宁波滩涂贝类养殖区沉积物中有机氯农药和多氯联苯残留及生态风险评估

利用GC-ECD对宁波市主要滩涂贝类养殖区表层沉积物中的多氯联苯(PCBs)和有机氯农药六六六(HCHs)、滴滴涕(DDTs)的残留量进行测定,研究其分布状况,并进行生态风险评估.结果表明:贝类养殖区表层沉积物中的总有机氯农药含量为0.80～32.40ng·g-1,多氯联苯含量为3.20～33.33 ng·g-1.HCHs主要来自远距离大气传输及历史残留,部分区域有DDTs输入,其来源可能是三氯杀螨醇的使用.大部分站位的p,p’-DDT和DDTs存在潜在的生态风险,其中墙头和西店海域的p,p’-DDT残留超过生物效应中值,对底栖生物毒害效应较高.大多数站位PCBs的生态风险较低.     

燃煤烟气中汞排放对周边环境影响

研究了上海市内2个燃煤电厂所排放烟气中的汞对周边环境的影响,并利用高架连续点源大气污染模型分析了电厂烟气排放汞对周边大气汞浓度的影响.结果表明,G电厂周边大气汞浓度范围为9.7～15.6 ng·m-3,J电厂为15.2～22.9 ng·m-3.利用高架连续点源大气污染模型,估算出G电厂和J电厂所排放的烟气下风向3 km处元素态汞的落地浓度分别为0.218和3.034 ng·m-3,颗粒态汞的落地浓度分别为0.038和1.199ng·m-3.G电厂周边表层土壤汞浓度为36.3～136.5 ng·g-1,J电厂为44.3～115.9ng·g-1.G电厂周边植物叶片中汞浓度为215.3～342.3 ng·g-1,J电厂为223.4～396.9 ng·g-1.现场监测数据和模型估算均表明:燃煤电厂所排放的烟气对周边环境中汞的分布和积累有贡献.     

南极食物链顶端海鸟卵中PCBs和OCPs积累水平及其全球意义

采用气相色谱-电子捕获检测器(GC-ECD)内标法定量测定了南极乔治王岛世袭栖息地海鸟(棕贼鸥、灰贼鸥、巨海燕、白眉企鹅)卵样中持久性有机氯污染物多氯联苯(PCBs)和有机氯农药(OCPs)残留量,研究探讨南极海洋食物链顶级生物体有机毒物积累水平探讨其环境意义。结果显示,卵样中有机毒物积累水平依次为:多氯联苯>滴滴涕>氯代苯>六六六。贼鸥卵样多氯联苯含量范围在91.9~515.5ng/g,滴滴涕56.6~304.4ng/g,氯代苯6.5~70.5ng/g,六六六<0.5~2.0ng/g;企鹅卵样多氯联苯含量范围在0.4~0.9ng/g,滴滴涕2.4~10.3ng/g,氯代苯6.0~10.2ng/g,六六六0.1~0.4ng/g;巨海燕卵样多氯联苯含量范围在38.1~81.7ng/g,滴滴涕12.7~53.7ng/g,氯代苯4.2~8.8ng/g,六六六0.5~1.5ng/g。研究结果还显示,不同种类海鸟卵样检出多氯联苯和有机氯农药均以七氯、六氯联苯、滴滴涕同系物(P,P′-DDE)和氯代苯化合物为主体。贼鸥、巨海燕卵样检出9种多氯联苯同系物(大小依次为PCB-180>PCB-153>PCB-194>PCB-138>PCB-118>PCB-170>PCB-101>PCB163>PCB-149)。贼鸥卵样七氯、六氯取代物的多氯联苯同系物含量在17.5~205.5ng/g占其总多氯联苯的62%;巨海燕卵样在14.5~30.5ng/g,占其总多氯联苯的69%;企鹅卵样检出5种多氯联苯同系物相对积蓄较低,其卵样之间变化相对稳定。对不同种类海鸟卵样的有机污染物数据进行统计分析,结果显示不同鸟种有机毒物积累水平的差异取决于不同鸟种的生态习性,如活动范围、迁徒距离、觅食习性以及巢址选择等,最主要是海鸟在海洋生态食物链中的位置,其食谱的宽窄,同时表明海鸟体内PCBs和OCPs积累通过食物链逐级加强的结果。有机毒物最高积累水平出现在棕贼鸥卵样中,灰贼鸥和巨海燕次之,企鹅最低。因为贼鸥不仅食性杂食谱宽,而且贼鸥与企鹅及其他小型海鸟之间存在着一定的捕食与被捕食的关系。南极海鸟卵样多氯联苯和有机氯农药的检出,是全球性有机氯污染又一新的重要证据。南极海鸟卵样中有机毒物的检出,揭示了人造有机污染物在南极鸟类代间转移的存在,它们在南大洋生态系统中的消除将会需要较长的时间过程,表明人类活动对南极生物圈与南极海洋环境的持久影响,南极是全球唯一无污染地区的价值正在丧失。     

油茶花芽分化形态结构及内源激素变化

以普通油茶(Camellia oleifera) 4个无性系为材料,结合油茶成花的动态观察和花芽分化过程的石蜡切片形态观察,采用酶联免疫吸附分析法测定花芽中玉米素核苷(ZR)、脱落酸(ABA)、生长素(IAA)、赤霉素(GA) 4种内源激素含量,探讨油茶花芽分化与内源激素的关系。油茶花芽分化过程可分为6个时期：前分化期(10 d)、萼片形成期(20 d)、花瓣形成期(30 d)、雌雄蕊形成期(20 d)、子房与花药形成期(10 d)和雌雄蕊成熟期(20 d),历时3～4个月。油茶不同无性系的花芽分化时间略有不同。油茶花芽中ZR含量相对较低(5.102～16.412 ng·g–1 FW),ABA含量相对较高(76.815～137.648 ng·g–1 FW)。其中,粤华5号和湘林8号的ZR、ABA含量变化趋势一致,岑软3号和岑软2号含量变化趋势一致。油茶花芽中IAA含量相对较高,为49.072～135.622 ng·g–1 FW,随着花芽分化进程,IAA含量均呈先升后降再升的变化趋势。GA含量相对较低,为5.616～13.720 ng·g–1 FW,随时间变化,呈现出不断降低的趋势。其中,不同无性系的IAA、GA含量变化趋势一致,而ZR、ABA含量变化趋势有所差异。ZR有利于花器官形成;高浓度IAA促进油茶花芽分化,低浓度IAA有利于开花;花芽中IAA与ABA存在明显的颉颃作用;GA抑制花芽分化。     

多氯联苯在模拟水生态系统中的分布、积累与迁移动态研究

利用微宇宙模拟水生态系统对多氯联苯在水体环境中的行为 ,包括多氯联苯在水体、沉积物、生物体 (皇冠草、河蚬、鲢 )不同分配相及生物体不同组织、器官中含量、分布以及迁移、富集等时间变化动态过程进行了研究。结果表明 ,水草对PCB有一定程度的吸收 ;河蚬对PCBs有明显的吸收积累 ,并且吸收达到平衡的时间较长。鱼体对PCB的吸收积累在不同组织中有明显的差别 ,在内脏和肌肉组织中积累较高 ,鳃组织中积累较低。     

海南东寨港红树林区主要鱼类汞含量及生物质量指数

汞可以通过鱼类富集,危害人类健康.为了解东寨港红树林区鱼类的汞含量及其生物质量,本研究对林区内14种主要鱼类和不同环境介质的汞含量进行了分析.研究发现,鱼肉汞平均含量为67.7 ng·g-1,变化范围为34.9～154.9 ng·g-1.海水、红树植物叶片、沉积物中汞含量分别为0.4 μg·L-1、153.9 ng·g-1、314.1 ng·g-1.相对于海水,鱼对环境中的汞具有明显的生物富集作用,鱼体汞含量与其食物来源和生活习性有关,杂食性鱼类汞含量高于植食性鱼类和肉食性鱼类汞含量.所有鱼类体内的生物质量指数均＜1,可安全食用.     

长白山高山冻原生态系统三种养分含量的空间分布

对长白山高山冻原生态系统中 3种养分 (N、P和 S)在植被 -凋落物 -土壤中的空间分布规律进行了研究。结果表明 :(1)在长白山高山冻原植被亚系统中 ,3种养分总含量分布规律是石质高山冻原 (ST) >典型高山冻原 (TT) >沼泽高山冻原 (WT) >草甸高山冻原 (MT) >石海高山冻原 (RT) ;3种养分积累总量为 72 .4 6 kg· hm- 2 ,其中 N、P和 S分别是 4 8.5 5 kg· hm- 2 ,10 .33kg· hm- 2 和 13.6 1kg· hm- 2 ;生物量与养分积累分布规律是 WT>TT>MT>ST>RT。 (2 )在长白山高山冻原凋落物亚系统中 ,平均凋落物量是 1.96 kg· hm- 2 ;3种养分积累总量为 :82 .5 kg· hm- 2 ,其中 N、P和 S分别是 4 6 .2 8kg· hm- 2 ,2 1.14 kg· hm- 2 和 15 .0 8kg· hm- 2 ;养分积累总量分布规律是 TT>WT>RT>MT>ST。 (3)长白山高山冻原土壤 (0～ 2 0cm)亚系统中 ,养分积累总量为 39.6 t· hm- 2 ,其中 N、P和 S分别是 2 3.76 t· hm- 2 ,5 .86 t· hm- 2和 9.98t· hm- 2。 4 )在长白山高山冻原生态系统中 ,3种养分总积累量为 4 0 6 4 4 .98kg· hm- 2 ,其中 N、P和 S分别是 2 4 734.85 kg· hm- 2 ,10 0 18.7kg·hm- 2 和 5 891.4 3kg· hm- 2 ,土壤库是长白山高山冻原的主要养分储存库     

汕头南澳海域不同养殖区浮游纤毛虫群落结构的比较

为比较不同海水养殖模式对纤毛虫原生动物群落结构和水环境的影响,于2014年4—6月,对汕头南澳海域鱼类养殖区、贝类养殖区、大型海藻龙须菜栽培区和自然水体(对照海区)的纤毛虫和主要水质指标进行了每3~4 d一次的高频次监测,并应用沉积物捕捉器研究了纤毛虫包囊的沉降通量。结果表明:调查区域共发现纤毛虫17种,纤毛虫丰度为75~150 ind·L-1,对照海区和鱼类养殖区内纤毛虫丰度变化相对剧烈;龙须菜栽培区纤毛虫功能群中食藻者所占比例达50%;鱼类养殖区纤毛虫包囊沉降通量最高,平均沉降1.9×104cysts·d-1·m-2,显著高于对照海区和龙须菜栽培区;不同养殖区水体纤毛虫群落结构与沉积物中包囊群落结构有较大差异,龙须菜栽培区纤毛虫群落结构最稳定。     

东海大陆架鱼类群落的空间结构

根据1997～2000年东海大陆架水深30～200米海域4个航次的底拖网调查资料,运用多元分析(聚类分析和非度量多维标度(NMDS))、SIMPER以及BIO-ENV方法分析了东海鱼类群落的空间格局以及与非生物环境因子之间的关系。结果表明,东海大陆架海域鱼类群落在空间上可分为3个群落类型,分别为东海近海群落、东海大陆架外缘群落以及这两个群落之间的东海大陆架混合群落。东海大陆架鱼类群落的种类组成沿着水深梯度的变化明显,每种鱼类均有一定的水深范围。不同的流系具有不同的温盐特征,影响了鱼类的分布及其洄游,从而控制了不同鱼类群落类型的种类组成。东海大陆架鱼类群落类型中,大陆架外缘群落类型各调查季节在空间分布和种类组成上相对稳定,而东海近海群落类型和东海大陆架混合群落类型在夏季融合在一起,其它季节保持各自的空间结构。同时东海陆架区只在一种群落类型中出现的鱼类相对较少,多数鱼类同时出现在两个群落类型中或3个群落类型中,但是它们相对较集中的区域明显不同,在不同群落类型中的生物量和出现频率有很大的差异,这些鱼类在其不同的生长发育阶段由于对海洋环境的不同需求,它们根据繁殖或摄食需求而在东海陆架区范围内洄游以寻找最适的海洋环境,因此对3个群落类型定义是相对的,很难严格确定一个永久的鱼类群落地理区域,以形成相互隔离的鱼类群落,而且鱼类群落之间的边界随着季节不同发生变化。     

贵州百花湖鱼体汞污染现状

以西南汞污染严重的贵州百花湖为对象,选取湖中优势鱼、贝类,通过测定其总汞和甲基汞含量,并结合水体、沉积物汞含量和相关水质参数,探讨了百花湖鱼类汞污染的现状及其影响因素.百花湖鱼体总汞平均含量为28.0ng·g-1,变化范围为4.2～143ng·g-1;甲基汞的平均含量为10.9ng·g-1,变化范围为3.0～39.3ng·g-1.虽然百花湖遭受上游贵州有机化工厂含汞废水的严重污染,但鱼体汞含量并没有超过国家食品卫生标准.其主要原因可能是:百花湖的鱼主要是人工养殖的草食性或杂食性鱼类,鱼龄较小,且其摄取的食物汞含量低、食物链简单,不利于汞的富集;其次,其较快的生长速度对鱼体汞具有生物稀释的作用.     

Distributions and Congener Patterns of PCBs in Fish from Major Aquaculture Areas in the Pearl River Delta,South China

The distribution and concentrations of polychlorinated biphenyls (PCBs) were determined in surface sediments and fish collected from freshwater fishponds in six major aquaculture areas of the Pearl River Delta. The concentrations of total PCBs ranged from 7.32 to 36.2 ng/g (dry weight) in sediments and 5.15 to 226 ng/g (lipid weight) in five species of fish, with higher concentrations in fishponds from two industrialized areas. Feeding habits of fishes played a significant role on the accumulation of PCBs and their homologue patterns in fish tissues, with higher concentrations in muscle and viscera of mandarin fish (Siniperca kneri), and tilapia (Tilapia mossambica) and lower in grass carp (Ctenopharyngodon idellus). In muscle, IUPAC No. 118, 138, 81/87, 153, 180, 52, 49, 99, and 44 congeners were the most dominant out of the 36 congeners measured in the present study. The contents of PCBs in fish cultivated in the Pearl River Delta were rather low when compared with the maximum concentration of total PCBs of 2.0 μg/g (wet weight), imposed by the U.S. Food and Drug Administration edible seafood. However, due to the bioaccumulation and biomagnification nature of PCBs through the food chain, continuous monitoring of PCBs as well as other Persistent Organic Pollutants in this rapidly developed region is encouraged.     

Characterization of proteins in the gonad of Limanda yokohamae from Masan Bay, Korea

The putative biological effects of the toxic organic pollutants polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and the dioxin-like polychlorinated biphenyls (DLPCBs) in the sediments of Masan Bay, Korea, on the gonad of Limanda yokohamae were investigated using proteomic and bioinformatic analyses. The results demonstrated that 11 protein spots from the bay site, Duckdong, were statistically different from the reference site Gaduck Island. We identified 20 proteins from the 11 altered protein spots and these were found to be involved in multi-cellular functions as previously demonstrated in a variety of species. The concentrations of toxic equivalents of PCDD/Fs and DLPCBs in the sediments of Masan Bay were approximately twenty six-fold higher than those from Gaduck Island. These findings indicate that the organic contaminants in the sediments of Masan Bay may have contributed to the change in the phenotypes of fish gonads.     

Organochlorine,Organophosphoric and Organotin Contaminants,Aromatic and Aliphatic Hydrocarbons and Heavy Metals in Sediments of the Ports from the Polish Part of the Vistula Lagoon (Baltic Sea)

The concentrations of polycyclic aromatic and petroleum hydrocarbons, polychlorinated biphenyls, dioxins, organochlorine and organophosphoric pesticides, tributyltin and metals were determined in sediments of the approach fairways to the main ports in the Polish part of the Vistula Lagoon and of the Elbl?g River. Analyzed sediments contained low concentrations of all contaminants, except petroleum hydrocarbons. The average petroleum hydrocarbons’ (PHCs) concentration was 630 mg kg^?1, indicating significant pollution with petroleum hydrocarbons. The highest concentrations of analyzed contaminants were identified in the vicinity of Elbl?g, part of the Vistula Lagoon under the most anthropogenic pressure.     

Assessment of persistent organochlorine compounds contamination on the Lake Victoria water and sediments: a case study in Tanzania

The current study was conducted to establish the levels of organochlorine pesticides (OCPs), its degradation products, and indicatory polychlorinated biphenyls (PCBs) in water and sediments from Lake Victoria in Tanzania. Seven indicator PCBs were identified in sediments, and five were identified in water. The PCBs loading ranged from lower than the limit of detection (LOD) to 10.28 µg kg^?1 DW and 0.95 to 2.24 µg l^?1 in sediments and water, respectively. PCBs, CB 138 and CB 153 dominated the load, because of their chemical stability and high degree of chlorination. In addition, ten OCPs were identified in sediments, and seven OCPs were identified in water. The levels of organochlorine compounds in sediments were higher than in water samples, implying that sediments may serve as a sink for these compounds. The presence of these compounds is probably as a result of either historical use, long-range environmental transport or environmental persistence. The levels of organochlorine compounds in the lake water and sediments are below the maximum residue limit set by EU and FAO, except for aldrin and dieldrin. Based on the Threshold Effect Concentration (TEC) for freshwater ecosystems, aldrin and dieldrin are the only OCPs that seem to be a threat to the lake environment.     

Mercury and persistent organic pollutant concentrations in African fish eagles, marabou storks, and Nile tilapia in Uganda

The purpose of this research was to evaluate persistent organic pollutant (POP) and mercury concentrations in tissues of African fish eagles (Haliaeetus vocifer) and Nile tilapia (Oreochromis niloticus) from Lake Victoria near Entebbe and Lake Mburo, Uganda. Marabou stork (Leptoptilos crumeniferus) nestlings from urban Kampala (40 km from Entebbe) also were sampled for POPs and mercury. Total mercury was measured in the breast feathers of eight nestling and 10 adult African fish eagles from Lake Mburo, 10 nestling and five adult African fish eagles from Lake Victoria near Entebbe, and 20 nestling marabou storks from Kampala from June 2002 through January 2003. Mercury concentrations in all samples were below levels associated with adverse effects in similar species. Mercury concentrations were significantly higher in eagle adults and nestlings from Entebbe than in adults and nestlings from Lake Mburo (P< or =0.05). No significant differences (P> or =0.05) were found in mercury concentrations between sexes or between the entire fish eagle population sampled at Entebbe and marabou stork nestlings sampled at nearby Kampala. Plasma samples from the same birds were analyzed for 1,1,1-trichloro-2,2-bis(4-chlorophenyl)ethane, aldrin, hexachlorocyclohexane (alpha-HCH), dieldrin, endrin, heptachlor and their metabolites, as well as total polychlorinated biphenyls (PCBs). Nile tilapia whole-body cross sections collected from Lake Mburo (n=3) and Lake Victoria near Entebbe (n=8) also were analyzed for these POPs and mercury. No samples contained POPs or PCBs at the limits of detection except for 4,4'-1,1-dichloro-2,2-bis(4-chlorophenyl)ethylene in five adult eagle plasma samples (0.0026+/-0.0015 ppm wet weight) and five Nile tilapia samples (0.002+/-0.001 ppm wet weight) from Entebbe.     

Degradation and total mineralization of monohalogenated biphenyls in natural sediment and mixed bacterial culture

Mixed bacterial cultures obtained from polychlorinated biphenyl-contaminated river sediments are capable of degrading monohalogenated biphenyls under simulated natural conditions. Culture conditions include river water as supportive medium and mixed bacterial cultures obtained from river sediments. Degradation occurs when the substrates are supplied as the sole carbon source or when added together with glucose. The degradation rates of 2-, 3-, and 4-chlorobiphenyl, at 30 micrograms ml-1, were 1.1, 1.6, and 2.0 micrograms ml-1 day-1, respectively. Monobrominated biphenyls, including 2-, 3-, and 4-bromobiphenyl, were degraded at rates of 2.3, 4.2, and 1.4 micrograms ml-1 day-1, respectively. Metabolites, including halogenated benzoates, were detected by high-performance liquid chromatography and mass spectrometry. By using chlorophenyl ring-labeled monochlorobiphenyls as substrates, total mineralization (defined as CO2 production from the chlorophenyl ring) was observed for 4-chlorobiphenyl but not for 2-chlorobiphenyl. Rates of total mineralization of 4-chlorobiphenyl (at 39 to 385 micrograms ml-1 levels) were dependent on substrate concentration, whereas variation of cell number in the range of 10(5) to 10(7) cells ml-1 had no significant effects. Simulated sunlight enhanced the rate of mineralization by ca. 400%.     

Degradation and total mineralization of monohalogenated biphenyls in natural sediment and mixed bacterial culture.

Mixed bacterial cultures obtained from polychlorinated biphenyl-contaminated river sediments are capable of degrading monohalogenated biphenyls under simulated natural conditions. Culture conditions include river water as supportive medium and mixed bacterial cultures obtained from river sediments. Degradation occurs when the substrates are supplied as the sole carbon source or when added together with glucose. The degradation rates of 2-, 3-, and 4-chlorobiphenyl, at 30 micrograms ml-1, were 1.1, 1.6, and 2.0 micrograms ml-1 day-1, respectively. Monobrominated biphenyls, including 2-, 3-, and 4-bromobiphenyl, were degraded at rates of 2.3, 4.2, and 1.4 micrograms ml-1 day-1, respectively. Metabolites, including halogenated benzoates, were detected by high-performance liquid chromatography and mass spectrometry. By using chlorophenyl ring-labeled monochlorobiphenyls as substrates, total mineralization (defined as CO2 production from the chlorophenyl ring) was observed for 4-chlorobiphenyl but not for 2-chlorobiphenyl. Rates of total mineralization of 4-chlorobiphenyl (at 39 to 385 micrograms ml-1 levels) were dependent on substrate concentration, whereas variation of cell number in the range of 10(5) to 10(7) cells ml-1 had no significant effects. Simulated sunlight enhanced the rate of mineralization by ca. 400%.     

Distribution of surface soil mercury of Wuda old mining area,Inner Mongolia,China

In this study, mercury (Hg) concentrations in dustfall and topsoil were investigated. Three hundred forty-four samples were collected, including dustfall and topsoil samples, across an area of ～180 km² in Wuda, China. Dustfall Hg concentration in Wuda ranged from 10 to 6453 ng·g^?1_, with an average of 305 ng·g^?1, and topsoil Hg concentration ranged from 3 to 1537 ng·g^?1, with an average value of 135 ng·g^?1. The average dustfall Hg concentrations in the coalfield, industrial park, and urban areas were 289 ng·g^?1, 809 ng·g^?1, and 160 ng·g^?1, respectively, and the corresponding average topsoil Hg concentrations were 216 ng·g^?1, 242 ng·g^?1, and 91 ng·g^?1. Hg concentrations were significantly higher in the coalfield, industrial park, and urban areas compared with background values for Wuda and China tide soil. The coal Hg concentrations ranged from 273 to 346 ng·g^?1, with an average value of 317 ng·g^?1. Comparison of the Hg concentrations of Wuda coal with other regions and countries, indicated that Hg concentrations were significantly enriched in coal, highlighting that coal is the primary Hg source for Wuda District. While coal fires provided the primary source of Hg, some higher Hg values were caused by factors such as gangue hills and coalfield topography, the use of activated carbon with HgCl₂ as a catalyst in the industrial park, and several coal washeries in wasteland areas. In addition to atmospheric Hg, underground coal seam emissions served as another potential Hg source in the coalfield. The surface soil Hg in the coalfield and industrial park areas should be given closer attention in the future.     

Identification of the Proton Source for the Microbial Reductive Dechlorination of 2,3,4,5,6-Pentachlorobiphenyl

Microbially mediated reductive dechlorination of polychlorinated biphenyls (PCBs) in anaerobic sediments has been observed during laboratory experiments. Reductive dechlorination is a two-electron transfer reaction which involves the release of chlorine as a chloride ion and its replacement on the aromatic ring by hydrogen. The exact mechanism of the electron transfer for PCBs is unknown; however, this work shows that the source of the hydrogen atom is the proton (H⁺) from water.