Concentrations of PAHs (polycyclic aromatic hydrocarbons) in various marine organisms in relation to those in sediments and to trophic level   总被引：4，自引：0，他引：4  

P. Baumard  H. Budzinski  P. Garrigues  J. C. Sorbe  T. Burgeot  J. Bellocq 《Marine pollution bulletin》1998,36(12):951-960

Sediments and marine organisms such as mussels (Mytilus galloprovincialis), fish (Mullus barbatus, Serranus scriba), crabs (Polybius henslowi) and shrimp-like crustaceans (mysids, euphausiids) were sampled on European coasts, France, Spain) and analysed for their PAH content by gas chromatography/mass spectrometry (GC-MS). The PAH concentrations determined in the organisms were significantly negatively correlated with logK_ow values, but to different extents according to the species. This was explained by the greater exposure of the organisms to the lower molecular weight compounds with differences resulting from different feeding habits, habitat, and biotransformation capacities of the organisms in relation to trophic levels. The influence of these observations on the use of different sentinel species in biomonitoring programmes is discussed.  相似文献   

风暴潮灾害情景下海岸带暴露指数时空演变研究——以福建省东山湾为例          下载免费PDF全文

王超  黄发明  陈华香  殷飞笺  施荣灿  杨黎静 《海洋科学》2023,47(11):12-23

暴露指数反映了环境在面对极端天气事件时承受灾害的潜在风险程度。研究利用遥感影像数据、数字高程数据(DEM)、海洋水深及风力数据等, 基于暴露指数模型, 以福建省东山湾为案例研究区域, 对风暴潮灾害情景下的海岸带暴露指数及其时空演变进行分析。研究结果显示: (1)近十年来, 东山湾海岸带暴露指数总体呈下降趋势, 潜在风险程度为“中”及以上区域占比由67.14%下降至59.06%, 海岸带在面对风暴潮灾害等极端天气事件时潜在的风险程度总体降低, 海湾地貌类型差异及其形态变化是影响东山湾暴露指数产生波动的主要原因; (2)基于暴露指数评价结果, 结合海岸带开发利用现状, 研究可对东山湾海岸带生态环境的敏感区域进行识别, 并制定具有针对性的开发利用与风险防范对策, 为海岸带空间规划、生态保护修复格局的科学划定提供理论支撑, 在助力海岸带陆海统筹和可持续发展上具有重要意义; (3)研究提出的一种基于时间序列的暴露指数研究技术路线和框架, 可为海岸带脆弱性评估、海岸带韧性评估、海岸带灾害监测预警等相关研究提供新的研究视角, 在基于深度学习的海岸带灾害风险预警与灾害模拟等方面也具有较为广阔的应用前景。  相似文献   

Minimum Bedrock Exposure Ages and Their Implications: Larsemann Hills and Neighboring Bolingen Islands, East Antarctica     

HUANG Feixin  LI Guangwei  LIU Xiaohan  KONG Ping  JU Yitai  David FINK  FANG Aimin  YU Liangjun 《《地质学报》英文版》2010,84(3):543-548

<正>Considerable controversy exists over whether or not extensive glaciation occurred during the global Last Glacial Maximum(LGM) in the Larsemann Hills.In this study we use the in situ produced cosmogenic nuclide ~(10)Be(half life 1.51 Ma) to provide minimum exposure ages for six bedrock samples and one erratic boulder in order to determine the last period of deglaciation in the Larsemann Hills and on the neighboring Bolingen Islands.Three bedrock samples taken from Friendship Mountain(the highest peak on the Mirror Peninsula,Larsemann Hills;～2 km from the ice sheet) have minimum exposure ages ranging from 40.0 to 44.7 ka.The erratic boulder from Peak 106(just at the edge of the ice sheet) has a younger minimum exposure age of only 8.8 ka.The minimum exposure ages for two bedrock samples from Blundell Peak(the highest peak on Stornes Peninsula,Larsemann Hills;～2 km from the ice sheet) are about 17 and 18 ka.On the Bolingen Islands(southwest to the Larsemann Hills;～10 km from the ice sheet),the minimum exposure age for one bedrock sample is similar to that at Friendship Mountain(i.e.,44 ka).Our results indicate that the bedrock exposure in the Larsemann Hills and on the neighboring Bolingen Islands commenced obviously before the global LGM(i.e.,20-22 ka),and the bedrock erosion rates at the Antarctic coast areas may be obviously higher than in the interior land.  相似文献   

X射线荧光光谱法测定地质样品中的氯     

杜淑兰 《吉林地质》2010,29(4):106-107,119

使用粉末压片法制样,X射线荧光光谱法测定地质样品中氯,探讨了样片背衬、样片接受X光照射时间对测量结果的影响。Cl的精密度(RSD,n=12)小于10%。Cl的方法检出限为12μg/g,采用国家一级标准物质分析验证方法,其结果与标准值相符。  相似文献   

Moraine chronosequence of the Donnelly Dome region, Alaska     

A. Matmon  J.P. Briner  P. Bierman 《Quaternary Research》2010,74(1):63-47

We present ¹⁰Be exposure ages from moraines in the Delta River Valley, a reference locality for Pleistocene glaciation in the northern Alaska Range. The ages are from material deposited during the Delta and Donnelly glaciations, which have been correlated with MIS 6 and 2, respectively. ¹⁰Be chronology indicates that at least part of the Delta moraine stabilized during MIS 4/3, and that the Donnelly moraine stabilized ∼ 17 ka. These ages correlate with other dates from the Alaska Range and other regions in Alaska, suggesting synchronicity across Beringia during pulses of late Pleistocene glaciation. Several sample types were collected: boulders, single clasts, and gravel samples (amalgamated small clasts) from around boulders as well as from surfaces devoid of boulders. Comparing ¹⁰Be ages of these sample types reveals the influence of pre/post-depositional processes, including boulder erosion, boulder exhumation, and moraine surface lowering. These processes occur continuously but seem to accelerate during and immediately after successive glacial episodes. The result is a multi-peak age distribution indicating that once a moraine persists through subsequent glaciations the chronological significance of cosmogenic ages derived from samples collected on that moraine diminishes significantly. The absence of Holocene ages implies relatively minor exhumation and/or weathering since 12 ka.  相似文献   

Computing least air pollution exposure routes     

Monir H. Sharker 《International journal of geographical information science》2014,28(2):343-362

Personalized routing counts on traveler’s preferences which are usually based on different criteria, such as shortest, fastest, least traffic, or less expensive (e.g., less fuel cost, toll free). However, people are increasingly becoming concerned about the adverse health effects of exposure to air pollution in chosen routes. Exposures to elevated air pollution concentrations particularly endanger children, pregnant women, elderly people, and people with asthma and other respiratory conditions. Choosing routes with least air pollution exposure (APE) is seen as one approach to minimize the level of pollution exposed, which is a major public health issue. Routing algorithms use weights on segments of road networks to find optimum routes. While existing weights are commonly distance and time, among a few others, there is currently no weight based on APE to compute least APE routes. In this paper, we present a weight function that computes weight based on APE. Two different approaches, geostatistical and non-geostatistical, were used to compute APE weight. Each approach was evaluated, and the results indicate that the APE weight is suitable for computing least APE routes.  相似文献   

Health risk assessment for typical and abandoned chromium-contaminated sites     

Hongyan Deng  Gangcai Chen 《中国地球化学学报》2014,33(4):382-386

Chromium pollution were investigated by sampling the abandoned chromium contaminated sites in Chongqing. Its health risk was assessed following the procedures made by USEPA. The results showed that the most seriously polluted land was found at the former production area （G4） with average Cr（VI） concentration of 3369.2 mg kg-1 on the surface soil. The assessment indicated that there was high risk of non-carcinogens for children. The assessed risk of the first layer of office area （G1） for children, chromium slag transition （G2）, drainage pipeline chromium slag transition （G3） and production area （G4） for both children and adults were not acceptable （〉1.00× 106）. It was strongly suggested that the accessible measures of remediation should be taken for a portion of contaminated sites before the reuse of abandoned lands.  相似文献   

Stone run (block stream) formation in the Falkland Islands over several cold stages,deduced from cosmogenic isotope (10Be and 26Al) surface exposure dating     

Peter Wilson  Michael J. Bentley  Christoph Schnabel  Richard Clark  Sheng Xu 《第四纪科学杂志》2008,23(5):461-473

Cosmogenic isotope (¹⁰Be and ²⁶Al) surface exposure dating has been applied to valley‐axis and hillslope stone runs (relict periglacial block streams) and their source outcrops in the Falkland Islands, South Atlantic. The data indicate that stone runs are considerably older landforms than previously envisaged and afford no evidence that they are a product of the Last Glacial Maximum; the samples range in apparent ¹⁰Be age from 42k to 731k yr BP, but some of these are minima. The results indicate that valley‐axis stone runs may be up to 700–800k yr old, have simple exposure histories and are composite landforms that developed over several cold stages. Analyses of some hillslope and outcrop samples also demonstrate simple exposure histories with ¹⁰Be ages from 42k to 658k yr BP. In contrast, isotopic ratios from other hillslope and outcrop samples reveal they have had a complex exposure history involving periods of burial or shielding; the samples range in ¹⁰Be age from 59k to 569k yr BP and these are regarded as minimum age estimates. Larger stone runs may be older than smaller runs and there is a possibility that stone runs older than 800k yr exist in other parts of the Falklands. The assertion that glaciation in the Falklands was restricted to the highest uplands is supported by the data, and the potential for age determination of other boulder‐strewn and bedrock landforms, using cosmogenic isotope analysis, in order to extend the geochronology of Quaternary events and processes is noted. Copyright © 2008 John Wiley & Sons, Ltd.  相似文献   

A 10Be production‐rate calibration for the Arctic     

NICOLÁs E. YOUNG  JOERG M. SCHAEFER  JASON P. BRINER  BRENT M. GOEHRING 《第四纪科学杂志》2013,28(5):515-526

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Converting Brazil's pastures to cropland: An alternative way to meet sugarcane demand and to spare forestlands     

《Applied geography (Sevenoaks, England)》2015

Brazil seeks to rapidly increase its agricultural production to meet future demands, especially for sugarcane, which is an agricultural commodity and a biofuel source. In this paper, we explore how to achieve this increase without compromising existing forestlands. We propose that it is possible to substantially expand sugarcane production in Brazil while avoiding further environmental losses and the indirect land use changes often associated with them, such as deforestation. This task could be accomplished by converting existing pasturelands with agricultural potential into cropland. A great deal of pastureland exists in Brazil. Thus, we addressed the following questions in this study: (1) where are the most suitable pasturelands for sugarcane located geographically and (2) what potential do these pasturelands have for sugarcane production regarding their physical suitability and other significant factors, such as infrastructure availability and socioeconomic factors. We conducted a land suitability analysis using a spatial location model based on multicriteria decision-making and geographic information systems (GIS) to identify the cultivated pasturelands most suitable for conversion to sugarcane production in Brazil. “What if” scenarios were built to determine how changes in the subjectively derived weights of the priority criteria would modify the spatial distribution of the suitability classes relative to the MCDA model and demonstrate the robustness of the crop suitability assessment. The most suitable pastureland areas for conversion to sugarcane production were predominantly located in Minas Gerais, São Paulo, Paraná, Goiás, Mato Grosso do Sul, Mato Grosso and Pará. These zones have large contiguous areas of pasture with moderate and high agricultural potentials for sugarcane production. The total estimated area of cultivated pasturelands with moderate or high suitability for sugarcane production was 50 million hectares, which is much larger than the area currently used for sugarcane production in Brazil.  相似文献