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Heli Routti Bert van Bavel Robert J. Letcher Augustine Arukwe Shaogang Chu Geir W. Gabrielsen 《Environmental pollution (Barking, Essex : 1987)》2009,157(8-9):2428-2434
The present study investigates the concentrations and patterns of organochlorine pesticides (OCPs) and their metabolites in liver and plasma of two ringed seal populations (Phoca hispida): lower contaminated Svalbard population and more contaminated Baltic Sea population. Among OCPs, p,p′-DDE and sum-chlordanes were the highest in concentration. With increasing hepatic contaminant concentrations and activities of xenobiotic-metabolizing enzymes, the concentrations of 3-methylsulfonyl-p,p′-DDE and the concentration ratios of pentachlorophenol/hexachlorobenzene increased, and the toxaphene pattern shifted more towards persistent Parlar-26 and -50 and less towards more biodegradable Parlar-44. Relative concentrations of the chlordane metabolites, oxychlordane and -heptachlorepoxide, to sum-chlordanes were higher in the seals from Svalbard compared to the seals from the Baltic, while the trend was opposite for cis- and trans-nonachlor. The observed differences in the OCP patterns in the seals from the two populations are probably related to the catalytic activity of xenobiotic-metabolizing enzymes, and also to differences in dietary exposure. 相似文献
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物种敏感性分布法(SSD,Species Sensitivity Distribution)是一种相对于传统评价因子法具有更高置信度的统计学外推方法,在环境质量基准制定及生态风险评价中得到广泛应用。本文对近年来国内外重金属和有机污染物的物种敏感性分布研究成果进行了综述,阐述了在水体、土壤和沉积物等环境介质中应用SSD方法开展生态风险评价的研究现状,从SSD模型选择、毒性数据点筛选等方面对影响SSD模型不确定性的因素进行探讨,并对SSD方法在生态风险评价领域的应用进行了展望。 相似文献
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水中的溴离子(Br-)和溴酸根离子(BrO3-)由于难挥发、易溶解、稳定性好而难以除去,因此,制备了一种对较低浓度的Br-和BrO3-都有良好吸附去除效果的季铵碱树脂(Quaternary ammonium base resin,QABR)并表征了其物化结构.同时,考察了初始浓度、QABR投加量、溶液pH、离子强度、吸附接触时间和吸附温度等因素对QABR吸附Br-和BrO3-性能的影响.结果表明,在0.05~4.00 mmol·L-1浓度范围内,在298 K、pH=7.0时QABR对Br-和BrO3-的吸附能力最佳,其最大吸附量分别为1.78 mmol·g-1和1.65 mmol·g-1;QABR对Br-和BrO3 相似文献
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洛阳盆地浅层地下水化学特征及其演化特征分析 总被引:2,自引:0,他引:2
在系统采集并分析洛阳盆地浅层地下水样品的基础上,综合描述性统计、相关性分析、运用Piper三线图、Gibbs模型以及离子比例系数等方法,对洛阳盆地浅层地下水化学特征及其形成机理进行了分析和探讨。结果表明:HCO~-_3和Ca~(2+)分别是研究区浅层地下水中优势的阴、阳离子;HCO_3-Ca和HCO_3-Ca·Mg型为主要地下水化学类型;浅层地下水TDS和总硬度的平均浓度相对较低,平均值分别为450.5 mg/L和329.3 mg/L。本区浅层地下水化学特征的形成主要受到岩石风化作用的影响,地下水水质成分主要来自于碳酸盐岩和硅酸盐岩等矿物的长期风化溶解。同时,逆向阳离子交换作用也在一定程度上影响着浅层地下水化学的形成。 相似文献
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For the system of water samples collected from Yangtze River,the effects of seasonal variation and Fe(III) concentrations on the formation and distribution of trihalomethanes (THMs) during chlorination have been investigated.The corresponding lifetime cancer risk of the formed THMs to human beings was estimated using the parameters and procedure issued by the US EPA.The results indicated that the average concentration of THMs (100.81 μg/L) in spring was significantly higher than that in other seasons,which ... 相似文献
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Chu S Covaci A Van de Vijver K De Coen W Blust R Schepens P 《Journal of environmental monitoring : JEM》2003,5(3):521-526
The enantiomeric composition of polychlorinated biphenyl (PCB) atropisomers, including PCB 95, PCB 149 and PCB 132, was measured in 11 livers of harbour porpoises (Phocoena phocoena) from the southern North Sea. Non-racemic enantiomeric ratios (ERs) were found in some samples. The value of ERs in three of the four juvenile porpoises was equal or almost equal to one, while the ERs in all adults differed from racemic and ranged from 1.31 to 2.54 for PCB 95; from 1.19 to 1.81 for PCB 149 and from 0.45 to 0.94 for PCB 132. There were no relationships between the total concentration of PCBs and ERs. To understand the phenomena, the relationships between the ER value of individual chiral congener with age, concentration of total PCBs and PCB congener pattern were discussed. A model of intake and elimination kinetics was set up and it was tested using the ratio between concentration of PCB 153 and PCB 101 in the liver samples. There was a clear trend between the enantiomeric ratios and the ratio between PCB 153 and PCB 101. Considering that PCB 153 is one of the most persistent PCB congeners in marine mammals and PCB 101 is a relatively easy metabolised congener, this trend means that the enantiomeric ratio most likely reflects the proportion of the metabolised congener. The exposure period in contaminated conditions has a strong impact on ERs, and it is suggested that ERs in wildlife, combined with information on their anthropometric data, health status, diet and habitat conditions, might be good indicators of pollution in coastal ecosystems. 相似文献
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The concentration and distribution of nonylphenol polyethoxylates (NPEOs represents the mixture, and NPnEO represents the monomer) and its metabolites in the influent and effluent of four municipal sewage treatment plants (STPs) in the north of China were measured. Moreover, the concentration and distribution of the above chemicals in the sludge of two STPs were also determined, and the transfer and fate of NPEOs in the sewage treatment process were discussed primarily by analyzing the distribution of the products in the effluent and the sludge. The results showed that NPEOs and its metabolites existed in all the samples of the influent, effluent, and sludge. NPEOs were degraded in the sewage treatment process with the removal efficiency in the range of 23.38%–77.11%, or an average of 52.86%. However, the large analogs of NPnEO were only degraded to small ones, whose degradation rate was rather slow, and consequently the degradation was not complete. Hence, the concentrations of some small metabolites, such as nonylphenol (NP), nonylphenol monoethoxylate (NP1EO), and nonylphenol diethoxylate (NP2EO) were elevated in the effluent. These small metabolites are more toxic than the large NPnEO analogs, and some of them were reported to exhibit environmental endocrine disrupting activity. From this point of view, the process of sewage treatment does not reduce but elevate the risk of NPEOs, which becomes the main source of these small NPnEO in the environment. The sludge exhibited good adsorption ability for NPEOs, especially for the small analogs, which led to the high level of NPEOs in the sludge. Hence, reasonable disposal of the surplus sludge to avoid re-pollution is very important. 相似文献