多溴联苯醚在海洋生物中的富集及毒性效应评述

多溴联苯醚(PBDEs)作为一种新型的持久性有机污染物,在海洋环境中广泛存在,对海洋生物的影响也日趋加大,因此评价PBDEs的海洋生态效应十分必要.本文在简介海水中PBDEs化学行为的基础上,依次阐述PBDEs在海洋浮游生物、底栖动物、游泳生物体内的富集,其沿海洋生态食物链(网)的传递规律与毒性效应,还展望了PBDEs海洋生态效应今后需加强的研究内容.     

海洋环境中的多溴联苯醚对海洋生物的潜在健康风险

多溴联苯醚(Polybrominated diphenyl ethers,PBDEs)是一种被广泛应用于纺织、家居、装潢、塑料、电子产品等行业的溴代阻燃剂,用以降低产品的可燃性。主要有3种商业产品:五溴联苯醚(Penta-BDE)、八溴联苯醚(Octa-BDE)和十溴联苯醚(Deca-BDE)。由于其具有持久性和生物毒性,Penta-BDE和Octa-BDE产品已经被禁止生产和使用,并于2009年被列入斯德哥尔摩公约。而Deca-BDE产品至今尚未在全球范围内禁止使用,并且亚洲是其主要生产基地。随着其它溴代阻燃剂产品的出现,PBDEs的使用量逐渐缩减,但是之前进入环境的PBDEs将长期滞留于此,仍对环境中的生物存在潜在的健康风险。主要对海洋环境中PBDEs的来源、污染现状及其对海洋生物存在的潜在健康风险进行概述。     

深圳湾海域多溴联苯醚(PBDEs)生物累积及其高分辨沉积记录

深圳湾,毗邻香港,是深圳经济特区的重要经济发展和生态调节区域。为了更好地了解该湾多溴联苯醚（PBDEs）的生物累积规律及其污染历史,作者采集该海域19个鱼、2个虾、2个蟹和柱状沉积物样品,分析其中PBDE的组分与含量,以及生物体的δ^15N同位素、总脂含量和柱状沉积物的沉积年龄（^210pb）、总有机碳（TOC）。结果表明,深圳湾海域鱼类∑15 PBDEs组分的残余量为21—167ng／g lw（或0．17—4．16ng／g fw）,平均为（67±42）ng／g lw或（2．00±1．14）ng／g fw,其含量与生物体的δ^15N同位素和脂含量正相关,BDE-47、BDE-100为生物体中PBDE最优势组分且在所有生物样品中均检出,分别占46．5％、13．5％,肉食性的鱼类较植食性的鱼类PBDEs的生物累积总体上较高。柱状沉积物中∑22 PBDEs含量（0．07—4．85ng／g dw）近二十几年来有明显的上升趋势,平均沉积通量为0．25ng／（cm^2·a）,丰度最高的PBDE组分为BDE-47、BDE-49、BDE-99、BDE-183（不包括BDE-209）;PBDEs在生物体和柱状沉积物中的含量位于全球PBDEs含量的中低端范围;鱼类等生物体中PBDE的生物-沉积物累积比值（BSAF）比值（〈0．8）较小,与相应的PBDE的log Kow（辛醇／水分配比）存在一定的正相关性。     

多溴联苯醚(PBDEs)在海洋环境中的行为研究进展

多溴联苯醚(PBDEs)被称作"二十一世纪的多氯联苯",是一类具有生态风险性的新型持久性有机污染物.本文在介绍PBDEs物理化学性质的基础上,分析了PBDEs在海洋中的时空分布变化趋势,重点总结了PBDEs在海洋中的生物积累、生物放大、生物转化行为及其对海洋生物的毒性,探讨了海洋环境中PBDEs未来的研究方向.     

中国主要红树林表层沉积物中重金属的分布特征及其影响因素

红树林生态系统处于海洋与陆地的动态交界面,遭受海水周期性浸淹,因而在结构与功能上具有既不同于陆地生态系统,也不同于海洋生态系统的特性。红树林作为初级生产者,为林区动物、微生物提供食物与营养,为鸟类、昆虫、鱼虾等提供栖息、繁衍场所。因此,红树植物对维护生态平衡、保护海岸生态系统起着重要的作用[1-2]。近年来由于工农业的发展,沿海城市人口与经济的增长,大量的污染物汇集于河口、海湾区,使这些地区的重金属污染日趋严重,特别是在直接向红树林区倾污排废的地区更是如此。     

中国主要红树林湿地沉积物中硫的分布特征及影响因素

以中国红树林主要分布地区--海南、广东、广西、福建的13个红树林区为研究对象,对沉积物中硫的分布特征及相关影响因素进行了分析.中国红树林地区沉积物中硫含量为0.009%～0.809%,平均含量为0.214%,远高于非红树林生长地区沉积物中硫的平均含量.海南、广东、广西、福建四省区红树林沉积物中硫的平均含量分别为:0.34%、0.19%、0.20%、0.18%.13个地区含硫量高低顺序为:三亚、东寨港、云霄、钦州、俄湾、姚家屿、高桥、山口、大冠沙、北仑河口、福田、洛阳桥、浮宫.各个不同红树林地区沉积物中的硫含量差异显著.硫含量与有机质含量、盐度显著正相关,与pH值显著负相关.土壤粒度组成以及铁含量对土壤中全硫含量有一定的影响.     

红树林海岸的沉积物输运和碳沉降特征

Mangroves play an important role in sequestering carbon and trapping sediments. However, the effectiveness of such functions is unclear due to the restriction of knowledge on the sedimentation process across the vegetation boundaries. To detect the effects of mangrove forests on sediment transportation and organic carbon sequestration, the granulometric and organic carbon characteristics of mangrove sediments were investigated from three vegetation zones of four typical mangrove habitats on the Leizhou Peninsula coast. Based on our results, sediment transport was often "environmentally sensitive" to the vegetation friction. A transition of the sediment transport mode from the mudflat zone to the interior/fringe zone was often detected from the cumulative frequency curve. The vegetation cover also assists the trapping of material, resulting in a significantly higher concentration of organic carbon in the interior surface sediments. However, the graphic parameters of core sediments reflected a highly temporal variability due to the sedimentation process at different locations. The sediment texture ranges widely from sand to mud, although the sedimentary environments are restricted within the same energy level along the fluvial-marine transition zone. Based on the PCA results, the large variation was mainly attributed to either the mean grain size features or the organic carbon features. A high correlation between the depth and δ13C value also indicated an increasing storage of mangrove-derived organic carbon with time.     

聚苯乙烯和四溴联苯醚对黑褐新糠虾抗氧化防御系统的联合效应

本文以黑褐新糠虾(Neomysis awatschensis)为受试生物,分别研究两者单独及联合暴露21 d后的氧化应激效应,并结合综合生物标志物响应(Integrated Biomarker Response,IBR)评估其毒性。结果表明:PS单独暴露时,过氧化氢酶(Catalase,CAT)、谷胱甘肽硫转移酶(Glutathione S-transferase,GST)、超氧化物歧化酶(Superoxide dismutase,SOD)和谷胱甘肽过氧化物酶(Glutathione peroxidase,GPX)活性随暴露浓度升高被显著抑制,丙二醛(Malondialdehyde,MDA)含量随暴露浓度增加逐渐上升,而谷胱甘肽(Glutathione,GSH)含量仅在97.4μg·L^-1暴露下显著上升;BDE-47单独暴露时,CAT、GST和GSH含量均被抑制,MDA和GPX活性仅在较高浓度下被显著诱导,SOD活性在低浓度被诱导,在最高浓度下恢复至空白水平。联合暴露时,CAT和SOD活性随PS投加浓度升高表现出先诱导后抑制的效应,且均显著高于BDE-47单独暴露组,MDA含量随PS投加浓度升高表现出诱导效应。GST和GPX活性与空白水平相近,低浓度PS暴露组中的GSH含量也有相似的变化规律。可见,PS能减缓BDE-47对黑褐新糠虾抗氧化防御系统的氧化胁迫,在低浓度PS联合暴露组中尤其显著。     

九龙江口及邻近港湾红树林区沉积物中多环芳烃污染现状及评价

本文应用沉积物质量评价基准法对九龙江口及邻近港湾红树林区表层沉积物中多环芳烃的污染现状进行了生态风险评价,并定量分析了多环芳烃的相对污染强度.研究结果表明:各测站区多环芳烃相对污染系数均小于1,范围为0.022~0.620,污染程度尚属较低,引起生物毒性效应的几率相对较小.低分子量多环芳烃芴、萘和二氢苊占总相对污染系数比例较高(平均分别为18.1%、16.7%和15.3%),因而具有相对较高的潜在生态危害风险.     

渤海多溴二苯醚的分布特征及其风险评价

多溴二苯醚(PBDEs)属于新兴污染物,是一种性能优良的阻燃剂,在各种工业产品中广泛应用,而且存在于世界各地的海洋环境中.PBDEs还有持久性、远距离迁移性、生物累积性等特点,对海洋生态系统和人类造成严重危害.与此同时渤海又是我国唯一一个半封闭型的内海,有较差的自净能力以及与外界海水交换的能力,因此渤海区域PBDEs的...     

Heavy metals,polycyclic aromatic hydrocarbons and organochlorine pesticides in the surface sediments of mangrove swamps from coastal sites along the Leizhou Peninsula, South China

Contents of heavy metals, polycyclic aromatic hydrocarbons （PA Hs）, dichlorodiphenyltrichloroethanes （DDTs） and hexachlorcy- clohexanes （HCHs） in surface sediments from mangrove areas of the Leizhou Peninsula were analyzed in July and November 2005. Risk assessment criteria applied by Long E R et al. （1995） and Long E D et al. （1995） （effects range low, ERL; effects range mean, ERM） of chemicals in sediments from the gulf or estuary were used to assess the potential ecological risks of heavy metals, PAHs, DDTs and HCHs to aquatic organisms in the studied area. The results indicated that the average contents of zinc, nickel, chromium, lead, copper, arsenic and mercury were （61.97 ± 55.87）, （59.99 ± 39.01 ）, （47.93 ± 28.37）, （26.64± 13.00） , （23.45 ± 41.96）, （9.32 ± 3.62）, （0.14 ± 0.18） mg/kg in dry weight in the sediment samples col- lected from five studied sites in the Leizhou Peninsula, respectively. Cadmium was not calculated due to its content being below the detection limit （ 〈 0.3 mg,/kg）. The average levels of Cr, Cu, Ni, Pb, Zn and Hg exceed their background values. The average contents of Ni were higher than ERM. The contents of PAHs in the sediments from the five studied sites were （79.78 ± 43.70） ng/g in dry weight, far lower than ERL（4 022 ng/g）. The contents of DDE, DDD and DDTs in the sediments from five studied sites were （2.60 ± 4.68）, （ 17.52 ± 27.25 ）, （27.78 ± 46.64） ng/g in dry weight respectively, clearly higher than ERL, and the average contents of DDT were （7.66 ± 15.93） ng/g in dry weight, much higher than ERM. HCHs could be detected in the sediments only from Gaoqiao sampling site, with the average contents （0.07 ± 0.08） ng/g in dry weight.     

辽东湾表层沉积物的重金属污染特征与质量评价

本文研究了辽东湾表层沉积物中重金属的分布及污染特征,评价其生态风险及环境质量。对辽东湾表层沉积物8种重金属（As、Cu、Cd、Cr、Hg、Ni、Pb、Zn）的空间分布进行了研究,采用Hankanson法和I_geo（地累积指数）分析了该海域重金属潜在生态风险,并评价了该海域的环境质量。在辽东湾葫芦岛附近海域、西南部六股河口东南部海域以及西部近岸海域表层沉积物中As、Cu、Cd、Cr、Hg、Ni、Pb和Zn含量偏高。地累积指数法及生态风险指数法对重金属污染程度评价结果一致,辽东湾生态环境具有潜在危害的重金属主要是Cd、Hg和As,8种重金属潜在生态风险系数由高到低依次为Cd、Hg、Cu、Pb、As、Zn、Ni和Cr,各站位重金属综合潜在生态风险指数均大于150,生态风险总体上处于中等生态风险等级。Cd和Hg是该海域沉积物重金属中主要污染物,局部区域达到中、中-强污染程度。环境质量评价表明,辽东湾表层沉积物重金属引发有害生物效应的可能性不大,但Cd和Hg显著富集,应予以重视。     

北部湾东北部表层沉积物主微量元素空间分布特征

A multi-index analysis including grain size, major and trace elements is performed on the surface sediments from the northeastern Beibu Gulf to trace the sources of the sediments and to understand the controlling factors for elements distribution. The mean grain size exhibits a wide variation ranging from 0.09Φ to 8.05Φ with an average value of 5.33Φ. The average contents of major elements descend in an order of c(SiO_2)c(Al_2O_3)c(Fe_2O_3)c(CaO)c(MgO)c(K_2O)c(Na_2O)c(TiO_2)c(P_2O_5)c(MnO), while those of trace elements exhibit a descending order of c(Sr)c(Rb)c(V)c(Zn)c(Cr)c(Pb)c(Ni)c(Cu)c(As). On the basis of elementary distribution characteristics and statistical analyses, the study area is divided into the four zones: Zone I is located in the northeastern coastal area of the gulf, which receives large amount of fluvial materials from local rivers in Guangxi and Guangdong, China, and the Qiongzhou Strait; Zone Ⅱ is located in the center of the study area, where surface sediments exhibits a multiple source; Zone Ⅲ is located in the Qiongzhou Strait, where surface sediments are dominated by materials from the Zhujiang River and Hainan; Zone IV is located in the southwest of the study area, where surface sediments are mainly originated from the Red River and Hainan. The statistical analyses of sediment geochemical characteristics reveal that the grain size, which is mainly influenced by hydrodynamics and mineral composition of terrigenous materials, is the leading factor controlling the elementary distribution.Meanwhile, impacts from anthropogenic activities and marine biogenic process will also be taken into consideration.     

Determination and ecological risk assessment of arsenic and mercury in sediments from the Changjiang River Estuary and adjacent East China Sea

Arsenic(As) and mercury(Hg) are pollutants presented in marine environment. A process of atomic fluorescence spectrometry was proposed for the simultaneous determination of As and Hg in marine sediment samples(n =38) collected from the Changjiang River Estuary and adjacent East China Sea. The proposed method used an optimized pretreatment procedure in an aqua regia–H_2 O digestion system. Recoveries of As and Hg increased to97% and 98%, respectively, with suitable precisions(2.7%–4.1%) under optimized process conditions. As and Hg were widely presented in these samples, with the ranges of content values were 2.39–8.77 μg/g for As and48.03–410.8 ng/g for Hg. Results indicate that anthropogenic factors strongly influence the abundances of As and Hg in investigated samples. The preliminary environmental risk assessment was investigated using the I_(geo)accumulation index(I_(geo)) and anthropogenic contribution rate(M). Findings reveal that Hg demonstrates a strong ecological risk(with average values of 1.3 and 72% for I_(geo) and M, respectively) in the sediments from the Changjiang River Estuary and adjacent East China Sea. Therefore, Hg should be considered in future investigations.     

同安湾表层沉积物重金属污染特征及潜在生态风险评价

对厦门同安湾表层沉积物7种重金属（Hg、Cd、Pb、As、Cu、Zn和Cr）、有机碳和硫化物含量进行了相关性分析和因子分析,并应用沉积物质量评价标准及潜在生态危害指数法对重金属的潜在生态风险进行了评价.结果表明：Cu、Pb、Zn、Cd、Cr、Hg、As含量范围和均值分别为6.49～46.20,16.95;6.68～46.90,23.93;45.4～162.0,87.4;0.028 9～0.402 0,0.147 6;8.50～33.20,15.95;0.013～0.117,0.047和1.5～6.8,4.8mg/kg.除As之外,各重金属含量之间有显著的相关性（相关系数为0.666～0.970）,且与有机碳含量的相关系数较高（相关系数为0.674～0.980）.重金属元素及有机碳与硫化物含量的相关系数较低.潜在生态风险评价显示：该海区沉积物中重金属生物毒性效应频繁发生的几率相对较小,生态危害程度也较低,尚属轻微生态危害.7种重金属潜在生物毒性风险大小依次为：Hg〉Cd〉Pb〉As〉Cu〉Zn〉Cr.