خيارات البحث
النتائج 51 - 60 من 3,208
Emerging issue of e-waste in Pakistan: A review of status, research needs and data gaps النص الكامل
2015
Iqbal, Mehreen | Breivik, Knut | Syed, Jabir Hussain | Malik, Riffat Naseem | Li, Jun | Zhang, Gan | Jones, Kevin C.
This review article focuses on the current situation of e-waste in Pakistan with the emphasis on defining the major e-waste recycling sites, current and future domestic generation of e-waste, hidden flows or import of e-waste and discusses various challenges for e-waste management. Needed policy interventions and possible measures to be taken at governmental level are discussed to avoid the increasing problem of e-waste in the country. Our findings highlight that there is still a general lack of reliable data, inventories and research studies addressing e-waste related issues in the context of environmental and human health in Pakistan. There is therefore a critical need to improve the current knowledge base, which should build upon the research experience from other countries which have experienced similar situations in the past. Further research into these issues in Pakistan is considered vital to help inform future policies/control strategies as already successfully implemented in other countries. | acceptedVersion
اظهر المزيد [+] اقل [-]Synthèse des connaissances sur le transfert des pesticides vers l’atmosphère par volatilisation depuis les plantes النص الكامل
2015
Lichiheb, Nebila | Bedos, Carole | Personne, Erwan | Barriuso, Enrique
Les niveaux de concentration des pesticides dans l’atmosphère méritent une attention particulière de la part de la recherche compte tenu de leurs impacts potentiels sur la population et les écosystèmes. L’activité agricole constitue la principale source de contamination de l’atmosphère par les pesticides. Bien que la volatilisation depuis la plante soit reconnue plus intense et plus rapide que la volatilisation depuis le sol, cette voie de transfert est à ce jour la moins bien renseignée avec peu de modèles disponibles pour sa description. Le manque de connaissances est lié essentiellement à la complexité des interactions entre les processus ayant lieu à la surface de la feuille et qui sont en compétition avec la volatilisation, notamment la pénétration foliaire et la photodégradation. Cet article présente une synthèse bibliographique sur l’état des lieux des connaissances sur le processus de volatilisation des pesticides depuis un couvert végétal, de la pénétration foliaire et de la photodégradation, ainsi que les facteurs de contrôle de ces processus. Les méthodes de mesure ainsi que les modèles existants décrivant ces processus sont également présentés et analysés | The agricultural activity presents the main source of the atmospheric contamination by pesticides. The occurrence of pesticides in the atmosphere concerns the research community due to their potential impacts on population and ecosystems. The volatilization from plants is higher and faster than the volatilization from soil. However, this transfer pathway is difficult to assess with few available models. The lack of knowledge on pesticide volatilization from plants is essentially linked to the complex interactions between processes occurring at the leaf surface and competing with volatilization, such as leaf penetration and photodegradation. This article presents a bibliographic synthesis of the state of knowledge on pesticide volatilization from plants, leaf penetration, photodegradation and control factors of these processes. Measuring methods and existing models describing these processes are also presented and analyzed
اظهر المزيد [+] اقل [-]Synthèse des connaissances sur le transfert des pesticides vers l’atmosphère par volatilisation depuis les plantes النص الكامل
2015
Lichiheb, Nebila | Bedos, Carole | Personne, Erwan | Barriuso, Enrique | Ecologie fonctionnelle et écotoxicologie des agroécosystèmes (ECOSYS) ; Institut National de la Recherche Agronomique (INRA)-AgroParisTech
The agricultural activity presents the main source of the atmospheric contamination by pesticides. The occurrence of pesticides in the atmosphere concerns the research community due to their potential impacts on population and ecosystems. The volatilization from plants is higher and faster than the volatilization from soil. However, this transfer pathway is difficult to assess with few available models. The lack of knowledge on pesticide volatilization from plants is essentially linked to the complex interactions between processes occurring at the leaf surface and competing with volatilization, such as leaf penetration and photodegradation. This article presents a bibliographic synthesis of the state of knowledge on pesticide volatilization from plants, leaf penetration, photodegradation and control factors of these processes. Measuring methods and existing models describing these processes are also presented and analyzed | Les niveaux de concentration des pesticides dans l’atmosphère méritent une attention particulière de la part de la recherche compte tenu de leurs impacts potentiels sur la population et les écosystèmes. L’activité agricole constitue la principale source de contamination de l’atmosphère par les pesticides. Bien que la volatilisation depuis la plante soit reconnue plus intense et plus rapide que la volatilisation depuis le sol, cette voie de transfert est à ce jour la moins bien renseignée avec peu de modèles disponibles pour sa description. Le manque de connaissances est lié essentiellement à la complexité des interactions entre les processus ayant lieu à la surface de la feuille et qui sont en compétition avec la volatilisation, notamment la pénétration foliaire et la photodégradation. Cet article présente une synthèse bibliographique sur l’état des lieux des connaissances sur le processus de volatilisation des pesticides depuis un couvert végétal, de la pénétration foliaire et de la photodégradation, ainsi que les facteurs de contrôle de ces processus. Les méthodes de mesure ainsi que les modèles existants décrivant ces processus sont également présentés et analysés
اظهر المزيد [+] اقل [-]Genotypic variations in the dynamics of metal concentrations in poplar leaves: a field study with a perspective on phytoremediation. النص الكامل
2015
Pottier, Mathieu | Garcia de la Torre, Vanesa S. | Victor, Cindy | David, Laure C. | Chalot, Michel | Thomine, Sebastien
peer reviewed | Poplar is commonly used for phytoremediation of metal polluted soils. However, the high concentrations of trace elements present in leaves may return to soil upon leaf abscission. To investigate the mechanisms controlling leaf metal content, metal concentrations and expression levels of genes involved in metal transport were monitored at different developmental stages on leaves from different poplar genotypes growing on a contaminated field. Large differences in leaf metal concentrations were observed among genotypes. Whereas Mg was remobilized during senescence, Zn and Cd accumulation continued until leaf abscission in all genotypes. A positive correlation between Natural Resistance Associated Macrophage Protein 1 (NRAMP1) expression levels and Zn bio-concentration factors was observed. Principal component analyses of metal concentrations and gene expression levels clearly discriminated poplar genotypes. This study highlights a general absence of trace element remobilization from poplar leaves despite genotype specificities in the control of leaf metal homeostasis.
اظهر المزيد [+] اقل [-]Comparison of translocation methods to conserve metallophyte communities in the Southeastern D.R. Congo النص الكامل
2015
Le Stradic, Soizig | Seleck, Maxime | Lebrun, Jean | Boisson, Sylvain | Handjila, G. | Faucon, Michel-Pierre | Enk, T. | Mahy, Grégory
peer reviewed | In southeastern Democratic Republic of Congo, unique metallophyte communities supporting numerous endemic species occurred on the highly mineralized copper cobalt (Cu–Co) hills throughout the province. These hills are economically valuable mineral reserves; mining activities represent therefore a threat to the long-term persistence of these communities. Ex situ conservation program was set up by a mining company to rescue and conserve the diversity of Cu–Co communities until restoration activities are initiated. Two kinds of Cu–Co communities: the steppe and the steppic savanna, were translocated using topsoil spreading and whole-turf translocation. In this study, we assessed the effectiveness of these two techniques in conserving Cu–Co communities and their potential use in future restoration programs. More than 2 years after the translocation, whole-turf translocation appeared to be the better technique for ex situ conservation of endemic Cu–Co species. Not only did whole-turf successfully translocate numerous target species that were not present in the topsoil areas, but it also resulted in fewer ruderal and non-target species compared to topsoil spreading. Topsoil spreading recorded low seedling emergence from seed bank due to large proportions of dormant seeds or the absence of a seed bank, especially for the steppic savanna. Restoration of the steppe is currently more successful than for steppic savanna where the lack of dominant and structuring species likely contributed to divergence in species composition compared to reference ecosystem. Our study stresses the fact that tropical old-growth grasslands, which require probably several centuries to assemble, are difficult to restore or translocate. © 2015 Springer-Verlag Berlin Heidelberg
اظهر المزيد [+] اقل [-]Developing biodiversity indicators on a stakeholders' opinions basis: the gypsum industry Key Performance Indicators framework. | Développement d'un cadre d'indicateurs de biodiversité sur base de l'opinion de parties prenantes: le cadre d'indicateurs de performance de l'industrie du gypse. النص الكامل
2015
Pitz, Carline | Mahy, Grégory | Vermeulen, Cédric | Marlet, Christine | Seleck, Maxime
peer reviewed | Aims: To establish a common Key Performance Indicators (KPIs) framework for reporting about the gypsum industry biodiversity at the European level. Methods: In order to integrate different opinions and to reach a consensus framework, an original participatory process approach has been developed among different stakeholder groups: Eurogypsum, European and regional authorities, universities scientists, consulting offices, European and regional associations for the conservation of nature and the extractive industry. The strategy is developed around four main steps: (i) building of a maximum set of indicators to be submitted to stakeholders based on the literature (Focus Group method); (ii) evaluating the consensus about indicators through a policy Delphi survey aiming at the prioritization of indicator classes using the Analytic Hierarchy Process method (AHP) and of individual indicators; (iii) testing acceptability and feasibility through analysis of Environmental Impact Assessments (EIAs) and visits to three European quarries; (iv) Eurogypsum final decision and communication. Results: The resulting framework contains a set of 11 indicators considered the most suitable for all the stakeholders. Conclusions: Our KPIs respond to European legislation and strategies for biodiversity. The framework aims at improving sustainability in quarries and at helping to manage biodiversity as well as to allow the creation of coherent reporting systems. The final goal is to allow for the definition of the actual biodiversity status of gypsum quarries and allow for enhancing it. The framework is adaptable to the local context of each gypsum quarry.
اظهر المزيد [+] اقل [-]Watershed-scale assessment of oil palm cultivation impact on water quality and nutrient fluxes: A case study in Sumatra (Indonesia) النص الكامل
2015
Comte I. | Colin F. | Grünberger O. | Whalen J. | Widodo R.H. | Caliman J.P.
High fertilizer input is necessary to sustain high yields in oil palm agroecosystems, but it may endanger neighboring aquatic ecosystems when excess nutrients are transported to waterways. In this study, the hydrochemical dynamics of groundwater and streams under baseflow conditions were evaluated with bi-monthly measurements for 1 year on 16 watersheds. Hydrochemical measurements were related to the spatial distribution of soil and fertilization practices across a landscape of 100 km2, dominated by oil palm cultivation, in Central Sumatra, Indonesia. The low nutrient concentrations recorded in streams throughout the landscape indicated that the mature oil palm plantations in this study did not contribute to eutrophication of aquatic ecosystems. This was ascribed to high nutrient uptake by oil palm, a rational fertilizer program, and dilution of nutrient concentrations due to heavy rainfall in the study area. Soil type controlled dissolved inorganic N and total P fluxes, with greater losses of N and P from loamy-sand uplands than loamy lowlands. Organic fertilization helped to reduce nutrient fluxes compared to mineral fertilizers. However, when K inputs exceeded the oil palm requirement threshold, high K export occurred during periods when groundwater had a short residence time. For higher nutrient use efficiency in the long term, the field-scale fertilizer management should be complemented with a landscape-scale strategy of fertilizer applications that accounts for soil variability. (Résumé d'auteur)
اظهر المزيد [+] اقل [-]Polychlorinated biphenyl exposure and corticosterone levels in seven polar seabird species النص الكامل
2015
Tartu, Sabrina | Angelier, Frédéric | Bustnes, J.O. | Moe, B. | Hanssen, S.A. | Herzke, D. | Gabrielsen, G.W. | Verboven, N. | Verreault, J. | Labadie, P. | Budzinski, H. | Wingfield, J.C. | Chastel, Olivier | Centre d'Études Biologiques de Chizé - UMR 7372 (CEBC) ; Institut National de la Recherche Agronomique (INRA)-La Rochelle Université (ULR)-Centre National de la Recherche Scientifique (CNRS) | Division of Arctic Ecology (NINA) ; Norwegian Institute for Nature Research (NINA) | Norwegian Institute for Nature Research (NINA) | Norwegian Institute for Air Research (NILU) | Norwegian Polar Institute | Division of Cell Sciences ; Faculty of Veterinary Medicine | Centre de Recherche en Toxicologie de l'environnement (TOXEN) ; Département des Sciences Biologiques [Montréal] ; Université du Québec à Montréal = University of Québec in Montréal (UQAM)-Université du Québec à Montréal = University of Québec in Montréal (UQAM) | Environnements et Paléoenvironnements OCéaniques (EPOC) ; École Pratique des Hautes Études (EPHE) ; Université Paris Sciences et Lettres (PSL)-Université Paris Sciences et Lettres (PSL)-Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS) | Department of Neurobiology, Physiology, and Behavior ; University of California (UC)
Polychlorinated biphenyl exposure and corticosterone levels in seven polar seabird species النص الكامل
2015
Tartu, Sabrina | Angelier, Frédéric | Bustnes, J.O. | Moe, B. | Hanssen, S.A. | Herzke, D. | Gabrielsen, G.W. | Verboven, N. | Verreault, J. | Labadie, P. | Budzinski, H. | Wingfield, J.C. | Chastel, Olivier | Centre d'Études Biologiques de Chizé - UMR 7372 (CEBC) ; Institut National de la Recherche Agronomique (INRA)-La Rochelle Université (ULR)-Centre National de la Recherche Scientifique (CNRS) | Division of Arctic Ecology (NINA) ; Norwegian Institute for Nature Research (NINA) | Norwegian Institute for Nature Research (NINA) | Norwegian Institute for Air Research (NILU) | Norwegian Polar Institute | Division of Cell Sciences ; Faculty of Veterinary Medicine | Centre de Recherche en Toxicologie de l'environnement (TOXEN) ; Département des Sciences Biologiques [Montréal] ; Université du Québec à Montréal = University of Québec in Montréal (UQAM)-Université du Québec à Montréal = University of Québec in Montréal (UQAM) | Environnements et Paléoenvironnements OCéaniques (EPOC) ; École Pratique des Hautes Études (EPHE) ; Université Paris Sciences et Lettres (PSL)-Université Paris Sciences et Lettres (PSL)-Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS) | Department of Neurobiology, Physiology, and Behavior ; University of California (UC)
International audience | The role of polychlorinated biphenyls (PCBs) on exposure-related endocrine effects has been poorlyinvestigated in wild birds. This is the case for stress hormones including corticosterone (CORT). Somestudies have suggested that environmental exposure to PCBs and altered CORT secretion might beassociated. Here we investigated the relationships between blood PCB concentrations and circulatingCORT levels in seven free-ranging polar seabird species occupying different trophic positions, and hencecovering a wide range of PCB exposure. Blood P7PCB concentrations (range: 61e115,632 ng/g lw) werepositively associated to baseline or stress-induced CORT levels in three species and negatively associatedto stress-induced CORT levels in one species. Global analysis suggests that in males, baseline CORT levelsgenerally increase with increasing blood P7PCB concentrations, whereas stress-induced CORT levelsdecrease when reaching high blood P7PCB concentrations. This study suggests that the nature of thePCB-CORT relationships may depend on the level of PCB exposure.
اظهر المزيد [+] اقل [-]Polychlorinated biphenyl exposure and corticosterone levels in seven polar seabird species النص الكامل
2015
Tartu, S. | Angelier, F. | Bustnes, Jan Ove | Moe, Børge | Hanssen, Sveinn Are | Herzke, Dorte | Gabrielsen, Geir W. | Verboven, N. | Verreault, J. | Labadie, P. | Budzinski, H. | Wingfield, J.C. | Chastel, O.
acceptedVersion
اظهر المزيد [+] اقل [-]Polychlorinated biphenyl exposure and corticosterone levels in seven polar seabird species النص الكامل
2015
Tartu, S. | Angelier, F. | Bustnes, Jan Ove | Moe, Børge | Hanssen, Sveinn Are | Herzke, Dorte | Gabrielsen, Geir W. | Verboven, N. | Verreault, J. | Labadie, P. | Budzinski, H. | Wingfield, J.C. | Chastel, O.
The role of polychlorinated biphenyls (PCBs) on exposure-related endocrine effects has been poorly investigated in wild birds. This is the case for stress hormones including corticosterone (CORT). Some studies have suggested that environmental exposure to PCBs and altered CORT secretion might be associated. Here we investigated the relationships between blood PCB concentrations and circulating CORT levels in seven free-ranging polar seabird species occupying different trophic positions, and hence covering a wide range of PCB exposure. Blood P7PCB concentrations (range: 61e115,632 ng/g lw) were positively associated to baseline or stress-induced CORT levels in three species and negatively associated to stress-induced CORT levels in one species. Global analysis suggests that in males, baseline CORT levels generally increase with increasing blood P7PCB concentrations, whereas stress-induced CORT levels decrease when reaching high blood P7PCB concentrations. This study suggests that the nature of the PCB-CORT relationships may depend on the level of PCB exposure. Arctic Antarctic Birds PCBs Glucocorticoids Stress | acceptedVersion
اظهر المزيد [+] اقل [-]Polychlorinated biphenyl exposure and corticosterone levels in seven polar seabird species النص الكامل
2015
Tartu, S. | Angelier, F. | Bustnes, J.O. | Moe B., | Hanssen, S.A. | Herzke, D. | Gabrielsen, G.W. | Verboven, N. | Verreault, J. | Labadie, P. | Budzinski, H. | Wingfield, J.C. | Chastel, O.
The role of polychlorinated biphenyls (PCBs) on exposure-related endocrine effects has been poorly investigated in wild birds. This is the case for stress hormones including corticosterone (CORT). Some studies have suggested that environmental exposure to PCBs and altered CORT secretion might be associated. Here we investigated the relationships between blood PCB concentrations and circulating CORT levels in seven free-ranging polar seabird species occupying different trophic positions, and hence covering a wide range of PCB exposure. Blood ∑7PCB concentrations (range: 61–115,632 ng/g lw) were positively associated to baseline or stress-induced CORT levels in three species and negatively associated to stress-induced CORT levels in one species. Global analysis suggests that in males, baseline CORT levels generally increase with increasing blood ∑7PCB concentrations, whereas stress-induced CORT levels decrease when reaching high blood ∑7PCB concentrations. This study suggests that the nature of the PCB-CORT relationships may depend on the level of PCB exposure.
اظهر المزيد [+] اقل [-]Genotypic variations in the dynamics of metal concentrations in poplar leaves: A field study with a perspective on phytoremediation النص الكامل
2015
Pottier, Mathieu | Delatorre, Vanesa S. | Victor, Cindy | David, Laure | Chalot, Michel | Thomine, Sébastien | Interactions Arbres-Microorganismes (IAM) ; Université de Lorraine (UL)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE) | Laboratoire Chrono-environnement (UMR 6249) (LCE) ; Centre National de la Recherche Scientifique (CNRS)-Université de Franche-Comté (UFC) ; Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université Bourgogne Franche-Comté [COMUE] (UBFC) | Région Ile-de-France DIM ASTREA
International audience | Poplar is commonly used for phytoremediation of metal polluted soils. However, the high concentrations of trace elements present in leaves may return to soil upon leaf abscission. To investigate the mechanisms controlling leaf metal content, metal concentrations and expression levels of genes involved in metal transport were monitored at different developmental stages on leaves from different poplar genotypes growing on a contaminated field. Large differences in leaf metal concentrations were observed among genotypes. Whereas Mg was remobilized during senescence, Zn and Cd accumulation continued until leaf abscission in all genotypes. A positive correlation between Natural Resistance Associated Macrophage Protein 1 (NRAMP1) expres-sion levels and Zn bio-concentration factors was observed. Principal component analyses of metal concentrations and gene expression levels clearly discriminated poplar genotypes. This study highlights a general absence of trace element remobilization from poplar leaves despite genotype specificities in the control of leaf metal homeostasis.
اظهر المزيد [+] اقل [-]Estimation of PM10-bound As, Cd, Ni and Pb levels by means of statistical modelling: PLSR and ANN approaches النص الكامل
2015
Santos Bregel, Germán | Fernández Olmo, Ignacio | Irabien Gulías, Ángel | Universidad de Cantabria
Air quality assessment regarding metals and metalloids using experimental measurements is expensive and time consuming due to the cost and time required for the analytical determination of the levels of these pollutants. According to the European Union (EU) Air Quality Framework Directive (Directive 2008/50/EC), other alternatives, such as objective estimation techniques, can be considered for ambient air quality assessment in zones and agglomerations where the level of pollutants is below a certain concentration value known as the lower assessment threshold. These conditions occur in urban areas in Cantabria (northern Spain). This work aims to estimate the levels of As, Cd, Ni and Pb in airborne PM10 at two urban sites in the Cantabria region (Castro Urdiales and Reinosa) using statistical models as objective estimation techniques. These models were developed based on three different approaches: partial least squares regression (PLSR), artificial neural networks (ANNs) and an alternative approach consisting of principal component analysis (PCA) coupled with ANNs (PCA-ANN). Additionally, these models were externally validated using previously unseen data. The results show that the models developed in this work based on PLSR and ANNs fulfil the EU uncertainty requirements for objective estimation techniques and provide an acceptable estimation of the mean values. As a consequence, they could be considered as an alternative to experimental measurements for air quality assessment regarding the aforementioned pollutants in the study areas while saving time and resources. | The authors gratefully acknowledge the financial support from the Spanish Ministry of Economy and Competitiveness through the Project CMT2010-16068. The authors also thank the Regional Environment Ministry of the Cantabria Government for providing the PM10 samples at the Castro Urdiales and Reinosa sites.
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