鼋头渚不同年龄夜鹭卵中多氯联苯污染状况及分布特征

通过对太湖鼋头渚2000年采集的2龄、3龄和4龄夜鹭所产卵中15种多氯联苯同系物残留状况的研究,发现所有样品中均检出多氯联苯,残留量最高的为PCB₁₁₈,PCB₈₇,PCB₁₀₁和PCB₁₅₃,占PCBs残留量的75%～85%.含5～6个氯原子的同系物在夜鹭卵中的PCBs残留量明显高于其它类型的同系物.同时,多氯联苯残留量随亲鸟年龄增加而明显增加.4龄卵样分别比3龄、2龄卵样中PCBs残留量高出47.5%和60.9%.统计处理结果表明:多氯联苯残留总量与亲鸟年龄呈正相关(p=0.05).PCBs总量与亲鸟年龄呈正相关(p=0.05).与欧美日等国家同类研究结果中PCB₁₅₃残留量最高的情况略有不同,本研究在夜鹭卵中发现残留量最高的是PCB₁₁₈,占PCBs残留总量的30%左右,PCB₁₅₃含量仅为PCBs残留总量的17%左右.     

不同年龄夜鹭卵中有机氯农药污染的生物指示

通过对太湖鼋头渚 2 0 0 0年采集的二龄、三龄和四龄夜鹭卵以及相应年龄组夜鹭的捕食物中有机氯残留的检测 ,发现捕食物中HCH和DDT的平均残留量随年龄增加而增加 .除γ HCH外 ,其它 15种有机氯农药在卵样中均有检出 ,残留水平最高的为p ,p′ DDE ,占有机氯农药残留总量的 85 %以上 .β HCH是六六六类中持留性最强的组分 ,其残留量仅次于p ,p′ DDE .研究发现 ,p ,p DDT和 β HCH检出率为 10 0 % ,而其它类型农药只有很低的检出率 ,这与我国有机氯农药使用的历史情况相吻合 .随着亲鸟年龄增加 ,卵中 β HCH残留量有所提高 ,p ,p′ DDE残留量似有先升后稍降的趋势 .统计结果表明 :各年龄组有机氯残留量差异不明显 ,因此在用夜鹭卵作有机氯污染的生物指示时可以不考虑年龄差异所带来的影响 .     

无锡鼋头渚夜鹭卵中有机氯农药残留及其环境指示意义

分析了太湖鼋头渚夜鹭卵中的有机氯农药残留情况,发现在禁用近20年后,HCH的异构体、DDT及其代谢物、异狄氏剂以及环氧七氯在夜鹭卵中都不有同程度的检出,其中β－HCH和p,p‘-DDE的残留水平和检出率均很高,p,p‘-DDE平均达到了0.906ug/g(干重）。研究发现无锡夜鹭卵中多数有机氯农药残留水平平均高于江西共青城地区的样品。无锡夜鹭卵孵化率较低。可能与DDE残留量较高有关。夜鹭卵中有机氯农药残留水平具有指示环境污染的意义。     

多氯联苯(PCBs)近期研究进展

对PCBs的理化特性、生产应用历史、污染现状以及近期的研究趋势作简要介绍.近期PCBs污染研究的趋势为1.由PCBs的总量测定到测定其同系物和异构体.2.迁移转化和行为研究受到充分的注意.3.PCBs降解的研究.4.广大区域内PCBs污染时空规律研究.     

多氯联苯(PCBs)焚烧企业处理工艺与污染物减排研究

多氯联苯(PCBs)是一类重要的环境持久性污染物。阐述了PCBs的理化性质及其对环境的危害,从企业入手,探索PCBs处理工艺与污染物减排措施。     

淮河信阳和淮南段沉积物中PCBs的生态风险评估

测定了57种多氯联苯同系物在淮河信阳和淮南段水体沉积物、鲤鱼(Grass Carp)和三 油酸甘油酯半渗透膜生物模拟采样器(Triolein-SPMD)中的浓度.结果表明,Triolein-SPMD和 鲤鱼对沉积相多氯联苯的富集有显著相关性.利用Triolein-SPMD得到的三油酸酯/沉积物富 集因子(TSAF)和利用鲤鱼得到的生物/沉积物富集因子(BSAF)在数值上基本相同.     

典型污染地区底泥和土壤中残留多氯联苯（PCBs）的情况调查

为了解PCBs在生态系统中的分布,利用毛细管气相色谱对受PCBs污染地区的土壤、底泥进行实际环境样品的调查。在底泥和土壤样品中测定近50个同属物的含量,并对其分市规律进行了探讨。指出在实际环境样品中PCBs的同属物分布和工业产品有明显不同。通过不同深度底泥样品测定,证明PCBs在底泥中的渗透作用较弱。     

上海崇明岛农田土壤中多氯联苯的残留特征

在上海崇明岛采集了101个耕层土壤样品,利用GC-μECD测定了8种多氯联苯(PCBs)浓度,并对其进行多元统计分析,探讨了其可能的污染来源.结果表明,样品PCBs浓度范围为n.d.~261ng/g,均值为56.0ng/g,低氯联苯含量和检出率均较高.不同土壤利用方式对PCBs残留量有一定影响,表现为水稻田土壤>大棚蔬菜西瓜田土壤>露天蔬菜西瓜田土壤.主成分分析和相关性研究结果显示,土壤中低氯联苯同系物间相关性较好,污染来源可能为同一类.     

中国近海海洋环境多氯联苯(PCBs)污染现状及影响因素

对中国近海海洋环境(水体、表层沉积物和生物体)中多氯联苯(PCBs)的空间分布、污染程度、来源及影响因素进行了总结,得出如下结果:①我国近海海域水体中,PCBs的含量水平呈现由北向南逐渐增加的趋势,以东部沿海工农业发达地区为最高,我国大部分近海海域水体中PCBs都超过美国EPA制定的30 ng·L-1的标准,污染比较严重;②我国近海海域表层沉积物中PCBs只有小部分超过ISQG(interim sediment quality guideline)和ERL(effects range-low)值,引起生物负效应的几率比较小,污染程度较轻;③生物体内富集的PCBs以4、5和6等高氯代联苯为主,其含量都低于《食品中污染物限量标准》2 000ng·g-1,不会对人类健康造成影响.④我国近海海洋环境中PCBs主要来源于周围大型工厂排放的废水以及电子垃圾拆解造成的PCBs泄漏,影响PCBs含量水平的主要因素有距离陆地的远近程度、水流交换情况、水量大小、季节的变化、沉积物颗粒大小、有机碳含量等等.     

多氯联苯在土壤中的吸附行为

对多氯联苯在多组分体系中的吸附行为进行了初步研究, 考察了多氯联苯在土壤中的 吸附动力学及在5种不同性质土壤中的吸附行为.结果表明,多氯联苯在5种土壤上的吸附等温 线无法用线性、Freundlich或Langmuir中的一个方程来描述,而本实验建立的组合模型可以 很好地反映多氯联苯在各种土壤中的吸附行为,其数据拟合结果明显优于其他3种模型.多氯 联苯在土壤中的吸附分为两个部分,一部分是线性吸附,另一部分是Langmuir非线性吸附.随 着土壤有机碳含量的增加, 非线性吸附愈明显.     

宜宾夜鹭卵中有机氯农药及其代谢物的赋存特征

于2017年在四川省宜宾市采集黑冠夜鹭(Nycticorax nycticorax)卵样30枚(包括9枚无胚卵和21枚胚胎卵),分析了样品中有机氯农药(OCPs)的残留状况.结果表明,宜宾夜鹭卵中检出了8种OCPs残留物,总含量为4.76～97.9 ng·g~(-1)(以湿重计).其中,p,p′-滴滴伊(p,p′-DDE)含量最高((20±18) ng·g~(-1)),其次为六氯苯(HCB,(5.3±3.4) ng·g~(-1))和β-六六六(β-HCH,(1.1±0.8) ng·g~(-1));滴滴涕类(∑DDTs)中的稳定代谢物p,p′-DDE和六六六类(∑HCHs)中的稳定同分异构体β-HCH占比均在99%以上.p,p′-滴滴涕(p,p′-DDT)和p,p′-DDE在无胚卵蛋液中的残留水平比在胚胎卵蛋液中更高一些,而反式九氯则相反,其余OCPs无差别,这说明鹭卵在孵化过程中p,p′-DDT可能易于代谢,而稳定的p,p′-DDE更容易向胚胎传递.宜宾夜鹭卵中p,p′-DDE的最高含量为84 ng·g~(-1),远低于鹭科繁殖效应阈值(1000 ng·g~(-1)).总体上,夜鹭卵中OCPs的赋存状况较好地反映出长江上游地区OCPs污染水平较低,对夜鹭繁殖的影响较小.     

长江口潮滩表层沉积物中PCBs和OCPs的分布

对长江口潮滩表层沉积物中的多氯联苯(PCBs)和有机氯农药(OCPs)进行GC-ECD测试,结果表明PCBs含量分布在0.19～18.95ng/g,平均值为2.70ng/g,其分布随采样点的位置变化显著:排污口附近出现最大值,离排污口越远,即受排污影响的程度越小,其含量越低.OCPs含量在1.25～36.01ng/g,平均值为8.50ng/g,分布特征与PCBs相似,表明了它们来源的相似性.研究区内PCBs和OCPs的含量低于ER-L值,尚未对生物造成显著的负面影响.     

水体中溶解有机物对多氯联苯在淮河水体沉积物上的吸附和生物富集作用的影响

利用淮河4个采样点同时采集的水、表层沉积物和鲤鱼体内多氯联苯不同同系物的浓度分析数据,讨论该类污染物在水体多介质体系中转移分配规律．研究结果表明,在现场条件下观察到的水,沉积物有机碳分配系数(KOC)的对数及生物富集因子(BCF)的对数与正辛醇,水分配系数(KOW)的对数之间没有相关性．但是当假定水中的多氯联苯同系物与溶解有机碳相互作用并改变了有机污染物在水中形态分布时,以游离态多氯联苯浓度重新计算得到的log KOC和log BCF正比于log KOW,因此,在评价多氯联苯污染生态效应时,溶解有机物的影响不可忽视．     

滴水湖水系表层沉积物中多氯联苯残留与风险评价

于2012年,每2个月采集一次上海人工滩涂湖泊——滴水湖水系表层沉积物,对其多氯联苯(PCBs)的残留水平进行了检测和分析.结果表明,研究期间闸外引水河和闸内引水河沉积物中7种PCBs的总量各月间变化较大,且总体呈上升趋势,而滴水湖沉积物中其总量四季变化幅度不大;空间分布上,闸外引水河[(844.74±687.62)ng/g]>闸内引水河[(516.83±645.45)ng/g]>>滴水湖[(81.63±72.18)ng/g].研究区PCBs组成以六氯联苯和七氯联苯为主,其次为五氯联苯和三氯联苯.采用主成分分析法对PCBs进行源解析,结果显示:PCBs污染源中进口电容器中PCBs的迁移占43%,油漆添加剂污染占33%;国产电容器和变压器污染占11%.生态风险评估表明,闸外引水河和闸内引水河沉积物PCBs对生物体的暴露有严重威胁;滴水湖沉积物PCBs对生物体的暴露有一定的潜在威胁.与国内外研究相比,闸外引水河和闸内引水河属于严重污染水平,滴水湖属于中等污染水平,相关部门应加强污染监管.     

Distribution of organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) in surface water and sediments from Baiyangdian Lake in North China

Persistent organochlorine compounds, including hexachlorocyclohexanes (HCHs), dichlorodiphenyltrichloroethanes (DDTs) and polychlorinated biphenyls (PCBs) were analyzed in surface water and sediments from Baiyangdian Lake, North China. Total concentrations of HCHs, DDTs and PCBs in surface water were in the range of 3.13-10.60, 4.05-20.59 and 19.46-131.62 ng/L, respectively, and total concentrations of HCHs, DDTs and PCBs in sediments were 1.75-5.70, 0.91-6.48 and 5.96-29.61 ng/g dry weight, respectively. Among the groups of HCHs (sum of α-HCH, β-HCH, γ-HCH and δ-HCH) and DDTs (sum of DDT, DDD and DDE), the predominance of β-HCH, DDE and DDD in water and sediment samples was clearly observed. This observation suggested that β-HCH was resistant to biodegradation and the DDTs had been transformed to its metabolites, DDE and DDD. For PCBs, penta-, hexa- and hepta-chlorinated congeners were the most abundant compounds in the both phases. Furthermore, the partitioning of chlorinated compounds between sediment and water was investigated to understand their transport and fates in aquatic ecosystems. The results indicated that average logs of organic carbon-normalized sediment-water partition coefficients (logK_oc') for OCPs varied between 3.20 and 5.53, and for PCBs, logK_oc' values ranged from 3.19 to 5.57. The observed logK_oc' was lower than their equilibrium logK_oc predicted from linear model, which may be attributed to the solubility enhancement effect of colloidal matter in water phase and the disequilibrium between sediment and water.     

Sources and health risks of PM2.5-bound polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) in a North China rural area

Polychlorinated biphenyls(PCBs) and organochlorine pesticides(OCPs) are typical persistent organic pollutants(POPs),which have high toxicity,bioaccumulation and long-distance transfer capability.Daily variation,sources of PcBs and OcPs in PM_2.5 are rarely explored in polluted rural area.Here,the sources and health risks of the PcBs and OcPs were evaluated for 48 PM_2.5 samples collected in winter 2017 in Wangdu,a heavy polluted rural area in the North China Plain.The average...     

Benefits and risks associated with consumption of Great Lakes fish containing omega-3 fatty acids and polychlorinated biphenyls (PCBs)

正Introduction Assessment of environmental health effects arising from exposure to multiple substances is often very challenging.This is particularly true when humans are exposed to a mixture that contains both beneficial and harmful substances.A good example relates to the risk and benefits of fish consumption.     

Kinetic and thermodynamic studies on partitioning of polychlorinated biphenyls (PCBs) between aqueous solution and modeled individual soil particle grain sizes

The significance of soil mineral properties and secondary environmental conditions such as pH, temperature, ionic strength and time in the partitioning of eight selected polychlorinated biphenyl(PCB) congeners between aqueous solution and soil particles with different grain sizes was studied. The mineral properties of a model soil sample were determined, and Brunauer–Emmett–Teller(BET) adsorption–desorption isotherms were employed to observe the surface characteristics of the individual modeled soil particles.Batch adsorption experiments were conducted to determine the sorption of PCBs onto soil particles of different sizes. The results revealed that the sorption of PCB congeners onto the soil was dependent on the amount of soil organic matter, surface area, and pore size distribution of the various individual soil particles. Low pH favored the sorption of PCBs,with maximum sorption occurring between pH 6.5 and 7.5 with an equilibration period of 8 hr.Changes in the ionic strength were found to be less significant. Low temperature favored the sorption of PCBs onto the soil compared to high temperatures. Thermodynamic studies showed that the partition coefficient(K_d) decreased with increasing temperature, and negative and low values of ΔH° indicated an exothermic physisorption process. The data generated is critical and will help in further understanding remediation and cleanup strategies for polluted water.