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1.
余世清  唐伟  卢滨 《环境科学》2011,32(9):2645-2653
研究了某农药厂废弃场地土壤中六六六(α,β,γ,δ-HCH)和滴滴涕(p,p'-DDT,o,p'-DDT,p,p'-DDD,p,p'-DDE)的污染分布特征,并对其进行了风险评价.从该场地72个点位的0~400 cm深度土壤中共采集了232个样品,分析表明六六六残留含量为2.6~80 130μg/kg,滴滴涕残留含量为...  相似文献   

2.
深圳市冬、夏两季大气中有机氯农药的研究   总被引:1,自引:0,他引:1       下载免费PDF全文
利用大流量主动采样器,选择深圳市13个有代表性采样点,于2009年12月~2010年1月和2010年6月,分2个采样时期对深圳市大气中有机氯农药(OCPs)进行监测.结果显示,深圳市冬、夏大气中,13个点位总有机氯农药浓度变化范围分别为742~3522 pg/m3(平均值1769pg/m3)和507~2197pg/m3(平均值1163pg/m3).冬季大气中有机氯农药主要是DDTs、林丹、七氯、氯丹、六氯苯,占有机氯农药总量的87%;夏季大气中有机氯农药主要为DDTs、氯丹、林丹,三者总量占有机氯农药的89%.研究表明,深圳市大气中存在“新”DDT的输入,认为工业DDT是其主要来源,而γ-HCH以及氯丹的高检出与林丹和用于杀灭白蚁的氯丹的继续使用有关.  相似文献   

3.
刘佳  丁洋  祁士华  瞿程凯 《环境科学》2018,39(11):5127-5134
本文选取韩江流域作为研究对象,于2013年4月,沿韩江干流采集土壤样品17个,利用气相色谱(GC-ECD)检测13种有机氯农药的含量.并以此为依据,进一步分析土壤中该污染物的分布组成特征和污染来源,根据美国环境保护署(U. S.EPA)的计算标准,对当地居民做出健康风险影响评价.结果表明,13种有机氯农药的含量区间为2. 97~1 275. 79 ng·g~(-1),检出率为75%~100%.其中HCHs和DDTs的含量变化趋于一致,即上游中游下游,在国内外均属于较低水平.另外,根据比值法推断,该区域的HCHs主要来源于工业HCH的输入,且近期仍有DDTs的输入,主要为工业DDT和三氯杀螨醇的混合输入. DDTs与总有机碳有较显著的相关性.致癌风险值(10~(-12)~10~(-8))和非致癌风险值(10~(-6)~10~(-3))均低于阈值(10~(-6)和1),因而表明该流域土壤对当地居民无危害.  相似文献   

4.
Adding organic amendments to stimulate the biodegradation of pesticides is a subject of ongoing interest. The effect of sewage sludge on the bioremediation of dichlorodiphenyltrichloroethane(DDT) and hexachlorocyclohexane(HCH) contaminated soil was investigated in bench scale experiments,and intermittent aeration strategy was also used in this study to form an anaerobic–aerobic cycle. Bioremediation of DDT and HCH was enhanced with the addition of sewage sludge and the intermittent aeration. The removal rates of HCH and DDT were raised by 16.8%–80.8% in 10 days. Sewage sludge increased the organic carbon content from 6.2 to218 g/kg,and it could also introduce efficient degradation microbes to soil,including Pseudomonas sp.,Bacillus sp. and Sphingomonas sp. The unaerated phase enhanced the anaerobic dechlorination of DDT and HCH,and anaerobic removal rates of β-HCH,o,p′-DDT and p,p′-DDT accounted for more than 50% of the total removal rates,but the content of α-HCH declined more in the aerobic phase.  相似文献   

5.
Agriculture, pesticides, food security and food safety   总被引:2,自引:0,他引:2  
Decades ago, agrochemicals were introduced aiming at enhancing crop yields and at protecting crops from pests. Due to adaptation and resistance developed by pests to chemicals, every year higher amounts and new chemical compounds are used to protect crops, causing undesired side effects and raising the costs of food production. Eventually, new techniques, including genetically modified organisms (GMOs) resistant to pests, could halt the massive spread of agrochemicals in agriculture fields. Biological chemical-free agriculture is gaining also more and more support but it is still not able to respond to the need for producing massive amounts of food. The use of agrochemicals, including pesticides, remains a common practice especially in tropical regions and South countries. Cheap compounds, such as DDT, HCH and lindane, that are environmentally persistent, are today banned from agriculture use in developed countries, but remain popular in developing countries. As a consequence, persistent residues of these chemicals contaminate food and disperse in the environment. Coordinated efforts are needed to increase the production of food but with a view to enhanced food quality and safety as well as to controlling residues of persistent pesticides in the environment.  相似文献   

6.
Seventeen topsoil samples (9 urban, 4 suburban, 3 rural and 1 background) were collected in/around Harbin, a typical city in northeast of China, to measure concentration levels of organocholrine pesticides (OCPs) in topsoil of Northeastern China in 2006. Hexachlorohexanes (HCH), dichlorodiphenyltrichloroethane (DDT), and hexachlorobenzene (HCB) were detected in soil samples with mean concentrations (in pg/g dry weight (dw)) of 7120, 5425, and 1039, respectively. The mean concentrations for other OCPs were very low, 4.8 pg/g dw for chlordane and 3.3 pg/g dw for endosulfan. Source identification analysis reveals that all OCPs found in soil samples were due to historical use of these chemicals or from other source regions through long- and short-range atmospheric transport. DDT was mainly used in the rural sites, whereas the sources of HCB, chlordane and endosulfan were mainly in the urban area. HCH was found almost equally in both urban and rural area. Soil concentrations of all detected OCPs, except HCHs, in and around Harbin were much lower than those in the southeast of China, which is expected since the use of these OCPs in the former was much lower than that in the latter, however higher HCH concentrations in and around Harbin than those found in most places of the Southeast China is not expected. It is suggested that high HCH concentration in soil of Northeast China was most likely due to long-range atmospheric transport (LRAT) from Southeast China and the cold condensation process.  相似文献   

7.
松叶中有机氯农药HCH、DDT的研究   总被引:5,自引:0,他引:5       下载免费PDF全文
利用气相色谱-电子捕获检测(GC-ECD)方法对我国华北、华东、华南和西南地区松叶中六六六(HCH)和滴滴涕(DDT)的残留量进行了测定,结果表明,松叶中HCH 4种异构体(a,b,g,d)的含量以b-HCH为最高,占HCH总量的38%~46%.HCH、DDT和滴滴伊(DDE)的含量范围分别为24.7~35.5ng/g干重,2.4~7.0ng/g干重,2.4~2.8ng/g干重.DDE的含量趋势为华北>华东>华南>西南.总HCH为华东>华北>华南>西南.华北和华东地区DDE/DDT>1,华南和西南地区DDE/DDT<1,这表明在华南和西南地区大气中新近有DDT的输入.  相似文献   

8.
北京东南化工区土壤有机氯农药污染特征和分布规律   总被引:4,自引:1,他引:4  
采集北京原东南化工区表层土壤样品,测定了土壤有机氯农药(滴滴涕、六六六和六氯苯)残留浓度,结果表明化工区土壤有机氯农药浓度较高,滴滴涕和六六六平均浓度高达5470ng/g和2110ng/g,比一般农业和城市土壤中的浓度高出很多;某些点位甚至超过国家土壤三级标准,高浓度的点位主要集中在原农药厂的生产车间和存储点。六氯苯由于来源和挥发性跟滴滴涕和六六六不同,所以六氯苯残留在化工区土壤中的分布相对比较均匀。化工区土壤滴滴涕和六六六的异构体组成特征表明工业区土壤的有机氯农药降解速度较慢,滴滴涕残留来源于工业滴滴涕和三氯杀螨醇,而六六六主要来源于工业六六六。化工区的有机氯农药污染主要来自于原农药厂的生产和存储,重污染点位对周围化工厂的有机氯残留有一定的影响。由于高残留浓度和较低的降解速度,化工区土壤有机氯农药残留的环境风险值得进一步关注。  相似文献   

9.
北京石景山区夏季大气中有机氯农药的研究   总被引:1,自引:1,他引:1       下载免费PDF全文
利用气相色谱对北京石景山区大气中气态和总悬浮颗粒物中有机氯农药(OCPs)含量进行了分析测定.结果表明,北京石景山区大气中气态和颗粒物中HCHs、p,p¢- DDT、p,p¢-DDE、p,p¢-DDD、o,p¢-DDT、七氯、氯丹的平均含量分别为:4344.4, 1000.2, 778.0, 213.4, 1319.3, 645.7, 376.6 pg/m3和37.3, 5.3, 0, 0.7, 15.8, 1.6, 0.6 pg/m3,有机氯农药主要以气态存在于大气中.HCHs和DDTs是有机氯农药类污染物的主要成分,两者之和在气态和颗粒物中所占总OCPs的比例分别为87.2%和90.9%.α-HCH/γ-HCH 和p,p’-DDE/p,p’-DDT的浓度比值分别<1.5和<1.0,表明新近该区大气中有γ-HCH和DDT的输入.三氯杀螨醇的使用是环境中DDTs的一个重要来源.  相似文献   

10.
应用物种敏感性分布评估DDT和林丹对淡水生物的生态风险   总被引:22,自引:6,他引:16  
介绍了利用物种敏感性分布(SSD)进行生态风险评价的原理与步骤,构建了淡水生物对DDT和林丹的物种敏感性分布.在此基础上,计算了DDT和林丹对不同类别生物的HC5(Hazardous Concentration for 5% the species)阈值,预测了不同浓度DDT和林丹对生物可能造成的危害,并比较了不同类别生物对DDT和林丹的敏感性,以及DDT和林丹对淡水生物的生态风险.结果表明,DDT和林丹对淡水生物的HC5值分别为1.70μg·L-1和5.96μg·L-1 ,DDT对生态系统的危害大于林丹.当DDT或林丹的浓度为5μg·L-1时,对生态系统仅有轻微影响,而当DDT或林丹的浓度为500μg·L-1时,将有81.5%的物种受到DDT的危害,或有68.1%的物种受到林丹的危害.不同类别生物对DDT的敏感性从甲壳类、昆虫和蜘蛛类到鱼类依次降低,对林丹的敏感性大小依次为昆虫和蜘蛛类、甲壳类、鱼类.与林丹相比,DDT对淡水脊椎动物与无脊椎动物以及甲壳类和鱼类的生态风险较大,而对昆虫和蜘蛛类,林丹与DDT的生态风险差别不大.  相似文献   

11.
A field study was conducted in the Taihu Lake region, China in 2004 to reveal the organochlorine pesticide concentrations in soils after the ban of these substances in the year 1983. Thirteen organochlorine pesticides (OCPs) were analyzed in soils from paddy field, tree land and fallow land. Total organochlorine pesticide residues were higher in agricultural soils than in uncultivated fallow land soils. Among all the pesticides, ΣDDX (DDD, DDE and DDT) had the highest concentration for all the soil samples, ranging from 3.10 ng/g to 166.55 ng/g with a mean value of 57.04 ng/g and followed by ΣHCH, ranging from 0.73 ng/g to 60.97 ng/g with a mean value of 24.06 ng/g. Dieldrin, endrin, HCB and α-endosulfan were also found in soils with less than 15 ng/g. Ratios of p,p'-(DDD DDE)/DDT in soils under three land usages were: paddy field > tree land > fallow land, indicating that land usage inlfuenced the degradation of DDT in soils. Ratios of p,p'-(DDD DDE)/DDT >1, showing aged residues of DDTs in soils of the Taihu Lake region. The results were discussed with data from a former study that showed very low actual concentrations of HCH and DDT in soils in the Taihu Lake region, but according to the chemical half-lives and their concentrations in soils in 1980s, the concentration of DDT in soils seemed to be underestimated. In any case our data show that the ban on the use of HCH and DDT resulted in a tremendous reduction of these pesticide residues in soils, but there are still high amounts of pesticide residues in soils, which need more remediation processes.  相似文献   

12.
DDT和三氯杀螨醇对蚯蚓的急性和亚急性毒性影响   总被引:12,自引:3,他引:12  
采用人工土培养法,通过急性和亚急性暴露实验,研究了DDT和三氯杀螨醇对蚯蚓(赤子爱胜蚓)的存活、生长和繁殖能力的影响.结果表明,DDT在急性暴露期对蚯蚓存活具有一定的毒性,其14 d的LC50为484.76 mg·kg-1;三氯杀螨醇对蚯蚓的存活基本没有影响(LC50>4000 mg·kg-1).DDT在急性和亚急性暴露期(10~28 d)对蚯蚓的生长都具有显著的抑制作用(p<0.05),三氯杀螨醇在急性期对蚯蚓的生长没有抑制作用(p>0.05),在亚急性期对蚯蚓生长的影响尚不确定.DDT和三氯杀螨醇都显著抑制蚯蚓的繁殖能力(p<0.05).  相似文献   

13.
地下河流域土壤中有机氯农药分布及来源分析   总被引:3,自引:0,他引:3       下载免费PDF全文
为研究有机氯农药在重庆青木关地下河流域土壤中的分布特征及来源,采用GC-μECD对17个代表性表层土壤样品进行分析.结果显示,研究区土壤中OCPs的含量范围是7.29~222.42ng/g,平均值为46.15ng/g.HCHs、DDTs在所有样品中均有检出,HCHs的含量范围是0.55~26.54ng/g,DDTs的含量范围是4.31~213.50ng/g.HCB的检出率达到88%,其含量范围是n.d.~1.78ng/g.研究区土壤中HCHs可能来源于工业HCHs残留和林丹的混合源,且由于环境影响,土壤中HCH的同系物之间发生了明显变化.DDTs主要来源于工业DDTs的非法使用,而非三氯杀螨醇类型的DDTs,并且仍有新的DDTs输入.与国内其他地区同类研究相比,本研究区土壤中HCHs、DDTs的残留水平较低;与国外相关研究相比,研究区内土壤中HCHs和DDTs的含量均高于德国、埃及、罗马尼亚土壤中HCHs和DDTs的含量.  相似文献   

14.
田间试验表明,在河南地区施用农药林丹的残留量,玉米为1~1.7μg/kg,平均1.4μg/kg;大豆为3.3~5.7μg/kg,乎均4.8 μg/kg。直接喷于作物上,大豆为5.2~6.4μg/kg,平均5.7μg/kg,土壤为6.2~10.1μg/kg,平均8.2μg/kg。残留消解动态曲线表明,林丹在土壤中的半衰期为1~4.5 d。作物籽粒吸收林丹有一个过程。玉米籽粒在施药3 d后、大豆在施药34 d后籽粒中残留量达最高点,往后便逐渐降解。林丹在籽粒中的残留动态曲线呈一缓慢的峰形。林丹在大豆中的残留量明显高于玉米。大豆在被收获前31~11 d施药时,籽粒中的残留量超过联合国推荐的允许量100μg/kg。   相似文献   

15.
Since the ban on the use of organochlorine pesticides (OCPs) such as dichloro-diphenyl-trichloroethane (DDT) and hexachlorocyclohexane(HCH) in agriculture, their levels have generally dropped. In a number of cases, however, the levels of these OCPs were found to be unchanging or even increasing after the ban. With the aim to unveil the possible causes of these exceptions, we collected two lake cores from King George Island, West Antarctica, and determined their accumulation flux profiles and temporal trends of these OCPs. In the lake core sediments with glacier meltwater input, the accumulation flux of DDT shows an abnormal peak around 1980s in addition to the expected one in 1960s. In the lake core sediments without glacier meltwater input, the accumulation flux of DDT shows a gradual decline trend after the peak in 1960s. This striking difference in the DDT flux profiles between the two lake cores is most likely caused by the regional climate warming and the resulted discharge of the DDT stored in the Antarctic ice cap into the lakes in the Antarctic glacier frontier. Furthermore, to investigate the change of OCPs loadings in the Antarctic coastal ecosystem, we reconstructed the HCH and DDT concentration profiles in penguin droppings and observed a gradual increase for the former and a continuous decrease for the latter during the past 50 years. The increase of HCH seems to be due to the regional warming from the early 1970s and the resulted HCH discharge to the coastal ecosystem by glaciers' meltwater and the illegal use of HCH in the Southern Hemisphere in the recent decade. The different temporal trends of HCH and DDT accumulation rate in the lake core with glacier meltwater input and the aged penguin droppings can be explained by their different water-soluble property.  相似文献   

16.
The Yellow River Delta (YRD) is a typical agricultural and petrochemical industrial area of China. To assess the current status of soil dichlorodiphenyltrichloroethane (DDT) and polychlorinated biphenyls (PCB) residues, topsoil samples (0-15 cm) (n = 82) were collected in Bincheng District, at the geographic center of the YRD. The total concentrations of six DDT homologues were within 3.3-3819 μg/kg, with a mean concentration of 191 μg/kg, showing significant increase along urban-rural gradient. Soil concentrations of seven indicator PCBs in the area ranged from non-detectable to 87.0 μg/kg, dominated by heavily chlorinated PCBs (PCB-101 and -118). Soil PCBs concentrations were significantly greater in urban than suburban and rural areas. Principal component and multiple linear regression analysis suggest that 86.4% of soil DDTs originate from past DDT usage, and 13.6% originate from dicofol application. Soil PCBs most likely originate from the petrochemical industry (77.1%), municipal solid waste disposal (16.5%), local commercial PCB homologues usage (5.2%), and long-range atmospheric deposition (1.2%). In general, soil DDTs pollution was classified as low level, and mean PCBs concentrations were below the severe contamination classification range. Because PCB-118 is a dioxin-like congener, monitoring and remediation is advised to assess and reduce negative environmental and human health effects from soil DDTs and dioxin-like congeners in the study area.  相似文献   

17.
土壤及果树中HCH和DDT残留及分布规律研究   总被引:5,自引:0,他引:5  
采用索氏提取、弗罗里土固相微萃取小柱净化结合GC-ECD测定了苹果园土壤和果树样品中4种六六六(HCH)和4种滴滴涕(DDT)的残留量,并对果树的根、枝、叶中HCH和DDT的分布规律进行了研究。实验结果表明,土壤和果树样品中均有HCH和DDT检出。土壤样品中两类农药的含量分别在0.51~3.97ng/g和1.46~15.55ng/g之间,其中β-HCH是六六六残留的主体,滴滴涕类的含量以p,p'-DDT为最高,并且(DDE+DDD)/DDT<1表明近期果园中有新的DDT输入。果树样品中,HCH和DDT的残留量分别在0.22~2.01ng/g和0.38~6.08ng/g之间,都要低于相应土壤中有机氯农药的浓度。果树中总OCPs的含量在4.88~17.94ng/g之间,是土壤和大气中OCPs污染共同作用的结果。根部的OCPs的含量明显高于枝和叶,其分布规律为根>叶>枝,这主要取决于根、枝、叶各组织的结构以及农药的理化性质。  相似文献   

18.
果园土壤有机氯农药残留的时间趋势研究   总被引:16,自引:0,他引:16  
以天然荒地和蔬菜基地作为对照 ,于 1993年和 2 0 0 3年对北京市某果园中具有不同树龄的老果园和新果园的土壤有机氯农药 (HCH ,DDT)残留情况进行了定位监测 .结果表明 ,在禁用 2 0年后 ,土壤中的有机氯农药残留水平大幅度降低 ,其中老果园的有机氯农药残留浓度显著高于新果园 (P <0 0 5 ) .果园土壤有机氯残留浓度显著高于荒地和蔬菜基地对照 (P <0 0 5 ) .DDT是当地主要的有机氯污染物 ,利用绿色食品生产基地环境质量标准作为评价标准对该果园土壤的污染程度进行了评估 .评估结果表明 ,新果园的土壤质量能够满足绿色食品生产的要求 ,老果园由于土壤中DDT和HCH残留超标严重不适合作为绿色食品生产基地  相似文献   

19.
分4批次分别采集某废弃农药厂拆除前和拆除后周边土壤,研究土壤中DDTs含量、分布和组成的变化特征.结果表明,拆除1个月后,土壤中DDTs残留量(平均为334ng/g)明显大于拆除前(平均为97.0ng/g),之后土壤中DDTs的残留量明显下降.拆除前,周边土壤中以p,p'-DDE和p,p'-DDD为主,平均浓度分别为35.6和31.0ng/g;拆除后以p,p'-DDT为主要残留污染物,平均浓度为289ng/g,较拆除前(9.69ng/g)增长了28.9倍.来源分析表明,农药厂拆除前周边土壤中DDTs的污染主要受厂区内历史工业品DDTs生产和农田使用的三氯杀螨醇共同影响,而拆除过程周边土壤DDTs污染的贡献主要来自于厂区内工业品DDTs的挥发.在空间分布上,拆除前和拆除后整体上西部区域土壤的污染程度高于东部区域.  相似文献   

20.
有机氯农药在天津耕作土壤剖面中的分布   总被引:19,自引:3,他引:19  
研究了天津耕作区典型土壤剖面中有机氯农药的分布特征,结果表明:在典型剖面的表层土壤中,六六六在菜地中的质量分数最高,其次是在高粱地、水稻田和玉米地;DDTs在菜地中的质量分数最高,其次是在高粱地,在水稻田与玉米地中的质量分数差别不大。有机氯农药质量分数在土壤剖面的纵向分布总体上是随着土壤剖面的加深而降低,有机氯农药的各个组分(α-HCH,β-HCH,γ-HCH,δ-HCH,DDE,DDD,DDT)质量分数也有类似的分布趋势。有机氯农药的物化性质、土壤黏粒含量、有机碳和微生物影响着它们在土壤剖面上的分布。六六六的4个异构体与原粉中各个异构体的质量分数相比有较大差异,这与4个异构体在土壤中的降解速度不同和各个异构体之间的转化有关。在表层土壤中w(DDT) w(DDTs)为0 033~0 188,远小于0 5,说明在这些耕作区中没有新的DDT污染。   相似文献   

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