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.     

象山港南沙岛不同养殖类型沉积物酸可挥发性硫化物的时空分布

2007年分4个航次测定了象山港南沙岛不同养殖类型(贝类养殖、藻类养殖和网箱养殖)沉积物酸可挥发性硫化物(AVS)含量的时空变化规律.研究结果表明,南沙岛养殖区沉积物AVS变化范围为0.01-30.03μmoL/g,平均3.75μmol/g,其中贝类养殖区、藻类养殖区、网箱养殖区和对照区AVS年平均含量分别为1.03、0.64、5.06和0.70 μmol/g.网箱养殖中心区(S10)AVS的含量分别是贝类养殖区、藻类养殖区和对照区的8.5倍、13.6倍和12.6倍.ANOVA分析表明,表层沉积物(0-3cm) AVS含量的季节变化差异不显著,但柱状样(0-15 cm)平均含量差异显著,夏秋季明显高于冬春季.AVS含量总体上随着沉积物深度的增加而增加,6-9 cm达到最大值,夏秋季尤为明显.聚类分析表明,南沙岛养殖区调查站位分为3类,网箱养殖中心区(S10)和距离较近的S13和S12为一个类群,贝类养殖区、藻类养殖区和对照区为一个类群,其余站位为一个类群.总体上,养殖中心区AVS含量最高,随着与养殖中心区距离的增加含量逐渐降低,网箱养殖对底质AVS的影响主要集中在200 m以内,500 m以外则影响较小.     

缢蛏滩涂养殖环境的细菌群落组成及分析

1引言滩涂贝类养殖由于实行生态养殖,目前已成为宁波市海水养殖业的一大热点.近几年来,随着沿海经济的高速发展,滩涂环境污染问题日趋严重,养殖贝类大规模死亡的现象时有发生,给海洋水产经济造成了严重损失.而微生物数量及种群分布与区域环境有着密切联系,它可直接或间接地反映区域环境的营养水平、污染程度及底质状况等.目前有关养殖环境微生物学的研究主要是针对水体及养殖池底泥中的细菌[1,4,7～10],而对养殖滩涂环境细菌的研究很少[15,18,19].为此,本文以宁波市昆亭缢蛏滩涂养殖区为研究对象,从细菌生态学角度对滩涂缢蛏养殖环境进行研…     

持久性有机污染物γ-六六六生物降解研究进展

γ-六六六(γ-Hexachlorocyclohexane,γ-HCH)是一种有机氯杀虫剂,由于它具有持久性和很高的毒性,成为顽固性的世界性污染物。目前从世界上不同的受HCH污染的地区中已经分离出许多能够降解HCH的微生物,其中一些微生物对γ-HCH的降解途径得到了阐明,降解基因/酶也得到了鉴定。综述了γ-HCH降解菌的多样性、降解途径、降解基因和酶,为γ-HCH的生物修复提供了参考。     

赣江流域底泥中有机氯农药残留特征及空间分布

基于"临水垂直插管法"采集赣江流域32个采样点的底泥样品,经索氏提取方法(Soxhlet Extraction,SE)前处理及气相色谱法(GC-ECD)检测样品中有机氯农药(OCPs)含量。结合多元统计学和ArcGIS9.3,研究了8种有机氯农药的残留状况及空间分布情况。结果表明,所检测8种OCPs中,除β-HCH有2个点未检出,其它7种OCPs检出率为100%。以DDTs残留含量最高,DDTs平均值为10.40μg/kg,其异构体以p,p’-DDT为主;HCHs的平均值为8.24μg/kg,其异构体以β-HCH为主。它们除了来自环境中的早期残留外,仍然具有新的外源HCHs和DDTs的输入。不同OCPs在研究区分布存在很大差异,HCHs总量分布较高的地区位于流域的中下游,DDTs总量分布较高的地区位于流域的中上游。     

汕头南澳养殖区表层沉积物中生源要素的分布及其污染评价

于2010年9月采集南澳海域鱼类养殖区、贝类养殖区、大型藻类栽培区和对照区4个功能区表层沉积物样品,分析沉积物中生物硅(BSi)、总有机碳(TOC)、总氮(TN)和总磷(TP)4种生源要素的含量。结果表明,南澳海域生源要素含量与国内外养殖区相比属于中等水平。鱼类养殖区TOC、TN、TP的含量最高,而BSi的最高含量出现在藻类栽培区(平均含量为0.30%)。鱼类养殖区BSi、TOC、TN和TP的平均含量分别为0.24%、0.89%、0.13%和0.097%。根据沉积物中TOC/TN比值分析,发现鱼类养殖区的TOC主要来源于水生,贝类、藻类和对照区TOC则主要来源于陆源。生源要素污染评价表明,4个功能区的TN均属于Ⅱ类污染,鱼类和贝类养殖区的TP属于Ⅱ类轻度污染。     

六六六(HCH)降解菌Sphingomonas sp. BHC-A的分离与降解特性的研究

从长期受六六六污染的土壤中分离得到一株能以HCH为唯一碳源的高效降解菌株BHC-A。通过对其主要生理生化特征分析,以及16S rDNA序列的测定和同源性比较分析,将BHC-A鉴定为鞘氨醇单胞菌属(Sphingomonassp.)。BHC-A菌株在12h以内能够完全矿化浓度分别为5mg/L的α-、β-、γ-、δ-HCH4种异构体,特别是对β-HCH的降解在国际上也属少例。而前人所报道的γ-HCH降解菌Sphingomonas paucimobilisUT26菌株对β-HCH和δ-HCH不产生降解作用,即使经过24h的培养,对5mg/L的α-HCH的降解率也只有12.6%。在黄瓜的盆钵试验中发现,15d后BHC-A在土壤中对α、β-、γ-、δ-HCH4种异构体的降解率为84.3%,能够有效地消除土壤中六六六的污染,缓解植株受药害症状。     

福建漳江口水环境中滴滴涕（DDTs）的分布与溯源

采用气相色谱(GC-ECD)方法分析了漳江口水环境中表层水、沉积物和水生生物体内滴滴涕(DDTs)的污染水平,初步研究了其在多介质中的含量、转移分配规律,并根据其沿江分布规律、组成特征,结合三氯杀螨醇同步调查结果进行了溯源分析.结果表明: 漳江口表层水中的DDTs平均含量为枯水期10.5 ng·L^-1(未检出～20.1 ng·L^-1)、丰水期28.3 ng·L^-1 (未检出～45.2 ng·L^-1)、平水期5.03 ng·L^-1 (未检出～18.8 ng·L^-1);表层沉积物中DDTs含量(以干质量计)为1.87～144 ng·g^-1,平均17.3 ng·g^-1;11种水生生物中DDTs的含量范围为1.09～432 ng·g^-1,平均37.0 ng·g^-1.与其他地区相比,漳江口表层水和沉积物中的DDTs残留属于中等水平.DDT在沉积物中的富集因子为1185;在生物体中的富集因子平均为2534,富集能力依次为水生植物<虾类<贝类<鱼类.DDTs沿江分布基本呈下降趋势,推断其残留与船舶防污剂释放关系不大,主要来源于陆源性污染.组成特征分析显示,漳江口DDTs主要来源于环境中的早期残留,而Y-8站(江心岛后)近期有新的DDTs输入,可能与三氯杀螨醇的使用有关.同步调查结果显示,Y-8站表层水和沉积物中均检出三氯杀螨醇,且含量最高,近期存在三氯杀螨醇的施用.     

降解木质素的真菌在降解有毒废物方面表现出希望

<正> 某些环境污染物,例如 DDT、多氯联苯、多氯二苯并-对-diorins、林丹和苯并蓖,能通过真菌降解后生成二氧化碳。密执安州立大学的 John Bumpus 及事研究发现,通常降解枯木的一种真菌 phanerochaete chrysosporium(也叫白腐真菌),在缺氮和葡萄糖丰富的     

乳山湾东流区沉积物中不同形态磷的分布特征

对2003年8月在乳山湾东流区采集的沉积物样品中的不同形态磷的平面和垂直分布特征进行了分析,并探讨了这些磷的形态分布与贝类养殖的关系,结果表明,不同形态磷在贝类高密度养殖区含量大于低密度养殖区.养殖区的垂直分布比较复杂,在1～20cm范围含量均出现较大波动,这与贝类养殖活动有关.Fe-P、Al-P含量出现较大波动还与污染程度有关,Or-P还与浮游植物活动有关.养殖区Ex-P、Fe-P、NAIP占TP的平均百分含量大于非养殖区,De-P、Oc-P恰好相反.Ca-P是乳山湾沉积物中含量最高的磷形态,Fe-P 和Or-P是最主要的两种生物可获得磷.TP、Or-P含量在养殖区与非养殖区之间没有显著差异,养殖区Fe-P含量高于非养殖区,3种磷的平均含量一般大于其它海区.非生物可获得磷约占TP的60%左右.     

Accumulation and degradation of organochorine pesticides in shellfish culture environment in Xiamen sea area

By using GC-ECD, the concentrations of organochlorine pesticides hexachlorocyclohexane (HCH) and dichlorodiphenyltrichloroethane (DDT) in the shellfish culture environment (sea water, sediments, and culture-shellfishes) in Xiamen sea area were analyzed, and the accumulation and degradation patterns of the HCH and DDT were preliminarily approached. In the sea area, there existed remarkable differences in the accumulation and degradation of HCH and DDT among different shellfish culture environments, being mostly associated with the habitation environment and physiological life habits of shellfish. The accumulated HCH isomers (Rx > 1) were mainly beta-HCH, delta-HCH, and gamma-HCH, whereas the degraded HCH isomers (Rx < 1) were mainly alpha-HCH. The ratio of alpha-HCH to gamma-HCH was less than or equal to 1.0, suggesting that the HCH was come from industrial HCH and lindane, most of the HCH had remained in the culture environment for a longer time, and a small amount of lindane was imported. The DDT in the sea water was aerobically degraded, its main degradation product was DDE, and the ratios of (DDD+DDE) to DDTs (p,p-DDE+p,p-DDD+o,p-DDT+p,p-DDT) was less than 0.5, whereas the DDT in sediments and shellfishes was anaerobically degraded, its main degradation product was DDD, and the ratios of (DDD+DDE) to DDTs was greater than 0.5, suggesting that there was a small amount of DDT newly imported in the sea water, and most DDT in sediments and shellfishes were already degraded and transformed into DDD and DDE. There were definite differences in the degradation rates of HCH isomers in the culture environment, suggesting the conformational change of HCH in its transformation processes in the shellfish culture ecosystem.     

DDT and HCH (Organochlorine Pesticides) in Residential Soils and Health Assessment for Human Populations in Korba,India

Dichlorodiphenyltrichloroethane (DDT), hexachlorocyclohexane (HCH), and their isomers’ levels in residential soils were determined for the assessment of health risk in Korba, India. Observed concentrations of total HCH and total DDT in soils were more or less comparable with other parts of India and the world. ΣHCH and ΣDDT concentrations ranged between 0.9–20 μg kg^?1 and 2–315 μg kg^?1, respectively, which were lower than recommended soil quality guidelines indicating low ecotoxicological risk. Carcinogenic and non-carcinogenic impacts of HCH and DDT on human populations through soil ingestion were evaluated and presented. The incremental lifetime cancer risk (ILCR) for adults and children ranged between 7.8 × 10^?10–1.6 × 10^?7 and 4.1 × 10^?9–8.2 × 10^?7, respectively. Non-cancer health hazard quotient (HQ) ranged between 5.9 × 10^?7–1.8 × 10^?3 and 3.1 × 10^?6–9.4 × 10^?3, respectively, for adults and children. The estimated ILCR and HQ were within the safe acceptable limits of 10^?6–10^?4 and ≤1.0, respectively, indicating low risk to human populations from exposure to organochlorine pesticides (HCH and DDT) in the study area.     

厦门大嶝岛海域贝类的养殖容量

对厦门大嶝岛海域叶绿素a、初级生产力、浮游植物有机碳含量、潮下带、潮间带和吊养区非养殖滤食性动物生产量、养殖贝类的滤水率、有机碳含量和贝类含壳重与鲜组织重的比值等模型参数的调查测定和检测分析,采用营养动态模型和沿岸海域能流分析模型估算该海域贝类生态容量,进而扣除野生滤食性动物生产量,估算贝类养殖容量;同时应用方建光模型估算贝类的养殖容量;采用统计分析法估算贝类及其各养殖品种的适养殖面积,以控制该海域贝类的养殖量和对各种贝类养殖量进行优化配置.结果表明,3种模型估算的贝类养殖容量为35248～39990t(平均37488t),140008～158850×10⁴个(平均148903×10⁴个);适养面积2145hm²,其中牡蛎1900hm²、缢蛏81hm²、泥蚶20hm²、凸壳肌蛤144hm².2000年贝类及其各养殖品种的养殖面积已超过了估算的适宜养殖面积,应予以削减.     

Health Risk Assessment of Chemical Mixtures Exposure to Residents in the Lake Taihu Region,China

This study assessed the mixture health risk for the residents of China's Lake Taihu region posed by a Persistent Organic Pollutants (POPs) mixture of dichloro-diphenyl-trichloroethane (DDT) and hexachlorocyclohexane (HCH). Multiple-pathway exposure models were used for exposure assessment in order to estimate the DDT and HCH exposure dose. The DDT and HCH PBPK models were developed and used for consequence assessment in order to analyze the pollutant distribution and accumulation process in human tissues. The tissue dose hazard index (HI) was used to estimate the mixture health risk. The results showed that the total exposure doses for male residents and female residents were 4.01 × 10^{? 4}～ 7.67 × 10^{? 3} mg/kg/day and 3.73 × 10^{? 4}～ 6.75 × 10^{? 3} mg/kg/day for DDT, respectively, and 3.78 × 10^{? 4}～ 5.14 × 10^{? 3} mg/kg/day and 3.53 × 10^{? 4}～ 4.66 × 10^{? 3} mg/kg/day for HCH, respectively. The maximum tissue concentrations in fat for male and female residents reached 110.51 mg/l and 97.21 mg/l for DDT, respectively, and 189.66 mg/l and 171.72 mg/l for HCH, respectively. The tissue dose hazard indexes for male and female residents were 0.1472 ～ 2.4990 and 0.1377 ～ 2.2230, respectively, and the probabilities of the risk exceeding the acceptable risk (HI = 1) for male and female were 24.60% and 16.51%, respectively.     

Responses of Anopheles culicifacies sibling species A and B to DDT and HCH in India: implications in malaria control

Differential responses of Anopheles culicifacies Giles sibling species A and B to DDT were evident from higher survival rate of species B in laboratory bioassays and greater proportions of species B in DDT-sprayed villages of northern India, compared with those under HCH pressure. Both species A and B have become almost completely resistant to HCH in this area due to regular house-spraying with HCH for about the last 10 years. Because species A predominates in northern India, where it has been incriminated as an important vector of malaria, and species A is more susceptible than species B to DDT, it is suggested that DDT would control malaria transmission more effectively than HCH in this situation. Monitoring of insecticide resistance in species A is therefore recommended as the basis for future choice of insecticides to be used by the National Malaria Eradication Programme.     

The Health and Ecological Impacts of Organochlorine Pesticide Pollution in China: Bioaccumulation of Organochlorine Pesticides in Human and Fish Fats

The levels of organochlorine pesticides (OCPs) in the environment and foods have declined significantly in China since 1983, the year when their use in agriculture was officially banned. The levels today of these contaminants in soil, water, and agricultural products are well below 50 μg/kg in many parts of China. Yet in spite of such a decline, the current levels of pollution still pose a significant health risk to many people in China because OCPs are highly persistent and bioaccumulative substances. This preliminary study was conducted to monitor the levels of hexachlorocyclohexane (HCH) and dichloro-diphenyl-trichloroethane (DDT) in human and fish fats from southeast China in an effort to corroborate the above health concern. The data reconfirmed that pollution by HCH and DDT, which are the major components of OCPs, is a serious ecological problem in the study region, and likely in other parts of China as well. The HCH contents in the human samples were between 0.25 and 2.20 mg/kg, with an average of 0.90 mg/kg. The DDT contents in these human samples were much higher, between 0.54 and 9.22 mg/kg with an average of 3.50 mg/kg. The major isomers found in the human samples were β-HCH and p, p′-DDE, representing 94.9 to 99.5% of total HCH and 72.3 to 96.7% of total DDT, respectively. The HCH and DDT content in the grass carp samples averaged 0.03 and 0.67 mg/kg, respectively. The levels of bioaccumulation reflected in these human and fish samples were considered substantial, particularly when residents in the study region continue to be exposed to the OCPs remaining so persistently in their environment. It is therefore important for the health authorities to launch a large-scale investigation into the potential health and ecological impacts of OCP pollution in China. The data also suggested that the current national standards might need to be lowered for the levels of OCPs in the environment in China.     

Surfactant mediated enhanced biodegradation of hexachlorocyclohexane (HCH) isomers by Sphingomonas sp. NM05

Environmental biodegradation of several chlorinated pesticides is limited by their low solubility and sorption to soil surfaces. To mitigate this problem we quantified the effect of three biosurfactant viz., rhamnolipid, sophorolipid and trehalose-containing lipid on the dissolution, bioavailability, and biodegradation of HCH-isomers in liquid culture and in contaminated soil. The effect of biosurfactants was evaluated through the critical micelle concentration (CMC) value as determined for each isomer. The surfactant increased the solubilization of HCH isomers by 3-9 folds with rhamnolipid and sophorolipid being more effective and showing maximum solubilization of HCH isomers at 40 μg/mL, compared to trehalose-containing lipid showing peak solubilization at 60 μg/mL. The degradation of HCH isomers by Sphingomonas sp. NM05 in surfactant-amended liquid mineral salts medium showed 30% enhancement in 2 days as compared to degradation in 10 days in the absence of surfactant. HCH-spiked soil slurry incubated with surfactant also showed around 30-50% enhanced degradation of HCH which was comparable to the corresponding batch culture experiments. Among the three surfactants, sophorolipid offered highest solubilization and enhanced degradation of HCH isomers both in liquid medium and soil culture. The results of this study suggest the effectiveness of surfactants in improving HCH degradation by increased bioaccessibility.     

杀虫剂类POPs对土壤中微生物群落多样性的影响

农药类持久性有机污染物(POPs)如DDT和HCH在我国2 0世纪5 0年代到80年代曾广泛使用,在停止使用2 0 a后,在土壤中仍然可以检测到DDT和HCH的残留。利用BIOL OG微平板研究土壤微生物群落功能多样性,意在反映有机氯杀虫剂类POPs对土壤微生物群落多样性的影响。结果表明,加了HCH后土壤微生物群落的颜色平均变化值(AWCD)的变化速度和最终能达到的AWCD值要高于空白土壤,并且随着农药浓度的加大,AWCD值的变化速率也越来越快,最终能达到的最大值也呈比例增大。加了DDT后的土壤与空白土壤的AWCD变化速度和程度相差不大。方差分析结果表明:空白土壤、HCH0 .5mg/kg、HCH1.5 mg/kg各处理间土壤的AWCD值有显著性差异(p<0 .0 1) ,空白土壤、DDT0 .5 m g/kg、DDT1.5 m g/kg各处理间土壤的AWCD值达不到显著性差异的水平(p>0 .0 5 ) ,表层土壤的AWCD值要高于第2层土壤(p<0 .0 1)。从多样性指数的变化来看,当加入到土壤中的DDT和HCH含量稍低时,微生物会利用农药为碳源进行分解作用,从而刺激了微生物的生长,这时表现出丰富度、均匀性和多样性都呈增长趋势。但当农药的浓度进一步加大时,反而会抑制某些种的微生物生长,另外一些种则对加入到土壤中的农药有一定的耐受性,从而表现出群落的均匀性下降,而丰富度升高。在相同施用浓     

Environmental quality assessment of water body and surface sediment in the sea area of Jiaozhou Bay wetland

Based on the investigation data from 48 sampling stations in the sea area of Jiaozhou Bay wetland in 2009, and by using Nemerow index, eutrophication index (EI), and Hakanson potential ecological risk index, an assessment was conducted on the environmental quality of water body and surface sediment in the sea area. According to the assessment on the 16 indicators including pH, dissolved oxygen (DO), dissolved inorganic nitrogen (DIN), dissolved inorganic phosphorous (DIP), chemical oxygen demand (COD(Mn)), petroleum hydrocarbons, Cu, Zn, Pb, Cd, Hg, As, hexachlorocyolohexane (HCH), dichlorodiphenyltrichloroethane (DDT), coliform, and faecal coliform, the water quality was at moderate and serious pollution level in the tidal reach of Dagu River, at slight and moderate pollution level in the intertidal zone, and at slight pollution level in the shallow sea. The eutrophication level differed markedly with the regions, being very serious in the tidal reach of Dagu River (EI value 58.13-327.89), serious in the intertidal zone (EI value 1.34-19.96), and slight in the shallow sea (EI value 0.65-2.10). The surface sediments in the sea area were basically at slight pollution level. The sediment quality was at slight pollution level in the tidal reach of Dagu River, at slight and moderate pollution level in the intertidal zone, and at cleaner and slight pollution level in the shallow sea. The pollution parameter (C(f)(i)) and contamination index (Cd) of the heavy metals in the surface sediments were low, suggesting that the pollution degree was at a lower level. The Cu and Zn were the primary pollution factors in the sediments. The potential ecological risk parameter (E(r)(i)) and risk index (RI) of the heavy metals in the surface sediments were lower, indicating a slight ecological risk of heavy metals pollution.     

Elevated Concentrations of Pesticides and PCBs in Soils at the Southern Caspian Sea (Iran) are Related to Land Use

Soil contamination by organochlorine pesticides or PCBs is almost undocumented for Iran. Here we report a soil survey in Mazandaran and Guilan provinces that hold >30% of the agricultural areas of Iran where pesticide use is widespread. Concentration of DDTs, HCHs, cyclodienes, and PCBs were measured in 45 soil samples from different agricultural land uses and forest land. The average concentrations of ∑DDT (37 μg kg^?1) and ∑HCH (21 μg kg^?1) in agricultural soils are among the largest ever reported and exceed international soil screening standards. All residues were larger in agricultural than in forest soil. Within agricultural land, ∑DDT were largest for tea gardens, lindane was largest in rice fields, and cyclodiens largest in citrus orchards. The ratio of (DDD + DDE)/DDT is an index of the extent of DDT degradation in soil and was lower in tea gardens than in other soils (0.7 versus 2–5), indicating either ongoing DDT input or lower degradation rate in the tea gardens that are more acid than the other soils (pH 4.5 versus 6.5–7.0). The o,p′–DDT/p,p′–DDT ratio was about 3 in forest soils, suggesting that DDT is derived from dicofol application and not from technical DDT as in agricultural soils. The PCB 28, 180, and 138 showed the highest mean concentration compared with other PCB congeners in all land uses. This survey is the first of this kind for Iran and illustrates that concentrations of organochlorine pesticide in soil are relatively large.