排序方式： 共有6条查询结果，搜索用时 15 毫秒
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Norihiro Kobayashi Tomomi Eriguchi Kisaburo Nakata Shigeki Masunaga Fumio Horiguchi Junko Nakanishi 《Estuarine, Coastal and Shelf Science》2006,70(4):621
A 3-D chemical fate prediction model (FATE3D) was applied to predict the dioxin concentrations in the seawater of Tokyo Bay, Japan. The simulations were carried out for a period of one year (from September 2002 to August 2003). Parameters such as meteorological data, flow field conditions, concentrations and sinking rates of organic particulate matter, initial and boundary conditions, and loading fluxes and physico-chemical properties of dioxins were used as the model inputs.The simulation results compared favorably with the field measurements of dioxin concentrations in the bay for both the particulate and dissolved phases, indicating the validity and predictive capability of the model. Furthermore, the differences in the seasonal cycles and distributions between the particulate- and dissolved-phase dioxins in the bay were estimated from the simulation results.However, the particulate-phase dioxin concentrations in the bottom layers (+1 m from the bottom) were underestimated, probably because the resuspension process was not taken into account in the model. The improvement of the model's predictive capability, including the resuspension process, shall be the focus of our next study. 相似文献
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Russell Fairey Karen Taberski Stewart Lamerdin Eric Johnson Ross P. Clark James W. Downing John Newman Myrto Petreas 《Marine pollution bulletin》1997,34(12):1058-1071
Edible fish species were collected from 13 locations throughout San Francisco Bay, during the spring of 1994, for determination of contaminant levels in muscle tissue. Species collected included white croaker, surfperch, leopard and brown smoothhound sharks, striped bass, white sturgeon and halibut. 66 composite tissue samples were analysed for the presence of polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (P0CBs), pesticides, trace elements and dioxin/furans. The US EPA approach to assessing chemical contaminant data for fish tissue consumption was used for identifying the primary chemicals of concern. Six chemicals or chemical groups were found to exceed screening values (SVs) established using the US EPA approach. PCBs (as total Aroclors) exceeded the screening level of 3 ng g−1 in all 66 muscle tissue samples, with the greatest concentrations (638 ng g−1) found near San Francisco's industrial areas. Mercury was elevated (> 0.14 μg g−1) in 40 of 66 samples with the greatest concentrations (1.26 μg g−1) occurring in shark muscle tissues. Concentrations of the organochlorine pesticides dieldrin, total chlordane and total dichlorodiphenyltri-chloroethane (DDT) exceeded screening levels in a number of samples. Dioxin/furans (as toxic equivalent concentrations (TEQ's)) were elevated (> 0.15 pg g−1) in 16 of the 19 samples analysed. Fish with high lipid content (croaker and surfperch) in their muscle tissue generally exhibited higher organic contaminant levels while fish with low lipid levels (halibut and shark) exhibited lower organic contaminant levels. Tissue samples taken from North Bay stations most often exhibited high levels of chemical contamination. The California Office of Health Hazard Assessment is currently evaluating the results of this study and has issued an interim Health Advisory concerning the human consumption of fish tissue from San Francisco Bay. 相似文献
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Sampling and prediction strategies relevant at the planning stage of the cleanup of environmental hazards are discussed. Sampling designs and models are compared using an extensive set of data on dioxin contamination at Piazza Road, Missouri. To meet the assumptions of the statistical model, such data are often transformed by taking logarithms. Predicted values may be required on the untransformed scale, however, and several predictors are also compared. Fairly small designs turn out to be sufficient for model fitting and for predicting. For fitting, taking replicates ensures a positive measurement error variance and smooths the predictor. This is strongly advised for standard predictors. Alternatively, we propose a predictor linear in the untransformed data, with coefficients derived from a model fitted to the logarithms of the data. It performs well on the Piazza Road data, even with no replication. 相似文献
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O. Magnus Karlsson J. Mikael Malmaeus Sarah Josefsson Karin Wiberg Lars Håkanson 《Estuarine, Coastal and Shelf Science》2010
A dynamical, process-based mass-balance model was applied to quantify the transports of polychlorinated-p-dibenzodioxins and dibenzofurans (PCDD/Fs) to, within and from the Kallrigafjärden Bay, a coastal estuary in the Baltic Sea, and to predict the PCDD/F levels in the water and sediments of the bay. Before the modelling, a one-year sampling programme was implemented in 2007–2008 to measure the flows of PCDD/Fs in tributaries entering the system, the fluxes from the adjacent sea and the levels in water, sediment and fish within the estuary. The collected data set was used as input data to the model and for validation purposes. 相似文献
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环境污染物二噁英中毒性最强的2，3，7，8-四氯二苯并对二噁英(2，3，7，8-tetrachlorodibenzo-p-dioxin，以下简称TCDD)经由芳烃基受体(aryl hydrocarbon receptor，Ahr)引起啮齿类口唇开裂，斑马鱼下颌短小等典型特征，本试验研究了TCDD引起的下颌短小与形态发育基因Sonic hedgehog(shh)的关系，用0-1．0μg／L的TCDD给受精后24h(24hpf)的斑马鱼胚染毒直至观察并进行形态学观察及原位杂交，结果观察到TCDD引起斑马鱼的下颌短小与其浓度相依存．同时观察到TCDD染毒群的Shh基因表达以及类似基因tiggy-winkle hedgehog(twhh)的低下．观察Shh缺失的斑马鱼变异体Syu，或给正常斑马鱼染毒，添加Shh阻断药Cycopamant Cyclopamine，可以同样观察到斑马鱼的下颌短小，本试验表明TCDD引起的下颌短小与shh和twhh表达是相关联的．同时也说明斑马鱼有可能作为二噁英类污染物的生物学毒性评价生物。 相似文献
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三峡库区是我国值得高度关注的生态及人群健康风险区域.二噁英是典型的持久性有机污染物.本文阐述了三峡库区水环境中二噁英的污染状况,并介绍了三峡库区人群健康危害研究,最后提出预防解决措施. 相似文献
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