污泥中病原物的环境与健康风险及其削减途径

污泥含有多种病原性生物体或病原物,主要包括细菌、病毒、原生动物和寄生虫。污泥中的病原物进入土壤后有再发的现象,存在环境与健康风险。对污泥的消化、碱性稳定、堆沤、辐射处理和巴氏灭菌,以及完善污泥土地堆放或土地施用的法律法规等是削减污泥中病原物的环境和健康风险的主要措施。建议在我国尽快开展污泥和受其影响环境介质中病原物的环境行为、生态效应与健康风险研究,并发展相关的削减对策和关键技术。     

饲料中二噁英赋存特征及其向养殖动物体内迁移规律

二噁英(Polychlorinated dibenzo-p-dioxins and dibenzofurans, PCDD/Fs)因其高毒性、蓄积性、持久性和长距离迁移特性而备受全球关注。由于二噁英容易沿着食物链富集放大,因此,饲料中二噁英极容易在养殖动物体内富集并对动物产生健康风险。本文在国内外最新研究基础上,总结并探讨饲料中二噁英的赋存现状以及其向养殖动物的迁移和蓄积规律,旨在对饲料和养殖动物二噁英的管控提供科学支持。     

长江三角洲地区土壤环境质量与修复研究Ⅰ.典型污染区农田土壤中多氯代二苯并二噁英/呋喃(PCDD/Fs)组成和污染的初步研究

通过同位素稀释高分辨率气相色谱-质谱方法(HRGC/HRMS)对长江三角洲地区某典型污染区农田土壤中多氯代二苯并二噁英(PCDDs)/呋喃(PCDFs)组成、含量及毒性当量进行了初步研究.结果表明,该地区农田土壤中PCDD/Fs总含量的平均值达2 639.1pg g-1dw,并检测出PCDD/Fs的四氯～八氯多种异构体.根据世界卫生组织毒性当量(TEQ,哺乳动物)计算结果显示,农田土壤中PCDD/Fs的毒性当量为TEQ20.8～21.3pg g-1 dw,超过加拿大国家居住环境土壤二噁英含量控制标准的5倍多,其中2,3,4,7,8-PCDF和1,2,3,7,8-PCDD对PCDD/Fs的TEQ值贡献最大.该地区农田土壤中已经出现一定程度的二噁英/呋喃污染.     

农药企业搬迁土地多环芳烃的风险评价

以常州市某农药厂搬迁土地为研究对象,在监测分析土壤中16种多环芳烃（PAHs）的基础上,对该区域土壤进行健康风险和生态风险评价。结果表明,研究区域土壤中∑PAHs的含量范围为0～1.546mg·kg-1,优势化合物中萘、菲等低环化合物含量大于高环的荧蒽、苯并[k]荧蒽和芘等化合物,且土壤中PAHs可能来源于石油源。健康风险评价结果在可接受的10-6～10-4范围内,而生态风险评价表明,尽管研究区域土壤中的多环芳烃不存在严重的生态风险,但是化合物苊和芴含量超出了风险评价低值（ER-L和ISQV-L）,存在着对生物的潜在危害。     

土壤中二噁英的污染现状及其控制与修复研究进展

本文介绍了近10年来世界各国土壤中二噁英的污染来源、污染水平与分布等方面的研究工作,并对我国土壤二噁英污染的控制与修复提出了建议。     

陕西秦岭地区生态干扰风险空间分异规律研究

[目的]揭示不同自然生态状况、资源环境禀赋以及人类干扰强度条件下秦岭地区的生态风险空间分布规律,对秦岭生态保护具有重要理论意义。[方法]以秦岭地区(陕西段)为研究区域,选取坡度、植被覆盖度、土地利用类型、生态空间类型等14个指标,基于层次分析权重赋值法和地理信息系统空间分析技术,构建生态干扰风险评估指标体系和评估模型,开展了秦岭地区(陕西段)生态干扰风险空间分异规律研究。[结果]秦岭地区(陕西段)生态干扰风险整体呈现“北高—中低—南中”的空间异质性分布格局,生态干扰较高和高风险区分布在秦岭北麓一带以及汉滨区、汉台区、城固县部分区域。低风险、较低风险、中风险、较高风险和高风险区分别占比26.46%,42.44%,19.92%,8.62%和2.56%。秦岭地区(陕西段)人类活动分布较为集中,占研究区面积11.18%的生态干扰较高和高风险区域集中了研究区内36.26%的人类活动面积,并提出了县域单元生态干扰风险预警机制。[结论]陕西秦岭地区生态干扰风险存在显著的空间分异特征,整体生态干扰风险程度较低,研究结果对于秦岭地区人类干扰活动监管策略优化和生态环境保护工作具有重要参考价值。     

用于检测芳香烃类化合物的重组细胞构建

芳香烃类化合物是自然界中广泛存在的一类对人体健康有重要影响的物质。芳香烃受体(AhR)是配体依赖性转录因子,能够被多种天然或化学合成的物质激活,介导AhR配体的毒性效应和生物学效应。为了探究AhR对其配体的应答,实验利用质粒pGl4.43[luc2P/XRE/Hygro]转染鼠肝癌细胞Hepa1.6和人肝癌细胞HepG2,构建了两株受XRE应答元调控的、以荧光素酶作为报告基因的重组细胞株。浓度为100pM的二噁英(TCDD)即能诱导此细胞株荧光素酶活性值升高,且重组细胞的荧光素酶活性值呈浓度依赖性。为了验证实验结果的准确性,利用TCDD、FICZ刺激野生型鼠肝癌细胞Hepa1.6和人肝癌细胞HepG2,检测细胞色素酶CYP1A1、CYP1B1的表达量,结果与重组细胞株呈现相同的趋势。因此,本实验成功构建了应答芳香烃类化合物的高灵敏细胞系,可以利用构建的重组细胞系对芳香烃类化合物进行检测,也可用于探究AhR配体对AhR的调控机制。     

典型农业区农田土壤重金属潜在生态风险评价

采用野外采样和室内分析相结合的方法,以典型农业区山东禹城的农田表层土壤（0-20 cm）为研究对象,分析了土壤中重金属Cr、Ni、Pb、As、Hg、Cd、Cu和Zn的含量,探讨了土壤中重金属的含量与不同人类活动的关系并进行了潜在生态风险评估。结果显示,8种重金属的含量均超过黄河下游潮土区的背景值。潜在生态风险评估表明,当地的农田土壤Cr、Ni、Pb、As、Cu、Zn有轻度的生态风险,Hg和Cd存在较大的生态风险。城市化进程、畜禽养殖和污灌是造成土壤Cd高生态风险的主要因素,城市化进程和污灌也是造成土壤Hg高生态风险的主要因素。禹城各区域土壤受8种重金属的综合潜在生态风险程度大小依次为城郊农田〉污灌农田〉典型施肥农田〉井灌农田〉引黄灌农田,不同人类活动区域土壤Cd生态风险和8种重金属的综合潜在生态风险存在显著差异。     

当今人类面临的健康风险与健康负债

什么是健康风险或造成健康负债的危险因 素?世界卫生组织经过为期3年的研究,分析了 人类主要疾病、残疾和死亡的资料,界定和评估 了世界范围的各种健康风险,对主要健康风险 进行了定量性测量,讨论了减少各类不同健康 风险的战略,并预测了各种减险战略对增加健 康预期寿命(减慢衰老过程)的潜在作用。在 《2002年世界卫生报告》中,世界卫生组织确定     

基于生态导向的厦门生态城市综合评价与分析

基于生态学理论,通过对厦门市的环境特征分析,根据生态城市的内涵,将健康、安全和发展这3个概念引入生态城市的综合评价,建立厦门市的生态城市评价指标体系。利用主成分分析法对数据进行生态健康指数、生态安全指数和生态发展指数的计算,最终得出各城区的生态城市评价综合指数并进行了相关分析。研究结果表明:(1)基于生态导向的生态城市评价与分析是从生态健康、生态安全、生态发展3个方面将城市规划引向重建自然和保护自然的过程。(2)在厦门生态城市的评价中,岛内城区与岛外城区存在明显的差距,岛内的思明区和湖里区的评价指数明显高于岛外的集美区、海沧区、同安区和翔安区。(3)生态导向下的生态城市是集自然与人类影响于一体的和谐平衡的复合系统,在城市规划中应以生态功能为基础进行城市的布局,以生态功能区划来引导区域的建设模式,让生态理念更好地融入到城市建设中。     

Determination of polychlorinated dibenzo-p-dioxins and dibenzofurans in commercial pentachlorophenols by combined gas chromatography-mass spectrometry.

Samples of commercial pentachlorophenol (PCP) and its sodium salt (PCP-Na) were examined for the presence of polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs), using a rapid, highly specific method of analysis. Phenolic compounds are removed by alkaline extraction, and the neutral components are fractionated on an alumina minicolumn. After gas chromatographic separation, individual PCDDs and PCDFs are detected by mass fragmentography and their presence is confirmed by complete mass spectral analysis. While some samples had only low amounts of PCDDs and PCDFs, others contained much higher amounts of these components. PCP-Na samples showed the unexpected presence of a tetrachlorodibenzo-p-dioxin. Re-analysis of PCP and PCP-Na samples with high PCDD contents on a high-resolution glass capillary column showed the presence of 3 hexa- and the 2 heptachlorodibenzo-p-dioxins with nearly constant isomeric ratios.     

Experimental study on the removal of dioxins and coplanar polychlorinated biphenyls (PCBS) from fish oil

Recently, it has been found that fish oils contain a high proportion of contaminants, namely, polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and coplanar polychlorinated biphenyls (cPCBs). In this study, the removal of contaminants from fish oil by supercritical CO2 extraction (SCE) and by using adsorbents (0.13 wt % of oil) was investigated. Dioxins and cPCBs were extracted from fish oil by SCE at a temperature of 60 degrees C and a pressure of 28 MPa, and the removal efficiencies for PCDDs and PCDFs were in the range of 15-90% and those for cPCBs were in the range of 70-90%. However, 40% of the oil was extracted simultaneously with contaminants. On the adsorbent treatment, activated carbon showed high efficiency, and the removal efficiencies were >90% for PCDDs and PCDFs, but below 30% for cPCBs. A combination of both of these methods is more effective, and almost 100% of the total toxicity equivalence quantity value could be reduced.     

Toxic potency of polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans, and polychlorinated biphenyls in food samples from Catalonia (Spain)

A surveillance program on polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and polychlorinated biphenyls (PCBs) in 29 foodstuff samples produced all over the four provinces in Catalonia (Spain) is presented. The study included the analyses of milk, egg, meat (beef, chicken, and pork), mussel, and olive oil samples. A previously developed method for the simultaneous analysis of the 2,3,7,8-substituted PCDDs/PCDFs and the dioxin-like PCBs, as well as the indicator PCBs, was employed. Total toxicity equivalent (TEQ) values were calculated using the toxicity equivalent factors (TEFs) proposed by the World Health Organization (WHO) for dioxin-like PCBs, PCDDs, and PCDFs. The TEQ(PCDD/F) levels were below the limits proposed in the draft of the EC regulation for food commercialization in the European countries. These limits are the following: 2 pg WHO-TEQ/g fat for pork, 3 pg WHO-TEQ/g fat for milk and chicken, 5 pg WHO-TEQ/g fat for egg and beef, and 3 pg WHO-TEQ/g whole product for fish. The contributions of PCDDs/Fs and dioxin-like PCBs in the total toxicity of the samples were calculated for each matrix. The results showed that the TEQ(PCB) contribution varied from 27% in olive oil samples to 81% in mussel samples. These findings suggest that the regulation of TEQ contents in food should include not only the TEQ(PCDD/F), but also the TEQ(PCB).     

Determination of dioxins and furans in foods and biological tissues: review and update

Determination of trace residues of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDDs and PCDFs) in various matrixes is carried out by a limited number of laboratories in the United States, Canada, and other countries. Current methods for analysis of foods and biological tissues include a combination of preparation, extraction, cleanup, isolation, determination, and identity confirmation procedures. Soxhlet, liquid/liquid, solid-phase, and column extraction procedures are used as well as treatment with acid or base before solvent extraction. Cleanup and isolation steps include sulfuric acid partitioning; adsorption chromatography on Florisil, silica gel, or alumina; gel permeation chromatography; multi-stage column chromatography on sulfuric acid silica and alkali silica; carbon column chromatography; and liquid chromatography fractionation with size exclusion, normal-phase, and reverse-phase columns. Activated carbon and multistage chromatographic columns are widely used in cleanup schemes. Isomer-specific identification and quantitation of PCDD and PCDF congeners at parts-per-trillion levels or lower are carried out by high resolution (capillary) gas chromatography (HRGC) and multiple ion detection mass spectrometry. In addition to chemical methods, bioassay procedures have been recommended (e.g., use of monoclonal antibodies, for immunoassay determination of PCDDs and PCDFs).     

用HRGC／HRMS测定开放式生活垃圾焚烧残余物及周边土壤中的PCDDs／PCDFs

以广东省东南沿海某开放式生活垃圾焚烧场为研究对象,用高分辨气相色谱／高分辨质谱同位素稀释法测定了垃圾焚烧场底灰、焚烧残余物及周边土壤中的多氯代二苯并对二嗯英和多氯代二苯并呋喃（PCDDs／PCDFs）。结果表明,PCDDs／PCDFs的总浓度为161～4670ng·kg^-1,毒性当量为1．10～45．8ngWHO1998-TEQ·kg^-1,其中采自垃圾焚烧场的3个样品浓度为30～45ngWHO1998-TEQ·kg^-1,剩余的土壤样品中有3个样品其浓度为4～35ngWHO1998-TEQ·kg^-1,其余的2个样品浓度〈4ngWHO1998-TEQ·kg^-1。对比加拿大的土壤指导性标准,75％的测定样品浓度高于该标准,即土壤背景浓度,有25％的样品低于此背景浓度。将垃圾焚烧场焚烧残余物作为土壤改良剂造成受施土壤的PCDDs／PCDFs污染严重,需引起有关部门的高度重视。     

Complete mass balance of dietary polychlorinated dibenzo-p-dioxins and dibenzofurans in dairy cattle and characterization of the apparent synthesis of hepta- and octachlorodioxins

Mass balances of 2,3,7,8-substituted dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) were measured in cows following administration of pentachlorophenol (PCP)-treated wood. Fecal excretion accounted for the major fraction of all congeners. Recovery in feces increased with increasing chlorination, while storage in body fat and excretion in milk decreased with increasing chlorination. The PCDFs with no chlorines in the 4- and 6-positions were apparently metabolized because residues were not detected in milk and body fat. Storage and excretion of 1,2,3,4,6,7,8-HpCDD and 1,2,3,4,6,7,8,9-OCDD exceeded intake by factors of 1.7 and 3.4, but recovery of other PCDD/Fs did not exceed intake significantly. Excess excretion of OCDD, but not HpCDD, was confirmed in a follow-up study. Synthesis of HpCDD and OCDD did not occur when PCP-treated wood was fermented with rumen microorganisms, and enhanced concentrations of HpCDD and OCDD were not found in gastrointestinal tract contents of dosed animals. Formation of OCDD during incubation of feces spiked with PCP-treated wood led to the conclusion that synthesis was postexcretion during sample preparation.     

Polychlorinated dibenzo-<Emphasis Type="Italic">p</Emphasis>-dioxins,dibenzofurans, and biphenyls in soils of Moscow

The contents of polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs), and biphenyls (PCBs) in the soils of Moscow were estimated. The concentrations of PCDDs and PCDFs mainly vary in the range of 0.27–16.1 ng WHO-TEQ/kg with single points of very high contamination up to 57.3 ng WHO-TEQ/kg; the concentrations of PCBs are in the range of 2.1–50.8 ng/g with sites of high contamination up to 4020 ng/g. The contribution of dioxin-like PCBs to the total dioxin toxic equivalent is very high: from 16 to 85%. The high levels of PCDDs and PCDFs in the soils indicate the strong contamination of the atmospheric air. The main source of these compounds is apparently motor transport.     

Survey of polychlorinated dibenzo-p-dioxins (PCDDs), Polychlorinated Dibenzo-p-furans (PCDFs), polychlorinated biphenyls (PCBs), and mineral components in Italian citrus cold-pressed essential oils

Investigation of PCDDs, PCDFs, PCBs, Al, As, Pb, Ba, Co, Cu, Cr, Fe, Mn, Cd, Ag, Sn, Zn, and Hg contents in 60 samples of cold-pressed essential oils produced in Calabria and Sicily in 2003-2005 was carried out. PCDDs, PCDFs, and PCBs were analyzed by HRGC-HRMS techniques using U.S. EPA 1613/94 and U.S. EPA 1668/A (1999) analytical methods. Mineral components were determined through GFAAS techniques; Hg content was determined by FI-M/H-AAS. The results of this study showed that essential oil contamination was due to a widespread pollution, typical background of rural areas, with relatively higher concentrations of PCDDs compared to PCDFs and little presence of PeCDF. Congeners OCDD, HpCDF, and OCDF were found at high concentrations. Regarding mineral components, mean values of Cr, Fe, and Ni were in agreement with data reported in the literature. Concentrations of As and Pb were below the maximum limits accepted by the current legislation. Finally, none of the samples analyzed were contaminated with Hg.     

An assessment of the concentrations of PCDDs/Fs in contaminated bottom sediments and their sources and ecological risk

Purpose

The purpose of the study was to determine the levels of polychlorinated dibenzo-p-dioxin and polychlorinated dibenzofuran (PCDD/F), two types of persistent organic pollutant (POP), in an urban retention reservoir located in an industrial zone within a coal-mining region. It also assesses the potential ecological risk of the PCDDs/Fs present in bottom sediments and the relationship between their content and the fraction of organic matter.

Materials and methods

The sediment samples were collected from Rybnik Reservoir, located in the centre of the Rybnik Coal Region, Silesia, one of Poland’s major industrial centres. Seventeen PCDD/F congeners in the surface of the sediments were analysed using high-resolution gas chromatography and high-resolution mass spectrometry (HRGC/HRMS).

Results and discussion

The toxic equivalency (TEQ) of the PCDDs/Fs in the sediments ranged from 1.65 to 32.68 pg TEQ g^?1. PCDDs constituted 59–78% of the total PCDDs/Fs, while the PCDFs accounted for 22–41%. The pattern of PCDD/F congeners in the sediments was dominated by OCDD. However, the second-most prevalent constituents were OCDF and ∑HpCDFs in the low TOC sediment (< 10 g TOC kg^?1), but HpCDD in the rich TOC samples (> 10 g TOC kg^?1). PCDD/F concentrations in the sediment samples were 2- to 38-fold higher than the sediment quality guidelines limit, indicating high ecological risk potential. Although a considerable proportion of PCDDs/Fs in the bottom sediments from the Rybnik Reservoir were derived from combustion processes, they were also obtained via transport, wastewater discharge, high-temperature processes and thermal electricity generation. The PCDD/F concentrations were significantly correlated with all fractions of organic matter; however, the strongest correlation coefficients were found between PCDDs/Fs and humic substances. Besides organic matter, the proportions of silt/clay fractions within sediments played an important role in the transport of PCDDs/Fs in bottom sediments.

Conclusions

The silt/clay fraction of the bottom sediments plays a dominant role in the movement of PCDDs/Fs, while the organic matter fraction affects their sorption. The results indicate that the environmental behaviour of PCDDs/Fs is affected by the quantity and quality of organic matter and the texture of sediments.

     

鄱阳湖平原区农田土壤重金属Cd、Hg空间特征及潜在风险影响因素探析

为了解鄱阳湖平原区农田土壤重金属的空间特征,探析其潜在生态风险及影响风险状况的因子,采用地统计学、潜在生态风险指数法、Person相关分析及地理探测器方法,分析研究区农田土壤重金属镉(Cd)、汞(Hg)的空间分异特征、潜在生态风险评价及风险状况影响因素。结果表明,研究区土壤重金属Cd、Hg均为中等程度的变异,空间分布差异较为明显。丰城大部分地区Cd含量均在江西省土壤元素背景值与我国农田土壤污染风险筛选值之间。Hg含量由南向北逐渐升高并超过江西省土壤元素背景值,但未达到全国风险管控值水平。Cd的潜在生态风险水平以轻微级别为主,Hg则以中等级别为主。在综合潜在生态风险方面,大部分地区被划分为低风险区,而中度风险区分布较为分散。重金属Cd、Hg综合潜在生态风险指数(RI)与土壤pH值、全磷、海拔、坡度以及距河流或道路的距离具有显著相关性(P<0.05)。影响综合潜在生态风险指数的第一个显著因子为全磷≤0.4 g·kg^-1,其次为pH值5.5～6.0。本研究对鄱阳湖平原区农田土壤重金属污染的监测与治理、维护生态环境安全及人类健康具有重要的现实意义。