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31.
Dewatered municipal biosolids (DMBs) were applied to a field at a rate of ~22 Mg dw ha(-1) in October 2008. Pharmaceuticals and personal care products (PPCPs) were monitored in groundwater, tile drainage, soil, DMB aggregates incorporated into the soil post-land application, and in the grain of wheat grown on the field for a period of ~1 year following application. Over 80 PPCPs were analyzed in the source DMB. PPCPs selected for in-depth monitoring included: antibiotics (tetracyclines, fluoroquinolones), bacteriocides (triclosan, triclocarban), beta-blockers (atenolol, propranolol, metaprolol), antidepressants (fluoxetine, citalopram, venlafaxine, sertraline), antifungals (miconazole), analgesics (acetaminophen, ibuprofen) and anticonvulsants (carbamazepine). PPCPs in tile were observed twice, ~3 weeks and 2 months post-application. Of all PPCPs measured in tile drainage, only carbamazepine, ibuprofen, acetaminophen, triclosan, triclocarban, venlafaxine, and citalopram were detected (5-74 ng L(-1)). PPCPs were not detected in groundwater >2 m depth below the soil surface, and concentrations above detection limits at 2 m depth were only observed once just after the first rain event post-application. In groundwater, all compounds found in tile, except carbamazepine, acetaminophen and citalopram, were detected (10-19 ng L(-1)). PPCPs were detected in DMB aggregates incorporated in soil up to 1 year post-application, with miconazole and fluoxetine having the lowest percent reductions over 1 year (~50%). For several compounds in these aggregates, concentration declines were of exponential decay form. No PPCPs were detected in the grain of wheat planted post-application on the field. No PPCPs were ever detected in water, soil or grain samples from the reference plot, where no DMB was applied.  相似文献   
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A small population of endangered northern bottlenose whales (Hyperoodon ampullatus) inhabits "The Gully" a Marine Protected Area on the Scotian Shelf, eastern Canada. Amid concerns regarding nearby oil and gas development, we took 36 skin and blubber biopsy samples in 1996-1997 (prior to major development) and 2002-2003 (five years after development began), and three samples from a population in the Davis Strait, Labrador in 2003. These were analysed for cytochrome P4501A1 (CYP1A1) protein expression (n=36), and for persistent contaminants (n=23). CYP1A1 showed generally low expression in whales from The Gully, but higher levels during 2003, potentially coincident with recorded oil spills, and higher levels in Davis Strait whales. A range of PCB congeners and organochlorine compounds were detected, with concentrations similar to other North Atlantic odontocetes. Concentrations were higher in whales from The Gully than from the Davis Strait, with significant increases in 4,4'-DDE and trans-nonachlor in 2002-2003 relative to 1996-1997.  相似文献   
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The geological storage of carbon dioxide is currently being considered as a possible technology for reducing emissions to atmosphere. Although there are several operational sites where carbon dioxide is stored in this way, methods for assessing the long-term performance and safety of geological storage are at an early stage of development. In this paper the similarities and differences between this field and the geological disposal of radioactive wastes are considered. Priorities are suggested for the development of performance assessment methods for carbon dioxide storage based on areas where experience from radioactive waste disposal can be usefully applied. These include, inter alia, dealing with the various types of uncertainty, using systematic methodologies to ensure an auditable and transparent assessment process, developing whole system models and gaining confidence to model the long-term system evolution by considering information from natural systems. An important area of data shortage remains the potential impacts on humans and ecosystems.  相似文献   
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The joint toxicity of mixtures of phosphamidon and methidathion to adult lobsters (Homarusamericanus) is greater than additive in tests with the combined 48-h toxicity unit of the mixtures totalling 0.25, 0.5 and 1.0 units. The largest magnification factor for greater than additive toxicity occurred where phosphamidon and methidathion contributed to the total toxicity unit in a ratio of 1:1.5 and was progressively smaller for ratios of 1:4.4 and 2:1.  相似文献   
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Estimates of soil N2O and NOemissions at regional and country scales arehighly uncertain, because the most widely usedmethodologies are based on few data, they do notinclude all sources and do not account forspatial and seasonal variability. To improveunderstanding of the spatial distribution of soilNO and N2O emissions we have developedsimple multi-linear regression models based onpublished field studies from temperate climates.The models were applied to create spatialinventories at the 5 km2 scale of soil NOand N2O emissions for Great Britain. The N2O regression model described soilN2O emissions as a function of soil N input,soil water content, soil temperature and land useand provided an annual N2O emission of 128 kt N2O-N yr-1. Emission rates largerthan 12 kg N2O-N ha-1 yr-1 werecalculated for the high rainfall grassland areasin the west of Great Britain.Soil NO emissions were calculated using tworegression models, which described NO emissionsas a function of soil N input with and without afunction for the water filled pore space. Thetotal annual emissions from both methods, 66 and7 kt NO-N yr-1, respectively, span the rangeof previous estimates for Great Britain.  相似文献   
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Cameron TC  Metcalfe D  Beckerman AP  Sait SM 《Ecology》2007,88(5):1225-1231
Many natural enemies do not immediately kill their host, and the lag this creates between attack and host death results in mixed populations of uninfected and infected hosts. Both competition and parasitism are known to be major structuring forces in ecological communities; however, surprisingly little is known about how the competitive nature of infected hosts could affect the survival and dynamics of remaining uninfected host populations. Using a laboratory system comprising the Indian meal moth, Plodia interpunctella, and a solitary koinobiont parasitoid, Venturia canescens, we address this question by conducting replicated competition experiments between the unparasitized and parasitized classes of host larvae. For varying proportions of parasitized host larvae and competitor densities, we consider the effects of competition within (intraclass) and between (interclass) unparasitized and parasitized larvae on the survival, development time, and size of adult moths and parasitoid wasps. The greatest effects were on survival: increased competitor densities reduced survival of both parasitized and unparasitized larvae. However, unparasitized larvae survival, but not parasitized larvae survival, was reduced by increasing interclass competition. To our knowledge, this is the first experimental demonstration of the competitive superiority of parasitized over unparasitized hosts for limiting resources. We discuss possible mechanisms for this phenomenon, why it may have evolved, and its possible influence on the stability of host-parasite dynamics.  相似文献   
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2015年国庆期间我国城市空气污染特征及成因分析   总被引:1,自引:0,他引:1       下载免费PDF全文
本文基于我国31个省会城市283个环境监测站的实时观测数据,分析了2015年国庆期间我国城市空气污染特征,并结合MODIS/Terra数据、欧洲中期天气预报中心(ECMWF)气压场及风场数据对其成因进行了讨论。结果表明:本次区域性空气污染最先出现在华中和华东地区,但是在华北地区最为严重。不同城市的主要污染物具有显著的时空差异。除西安和乌鲁木齐以外,其他城市的颗粒物污染主要由细颗粒物主导。NO_2、CO和SO_2的变化趋势基本一致,而O_3仅在北京、天津和济南三个城市与其他污染气体同步变化;在其他城市则与NO_2和CO等呈现相反的变化趋势。由卫星影像、天气形势和风场变化分析得知:不考虑本地背景排放源的前提下,本次污染事件主要由我国秋季的秸秆燃烧和不利的气象条件共同作用造成的。  相似文献   
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