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Assessment of the environmental persistence and long-range transport of endosulfan Texto completo
2011
Becker, Linus | Scheringer, Martin | Schenker, Urs | Hungerbühler, Konrad
Concentrations of the insecticide endosulfan (α- and β-isomer) and its degradation product endosulfan sulfate in air, seawater and soil are calculated with the global environmental fate model CliMoChem. As model input, physicochemical properties of all three compounds were assembled and a latitudinally and temporally resolved emission inventory was generated. For concentrations in air, model and measurements are in good agreement; a bimodal seasonality with two peaks in spring and fall as it is observed in Arctic air is reproduced by the model. For seawater, the agreement of model and measurements depends on the values of the hydrolysis activation energy of endosulfan used in the model; with relatively high values around 100kJ/mol, model results match field data well. The results of this assessment of the levels, persistence, and global distribution of endosulfan are also relevant for the evaluation of endosulfan as a Persistent Organic Pollutant under the Stockholm Convention.
Mostrar más [+] Menos [-]Indoor metallic pollution related to mining activity in the Bolivian Altiplano Texto completo
2011
Fontúrbel, Francisco E. | Barbieri, Enio | Herbas, Cristian | Barbieri, Flavia L. | Gardon, Jacques
The environmental pollution associated with mining and metallurgical activities reaches its greatest extent in several Andean cities and villages. Many locations in this area have accumulated through centuries a large amount of mining wastes, often disregarding the magnitude of this situation. However, in these naturally mineralized regions, there is little information available stating the exact role of mining and metallurgical industries in urban pollution. In this study, we demonstrated that the various metallic elements present in indoor dust (As, Cd, Cu, Pb, Sb, Sn, Zn) had a common origin and this contamination was increased by the proximity to the mines. Lead dust concentration was found at concerning levels for public health. In addition, wrong behaviors such as carrying mining workwear home contributed to this indoor dust pollution. Consequently, the constant exposure of the population could represent a potential health hazard for vulnerable groups, especially children.
Mostrar más [+] Menos [-]Temporal genetic variability and host sources of Escherichia coli associated with fecal pollution from domesticated animals in the shellfish culture environment of Xiangshan Bay, East China Sea Texto completo
2011
Fu, Ling-Lin | Shuai, Jiang-Bing | Wang, Yanbo | Ma, Hong-Jia | Li, Jian Rong
This study was conducted to analyze the genetic variability of Escherichia coli from domesticated animal wastes for microbial source tracking (MST) application in fecal contaminated shellfish growing waters of Xiangshan Bay, East China Sea. (GTG)₅ primer was used to generate 1363 fingerprints from E. coli isolated from feces of known 9 domesticated animal sources around this shellfish culture area. Jackknife analysis of the complete (GTG)₅-PCR DNA fingerprint library indicated that isolates were assigned to the correct source groups with an 84.28% average rate of correct classification. Based on one-year source tracking data, the dominant sources of E. coli were swine, chickens, ducks and cows in this water area. Moreover, annual and spatial changes of E. coli concentrations and host sources may affect the level and distribution of zoonotic pathogen species in waters. Our findings will further contribute to preventing fecal pollution in aquatic environments and quality control of shellfish.
Mostrar más [+] Menos [-]NitroScape: A model to integrate nitrogen transfers and transformations in rural landscapes Texto completo
2011
Duretz, S. | Drouet, J.L. | Durand, P. | Hutchings, N.J. | Theobald, M.R. | Salmon-Monviola, J. | Dragosits, U. | Maury, O. | Sutton, M.A. | Cellier, P.
NitroScape: A model to integrate nitrogen transfers and transformations in rural landscapes Texto completo
2011
Duretz, S. | Drouet, J.L. | Durand, P. | Hutchings, N.J. | Theobald, M.R. | Salmon-Monviola, J. | Dragosits, U. | Maury, O. | Sutton, M.A. | Cellier, P.
Modelling nitrogen transfer and transformation at the landscape scale is relevant to estimate the mobility of the reactive forms of nitrogen (Nᵣ) and the associated threats to the environment. Here we describe the development of a spatially and temporally explicit model to integrate Nᵣ transfer and transformation at the landscape scale. The model couples four existing models, to simulate atmospheric, farm, agro-ecosystem and hydrological Nᵣ fluxes and transformations within a landscape. Simulations were carried out on a theoretical landscape consisting of pig-crop farms interspersed with unmanaged ecosystems. Simulation results illustrated the effect of spatial interactions between landscape elements on Nᵣ fluxes and losses to the environment. More than 10% of the total N₂O emissions were due to indirect emissions. The nitrogen budgets and transformations of the unmanaged ecosystems varied considerably, depending on their location within the landscape. The model represents a new tool for assessing the effect of changes in landscape structure on Nᵣ fluxes.
Mostrar más [+] Menos [-]NitroScape: A model to integrate nitrogen transfers and transformations in rural landscapes Texto completo
2011
Duretz, Sylvia, S. | Drouet, Jean-Louis | Durand, Patrick | Hutchings, N.J., N.J. | Theobald, M.R., M.R. | Salmon-Monviola, Jordy | Dragosits, U., U. | Maury, Olivier, O. | Sutton, M.A., M.A. | Cellier, Pierre, P. | Environnement et Grandes Cultures (EGC) ; Institut National de la Recherche Agronomique (INRA)-AgroParisTech | Sol Agro et hydrosystème Spatialisation (SAS) ; Institut National de la Recherche Agronomique (INRA)-AGROCAMPUS OUEST | Department of Agroecology ; Aarhus University [Aarhus] | Department of Chemistry and Agricultural Analysis ; Universidad Politécnica de Madrid (UPM)
no sp Assessment of Nitrogen Fluxes to Air and Water from Site Scale to Continental Scale | Modelling nitrogen transfer and transformation at the landscape scale is relevant to estimate the mobility of the reactive forms of nitrogen (Nr) and the associated threats to the environment. Here we describe the development of a spatially and temporally explicit model to integrate Nr transfer and transformation at the landscape scale. The model couples four existing models, to simulate atmospheric, farm, agro-ecosystem and hydrological Nr fluxes and transformations within a landscape. Simulations were carried out on a theoretical landscape consisting of pig-crop farms interspersed with unmanaged ecosystems. Simulation results illustrated the effect of spatial interactions between landscape elements on Nr fluxes and losses to the environment. More than 10% of the total N2O emissions were due to indirect emissions. The nitrogen budgets and transformations of the unmanaged ecosystems varied considerably, depending on their location within the landscape. The model represents a new tool for assessing the effect of changes in landscape structure on Nr fluxes.
Mostrar más [+] Menos [-]NitroScape: A model to integrate nitrogen transfers and transformations in rural landscapes Texto completo
2011
Duretz, Sylvia, S. | Drouet, Jean-Louis | Durand, Patrick | Hutchings, N.J., N.J. | Theobald, M.R., M.R. | Salmon-Monviola, Jordy | Dragosits, U., U. | Maury, Olivier, O. | Sutton, M.A., M.A. | Cellier, Pierre, P. | Environnement et Grandes Cultures (EGC) ; Institut National de la Recherche Agronomique (INRA)-AgroParisTech | Sol Agro et hydrosystème Spatialisation (SAS) ; Institut National de la Recherche Agronomique (INRA)-AGROCAMPUS OUEST | Department of Agroecology ; Aarhus University [Aarhus] | Department of Chemistry and Agricultural Analysis ; Universidad Politécnica de Madrid (UPM)
no sp Assessment of Nitrogen Fluxes to Air and Water from Site Scale to Continental Scale | Modelling nitrogen transfer and transformation at the landscape scale is relevant to estimate the mobility of the reactive forms of nitrogen (Nr) and the associated threats to the environment. Here we describe the development of a spatially and temporally explicit model to integrate Nr transfer and transformation at the landscape scale. The model couples four existing models, to simulate atmospheric, farm, agro-ecosystem and hydrological Nr fluxes and transformations within a landscape. Simulations were carried out on a theoretical landscape consisting of pig-crop farms interspersed with unmanaged ecosystems. Simulation results illustrated the effect of spatial interactions between landscape elements on Nr fluxes and losses to the environment. More than 10% of the total N2O emissions were due to indirect emissions. The nitrogen budgets and transformations of the unmanaged ecosystems varied considerably, depending on their location within the landscape. The model represents a new tool for assessing the effect of changes in landscape structure on Nr fluxes.
Mostrar más [+] Menos [-]Transcriptional response of stress genes to metal exposure in zebra mussel larvae and adults Texto completo
2011
Navarro, Anna | Faria, Melissa | Barata, Carlos | Piña, Benjamin
Development of stress markers for the invader freshwater zebra mussel (Dreissena polymorpha) is of great interest for both conservation and biomonitoring purposes. Gene expression profiles of several putative or already established gene expression stress markers (Metallothionein, Superoxide dismutase, Catalase, Glutathione S transferase, Glutathione peroxidase, Cytochrome c oxidase, the multixenobiotic resistance P-gp1, and heat shock proteins HSP70 and HSP90) were analyzed by quantitative Real-Time PCR in adults and pediveliger larvae after exposure to metals (Hg, Cu, Cd). A defined pattern of coordinated responses to metal exposure and, presumably, to oxidative stress was observed in gills and digestive gland from adults. A similar, albeit partial response was observed in larvae, indicating an early development of stress-related gene responses in zebra mussel. The tools developed in this study may be useful both for future control strategies and for the use of zebra mussel as sentinel species in water courses with stable populations.
Mostrar más [+] Menos [-]Differentiation of nitrous oxide emission factors for agricultural soils Texto completo
2011
Lesschen, Jan Peter | Velthof, Gerard L. | de Vries, Wim | Kros, Johannes
Nitrous oxide (N₂O) direct soil emissions from agriculture are often estimated using the default IPCC emission factor (EF) of 1%. However, a large variation in EFs exists due to differences in environment, crops and management. We developed an approach to determine N₂O EFs that depend on N-input sources and environmental factors. The starting point of the method was a monitoring study in which an EF of 1% was found. The conditions of this experiment were set as the reference from which the effects of 16 sources of N input, three soil types, two land-use types and annual precipitation on the N₂O EF were estimated. The derived EF inference scheme performed on average better than the default IPCC EF. The use of differentiated EFs, including different regional conditions, allows accounting for the effects of more mitigation measures and offers European countries a possibility to use a Tier 2 approach.
Mostrar más [+] Menos [-]The formation of bound residues of diazinon in four UK soils: Implications for risk assessment Texto completo
2011
Fenlon, Katie A. | Andreou, Kostas | Jones, K. C. (Kevin C.) | Semple, K. T. (Kirk T.)
The behaviour of diazinon in the soil determines the likelihood of further pollution incidents, particularly leaching to water. The most significant processes in the control of the fate of diazinon in the soil are microbial degradation and the formation of bound residues. Soils from four sites in the UK were amended with diazinon and its ¹⁴C labelled analogue and incubated for 100 days. After 0, 10, 21, 50 and 100 days, the formation of bound residues was assessed by solvent extraction, and the microbial degradation of diazinon by mineralisation assay. In microbially active soils, diazinon is degraded rapidly, reducing the risk of future pollution incidents. However, where there was limited mineralisation there was also significantly lower formation of bound residues, which may lead to water pollution via leaching. The formation of bound residues was dependent on extraction type. Acetonitrile extraction identified bound residues in all soils, with the bound residue fraction increasing with increasing incubation time.
Mostrar más [+] Menos [-]Carbon exchange between ecosystems and atmosphere in the Czech Republic is affected by climate factors Texto completo
2011
Marek, Michal V. | Janouš, Dalibor | Taufarová, Klára | Havránková, Kateřina | Pavelka, Marian | Kaplan, Věroslav | Marková, Irena
By comparing five ecosystem types in the Czech Republic over several years, we recorded the highest carbon sequestration potential in an evergreen Norway spruce forest (100%) and an agroecosystem (65%), followed by European beech forest (25%) and a wetland ecosystem (20%). Because of a massive ecosystem respiration, the final carbon gain of the grassland was negative. Climate was shown to be an important factor of carbon uptake by ecosystems: by varying the growing season length (a 22-d longer season in 2005 than in 2007 increased carbon sink by 13%) or by the effect of short- term synoptic situations (e.g. summer hot and dry days reduced net carbon storage by 58% relative to hot and wet days). Carbon uptake is strongly affected by the ontogeny and a production strategy which is demonstrated by the comparison of seasonal course of carbon uptake between coniferous (Norway spruce) and deciduous (European beech) stands.
Mostrar más [+] Menos [-]Concentrations and assessment of exposure to siloxanes and synthetic musks in personal care products from China Texto completo
2011
Lu, Yan | Yuan, Tao | Wang, Wenhua | Kannan, Kurunthachalam
We investigated the concentrations and profiles of 15 siloxanes (four cyclic siloxanes, D₄–D₇; 11 linear siloxanes, L₄–L₁₄), four synthetic musks (two polycyclic musks, HHCB and AHTN; two nitro musks, MX and MK), and HHCB-lactone, in 158 personal care products marketed in China. Siloxanes were detected in 88% of the samples analyzed, at concentrations as high as 52.6 mg g⁻¹; Linear siloxanes were the predominant compounds. Among synthetic musks, more than 80% of the samples contained at least one of these compounds, and their total concentrations were as high as 1.02 mg g⁻¹. HHCB was the predominant musk in all of the samples analyzed, on average, accounting for 52% of the total musk concentrations. Based on the median concentrations of siloxanes and musks and the average daily usage amounts of consumer products, dermal exposure rates in adults were calculated to be 3.69 and 3.38 mg d⁻¹ for siloxanes and musks, respectively.
Mostrar más [+] Menos [-]Vertical distribution of hydrocarbons in the low troposphere below and above the mixing height: Tethered balloon measurements in Milan, Italy Texto completo
2011
Sangiorgi, G. | Ferrero, L. | Perrone, M.G. | Bolzacchini, E. | Duane, M. | Larsen, B.R.
A novel approach for measuring vertical profiles of HCs and particle number concentrations was described and applied in the low troposphere over Milan (Italy) during typical spring and summer days. Particle profiles yielded nearly homogeneous concentrations below the mixing height, with level-to-ground concentration ratios of 92–97%, while HCs showed a more pronounced decrease (74–95%). Vertical mixing and photochemical loss of HCs were demonstrated to cause these gradients. Much lower concentrations were observed for the profiles above the mixing height, where the HC mixtures showed also a different composition, which was partially explained by the horizontal advection of air with HC sources different to those prevailing at the site. The application of pseudo-first order kinetics for reactions between HCs and the hydroxyl radical allowed for the estimation of the vertical mixing time scale in the order of 100 ± 20 min.
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