十溴联苯醚(BDE-209)对紫红笛鲷鳃抗氧化酶活性的影响

十溴联苯醚(BDE-209)是目前唯一仍在全球范围内广泛使用的多溴联苯醚阻燃剂,其环境行为及生物效应逐渐成为环境污染领域研究的热点。选用2(LD组)、10(MLD组)、50(MHD组)及250μg.L-1(HD组)4个浓度的BDE-209作用于紫红笛鲷,探讨BDE-209对紫红笛鲷鳃抗氧化酶(SOD、CAT及POD)活性和MDA含量的影响。结果显示:BDE-209可以显著促进SOD和CAT活性,且随着暴露时间延长CAT活性呈现逐渐增加的趋势。暴露7d后,MLD组SOD活性达到最高68.31U.mg-1,是对照组(CK)的5.50倍,HD组CAT活性达到6.31U.mL-1,其次为MHD组的5.96U.mL-1。BDE-209对鳃POD活性呈现先促进后抑制的作用,暴露3d时各浓度POD活性均显著高于CK组(P<0.05);7d时各浓度POD活性则受到显著抑制(P<0.05),清水恢复15d后各浓度组与CK组没有显著差异(P>0.05)。暴露期间各浓度组MDA含量均显著高于CK组(P<,并且随暴露时间延长呈现先增加后减少的趋势,7d后HD组MDA含量达到最高,为6.99nmol.mg-1,清水恢复15d后,LD和MLD组MDA含量与CK组没有显著性差异(P>0.05)。以上结果表明:BDE-209可以诱导紫红笛鲷产生氧化应激效应,CAT和SOD则在氧自由基清除中发挥作用。     

The significance of PCBs in the atmosphere of the southern hemisphere

Air monitoring stations were set up at 2 sites in the southern hemisphere--Moody Brook, Falkland Island (51 degrees 25' S, 57 degrees 56' W) and Halley, Research Station, Antarctica (75 degrees 35' S, 26 degrees 30' W). PCBs were monitored at the stations throughout 1999. Highest concentrations were observed when temperatures were greater. In general, concentrations were greater at Moody Brook than at Halley, although the difference in concentrations between sites was less for more chlorinated congeners. Air concentrations at both sites were compared with samples collected nearby over-water. Over water air concentrations were found to be greater than over land air concentrations. Concentrations were also compared with literature data for air concentrations at a remote site in the Canadian Arctic. Atmospheric concentrations of tri-chlorinated biphenyls were found to be approximately double those reported for Ellesmere Island in the Canadian Arctic, whilst concentrations in samples from Antarctica were very similar to those found in the high Arctic. Most other PCBs were a factor of 2-4 greater in the Canadian Arctic.     

Man-made chemicals found in remote areas of the world: the experimental definition for POPs

Members of the United Nations Economic Commission for Europe (UN-ECE) signed a legally binding protocol on persistent organic pollutants (POPs) in February 1998 under the Convention on Long-Range Transboundary Air Pollution. A treaty that intends to control the production, import, export, disposal and use of toxic chemicals that persist for decades in the environment has been formally signed at a conference in May 2001 in Stockholm. The 2001 POP treaty, like the 1998 LRTAP POP protocol, contains a provision on adding further chemicals to the initial group of twelve or fifteen. The occurrence of a compound or a group of compounds in so called remote and pristine areas, e.g. in the Artic or in the Southern Hemisphere, proves its stability under the chemical and biological conditions of the environment. Compounds identified in this way, in samples taken primarily in very remote regions of the planet, are classified by their environmental fate and global distribution as persistent organic pollutants (POPs), regardless of any political assessments.     

海河与渤海湾水体中溶解态多氯联苯和有机氯农药污染状况调查

在夏季对海河与渤海湾表层水中溶解态的多氯联苯（PCBs）和有机氯农药（OCPs）的污染状况进行了调查．结果表明,海河和渤海湾表层水中PCBs、六六六和滴滴涕的含量分别为0.06～3.11 μg/L、0.05～1.07 μg/L和0.01～0.15 μg/L．海河干流流域内的工业废水排放等陆源输入可能是渤海湾中PCBs和OCPs的重要来源．研究表明该地区PCBs与水中的DOC（dissolved organic carbon）具有一定的正相关．与国内外类似水体相比,海河中PCBs和OCPs污染情况较为严重,而渤海湾则处于中等水平．     

安徽省持续性区域霾污染的时空分布特征

根据天气和气候特征,将安徽省分为沿淮淮北、江淮之间和沿江江南3个子区,并定义了持续性区域性霾过程.基于气象、环保及遥感资料,分析了安徽省持续性区域性霾过程及相应的气溶胶污染的时空分布特征.结果表明,江淮之间和沿江江南区域性霾日数自1980年开始总体呈增多趋势,沿淮淮北2000年开始增加趋势明显;1980年以来,城市持续性霾过程呈增多趋势,但城市之间差异较大;2000年之后持续性区域性霾过程明显增多,最长过程可达10d以上.62%以上的持续性区域性霾过程出现在冬季;江淮之间次数最多,沿江江南次数最少.区域性霾天气常对应着大范围的高湿、小风情况,并伴随着高浓度气溶胶污染,其光学厚度大于0.9,约是晴空天的2.3倍,气溶胶主要集中在400m以下,如近地面区域性霾天的消光系数是普通霾天的2~2.5倍,晴空天的3~5倍;地面PM_2.5污染而言,区域性霾天至少有一个或以上的城市AQI会达到轻度以上污染等级的概率超过了75%.     

持久性有机污染物在土壤中的老化行为研究进展

介绍了持久性有机污染物在土壤中的老化行为对生物可用性的影响，并介绍了老化行为的机理和影响封锁行为的因素。据此，提出了几种可以促进土壤生物修复的方法。     

持久性有机污染物的危害及污染现状

POPs-持久性有机污染物具有长期残留性、生物蓄积性、半挥发性和高毒性,能够在大气环境中长距离迁移并能沉积回地球,对人类健康和环境具有严重危害.本文介绍了POPs的分类、特性、危害以及中国污染现状和改进措施.     

练江沉积物中多溴联苯醚的污染特征、来源和潜在生态风险研究

为考察贵屿电子垃圾拆解区污染沿水体向下游的迁移行为和影响,本文对练江贵屿段及其上下游表层沉积物进行了系统采样和多溴联苯醚（PBDEs）分析,并对其污染来源和潜在生态风险进行了探讨.结果表明：PBDEs在练江上下游沉积物中普遍存在（检出率100%）,在贵屿上游浓度较低（10.2~2120 ng·g^-1）,进入贵屿段急剧升高（7470~193000 ng·g^-1）,至贵屿下游后有所起伏但整体下降（734~11300 ng·g^-1）.练江的PBDEs污染主要来自于沿途排放,贵屿电子垃圾拆解业是其中最大的污染排放源.贵屿下游沉积物的PBDEs浓度比上游高约一个数量级,说明贵屿高浓度的PBDEs污染可沿水体迁移至下游.主因子分析结果表明练江沉积物中的PBDEs污染存在3种模式,上游和下游主要支流（贵屿支流除外）呈现Deca-BDE污染模式（BDE-209为绝对优势单体）,这是我国沉积物中PBDEs的典型污染模式,可视为练江沉积物中PBDEs污染的背景模式;贵屿则呈现出两种特异模式：Penta-BDE模式（优势单体BDE-47&-99）和Deca-BDE脱溴降解模式（以BDE-197为主,其次是-209）,这分别与贵屿地区的电路板拆解和塑料的高温处理方式（烘烤、焚烧、熔融等）有关;贵屿下游支流和主干道样品中的PBDEs呈现与贵屿相似但多种模式共存的特征,进一步证实贵屿的PBDEs污染已沿水体迁移至下游并影响其PBDEs组成特征.练江上游和下游主要支流（贵屿支流除外）PBDEs的风险商值（HQ）均<1,表明生态风险可接受;贵屿段PBDEs的HQ值均>1,最高达63.9,存在严重生态风险;受贵屿污染迁移影响,贵屿下游支流及部分练江主干道样品的HQ值也>1,为PBDEs污染高风险区;Penta-BDEs（三-五溴代BDEs）为HQ值主要贡献污染物,其次是Hexa-BDEs和Deca-BDE.鉴于PBDEs具有环境持久性且在贵屿段的沉积通量高达（477±648）t（贵屿下游为（152±169）t）,其在贵屿及其下游20 km以内的污染急需开展进一步调查并采取相应的污染治理和修复措施.     

Advances on Toxicological Mechanism of AhR Pathway and Early Biomonitoring of Persistent Organic Pollutants (POPs)in Aquatic Animals

过去30年,随着工农业的不断发展,由持久性有机污染物(POPs)导致的癌症患者不断增加.目前POPs已广泛存在于水生态系统中,对水生动物的生长发育、种群繁衍、群落结构等产生重要影响.虽然POPs对水生动物的毒理机制非常复杂,但研究表明其毒理机制主要通过芳香烃受体通道(Ah Rpathway)来进行调控.为全面理解水生动物AhR通道中每一个基因在毒理调控过程中的作用,论文从水生动物芳香烃通道的角度详细阐述了POPs的毒理机制,同时对水生动物中POPs的早期监测进行了讨论,最后提出了未来POPs毒理机制研究的发展方向.     

Uptake of Polycyclic Aromatic Hydrocarbons (PAHS) by Broad Leaves: Analysis of Kinetic Limitations

A kinetic model for the uptake ofpolycyclic aromatic hydrocarbons (PAHs) wasdeveloped from the anatomical structure of broadleaves. The model, which is supported by fielddata, includes the uptake from two pathways: outercuticle pathway and stomatal pathway, and withgrowth rate incorporated as a dilution term. Allthe parameters for the calculation of total masstransfer coefficient, k_OL, were estimated fromthe conductance of water vapor diffusion throughleaves. The results indicate that the stomatalpathway is a dominant pathway for dry gaseousdeposition of POPs on leaves and the uptake fromouter cuticle pathway can be neglected for the PAHsof molar volumes larger than phenanthrene becauseof the rate limitation in outer layer cuticle. Model sensitivity analyses demonstrates that withinthe range of environmental conditions and normalleaf structure, the surface area in stomata has themost significant effect on the uptake rate. If thestomatal pathway is closed, the kinetics of uptakeare so slow that accumulation appears independentof compound lipophilicity or molecular size. Ineither case, the leaf growth rate has little effecton the predicted accumulation