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Size dependent bioaccumulation and ecotoxicity of gold nanoparticles in an endobenthic invertebrate: The Tellinid clam Scrobicularia plana Texte intégral
2012
Pan, Jin-Fen | Buffet, Pierre-Emmanuel | Poirier, Laurence | Amiard-Triquet, C. | Gilliland, Douglas | Joubert, Yolaine | Pilet, Paul | Guibbolini, Marielle | Risso de Faverney, Christine | Roméo, Michèle | Valsami-Jones, Eugenia | Mouneyrac, Catherine
Gold nanoparticles (AuNPs) have important technological applications resulting in an increased potential for release to the environment, and a greater possibility of toxicological effects. The marine bivalve Scrobicularia plana was exposed to AuNPs of size 5, 15 and 40nm during a 16 d laboratory exposure at 100μg Au L⁻¹. After exposure to AuNPs forming aggregates (>700nm), the clams accumulated Au in their soft tissues. Biochemical (biomarkers) and behavioral (burrowing and feeding) responses were investigated. Au NPs were responsible of metallothionein induction (5, 40nm), increased activities of catalase (15, 40nm) and superoxide dismutase (40nm) and of glutathione S-transferase by the three sizes of AuNPs indicating defense against oxidative stress. Exposure to AuNPs impaired burrowing behavior. However, it must be underlined that these effects were observed at a dose much higher than expected in the environment.
Afficher plus [+] Moins [-]Airborne psychotropic substances in eight Italian big cities: Burdens and behaviours Texte intégral
2012
Cecinato, Angelo | Balducci, Catia | Romagnoli, Paola | Perilli, Mattia
Psychotropic substances were monitored in eight big cities of Italy over one year, starting in May 2010, in the frame of the Ariadrugs Project. Yearly average concentrations ranged from 0.02 ± 0.01 to 0.26 ± 0.11 ng/m³ for cocaine, from 0.05 ± 0.05 to 0.96 ± 1.37 ng/m³ for cannabinoids, from 16 ± 6 to 61 ± 28 ng/m³ for nicotine, and from 1.0 ± 0.8 to 8 ± 7 ng/m³ for caffeine. Palermo and Turin were the cities suffering the lowest and the highest psychotropic substance concentrations, respectively. Nicotine and cocaine exhibited trends less seasonally modulated than common air toxicants. Caffeine and cannabinoids peaked in winter dropping close to zero from May to August. In Rome, where various anthropic contours were investigated in February 2011, differences were observed both in net concentrations and ratios of psychotropic substances vs. regulated toxicants. Ambient drugs look as a consequence of addiction and their burdens give insights about the corresponding consumes.
Afficher plus [+] Moins [-]Factors regulating the bioavailability of methylmercury to breeding rusty blackbirds in northeastern wetlands Texte intégral
2012
Edmonds, Samuel Trower | O'Driscoll, Nelson J. | Hillier, N Kirk | Atwood, Jonathan L. | Evers, David C.
Rusty blackbirds are undergoing rapid population decline and have elevated Hg concentrations while breeding in the Acadian ecoregion of North America. Factors regulating the bioavailability of methyl-Hg (MeHg) within this population's habitat were determined using water, invertebrates, and blood from adult rusty blackbirds collected for Hg-speciation, along with additional water column parameters: MeHg and THg, dissolved organic carbon, pH, dissolved oxygen, conductivity, redox potential, and temperature. Both DO₂ and pH were negatively related to biota MeHg, while water MeHg concentrations were positively related. Both invertebrate MeHg concentration and %MeHg increased with trophic level. Invertebrate MeHg concentrations were among the greatest reported when compared with those reported elsewhere for wetlands and waterbodies—often several times greater for similar taxa—while percent MeHg of THg were similar. An environment with high bioavailability of MeHg in combination with a high trophic position best explains elevated Hg concentrations for this species regional population.
Afficher plus [+] Moins [-]Evaluation through column leaching tests of metal release from contaminated estuarine sediment subject to CO₂ leakages from Carbon Capture and Storage sites Texte intégral
2012
Payán, M Cruz | Galan, Berta | Coz, Alberto | Vandecasteele, Carlo | Viguri, Javier R.
The pH change and the release of organic matter and metals from sediment, due to the potential CO₂ acidified seawater leakages from a CCS (Carbon Capture and Storage) site are presented. Column leaching test is used to simulate a scenario where a flow of acidified seawater is in contact with recent contaminated sediment. The behavior of pH, dissolved organic carbon (DOC) and metals As, Cd, Cr, Cu, Ni, Pb, Zn, with liquid to solid (L/S) ratio and pH is analyzed. A stepwise strategy using empirical expressions and a geochemical model was conducted to fit experimental release concentrations. Despite the neutralization capacity of the seawater-carbonate rich sediment system, important acidification and releases are expected at local scale at lower pH. The obtained results would be relevant as a line of evidence input of CCS risk assessment, in an International context where strategies to mitigate the climate change would be applied.
Afficher plus [+] Moins [-]Class 1 and 2 integrons, sul resistance genes and antibiotic resistance in Escherichia coli isolated from Dongjiang River, South China Texte intégral
2012
Su, Hao-Chang | Ying, Guang-Guo | Tao, Ran | Zhang, Rui-Quan | Zhao, Jian-Liang | Liu, You-Sheng
Antibiotic susceptibility, detection of sul gene types and presence of class 1, 2 and 3 integrons and gene cassettes using PCR assays were investigated in 3456 Escherichia coli isolates obtained from 38 sampling sites of the Dongjiang River catchment in the dry and wet seasons. 89.1% of the isolates were resistant and 87.5% showed resistance to at least three antibiotics. sul2 was detected most frequently in 89.2% of 1403 SXT-resistant isolates. The presence of integrons (class 1 and 2) was frequently observed (82.3%) while no class 3 integron was found. In these integrons, 21 resistance genes of 14 gene cassette arrays and 10 different families of resistance genes were identified. Three gene cassette arrays, aac(6')-Ib-cr-aar-3-dfrA27-aadA16, aacA4-catB3-dfrA1 and aadA2-lnuF, were detected for the first time in surface water. The results showed that bacterial resistance in the catchment was seriously influenced by human activities, especially discharge of wastewater.
Afficher plus [+] Moins [-]Air–soil exchange of PCBs: Seasonal variations in levels and fluxes with influence of equilibrium conditions Texte intégral
2012
Tasdemir, Yücel | Salihoglu, Güray | Salihoglu, Nezih Kamil | Birgül, Askın
The variations in the occurrences of PCB congeners both in soil and air were investigated in conjunction with each other, and the changes in the fugacity fractions and flux levels were examined on a seasonal basis. Air and soil samples were collected concurrently two or three times in a month during a one-year monitoring at two different locations in Bursa, located in the northwestern Turkey. Fugacity fractions and net flux levels of PCB congeners were calculated. Air and soil PCB levels increased together as the soil temperature increased, suggesting the influence of instantaneous air–soil exchange towards the equilibrium conditions. The flux levels and fugacity fractions also showed a positive significant correlation with soil temperature. Flux levels were positive for the dates with fugacity fractions above 0.5, indicating volatilization from soil to air.
Afficher plus [+] Moins [-]How healthy is urban horticulture in high traffic areas? Trace metal concentrations in vegetable crops from plantings within inner city neighbourhoods in Berlin, Germany Texte intégral
2012
Säumel, Ina | Kotsyuk, Iryna | Hölscher, Marie | Lenkereit, Claudia | Weber, Frauke | Kowarik, Ingo
Food production by urban dwellers is of growing importance in developing and developed countries. Urban horticulture is associated with health risks as crops in urban settings are generally exposed to higher levels of pollutants than those in rural areas. We determined the concentration of trace metals in the biomass of different horticultural crops grown in the inner city of Berlin, Germany, and analysed how the local setting shaped the concentration patterns. We revealed significant differences in trace metal concentrations depending on local traffic, crop species, planting style and building structures, but not on vegetable type. Higher overall traffic burden increased trace metal content in the biomass. The presence of buildings and large masses of vegetation as barriers between crops and roads reduced trace metal content in the biomass. Based on this we discuss consequences for urban horticulture, risk assessment, and planting and monitoring guidelines for cultivation and consumption of crops.
Afficher plus [+] Moins [-]Forests under climate change and air pollution: Gaps in understanding and future directions for research Texte intégral
2012
Matyssek, R. | Wieser, G. | Calfapietra, C. | de Vries, W. | Dizengremel, P. | Ernst, D. | Jolivet, Y. | Mikkelsen, T.N. | Mohren, G.M.J. | Le Thiec, D. | Tuovinen, J.-P. | Weatherall, A. | Paoletti, E.
Forests under climate change and air pollution: Gaps in understanding and future directions for research Texte intégral
2012
Matyssek, R. | Wieser, G. | Calfapietra, C. | de Vries, W. | Dizengremel, P. | Ernst, D. | Jolivet, Y. | Mikkelsen, T.N. | Mohren, G.M.J. | Le Thiec, D. | Tuovinen, J.-P. | Weatherall, A. | Paoletti, E.
Forests in Europe face significant changes in climate, which in interaction with air quality changes, may significantly affect forest productivity, stand composition and carbon sequestration in both vegetation and soils. Identified knowledge gaps and research needs include: (i) interaction between changes in air quality (trace gas concentrations), climate and other site factors on forest ecosystem response, (ii) significance of biotic processes in system response, (iii) tools for mechanistic and diagnostic understanding and upscaling, and (iv) the need for unifying modelling and empirical research for synthesis. This position paper highlights the above focuses, including the global dimension of air pollution as part of climate change and the need for knowledge transfer to enable reliable risk assessment. A new type of research site in forest ecosystems (“supersites”) will be conducive to addressing these gaps by enabling integration of experimentation and modelling within the soil-plant-atmosphere interface, as well as further model development.
Afficher plus [+] Moins [-]Forests under climate change and air pollution: Gaps in understanding and future directions for research Texte intégral
2012
Matyssek, R. | Wieser, G. | Calfapietra, C. | de Vries, W. | Dizengremel, Pierre | Ernst, D. | Jolivet, Yves | Mikkelsen, T. N. | Mohren, G. M. J. | Le Thiec, Didier | Tuovinen, J. -P. | Weatherall, A. | Paoletti, E. | Technische Universität Munchen - Technical University Munich - Université Technique de Munich (TUM) | Dept Alpine Timberline Ecophysiol ; Federal Office and Research Centre for Forests | Natl Res Council ; Inst Agroenvironm & Forest Biol | Environm Syst Anal Grp ; Wageningen University and Research [Wageningen] (WUR) | Ecologie et Ecophysiologie Forestières [devient SILVA en 2018] (EEF) ; Institut National de la Recherche Agronomique (INRA)-Université de Lorraine (UL) | Inst Biochem Plant Pathol ; Helmholtz Zentrum München = German Research Center for Environmental Health (HMGU) | Biosystems Division [Roskilde] ; Risø National Laboratory for Sustainable Energy (Risø DTU) ; Danmarks Tekniske Universitet = Technical University of Denmark (DTU)-Danmarks Tekniske Universitet = Technical University of Denmark (DTU) | Forest Ecology and Forest Management Group [Wageningen] ; Centre for Ecosystem Studies [Wageningen] ; Wageningen University and Research [Wageningen] (WUR)-Wageningen University and Research [Wageningen] (WUR) | Finnish Meteorological Institute (FMI) | Natl Sch Forestry ; Univ Cumbria | National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR) | EU Commission
Forests in Europe face significant changes in climate, which in interaction with air quality changes, may significantly affect forest productivity, stand composition and carbon sequestration in both vegetation and soils. Identified knowledge gaps and research needs include: (i) interaction between changes in air quality (trace gas concentrations), climate and other site factors on forest ecosystem response, (ii) significance of biotic processes in system response, (iii) tools for mechanistic and diagnostic understanding and upscaling, and (iv) the need for unifying modelling and empirical research for synthesis. This position paper highlights the above focuses, including the global dimension of air pollution as part of climate change and the need for knowledge transfer to enable reliable risk assessment. A new type of research site in forest ecosystems ("supersites") will be conducive to addressing these gaps by enabling integration of experimentation and modelling within the soil-plant-atmosphere interface, as well as further model development. (C) 2011 Elsevier Ltd. All rights reserved.
Afficher plus [+] Moins [-]Reducing total mercury and methylmercury accumulation in rice grains through water management and deliberate selection of rice cultivars Texte intégral
2012
Peng, Xiaoyan | Liu, Fengjie | Wang, Wen-Xiong | Ye, Zhihong
Rice consumption has been identified as a major route of methylmercury (MeHg) exposure in some areas of inland China. We investigated two potential mitigation methods (water management and deliberate selection of rice cultivars) to reduce the amount of total mercury (Hg) and MeHg within the grain. Rice grown aerobically had markedly reduced total Hg and MeHg concentrations as well as a much lower proportion of MeHg in the grain. Remarkably, there were considerable variations in the total Hg and MeHg concentrations as well as the proportion of MeHg in the grain among the 24 cultivars grown in the same paddy soil. The Hg tolerance index (expressed as % mean of control root growth) also varied substantially among the different cultivars. Furthermore, negative correlations were found between the total Hg and MeHg concentrations (P<0.05) of grain and the proportion of MeHg in the grain (P<0.01).
Afficher plus [+] Moins [-]Bioaccumulation of Fe₂O₃(magnetic) nanoparticles in Ceriodaphnia dubia Texte intégral
2012
Hu, Ji | Wang, Demin | Wang, Jiangtao | Wang, Jianmin
While nano-Fe₂O₃(magnetic) is generally considered non-toxic, it could serve as a carrier of other toxic chemicals such as As(V) and enhance their toxicity. The bioaccumulation of nano-Fe₂O₃(m) with different exposure times, NP concentrations, and pH conditions was investigated using Ceriodaphnia dubia (C. dubia) as the model organism. Under natural pH conditions, C. dubia significantly accumulated nano-Fe₂O₃(m) in the gut, with the maximum accumulation being achieved after 6 h of exposure. The concentration of nano-Fe₂O₃ also impacted its accumulation, with the maximum uptake occurring at 20 mg/L or more. In addition, the highest bioaccumulation occurred in a pH range of 7–8 where the highest feeding rate was reported, confirming that the ingestion of NPs is the main route of nano-Fe₂O₃(m) bioaccumulation. In a clean environment without NPs, depuration of nano-Fe₂O₃(m) occurred, and food addition accelerated the depuration process.
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