from the Ghalechay River,Baychebagh Copper Mine Area,Iran

The concentrations of selected heavy metals in sediments and waters in Baychebagh copper mine were determined using ICP-OES. Except for Co, the average concentrations of Cd, Cu, Pb, and Zn in sediments from the Ghalechay River in the district exceed the world-average shale and continental upper crust value. Enrichment factors for Pb, Cu, and Cd were significantly enriched in sediments, indicating environmental contamination. Geoaccumulation index calculated for different sampling stations indicates that the sediments are unpolluted with respect to Co and Zn while unpolluted to moderately polluted with Cu and highly polluted with Pb and Cd. The Sediment Quality Guidelines (SQGs) suggest that Cd and Pb may pose the highest risk for the environment. Sequential extraction analyses of sediments revealed that Cu, Co, Pb, and Zn bound to extractable, carbonate, reducible and oxidizable fractions are lower than residual fraction. About 10% of the total Pb was associated with the exchangeable fraction, indicating remobilization, while Cd (89%), Pb (73%) Co (58%), Cu (76%), and Zn (68%) closely associated with the residual and oxidizable fractions, resulting in their environmental immobility. The residual forms are not expected to be released under normal conditions in the river and could be considered an inert phase.     

Concentrations of heavy metals in vegetables between 2004 and 2018, and its impacts on human health in China

Abstract

Heavy metals in vegetables are of great concern worldwide due to their potential bioaccumulation in human. This review-based study researched the concentrations of heavy metals in vegetables from all provinces of China between 2004 and 2018, and assessed the health risk for the residents. The results displayed the highest Pb, Cd, Cu, and Zn concentrations in vegetables were 0.192?mg/kg (west area), 0.071?mg/kg (central area), 3.961?mg/kg (central area), and 10.545?mg/kg (central area), which were lower than the maximum allowable concentration. In the national scale, the weighted average level of heavy metals in vegetables was found to be in the order of Zn?>?Cu?>?Pb?>?Cd. The hazard index (HI) of each province showed that beside Anhui and Hunan province, residents in other provinces of China faced a low high risk of Pb, Cd, Cu, and Zn. However, people consuming vegetables faced a high risk of Pb, Cd, Cu, and Zn in Anhui and Hunan provinces. This research may provide insight into heavy metal accumulation in vegetables and forecast to residents to cope with these problems for improved human health.