113 research outputs found

    Study of lead phytoavailability for atmospheric industrial micronic and sub-micronic particles in relation with lead speciation

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    Particles from channelled emissions of a battery recycling facility were size-segregated and investigated to correlate their speciation and morphology with their transfer towards lettuce. Microculture experiments carried out with various calcareous soils spiked with micronic and sub-micronic particles (1650 20 mg Pb kg1) highlighted a greater transfer in soils mixed with the finest particles. According to XRD and Raman spectroscopy results, the two fractions presented differences in the amount of minor lead compounds like carbonates, but their speciation was quite similar, in decreasing order of abundance: PbS, PbSO4, PbSO4$PbO, a-PbO and Pb0. Morphology investigations revealed that PM2.5 (i.e. Particulate Matter 2.5 composed of particles suspended in air with aerodynamic diameters of 2.5 mm or less) contained many Pb nanoballs and nanocrystals which could influence lead availability. The soil– plant transfer of lead was mainly influenced by size and was very well estimated by 0.01 M CaCl2 extractio

    Characterization of lead-recycling facility emissions at various workplaces: Major insights for sanitary risks assessment

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    Most available studies on lead smelter emissions deal with the environmental impact of outdoor particles, but only a few focus on air quality at workplaces. The objective of this study is to physically and chemically characterize the Pb-rich particles emitted at different workplaces in a lead recycling plant. A multiscale characterization was conducted from bulk analysis to the level of individual particles, to assess the particles properties in relation with Pb speciation and availability. Process PM from various origins were sampled and then compared; namely Furnace and Refining PM respectively present in the smelter and at refinery workplaces, Emissions PM present in channeled emissions. These particles first differed by their morphology and size distribution, with finer particles found in emissions. Differences observed in chemical composition could be explained by the industrial processes. All PM contained the same major phases (Pb, PbS, PbO, PbSO4 and PbO·PbSO4) but differed on the nature and amount of minor phases. Due to high content in PM, Pb concentrations in the CaCl2 extractant reached relatively high values (40mgL−1). However, the ratios (soluble/total) of CaCl2 exchangeable Pb were relatively low (<0.02%) in comparison with Cd (up to 18%). These results highlight the interest to assess the soluble fractions of all metals (minor and major) and discuss both total metal concentrations and ratios for risk evaluations. In most cases metal extractability increased with decreasing size of particles, in particular, lead exchangeability was highest for channeled emissions. Such type of study could help in the choice of targeted sanitary protection procedures and for further toxicological investigations. In the present context, particular attention is given to Emissions and Furnace PM. Moreover, exposure to other metals than Pb should be considered

    Metal and metalloid foliar uptake by various plant species exposed to atmospheric industrial fallout: Mechanisms involved for lead

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    Fine and ultrafine metallic particulatematters (PMs) are emitted frommetallurgic activities in peri-urban zones into the atmosphere and can be deposited in terrestrial ecosystems. The foliar transfer ofmetals andmetalloids and their fate in plant leaves remain unclear, although this way of penetration may be a major contributor to the transfer of metals into plants. This study focused on the foliar uptake of various metals and metalloids from enriched PM(Cu, Zn, Cd, Sn, Sb, As, and especially lead (Pb)) resulting fromthe emissions of a battery-recycling factory.Metal and metalloid foliar uptake by various vegetable species, exhibiting different morphologies, use (food or fodder) and life-cycle (lettuce, parsley and rye-grass) were studied. The mechanisms involved in foliar metal transfer from atmospheric particulate matter fallout, using lead (Pb) as a model element was also investigated. Several complementary techniques (micro-X-ray fluorescence, scanning electron microscopy coupled with energy dispersive X-ray microanalysis and time-of-flight secondary ion mass spectrometry) were used to investigate the localization and the speciation of lead in their edible parts, i.e. leaves. The results showed lead-enriched PM on the surface of plant leaves. Biogeochemical transformations occurred on the leaf surfaces with the formation of lead secondary species (PbCO3 and organic Pb). Some compounds were internalized in their primary form (PbSO4) underneath an organic layer. Internalization through the cuticle or penetration through stomata openings are proposed as two major mechanisms involved in foliar uptake of particulate matter

    Experimental and theoretical investigation on conformational and spectroscopic properties of dimethyl dithiodiglycolate, [CH3OC(O)CH2S]2

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    Dimethyl dithiodiglycolate (DTG), [CH3OC(O)CH2S]2, was synthetized by complete oxidation of methyl thioglycolate (MTG) with I2, and characterized by gas chromatography coupled with electron-impact mass spectrometry. Fifteen stable conformers were found with the B3LYP/6-31 + G* approximation, with calculated populations at ambient temperature higher than 1%. The IR and Raman spectra of liquid DTG were interpreted for the first time, in terms of equilibrium between four conformers. The UV–visible spectra of DTG in solutions of ethanol, isopropanol and acetonitrile present a low-intensity band around 230 nm, interpreted mainly as arising from n → π* transitions localized at the C[dbnd]O groups, according to the prediction of TD-DFT calculations.Fil: Juncal, Luciana Celeste. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - La Plata. Centro de QuĂ­mica InorgĂĄnica ; ArgentinaFil: Bava, Yanina BelĂ©n. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - La Plata. Centro de QuĂ­mica InorgĂĄnica ; ArgentinaFil: Tamone, Luciana Mariel. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - La Plata. Centro de QuĂ­mica InorgĂĄnica ; ArgentinaFil: Seng, Samantha. UniversitĂ© de Lille 1 Sciences et Technologies; FranciaFil: TobĂłn, Yeny A.. UniversitĂ© de Lille 1 Sciences et Technologies; FranciaFil: Sobanska, Sophie. UniversitĂ© de Lille 1 Sciences et Technologies; FranciaFil: Picone, Andrea Lorena. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - La Plata. Centro de QuĂ­mica InorgĂĄnica ; ArgentinaFil: Romano, Rosana Mariel. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - La Plata. Centro de QuĂ­mica InorgĂĄnica ; Argentin

    Absorption foliaire des métaux présents dans des particules atmosphériques issues d'une usine de recyclage de batteries : biotest laitue

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    National audienceLes flux de polluants émis dans l'environnement ont été considérablement réduits en particulier par la mise en place par les industriels de systÚme de filtres performants. Cependant les particules trÚs fines et particuliÚrement réactives sont toujours émises dans l'environnement. De nombreuses études décrivent le transfert sol-plante des métaux mais trÚs peu concernent la voie de transfert atmosphÚre plante. Pourtant, selon le rapport parlementaire de Miquel (2001), l'enrichissement actuel des sols en plomb provient pour 68% des retombées atmosphériques qui sont aussi interceptées par les plantes. Le transfert foliaire direct via des aérosols particulaires a été démontré pour des radionucléides (137Cs, 85Sr, 133Ba et 123mTe) par Madoz-Escande et al. (2004). Or les voies de transport des radionucléides et métaux sont aussi celles des "oligoélements" (Zn, Co, Mo, Cu) dans les plantes. C'est pourquoi il paraßt pertinent de s'intéresser au transfert foliaire des métaux. De nombreuses questions scientifiques se posent en effet concernant le transfert foliaire des métaux. Est-il possible? Si oui sous quelle forme sont les métaux? Quels sont les mécanismes physico chimiques et biologiques impliqués? Quelle est l'importance de cette voie vis-à-vis du transfert sol plante ? Pour répondre à ces questions, le transfert du plomb et du cadmium vers les parties aériennes des plantes via le dépÎt atmosphérique de particules industrielles riches en métaux a été expérimenté et modélisé

    Influence of metal process micronic and submicronic particles on vegetables quality and ecosystems

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    International audienceImpact of atmospheric process particles enriched with metals (PM) on various vegetables was studied. Foliar metal interception was measured and calculated. Soil-plant transfer and phyto-toxicity were also studied. Influence of species and washing procedure on metal burning was observed. High correlation was obtained between measured and simulated lead plant uptake values. Ageing effect in polluted soils was highlighted with stabilisation or mobilization of metals in function of contact duration between soils and PM

    Photodegradation of methyl thioglycolate particles as a proxy for organosulphur containing droplets

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    Understanding the formation and transformation of sulphur-rich particles is of prime importance since they contribute to the global atmospheric sulphur budget. In this work, we performed a series of experiments on a photoactive organosulphur compound namely, methyl thioglycolate, as a model of an organosulphur species of marine origin. By investigating the photoproducts within levitated droplets, we showed that elemental sulphur (α-S8) and sulphate (SO4 2-) can be photochemically generated at the gas-liquid interface by heterogeneous interaction with gaseous O2 and H2O. These results demonstrate that the surface of levitated droplets facilitate the oxidation of methyl thioglycolate in the dark, while illumination is necessary to produce the oxidation in bulk experiments.Centro de Química Inorgånic

    Photodegradation of methyl thioglycolate particles as a proxy for organosulphur containing droplets

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    Understanding the formation and transformation of sulphur-rich particles is of prime importance since they contribute to the global atmospheric sulphur budget. In this work, we performed a series of experiments on a photoactive organosulphur compound namely, methyl thioglycolate, as a model of an organosulphur species of marine origin. By investigating the photoproducts within levitated droplets, we showed that elemental sulphur (α-S8) and sulphate (SO4 2-) can be photochemically generated at the gas-liquid interface by heterogeneous interaction with gaseous O2 and H2O. These results demonstrate that the surface of levitated droplets facilitate the oxidation of methyl thioglycolate in the dark, while illumination is necessary to produce the oxidation in bulk experiments.Fil: Seng, Samantha. Universite Des Sciences Et Technologies de Lille;Fil: Picone, A. Lorena. Facultad de Ciencias Exactas, Universidad Nacional de la Plata; ArgentinaFil: Bava, Yanina B.. Facultad de Ciencias Exactas, Universidad Nacional de la Plata; ArgentinaFil: Juncal, Luciana C.. Facultad de Ciencias Exactas, Universidad Nacional de la Plata; ArgentinaFil: Moreau, Myriam. Universite Des Sciences Et Technologies de Lille;Fil: Ciuraru, Raluca. Universite Des Sciences Et Technologies de Lille;Fil: George, Christian. Universite Claude Bernard Lyon 1;Fil: Romano, Rosana M.. Universite Claude Bernard Lyon 1;Fil: Sobanska, Sophie. Facultad de Ciencias Exactas, Universidad Nacional de la Plata; ArgentinaFil: Tobon, Yeny A.. Universite Des Sciences Et Technologies de Lille

    Photodegradation of methyl thioglycolate particles as a proxy for organosulphur containing droplets

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    Understanding the formation and transformation of sulphur-rich particles is of prime importance since they contribute to the global atmospheric sulphur budget. In this work, we performed a series of experiments on a photoactive organosulphur compound namely, methyl thioglycolate, as a model of an organosulphur species of marine origin. By investigating the photoproducts within levitated droplets, we showed that elemental sulphur (α-S8) and sulphate (SO4 2-) can be photochemically generated at the gas-liquid interface by heterogeneous interaction with gaseous O2 and H2O. These results demonstrate that the surface of levitated droplets facilitate the oxidation of methyl thioglycolate in the dark, while illumination is necessary to produce the oxidation in bulk experiments.Centro de Química Inorgånic

    Consensus Recommendations for Clinical Outcome Assessments and Registry Development in Ataxias: Ataxia Global Initiative (AGI) Working Group Expert Guidance

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    To accelerate and facilitate clinical trials, the Ataxia Global Initiative (AGI) was established as a worldwide research platform for trial readiness in ataxias. One of AGI's major goals is the harmonization and standardization of outcome assessments. Clinical outcome assessments (COAs) that describe or reflect how a patient feels or functions are indispensable for clinical trials, but similarly important for observational studies and in routine patient care. The AGI working group on COAs has defined a set of data including a graded catalog of COAs that are recommended as a standard for future assessment and sharing of clinical data and joint clinical studies. Two datasets were defined: a mandatory dataset (minimal dataset) that can ideally be obtained during a routine clinical consultation and a more demanding extended dataset that is useful for research purposes. In the future, the currently most widely used clinician-reported outcome measure (ClinRO) in ataxia, the scale for the assessment and rating of ataxia (SARA), should be developed into a generally accepted instrument that can be used in upcoming clinical trials. Furthermore, there is an urgent need (i) to obtain more data on ataxia-specific, patient-reported outcome measures (PROs), (ii) to demonstrate and optimize sensitivity to change of many COAs, and (iii) to establish methods and evidence of anchoring change in COAs in patient meaningfulness, e.g., by determining patient-derived minimally meaningful thresholds of change
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