Health Risks Assessment of Heavy Metal Pollution in the Soil-Crop System from an E-Waste Dismantling Area

Soil is an essential resource for agricultural production.In order to investigate the pollution situation of heavy metals in the soil-crop system in the e-waste dismantling area,the crop and soil samples(226 pairs,including leaf vegetables,solanaceous vegetables,root vegetables,and fruits)around the e-waste dismantling area in southeastern Zhejiang Province were collected.The concentrations of Cd,Cu,Pb,and Cr were determined.The average concentrations of Cd,Cu,Pb,and Cr in soils were 0.94,107.79,80.28,and 78.14 mg kg-1,respectively,and their corresponding concentrations in crops were 0.024,0.7,0.041,and 0.06 mg kg-1,respectively.The transfer capacity of leaf vegetables was significantly higher than that of non-leaf vegetables,and the accumulation of four heavy metals in crops tended to be Cd>Cu>Cr/Pb.The pollution index’s results revealed that the soil pollution degree under different land uses ranked as root vegetables soil>leaf vegetables soil>solanaceous vegetables soil>fruit soil.The carcinogenic and non-carcinogenic risks of heavy metal exposure were ranked as food intake>accidental ingestion>dermal contact>inhalation.The comprehensive non-carcinogenic risk was ranked as Cr>Cd>Pb/Cu.Our results could be used to provide useful information for further crop cultivation layout in the study area,which can guarantee the local residents’health and food safety.

Effects of Environmental Lead Pollution on Blood Lead and Sex Hormone Levels among Occupationally Exposed Group in An E-waste Dismantling Area

Objective To study the effects of environmental multi-media lead pollution on blood lead and sex hormone levels among lead exposed males engaged in E-waste dismantling, and the correlation between confounding factors and sex hormone levels. Methods An E-waste dismantling area in Taizhou of Zhejiang Province was selected as the research site. One hundred and fifty two samples were collected from the groundwater, soil, rice, corn, chicken, and pork in the dismantling area. The effects of the multi-media lead pollution on the male blood lead and sex hormone levels of FSH, LH, and T, as well as the correlation with confounding factors, were studied. Results The blood lead concentrations in the males aged under 31, from 31 to 45 and from 46 to 60 were 98.55, 100.23, and 101.45 I~/L, respectively. Of all the environmental media lead exposures, the groundwater, rice and soil were main contributing factors to the lead accumulation in humans. FSH and LH levels increased with the age while the T levels decreased with the age instead. There was a significant correlation between the FSH and LH levels and wearing masks. Conclusion There was correlation between the FSH, LH, and T levels, and the mean values of lead concentrations in environmental media, and the sex hormone levels were correlated with the confounding factor of wearing masks.

Colloid-facilitated release of polybrominated diphenyl ethers at an e-waste recycling site: evidence from undisturbed soil core leaching experiments

Polybrominated diphenyl ethers (PBDEs), a class of persistent organic pollutants, have been frequently detected in soil at e-waste recycling sites. However, the key factors controlling the transport of PBDEs from surface soil to the vadose zone and groundwater are unclear. Here, colloid-enhanced leaching of PBDEs from undisturbed soil cores collected at an e-waste recycling site in Tianjin, China, is reported. Spatially heterogeneous release of colloids and PBDEs was observed in all the tested soil cores under chemical and hydrodynamic perturbations, indicating the presence of preferential flow paths. Colloid concentration in the effluent significantly increased as ionic strength decreased (from 10 to 0.01 mmol/L), probably due to the stronger electrostatic repulsion between colloidal particles and the soil matrix at lower ionic strength. In contrast, colloid mobilization was not significantly affected by the changes in pH of the influent (from 4.0 to 10.0) and flow rate (from a Darcy velocity of 1.5 to 6.0 cm/h). The concentrations of 2,2′,3,3′,4,4′,5,5′,6,6′-decabromodiphenyl ether (BDE-209), the predominant PBDE congener at the site, detected in the leachate (ranging from 1.09 to 3.43 ng/L) were much lower than previously reported results from packed column leaching tests, and were positively correlated with colloid concentrations. This indicates that remobilization of colloids at e-waste recycling sites can promote the leaching and downward migration of PBDEs from surface soil. The findings highlight the potential risk of surface soil PBDE contamination to groundwater quality and call for further understanding of colloid-facilitated transport for predicting the fate of PBDEs at e-waste recycling sites.

Heavy Metal Profile of Oreochromis niloticus Harvested from E-Waste Polluted Vials and Associated Fungi

This study was designed to investigate the possible variation in bioaccumulation of heavy metals (lead, cadmium, zinc, cobalt, chromium, nickel, and manganese) in the tissue of harvested Oreochromis niloticus (tilapia) and the associated fungi from vials treated with soil from e-waste dumpsite and soil without e-waste. E-waste is electronic waste which contains valuable metals as well as potential environmental contaminants. The heavy metals in soil and fish samples were determined using flame atomic absorption spectrophotometer (AAS) after homogeneity and digestion of samples. The associated fungi were identified using standard microbiological methods. The genera of the associated fungi were: Penicillium, Candida, Articulospora, Aspergillus, Aspergillus, Aspergillus, Rhizopus, Mucor, Zoopage, Varicosporium and Rhodoturula. The quantity of fungi isolated from each pollution treatments showed that the number of fungi were inversely proportional to the quantity of e-waste soil pollution and directly proportional to the quantity of soil without e-waste pollution. The occurrence of the fungi species revealed that the untreated (control) vial had the highest occurrence (191) while the lowest occurrence (103) occurred in the vial polluted with the highest quantity of soil from e-waste dumpsite. The pH and the biochemical oxygen demand (BOD) of the vials were significantly affected by the pollutions. Variations were also observed in the bioaccumulation of the heavy metals by Oreochromis niloticus. Cadmium (0.01 mg/kg) and nickel (0.02 - 0.08 mg/kg) were the least recorded metal in the tissue of the fish while cobalt was not detected after the five weeks period. The sequence of the heavy metals concentrations in Oreochromis niloticus tissue samples was Zn > Mn > Pb > Cr > Ni > Cd > Co. The accumulation of the metals in the fish tissue were, however, lower than the international maximum guidelines, except for manganese (0.29 - 3.13 mg/kg) that exceeded the 0.01 - 0.05 mg/kg threshold levels for manganese by Federal Environmental Protection Agency (FEPA). Protecting the environments from toxic metals is necessary, hence a need for public awareness on the dangers of these toxic metals and law for proper disposal of e-waste.

我国电子废物拆解场地土壤新污染物研究进展

电子废物拆解过程中会排放大量的新污染物,对拆解场地土壤环境易造成污染。本文识别了电子废物拆解场地新污染物的种类,分析了场地土壤中新污染物的污染程度及空间分布特征,综述了新污染物对人体健康风险和生态风险的研究进展,以期为我国电子废物拆解场地土壤中新污染物研究和风险管控提供参考。

Extraction of heavy metals from e-waste contaminated soils using EDDS

Environmental contamination due to uncontrolled e-waste recycling activities is drawing increasing attention in the world. Extraction of these metals with biodegradable chelant [S,S]-ethylenediaminedisuccinic acid （EDDS） and the factors influencing extraction efficacy were investigated in the present study. Results showed that the addition of EDDS at low pH （5.5） produced higher metal extraction than that at high pH （8.0） solution. Metal speciation analysis indicated that Cu was completely complexed with EDDS at different pH conditions with various amounts of EDDS applied. For Pb and Zn, at low EDDS dose of 0.304 mol/kg soil, they were present as Pb- and Zn-EDDS. However, at high EDDS dose of 1.26 mol/kg soil, most of Pb was bound with dissolved organic matter. Ca and A1 were found to be strong competitors for trace metals to EDDS at low application dose and low pH condition.

电子废弃物拆解园区重金属排放特征和周边土壤重金属污染来源解析及风险评价

对某典型电子废弃物拆解园区排放的废气以及周边土壤中的重金属进行监测分析。结果显示,拆解过程中排放的重金属总量由高到低依次为:锡(Sn)、铬(Cr)、镍(Ni)、铅(Pb)、铜(Cu)、锑(Sb)、锰(Mn)、砷(As)、镉(Cd)、汞(Hg);从处理工艺来看,几个主要拆解工序均有重金属排放,排放量由高到低依次为:加热烤板、火法冶炼、塑料造粒和湿法冶炼工序。园区周边土壤中的Hg、Cd、Cu、Pb平均质量分数超过珠三角土壤污染风险筛选值。相关性和主成分分析结果表明,Pb、Cu、Cd、Ni、Zn等重金属来源于电子废弃物拆解过程,包括废水排放、大气干湿沉降和固体废弃物随意堆放等途径,Cr可能主要来源于成土母质,Hg有电子废弃物之外的其他来源。土壤生态风险评价结果表明,该区域属于很强生态风险,其中Cd和Hg对生态危害的贡献率达到91.6%。土壤环境容量评价结果表明,该区域仅有As和Cr的土壤现存容量较大,Zn和Ni的土壤现存环境容量较小,已达到警戒值,其余重金属均处于超载状态。该地区土壤重金属污染状况须引起足够重视,应尽快制定管控治理措施。

典型电子垃圾拆解区周边耕地土壤重金属污染特征及风险评价

为探究电子垃圾拆解活动对周边耕地土壤重金属的污染情况,采集代表性样品,分析了贵屿镇典型电子垃圾拆解区周边耕地土壤及水稻重金属污染特征,评价了土壤生态风险和食用水稻的人体健康风险,通过相关性分析及主成分分析初步探讨了土壤重金属有效态的来源,并运用物种敏感性分布法计算出土壤Cd有效态的阈值。结果表明:(1)土壤主要受Cu、Hg、Cd、Pb、Zn、Ni的污染且总体生态风险为中风险;(2)水稻籽粒中Cd富集严重,成人与儿童食用水稻均有潜在健康风险;(3)土壤中6种重金属(Cu、Hg、Cd、Pb、Zn、Ni)有效态部分来源为电子垃圾拆解源;(4)基于农产品安全的土壤中Cd有效态阈值为0.072 mg/kg。

电子废物无序拆解区土壤PAEs污染分析及其风险评估

电子废物无序拆解可能会导致邻苯二甲酸酯(PAEs)污染。为了量化拆解区土壤中PAEs含量及其健康风险,本研究选取某电子废物无序拆解区为调查对象,以GC-MS和美国环保署规定的暴露量化及风险表征方法进行分析,结果表明,调查区土壤中∑4PAEs含量为256.59~10866.47μg/kg,其中DEHP、DBP、BBP、DNOP的平均含量分别为控制标准的1.20、5.51、0.08和0.09倍。不同暴露途径下PAEs的人体健康风险水平:经口途径>皮肤接触>呼吸途径,尚在可接受范围内,但已对土壤造成污染。

某电子垃圾拆解园周边农田土壤中多环芳烃的污染特征及风险评估

研究了某电子垃圾拆解园周边151个农田土壤样品中16种多环芳烃（PAHs）的污染特征和环境风险。结果表明,125个表层土壤样品中PAHs总质量浓度在149.0~2.0×104μg/kg,均值为1 805.5μg/kg,随着剖面土壤深度增加,PAHs含量总体呈递减趋势。通过来源解析,电子拆解园周围土壤中PAHs污染主要由废弃的电子电器元件的粗放燃烧和汽车尾气排放共同引起。土壤风险评估表明,7种类二噁英毒性PAHs的毒性当量（TEQPAH）在6.000×10^-5~0.689pg TEQ/g,平均值为0.015pg TEQ/g;苯并（a）芘、二苯并（a,h）蒽、苯并（a）蒽、苯并（b）荧蒽、茚并（1,2,3-cd）芘致癌风险率超出百万分之一的样本比例分别为20.53%、6.62%、1.99%、2.65%、2.65%,其中采样点1、68两个点位表层土壤的苯并（b）荧蒽致癌风险率超过了万分之一。

典型电子废物处置场地表层土壤中的德克隆阻燃剂研究

以我国广东省汕头市贵屿镇典型电子废物处置场地为研究区域,对其表层土中的德克隆(DP)阻燃剂的污染水平及分布模式进行了研究.结果表明,DP在全部23个表层土样品中均被检出,浓度范围为0.308-209ng/g,东南部地区的污染水平显著高于西北部地区,各区域的污染水平也存在一定差异.DP浓度最高点(209ng/g)和次高点(46.2ng/g)均位于主要从事电子废物手工拆解及物理破碎的片区.表层土样品中anti-DP质量分数(fanti)的变化范围为0.444-0.754(平均值:0.652±0.064),同DP工业品中的fanti值(0.65)不存在显著性差异,表明在表层土中不存在明显的异构体选择性降解.不同的电子废物处置方式对各片区表层土中DP的分布模式影响不明显.

电子垃圾拆解区不同深度土壤重金属污染特征

以电子垃圾拆解区浙江台州温岭地区为研究对象,分别选择从事电子垃圾拆解时间较短和较长的A和B拆解点以及未从事电子垃圾拆解的C对照点,采集土壤剖面样品,测定不同深度土壤中重金属Cr、Ni、Cu、Zn、As、Cd、Pb的含量,评价污染状况,分析污染特征及来源。结果表明：重金属在各不同深度土壤中的含量均为电子垃圾拆解点高于对照点,土柱B比土柱A污染严重,在最上层土壤（0~5 cm）已有重金属为中度或重污染。电子垃圾拆解造成了该地区的土壤重金属污染,污染程度与从事拆解时间长短有关,不同深度土壤受污染情况不同。各重金属在土壤中垂直分布特征基本一致,一般为土壤最上层含量最高,含量随土壤深度的增加而减少。

土岩复合地层浅埋暗挖车站拆撑方案优选分析

隧道断面内临时格栅或型钢支撑的拆除,会打破结构系统原有的平衡。特别是在大断面浅埋隧道中,如果临时支撑拆除方式和时机不当,会造成初期支护变形过大或局部内力超过承载极限而发生安全事故。文章以某土岩复合地层中大跨度浅埋暗挖车站为例,通过建立三维模型,主要模拟了拱盖法施工的大断面隧道纵向撑拆过程,分析了不同拆撑顺序以及单次拆撑长度对隧道结构的影响。分析结果表明,选择交替拆撑顺序和单次6 m的拆撑长度,对拱顶沉降和地表沉降等周边环境的影响相对较小,施工更为安全。最后根据数值计算结果提出了拆撑引起成地表沉降控制标准的建议值,为以后类似工程提供参考。

电子垃圾拆解区土壤中多氯联苯的垂直分布

以典型电子垃圾拆解区作为研究区域,采集土芯样品,研究不同深度土壤中多氯联苯(PCBs)的污染状况.研究表明,从事电子垃圾拆解时间较短的采样点A土芯以及从事拆解时间较长的采样点B土芯不同深度土壤中PCBs总含量分别为0.54—45.43 ng·g-1干重和2.16—543.96 ng·g-1干重,两个采样点均受到了不同程度的PCBs污染,B土芯较A土芯污染严重.A和B土芯中PCBs含量由上到下呈下降趋势,表层(0—5cm)最高,5—10 cm层分别减少96.4%和92.6%.A土芯不同深度土壤中PCBs组成有所差异;B土芯各层土壤中PCBs组成较接近,含量较高的PCBs同系物均为5-CBs和6-CBs.相关性分析表明,土芯中1-CBs至9-CBs有相同的污染来源,即电子垃圾拆解,1-CBs至9-CBs随土壤深度向下迁移的能力接近.

电子废弃物拆解旧场地土壤重金属污染特征及生态风险评价初探

[目的]探讨历史污染与潜在生态风险之间的相关性。[方法]采用野外采样和实验室分析相结合的方法,以某电子废弃物拆解旧场地表层土壤为研究对象,分析了土壤中重金属Cd、Ni、Cr、Cu、Pb、As和Hg的含量及污染特征,并在此基础上采用地累积指数法和潜在生态危害指数法对土壤重金属污染进行了生态风险评价。[结果]研究区仍受到一定程度的重金属污染,土壤中各元素的含量均高于背景值,其富集程度依次为Cd>Hg>Cu>Cr>Pb>Ni>As;研究区土壤的潜在生态风险级别为D级,生态危害程度为很强,7种重金属中元素Cd的风险指数最高。[结论]因历史污染源造成的生态风险存在。

电子垃圾拆解区土壤污染与生物修复技术

近年来,随着经济和技术的快速发展,电子垃圾的产生量日益增加,已成为全球增速最快的固体废物流之一。由于电子垃圾的不当拆解,大量的重金属和持久性有机污染物(POPs)进入环境,从而对当地居民尤其是儿童的健康构成潜在威胁。生物修复技术是指利用生物有机体(绿色植物、微生物和酶类)的作用将环境中污染物转化为危害或低毒产物的过程。生物修复技术具有成本低、高效和环境安全等特征,被认为是可替代传统的土壤污染修复技术的最佳选择。因此,文章综述了电子垃圾拆解区土壤污染现状及其生物修复技术的最新研究进展,以期为今后电子垃圾污染土壤的修复提供有益参考。最后,文章对今后电子垃圾拆解区土壤污染的生物修复研究做了进一步讨论与展望。

固废拆解土壤的复合污染特性及其控制与修复

固废拆解造成了包括重金属、持久性有机污染物(POPs)[多环芳烃(PAHs)、多氯联苯(PCBs)、二噁英(PCDD/Fs)及多溴联苯醚(PBDEs)]的土壤复合污染。探讨了固废拆解土壤的污染源及污染现状,分析了复合污染物在土壤中的环境行为及迁移转化规律,提出了控制土壤污染物对策及污染土壤修复方法,旨在为发展绿色拆解产业提供可靠的依据,为固废拆解导致的土壤污染控制与修复提供参考。

大型深基坑支护、降水工程的施工质量控制要点

大型深基坑的土方开挖关键是做好基坑支护、降水工程,新城大厦工程采用三轴深搅支护有利于工程止水,在换撑过程中合理利用土体应力释放,大胆运用爆破法拆除支撑,采用深井降水及时监测有效达到开挖效果,成功解决深基坑开挖渗水漏水难题,工程达到质优效果。

浙江台州典型电子废弃物无序拆解区土壤多环芳烃污染风险评估

电子废弃物的无序拆解会导致其中多环芳烃(polycyclic aromatic hydrocarbons, PAHs)的无规律释放,进而对周边生态环境和人体健康构成威胁。为了量化电子废弃物无序拆解区土壤中PAHs的含量及其对人体健康的风险,本研究从浙江省台州市路桥区某典型电子废弃物无序拆解区采集了3个作坊式电子废弃物拆解点、3个作坊式塑料或金属加工点和1个电子废弃物拆解尾渣倾倒点的土壤样品,以气相色谱-质谱联用法和美国环保署规定的暴露量化及风险表征方法为分析手段开展PAHs含量分析及其风险评估。结果发现:上述7个土壤样品PAHs的总量范围为32.62～1053.71μg/kg,平均为414.05μg/kg,其中一个作坊式电子废弃物拆解点的PAHs含量属于重污染级别,土壤存在强烈的环境风险,单体菲(Phe)、蒽(Ant)、荧蒽(Fla)和芘(Pyr)对环境风险的贡献率最大。此外,PAHs通过不同途径对人体造成的健康风险程度为呼吸途径﹥皮肤接触﹥经口途径。结果表明,电子废弃物无序拆解区土壤PAHs污染急需建立相关环境管理措施及污染控制标准,逐步规范电子废弃物无序拆解活动。

典型区域土壤中PCB-11的污染特征

利用高分辨气相色谱/高分辨质谱法研究了土壤中PCB-11(3,3'-二氯联苯,CAS 2050-67-1)的污染特征和分布规律,探讨了土壤中PCB-11的污染来源.结果表明,我国一般城市地区(天津、鞍山)和电子垃圾拆解地周边土壤中PCB-11的检出率为100%,PCB-11可能广泛存在于土壤介质中.天津、鞍山、电子垃圾拆解地土壤中PCB-11的平均浓度分别为163 ng.kg-1(21—750 ng.kg-1)、90 ng.kg-1(16—215 ng.kg-1)、108 ng.kg-1(33—291 ng.kg-1).电子垃圾拆解地土壤中PCB-11对总PCBs浓度的贡献(0.02%—2.4%)明显低于一般城市地区(1.1%—23%).天津、鞍山土壤中PCB-11的来源可能不同于电子垃圾拆解区.