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941.
The results are presented of a survey planned to assess the presence of high concern chemicals in sediments collected in a northern sector of the Adriatic sea neighboring the Venice lagoon. For the assessment, persistent marker chemicals were selected from the families of polycyclic aromatic hydrocarbons, polychlorobiphenyls, polychlorodibenzo-p-dioxins (PCDDs), polychlorodibenzofurans (PCDFs), and chlorinated pesticides. Based on the chemical-specific concentrations and PCDD+PCDF profiles determined in the sediments analyzed, dumping zones appear to have existed approximately 5-6km away from lagoon shoreline. Contamination levels exceed the quality criteria established by the pertinent Italian national regulation at many sampling sites, eventually reflecting ("fingerprinting") industrial activities once performed in the industrial settlement of Porto Marghera within the Venice lagoon. In coastal samples, concentration levels appear to be lower than those determined at offshore sampling sites.  相似文献   
942.
In this study the effects of nickel (NiCl2) administered in drinking water (0.02; 0.2 and 2.0 mg NiCl2/L for 28 days) on laying hen body weight, egg production and egg quality is reported. Growth parameters during the experiment were significantly decreased mainly in the group with the highest nickel concentration. In total egg production dose-dependent decrease in all experimental groups was found. Egg weight was mainly affected in the group with the highest nickel concentration. Specific egg weight was not altered. Albumen weight and albumen content was significantly decreased in groups with the highest nickel concentration in comparison with the control group. Egg yolk analysis detected significantly decreased yolk weight in the group with the highest nickel experimental level. In yolk color a significant difference was detected between the group receiving 0.02 and 0.2 mg NiCl2/mL. Eggshell compactness was increased in all experimental groups what could be induced by altered mineralization of eggshell. Results of this study clearly report a negative effect of nickel as an environmental pollutant on laying hen body weight, egg production as well as egg quality.  相似文献   
943.
Perus J  Bonsdorff E  Bäck S  Lax HG  Villnäs A  Westberg V 《Ambio》2007,36(2-3):250-256
A new method for classifying soft-bottom zoobenthic assemblages along the Finnish coasts (northern Baltic Sea) is presented and tested against traditional physicochemical monitoring data in the complex Archipelago Sea. Although multivariate methods for assessing the state of the marine environment have become widely used, few numerical indices can operate over a wide salinity range. We compare indices currently in use and propose a new index, BBI (brackish water benthic index), for the low-saline and species-poor Baltic coastal waters. BBI offers a salinity-corrected tool for classification of the soft-bottom zoobenthos under the demands of the European Union Water Framework Directive.  相似文献   
944.
Mussels have the ability to control biomineral production and chemical composition, producing shells with a range of functions. In addition to biological control, the environment also seems to influence the process of biomineralization; thus, shells can be used as archives of ambient water parameters during the calcium carbonate deposition. Past and present environmental conditions are recorded in the shells in the form of various proxies including Mg/Ca or Sr/Ca ratios. For such proxies to be accurate and robust, the influence of biological effects including the size of studied organism must be examined and eliminated or minimized, so that the environmental signal can be efficiently extracted. This study considers mineralogy and elemental composition of shells representing four size classes of Mytilus trossulus from the Baltic Sea. Obtained results suggest that mineralogy and chemical composition change throughout the shell development due to most likely a combination of environmental and biological factors. The content of aragonite increases with increasing shell size, while the bulk concentrations of Na, Cd, Cu, U, V, Zn and Pb were found to decrease with increasing height of the shells. Therefore, using mussels for environmental monitoring requires analysis of individuals in the same size range.  相似文献   
945.
Atmospheric aerosols can consist of, amongst others, compounds like NH(4)NO(3) or (NH(4))(2)SO(4). Such components can suffer radiation damage and/or evaporate during EDXRF measurements, providing errors on successively applied analysis. The aim of this work is to investigate the influence of measurements using conventional EDXRF on the volatile compounds and to compare it with the influence of polarized beam EDXRF using secondary targets (and hence indirect irradiation). The effect of different parameters (acquisition time, accelerating voltage, current and medium) on the concentration loss was studied. The measurements performed in vacuum during a long period lead to the highest losses of volatile compounds. The influence of direct irradiation was proved to be larger than the indirect variant.  相似文献   
946.
This paper illustrates a step-by-step approach for evaluating chemical monitoring data in air and deposition and for prioritizing chemicals to be included in long-term air monitoring programs. The usability of the method is shown by application to data generated within the Swedish screening program. The suggested prioritization approach uses a novel methodology by combining empirical data on occurrence in air and deposition with publicly available quantitative structure activity relationship estimation tools that predict atmospheric persistence and bioaccumulation. A selection tree is presented, which may be used by regulatory bodies to prioritize chemicals for long-term air monitoring. A final ranking list is presented proposing a prioritization order for inclusion in monitoring programs. Based on the suggested strategy, the chemicals identified as most relevant to include in Swedish long-term monitoring programs were short-chain chlorinated paraffins(C10-C13), perfluorooctane sulfonate, octachlorostyrene, hexabromocyclododecane, hexachlorobenzene, pentachloroanisole, decamethylcyclopentasiloxane, octamethylcyclotetrasiloxane, pentachlorobenzene, 1,2,3,4-tetrachlorobenzene, hexachlorobutadiene, dodecamethylcyclohexasiloxane, perfluorodecane sulfonate, 1,2,4,5-tetrachlorobenzene, and pentabromophenol.  相似文献   
947.
948.
A correct characterization of the status and trend of forest condition is essential to support reporting processes at national and international level. An international forest condition monitoring has been implemented in Europe since 1987 under the auspices of the International Co-operative Programme on Assessment and Monitoring of Air Pollution Effects on Forests (ICP Forests). The monitoring is based on harmonized methodologies, with individual countries being responsible for its implementation. Due to inconsistencies and problems in sampling design, however, the ICP Forests network is not able to produce reliable quantitative estimates of forest condition at European and sometimes at country level. This paper proposes (1) a set of requirements for status and change assessment and (2) a harmonized sampling strategy able to provide unbiased and consistent estimators of forest condition parameters and of their changes at both country and European level. Under the assumption that a common definition of forest holds among European countries, monitoring objectives, parameters of concern and accuracy indexes are stated. On the basis of fixed-area plot sampling performed independently in each country, an unbiased and consistent estimator of forest defoliation indexes is obtained at both country and European level, together with conservative estimators of their sampling variance and power in the detection of changes. The strategy adopts a probabilistic sampling scheme based on fixed-area plots selected by means of systematic or stratified schemes. Operative guidelines for its application are provided.  相似文献   
949.
Amphipod crustaceans belong to the most successful invaders of aquatic environments. The work provides information concerning the spatial and temporal scales of expansion of four alien gammarid amphipods (three of them of Ponto-Caspian and one of North American origin): Pontogammarus robustoides (G.O. Sars, 1894), Obesogammarus crassus (G.O. Sars, 1894), Dikerogammarus haemobaphes (Eichwald, 1841), and Gammarus tigrinus Sexton, 1939 in the Vistula Lagoon (VL) and the Vistula Delta (VD) in 2008–2010. The mean abundance of these gammarids in nearshore zones was 382 ind?m?2 in VL and 89 ind?m?2 in VD. Their mean biomasses were likewise greater in VL (0.91 g?m?2) than in VD (0.49 g?m?2). G. tigrinus was the most dominant species in both nearshore zones of VL and VD and attained the highest frequency in these areas. The study gives evidence of total extinction of native gammarid species.  相似文献   
950.
This paper explores whether ambitions to open up the traditional Swedish model of top-down conservation methods to local influences are indicative of an actual transition in governance of Swedish national park policy (NPP), and examines whether such a shift entails an increase in local influence over local interests and needs. Methodologically, we analyse a combination of governance types and incorporate theoretical definitions of power and accountability. The establishment of new governance arrangements – where power is shared, interactions promoted and accountability is directed downwards – indicates that Sweden's NPP is undergoing a change in its mode of governance. This change also seems to include ceding some influence to local interests, and the possibility of combining conservation with the utilisation of certain natural resources. The results of our research also provide valuable insights into when the establishment of shared-governance arrangements are likely to succeed; in short, this seems more likely when there are established sectors sited in a robust legal framework and where strong international commitments potentially play a role. In conclusion, we contend that when seeking diversified governance arrangements it is not enough simply to take local practices and customs into consideration – they have to be strengthened.  相似文献   
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