广东沿海养殖牡蛎中多氯联苯残留水平及人体饮食暴露风险评估

文章利用气相色谱质谱法测定了广东沿海主要养殖区(汕头、汕尾、深圳、珠海、江门、阳江、湛江)养殖牡蛎体内30种多氯联苯(Polychlorinated biphenys,PCBs)的含量,评价了其污染水平和致癌风险。结果表明,广东养殖牡蛎中普遍检出PCBs,检出率为97.6%,其质量分数为nd~8.62 ng·g^-1(湿质量,下同),平均值为(0.57±1.23)ng·g^-1,其中以深圳水域养殖牡蛎体内的PCBs含量最高,珠海次之,汕头、阳江、江门、湛江及汕尾较低。不同地区养殖牡蛎中PCBs的组成模式类似,均以五氯代和六氯代PCBs为主。与国内外部分沿海海域贝类相比,广东省养殖牡蛎中PCBs含量处于较低水平。广东省养殖牡蛎中PCBs残留量低于中国《食品安全国家标准食品中污染物限量》及欧盟国家的贝类卫生标准,食用牡蛎的致癌风险及危害商数均小于美国环保局(EPA)推荐的可接受风险水平,致癌风险处于可接受风险水平。     

内蒙古解放闸灌域表层土壤多氯联苯污染特征和来源分析

在内蒙古解放闸灌域采集49个表层土壤样品,采用气相色谱-电子捕获检测器(GC-ECD)测定8种多氯联苯PCBs的浓度,探讨PCBs的污染特征、组成特征、空间分布和污染来源,以及土壤理化性质对PCBs浓度分布的影响。结果表明,解放闸灌域表层土壤中∑PCBs浓度范围为ND～209.95 ng·g~(-1),均值为15.09 ng·g~(-1),与国内外其他地区相比,处于较低污染水平。PCB1、PCB29和PCB47的均值和检出率均较高,是解放闸灌域表层土壤中的优势污染物。土壤中PCBs同系物组成表现为:PCB29(38.65%)PCB1(33.33%)PCB47(11.62%)PCB5(8.25%)PCB98(8.14%),其余单体的检出量很少,说明主要以低氯联苯污染为主。土壤中PCBs浓度的空间分布存在一定差异性,表现为东北高于西南,其西南部呈点状分布。土壤理化性质对PCBs浓度的影响表现为:PCBs浓度分布受pH值的影响,而不受有机质、EC值、砂粒、粉粒和黏粒的影响。相关性分析和因子分析结果显示,解放闸灌域表层土壤中PCBs的污染源主要来自电容器和变压器油的泄露。     

太原市农田土壤中多氯联苯污染特征及健康风险

[目的]研究多氯联苯(PCBs)在太原市农田土壤中的分布特征、来源以及对周围人群的健康风险.[方法]以太原市农田土壤为研究对象,分析测定土壤中7种指示性PCBs的含量,并根据太原市人群实际情况的暴露参数和USEPA的部分参数,对太原市农田土壤中PCBs的健康风险进行评价.[结果]太原市农田土壤中7种指示性PCBs的平均值为87.29μg/kg,以六氯及以上的高氯联苯为主;与国内外其他城市土壤中PCBs的残留量相比较,太原市农田土壤中PCBs残留量处于相对较高水平;且35%采样点的∑7PCBs残留量高于农业用地限定值;主成分分析结果表明,土壤中PCBs污染可能主要与大型企业电子电力设备绝缘材料、电容器浸渍剂和变压器的泄漏,以及含有Aroclor1254绝缘材料、油漆添加剂和化产车间使用Aroclor1260一类的工业产品有关;太原市农田土壤中的PCBs在敏感用地和非敏感用地方式下均不会对成人和儿童产生非致癌健康风险;在2种不同用地方式下太原市农田土壤中PCBs对成人的综合致癌风险较小,但对儿童会存在一定的致癌风险,3种暴露途径对健康风险贡献率依次为经口摄入皮肤接触呼吸吸入.[结论]该研究可为太原市土壤污染残留分布分析及其评价提供参考.     

吕四渔场近岸海域水质和沉积物中多氯联苯(PCBs)的分布特征

采用气相色谱测定了吕四渔场水质和沉积物样品中的多氯联苯(PCBs),并分析了其分布特征。结果显示,吕四渔场水质和沉积物中的PCBs平面分布特征为南部近岸高,而北部近岸较外海低,调查海域PCBs含量有逐年升高的趋势。水质中以低氯代PCBs同族体为主,沉积物中以高氯代PCBs同族体为主,含6个氯原子的PCBs在水中和沉积物中含量都比较高。为了削减PCBs对环境和人类的危害,我们要加强控制、管理、研究和合作。     

土壤的老化对PCB138的可提取性和生物可利用性的影响

为探讨老化行为对多氯联苯(Polychlorinated biphenyls,PCBs)在土壤中的可提取性和生物可利用性的影响,选取2,2′,3,4,4′,5-六氯联苯(PCB138)作为目标污染物,进行90 d的老化试验,比较了超纯水提取、正丁醇溶液提取、超声提取(正己烷/丙酮)和索氏抽提(正己烷/二氯甲烷)等4种方法对土壤中不同老化时间PCB138的提取率;以赤子爱胜蚓(Eisenia fetida)为土壤模式参照生物,在不同的老化时间里测定蚯蚓体内PCB138的含量与脂肪含量。结果表明,4种方法提取PCB138的能力依次为索氏抽提(正己烷/二氯甲烷)≈超声提取(正己烷/丙酮)正丁醇提取超纯水溶液提取;索氏抽提、超声提取和正丁醇溶液提取的提取率从最初的87%~93%、85%~90%、50%~60%分别下降到70%~76%、65%~73%、25%~45%,在30~45 d时总提取量保持稳定,而超纯水提取PCB138的量有限,显示出最低的提取能力且为非重复性结果。PCB138在蚯蚓体内富集量随接触时间增加而增加,在老化30 d左右其体内PCB138富集量最大;在老化30~60 d时,蚯蚓体内的PCB138的含量逐渐下降,健康状况良好的蚯蚓脂肪含量有所下降但不明显。正丁醇溶液提取、超声提取和索氏抽提对PCB138的提取率,以及老化土壤中蚯蚓对PCB138的富集量,均说明PCB138在土壤中的生物有效性随着老化时间的延长而降低。     

茶皂素诱导生物降解多氯联苯的初步研究

从土壤中筛选分离出两株茶皂素利用菌WTS和YTS,这两个菌株在利用茶皂素生长繁殖的同时,对多氯联苯(PCBs)的降解有明显的促进作用。在茶皂素共存的条件下,WTS菌对PCB 77、PCB 118和PCB 138的降解速率常数分别提高了4.3倍、4.8倍和2.8倍,YTS菌对PCB 77、PCB 118和PCB 138的降解速率常数分别提高了7.1倍、9.1倍和8.9倍。结果初步表明,茶皂素能明显促进微生物对多氯联苯的降解,可望开发成一种良好的PCBs降解诱导剂,值得进一步深入研究。     

多氯联苯对鱼肝功能的影响、机制及防治

多氯联苯(polychlorinated biphenyls,PCBs)是水体环境中广泛分布的典型持久性有机污染物,可通过食物链富集进入鱼、人及其他动物体内,并在脂肪中积蓄,严重危害机体健康,能引起生物体突变、畸变甚至癌变,引起了极大的关注。文章主要综述了PCBs对鱼类肝功能的影响、作用机理及预防PCBs对鱼类生长发育的毒害,旨在为搞好水体环境,保护和发展可持续的渔业提供参考依据。     

表面活性剂强化土壤中PCBs的解吸研究

[目的]为研究表面活性剂对PCBs的解吸效果的强化提供理论依据。[方法]通过研究十二烷基苯磺酸钠（SDBS）、Tween 80和十六烷基三甲基溴化铵（HTAB）三种表面活性剂对土壤中多氯联苯（PCBs）解吸效果及其本身在水和土壤中的分配,并分析了表面活性剂在水和土壤中的定量分配对PCBs的解吸行为的影响。[结果]单种表面活性剂对PCBs的解吸效果的强化作用为：Tween 80〉SDBS〉HTAB;3种表面活性剂在土壤上都有较大的吸附,吸附作用大小为：HTAB〉Tween 80〉SDBS;表面活性剂对PCBs解吸效果的强化作用主要由表面活性剂水相胶束浓度贡献,且PCBs的解吸率同水相胶束浓度正线性相关。[结论]得到了3种表面活性剂对土壤中的PCBs的解吸效果的强化作用,为进一步分析提供了理论依据。     

Interference elimination of PCB and its ramification in determining trace PBBs/PBDEs by GC/MS

The normal method to determine the trace brominated flame retardants such as polybrominated biphenyls (PBBs) and polybrominated diphenylethers (PBDEs) contained in the electronic and electrical products is gas chromatography/mass spectrometry (GC/MS). However, the method is based on the determinations of the persistent organic pollutants (POPs) such as polychlorinated biphenyls (PCBs), and polychlorinated naphthalene (PCNs) etc. The interferences of those compounds are inevitable. Therefore, in order to overcome this problem, two methods e.g. 1) The combination use of gas chromatography negative ion chemical ionization mass spectrometry (GC-NICI-MS) and gas chromatography-electron impact-mass spectrometry (GC-EI-MS) is employed, 2) a matrix solid-phase dispersion (MSPD) method with YMC ODS-C18 as carrier is developed. The result show that, by the former method, the brominated isomers or ramifications are distinguished remarkably from other halogen compounds because that anion fragment retention peaks of ［Br］-, ［HBr2］- and molecule chain fragment retention peaks of ［M+2］+，［M+4］+，［M+6］+，［M+8］+ are observed simultaneously, and thus the selectivity to determine bromine-containing retardant flames is greatly improved. Using the latter method, the gas chromatographic peaks of multiple polychlorinated biphenyls and polybrominated diphenylethers can be efficiently separated. Thus provides a project to solve interferences of POPs in brominated flame retardants’ determinations. The standard addition experimental results of 10 kinds of BDEs/PCBs belonging to 8 sorts of electronic and electrical equipment show this method has a high precision and reliability due to 60%～98% recovery and <9.5% relative error, which meet the needs regulated by the IEC Commission. It provides a technical support for electronic and eletrical industries in China to further comply with RoHS directive.     

Organochlorine and Metal Accumulation in Fish (Phoxinus phoxinus) Along a North-South Transect in the Alps

Southern populations of the European minnow fromremote oligotrophic mountain lakes along an Alpinenorth-south transect accumulated more p,p DDE andPCBs than northern populations. As these semi-volatileorganochlorines predominantly evaporate in warmcountries, higher rates of condensation (deposition)are assumed to occur in the southern slopes of theAlps. The higher accumulation of lead and cadmium insouthern population is rather attributed to geogenicand specific environmental impacts than to atmosphericdeposition. Increasing liver ratios of [glutathionedisulfide]/[glutathione], a potential indicator foroxidative stress, from north to south reflect thegenerally higher toxic load at remote sites at thesouthern edge of the Alps. However, histopathologicalchanges in the liver did not correlate withaccumulated toxicants indicating that deposition doesnot lead to severe lesions but induces specificmechanisms for detoxification.