18 research outputs found
Genome reduction and potential metabolic complementation of the dual endosymbionts in the whitefly Bemisia tabaci
Dynamique des Ă©lĂ©ments traces mĂ©talliques Ă lâinterface ville-estuaire : mĂ©taux classiques et terres rares.
Control of urban pollutants is a major issue, especially in coastal areas, in a context of rapidly growing urbanization and the emission of emerging potentially highly toxic contaminants, such as Rare Earth Elements (REEs). This study is a part of the REGARD project and aims at understanding the dynamics of âconventionalâ trace metals (Tms) and REEs in the Jalle River, the main urban hydrosystem draining the Bordeaux Metropole and to assess its influence on the Garonne section of the Gironde estuary after having characterized two major urban sources: domestic wastewater and stormwater runoff draining the Bordeaux Highway. Due to its use as a contrast agent for MRIs and its low removal in WWTPs, gadolinium (Gd) is an excellent tracer of the domestic/hospital urban source in the Jalle River. With an annual flux estimated at 27 kg.yr-1 (23 mg.hab-1.yr-1) of dissolved Gdantrh in the Garonne River, the Bordeaux Metropole contributes nearly 25% of the Gd in the main branch of the Gironde Estuary. This flux have probably evolved like those of the Garonne at its outlet (before Bordeaux Metropole) which have doubled over the past two decades (2003: 32 kg.yr-1; 2017: 75 kg.yr-1) due to the increase in MRIs on the Garonne watershed. The high temporal analysis of a major summer rainstorm showed that the relative contributions of the daily TM fluxes of the Jalle River ranged from: 5 %(Sr) - 40%(Cu) for dissolved phases and 30% (As) â 88% (Cu) for particulate phases. The first forty minutes of the event (<17% of time) accounted for 65% of the SPM flux (and associated particulate TMs) exported by the stormwater runoff because of the first-flush of road dust. If Cu and Zn fluxes had significant contribution for the Jalle River, they are not good tracers of traffic-related source because of their ubiquitous uses. Although cerium anomalies are still weak, it should be a future good tracer with higher traffic density and technological development in catalytic converters. Using a 2-year monitoring along the Jalle continuum, this study demonstrated the upstream watershed strongly influences the geochemical composition of the Jalle River for many majors and TMs (e.g. Al, Fe, REEs) and that it contributes the bulk of dissolved TM fluxes (Al: 96%; REEs: 96 - 99%). The domestic source, via the WWTP loads, continuously affects the quality of the Jalle waters by significantly increasing dissolved Ni, Sn, Cu, Ag and Gd concentrations, mainly during low water conditions due to lower dilution by the upstream Jalle River. Conversely, the traffic-related (highway) source influences the Jalle River only more intermittently with regard to dissolved and particulate Cu, Zn, Sb during major summer rainstorm. Finally, further works on geochemical cycles of TMs at the urban-estuarine interfaces will be essential to reduce dispersion of TMs in urban systems, in order to limit impacts on natural environmental systems and to develop methods for the recovery and recycling of technology-critical elements.La lutte contre les micropolluants mĂ©talliques urbains reprĂ©sente un enjeu vĂ©ritablement majeur et complexe, en particulier dans les zones cĂŽtiĂšres, du fait dâune urbanisation croissante et de lâĂ©mission de formes Ă©mergentes de contaminants mĂ©talliques comme les Terres Rares. Cette thĂšse sâinscrit dans le cadre du projet REGARD et vise Ă comprendre la dynamique des ETM classiques et des Terres Rares dans la Jalle, principale riviĂšre urbaine drainant lâagglomĂ©ration bordelaise, et Ă Ă©valuer son influence sur lâestuaire de la Gironde, aprĂšs avoir caractĂ©risĂ© deux sources urbaines majeures : les eaux usĂ©es domestiques et les eaux pluviales drainant la rocade bordelaise. Du fait, de son utilisation comme agent de contraste pour les IRM et de son faible abattement dans les STEU, le gadolinium (Gd) est un excellent traceur de la source urbaine domestique/hospitaliĂšre dans la Jalle. Avec des rejets estimĂ©s Ă 27 kg.an-1 (23 mg.hab-1.an-1) de Gdantrh dissous, la MĂ©tropole de Bordeaux contribue Ă prĂšs de 25% de Gd exportĂ© par la Garonne dans lâestuaire de la Gironde. Ces flux ont probablement Ă©voluĂ© comme ceux de la Garonne en amont de Bordeaux qui ont doublĂ© au cours des deux derniĂšres dĂ©cennies (2003 : 32 kg.an-1; 2017: 75 kg.an-1) du fait de la multiplication des IRM sur le bassin. Lâanalyse Ă haute frĂ©quence dâun Ă©vĂšnement orageux estival a dĂ©montrĂ© que les eaux pluviales pouvaient contribuer entre 5% (Sr) et 40% (Cu) pour les ETM dissous et 30% (As) et 88% (Cu) pour les ETM particulaires aux flux exportĂ©s par la Jalle. Les premiĂšres quarante minutes de cet Ă©vĂšnement ont nĂ©cessitĂ© dâĂȘtre caractĂ©risĂ©es avec prĂ©cision du fait dâun effet « first flush » qui a lessivĂ© les poussiĂšres de route et Ă©vacuĂ© vers le milieu naturel 65% du flux de MES (et dâETM associĂ©s) en 17% du temps. Si les flux de Cu et Zn provenant du collecteur de la rocade ont une contribution significative pour la Jalle, ils ne sont pas de bons traceurs de la source autoroutiĂšre en raison de leurs usages ubiquistes. Bien que les anomalies restent encore faibles, le cĂ©rium pourrait devenir un futur bon traceur de cette source avec la gĂ©nĂ©ralisation des convertisseurs catalytiques. A lâĂ©chelle annuelle, la qualitĂ© des eaux de la Jalle apparaĂźt majoritairement contrĂŽlĂ©e par des sources naturelles, en particulier le lessivage de podzosols localisĂ©s en amont, permettant dâexpliquer Ă eux seuls les flux annuels en Ald (96%) et en REE dissoutes (96%-99%) transitant Ă lâexutoire de la Jalle. La source domestique, via les rejets de la STEU, apparaĂźt comme une source de pollution chronique pour la Jalle pour plusieurs ETM dissous (e.g. Nid, Snd, Cud, Agd et Gdd) avec une importance accrue en Ă©tiage du fait dâune moindre dilution. A lâinverse, la source autoroutiĂšre influence la Jalle de maniĂšre plus ponctuelle avec des apports en Cu, Zn et Sb dissous et particulaires lors dâĂ©vĂšnements pluviaux. En raison de lâaugmentation de la population et de lâurbanisation croissante, il apparaĂźt nĂ©cessaire de poursuivre des travaux sur le cycle des ETM dans les grandes mĂ©tropoles estuariennes afin de rĂ©duire leur dispersion dâamĂ©liorer la qualitĂ© des Ă©cosystĂšmes rĂ©cepteurs et pour dĂ©velopper des techniques de rĂ©cupĂ©ration et recyclage des ETM, face Ă des difficultĂ©s dâapprovisionnement
Dynamique des Ă©lĂ©ments traces mĂ©talliques Ă lâinterface ville-estuaire : mĂ©taux classiques et terres rares.
Control of urban pollutants is a major issue, especially in coastal areas, in a context of rapidly growing urbanization and the emission of emerging potentially highly toxic contaminants, such as Rare Earth Elements (REEs). This study is a part of the REGARD project and aims at understanding the dynamics of âconventionalâ trace metals (Tms) and REEs in the Jalle River, the main urban hydrosystem draining the Bordeaux Metropole and to assess its influence on the Garonne section of the Gironde estuary after having characterized two major urban sources: domestic wastewater and stormwater runoff draining the Bordeaux Highway. Due to its use as a contrast agent for MRIs and its low removal in WWTPs, gadolinium (Gd) is an excellent tracer of the domestic/hospital urban source in the Jalle River. With an annual flux estimated at 27 kg.yr-1 (23 mg.hab-1.yr-1) of dissolved Gdantrh in the Garonne River, the Bordeaux Metropole contributes nearly 25% of the Gd in the main branch of the Gironde Estuary. This flux have probably evolved like those of the Garonne at its outlet (before Bordeaux Metropole) which have doubled over the past two decades (2003: 32 kg.yr-1; 2017: 75 kg.yr-1) due to the increase in MRIs on the Garonne watershed. The high temporal analysis of a major summer rainstorm showed that the relative contributions of the daily TM fluxes of the Jalle River ranged from: 5 %(Sr) - 40%(Cu) for dissolved phases and 30% (As) â 88% (Cu) for particulate phases. The first forty minutes of the event (<17% of time) accounted for 65% of the SPM flux (and associated particulate TMs) exported by the stormwater runoff because of the first-flush of road dust. If Cu and Zn fluxes had significant contribution for the Jalle River, they are not good tracers of traffic-related source because of their ubiquitous uses. Although cerium anomalies are still weak, it should be a future good tracer with higher traffic density and technological development in catalytic converters. Using a 2-year monitoring along the Jalle continuum, this study demonstrated the upstream watershed strongly influences the geochemical composition of the Jalle River for many majors and TMs (e.g. Al, Fe, REEs) and that it contributes the bulk of dissolved TM fluxes (Al: 96%; REEs: 96 - 99%). The domestic source, via the WWTP loads, continuously affects the quality of the Jalle waters by significantly increasing dissolved Ni, Sn, Cu, Ag and Gd concentrations, mainly during low water conditions due to lower dilution by the upstream Jalle River. Conversely, the traffic-related (highway) source influences the Jalle River only more intermittently with regard to dissolved and particulate Cu, Zn, Sb during major summer rainstorm. Finally, further works on geochemical cycles of TMs at the urban-estuarine interfaces will be essential to reduce dispersion of TMs in urban systems, in order to limit impacts on natural environmental systems and to develop methods for the recovery and recycling of technology-critical elements.La lutte contre les micropolluants mĂ©talliques urbains reprĂ©sente un enjeu vĂ©ritablement majeur et complexe, en particulier dans les zones cĂŽtiĂšres, du fait dâune urbanisation croissante et de lâĂ©mission de formes Ă©mergentes de contaminants mĂ©talliques comme les Terres Rares. Cette thĂšse sâinscrit dans le cadre du projet REGARD et vise Ă comprendre la dynamique des ETM classiques et des Terres Rares dans la Jalle, principale riviĂšre urbaine drainant lâagglomĂ©ration bordelaise, et Ă Ă©valuer son influence sur lâestuaire de la Gironde, aprĂšs avoir caractĂ©risĂ© deux sources urbaines majeures : les eaux usĂ©es domestiques et les eaux pluviales drainant la rocade bordelaise. Du fait, de son utilisation comme agent de contraste pour les IRM et de son faible abattement dans les STEU, le gadolinium (Gd) est un excellent traceur de la source urbaine domestique/hospitaliĂšre dans la Jalle. Avec des rejets estimĂ©s Ă 27 kg.an-1 (23 mg.hab-1.an-1) de Gdantrh dissous, la MĂ©tropole de Bordeaux contribue Ă prĂšs de 25% de Gd exportĂ© par la Garonne dans lâestuaire de la Gironde. Ces flux ont probablement Ă©voluĂ© comme ceux de la Garonne en amont de Bordeaux qui ont doublĂ© au cours des deux derniĂšres dĂ©cennies (2003 : 32 kg.an-1; 2017: 75 kg.an-1) du fait de la multiplication des IRM sur le bassin. Lâanalyse Ă haute frĂ©quence dâun Ă©vĂšnement orageux estival a dĂ©montrĂ© que les eaux pluviales pouvaient contribuer entre 5% (Sr) et 40% (Cu) pour les ETM dissous et 30% (As) et 88% (Cu) pour les ETM particulaires aux flux exportĂ©s par la Jalle. Les premiĂšres quarante minutes de cet Ă©vĂšnement ont nĂ©cessitĂ© dâĂȘtre caractĂ©risĂ©es avec prĂ©cision du fait dâun effet « first flush » qui a lessivĂ© les poussiĂšres de route et Ă©vacuĂ© vers le milieu naturel 65% du flux de MES (et dâETM associĂ©s) en 17% du temps. Si les flux de Cu et Zn provenant du collecteur de la rocade ont une contribution significative pour la Jalle, ils ne sont pas de bons traceurs de la source autoroutiĂšre en raison de leurs usages ubiquistes. Bien que les anomalies restent encore faibles, le cĂ©rium pourrait devenir un futur bon traceur de cette source avec la gĂ©nĂ©ralisation des convertisseurs catalytiques. A lâĂ©chelle annuelle, la qualitĂ© des eaux de la Jalle apparaĂźt majoritairement contrĂŽlĂ©e par des sources naturelles, en particulier le lessivage de podzosols localisĂ©s en amont, permettant dâexpliquer Ă eux seuls les flux annuels en Ald (96%) et en REE dissoutes (96%-99%) transitant Ă lâexutoire de la Jalle. La source domestique, via les rejets de la STEU, apparaĂźt comme une source de pollution chronique pour la Jalle pour plusieurs ETM dissous (e.g. Nid, Snd, Cud, Agd et Gdd) avec une importance accrue en Ă©tiage du fait dâune moindre dilution. A lâinverse, la source autoroutiĂšre influence la Jalle de maniĂšre plus ponctuelle avec des apports en Cu, Zn et Sb dissous et particulaires lors dâĂ©vĂšnements pluviaux. En raison de lâaugmentation de la population et de lâurbanisation croissante, il apparaĂźt nĂ©cessaire de poursuivre des travaux sur le cycle des ETM dans les grandes mĂ©tropoles estuariennes afin de rĂ©duire leur dispersion dâamĂ©liorer la qualitĂ© des Ă©cosystĂšmes rĂ©cepteurs et pour dĂ©velopper des techniques de rĂ©cupĂ©ration et recyclage des ETM, face Ă des difficultĂ©s dâapprovisionnement
Dynamics of trace elements at the urban-estuarine interface : classical metals and rare earth elements.
La lutte contre les micropolluants mĂ©talliques urbains reprĂ©sente un enjeu vĂ©ritablement majeur et complexe, en particulier dans les zones cĂŽtiĂšres, du fait dâune urbanisation croissante et de lâĂ©mission de formes Ă©mergentes de contaminants mĂ©talliques comme les Terres Rares. Cette thĂšse sâinscrit dans le cadre du projet REGARD et vise Ă comprendre la dynamique des ETM classiques et des Terres Rares dans la Jalle, principale riviĂšre urbaine drainant lâagglomĂ©ration bordelaise, et Ă Ă©valuer son influence sur lâestuaire de la Gironde, aprĂšs avoir caractĂ©risĂ© deux sources urbaines majeures : les eaux usĂ©es domestiques et les eaux pluviales drainant la rocade bordelaise. Du fait, de son utilisation comme agent de contraste pour les IRM et de son faible abattement dans les STEU, le gadolinium (Gd) est un excellent traceur de la source urbaine domestique/hospitaliĂšre dans la Jalle. Avec des rejets estimĂ©s Ă 27 kg.an-1 (23 mg.hab-1.an-1) de Gdantrh dissous, la MĂ©tropole de Bordeaux contribue Ă prĂšs de 25% de Gd exportĂ© par la Garonne dans lâestuaire de la Gironde. Ces flux ont probablement Ă©voluĂ© comme ceux de la Garonne en amont de Bordeaux qui ont doublĂ© au cours des deux derniĂšres dĂ©cennies (2003 : 32 kg.an-1; 2017: 75 kg.an-1) du fait de la multiplication des IRM sur le bassin. Lâanalyse Ă haute frĂ©quence dâun Ă©vĂšnement orageux estival a dĂ©montrĂ© que les eaux pluviales pouvaient contribuer entre 5% (Sr) et 40% (Cu) pour les ETM dissous et 30% (As) et 88% (Cu) pour les ETM particulaires aux flux exportĂ©s par la Jalle. Les premiĂšres quarante minutes de cet Ă©vĂšnement ont nĂ©cessitĂ© dâĂȘtre caractĂ©risĂ©es avec prĂ©cision du fait dâun effet « first flush » qui a lessivĂ© les poussiĂšres de route et Ă©vacuĂ© vers le milieu naturel 65% du flux de MES (et dâETM associĂ©s) en 17% du temps. Si les flux de Cu et Zn provenant du collecteur de la rocade ont une contribution significative pour la Jalle, ils ne sont pas de bons traceurs de la source autoroutiĂšre en raison de leurs usages ubiquistes. Bien que les anomalies restent encore faibles, le cĂ©rium pourrait devenir un futur bon traceur de cette source avec la gĂ©nĂ©ralisation des convertisseurs catalytiques. A lâĂ©chelle annuelle, la qualitĂ© des eaux de la Jalle apparaĂźt majoritairement contrĂŽlĂ©e par des sources naturelles, en particulier le lessivage de podzosols localisĂ©s en amont, permettant dâexpliquer Ă eux seuls les flux annuels en Ald (96%) et en REE dissoutes (96%-99%) transitant Ă lâexutoire de la Jalle. La source domestique, via les rejets de la STEU, apparaĂźt comme une source de pollution chronique pour la Jalle pour plusieurs ETM dissous (e.g. Nid, Snd, Cud, Agd et Gdd) avec une importance accrue en Ă©tiage du fait dâune moindre dilution. A lâinverse, la source autoroutiĂšre influence la Jalle de maniĂšre plus ponctuelle avec des apports en Cu, Zn et Sb dissous et particulaires lors dâĂ©vĂšnements pluviaux. En raison de lâaugmentation de la population et de lâurbanisation croissante, il apparaĂźt nĂ©cessaire de poursuivre des travaux sur le cycle des ETM dans les grandes mĂ©tropoles estuariennes afin de rĂ©duire leur dispersion dâamĂ©liorer la qualitĂ© des Ă©cosystĂšmes rĂ©cepteurs et pour dĂ©velopper des techniques de rĂ©cupĂ©ration et recyclage des ETM, face Ă des difficultĂ©s dâapprovisionnement.Control of urban pollutants is a major issue, especially in coastal areas, in a context of rapidly growing urbanization and the emission of emerging potentially highly toxic contaminants, such as Rare Earth Elements (REEs). This study is a part of the REGARD project and aims at understanding the dynamics of âconventionalâ trace metals (Tms) and REEs in the Jalle River, the main urban hydrosystem draining the Bordeaux Metropole and to assess its influence on the Garonne section of the Gironde estuary after having characterized two major urban sources: domestic wastewater and stormwater runoff draining the Bordeaux Highway. Due to its use as a contrast agent for MRIs and its low removal in WWTPs, gadolinium (Gd) is an excellent tracer of the domestic/hospital urban source in the Jalle River. With an annual flux estimated at 27 kg.yr-1 (23 mg.hab-1.yr-1) of dissolved Gdantrh in the Garonne River, the Bordeaux Metropole contributes nearly 25% of the Gd in the main branch of the Gironde Estuary. This flux have probably evolved like those of the Garonne at its outlet (before Bordeaux Metropole) which have doubled over the past two decades (2003: 32 kg.yr-1; 2017: 75 kg.yr-1) due to the increase in MRIs on the Garonne watershed. The high temporal analysis of a major summer rainstorm showed that the relative contributions of the daily TM fluxes of the Jalle River ranged from: 5 %(Sr) - 40%(Cu) for dissolved phases and 30% (As) â 88% (Cu) for particulate phases. The first forty minutes of the event (<17% of time) accounted for 65% of the SPM flux (and associated particulate TMs) exported by the stormwater runoff because of the first-flush of road dust. If Cu and Zn fluxes had significant contribution for the Jalle River, they are not good tracers of traffic-related source because of their ubiquitous uses. Although cerium anomalies are still weak, it should be a future good tracer with higher traffic density and technological development in catalytic converters. Using a 2-year monitoring along the Jalle continuum, this study demonstrated the upstream watershed strongly influences the geochemical composition of the Jalle River for many majors and TMs (e.g. Al, Fe, REEs) and that it contributes the bulk of dissolved TM fluxes (Al: 96%; REEs: 96 - 99%). The domestic source, via the WWTP loads, continuously affects the quality of the Jalle waters by significantly increasing dissolved Ni, Sn, Cu, Ag and Gd concentrations, mainly during low water conditions due to lower dilution by the upstream Jalle River. Conversely, the traffic-related (highway) source influences the Jalle River only more intermittently with regard to dissolved and particulate Cu, Zn, Sb during major summer rainstorm. Finally, further works on geochemical cycles of TMs at the urban-estuarine interfaces will be essential to reduce dispersion of TMs in urban systems, in order to limit impacts on natural environmental systems and to develop methods for the recovery and recycling of technology-critical elements
Les consultations répétées aux urgences pédiatriques du CHU de Caen (une étude prospective observationnelle)
CAEN-BU MĂ©decine pharmacie (141182102) / SudocSudocFranceF
European fluxes of medical gadolinium to the ocean: A model based on healthcare databases
Marine ecosystems are exposed to a multitude of stresses, including emerging metals as Rare Earth Elements. The management of these emerging contaminants represents a significant environmental issue. For the past three decades, the increasing medical use of gadolinium-based contrast agents (GBCAs) has contributed to their widespread dispersion in hydrosystems, raising concerns for ocean conservation. In order to control GBCA contamination pathways, a better understanding of the cycle of these elements is needed, based on the reliable characterization of fluxes from watersheds.Our study proposes an unprecedented annual flux model for anthropogenic gadolinium (Gdanth) based on GBCA consumption, demographics and medical uses. This model enabled the mapping of Gdanth fluxes for 48 European countries. The results show that 43Â % of Gdanth is exported to the Atlantic Ocean, 24Â % to the Black Sea, 23Â % to the Mediterranean Sea and 9Â % to the Baltic Sea. Together, Germany, France and Italy contribute 40Â % of Europeâs annual flux. Our study was therefore able to identify the current and future major contributors to Gdanth flux in Europe and identify abrupt changes related to the COVID-19 pandemic
Corbicula fluminea: A sentinel species for urban Rare Earth Element origin
International audienceThe increase in the global population, coupled with growing consumption of Rare Earth Elements (REEs), has led to increasing transfer of these emerging contaminants into the environment, particularly through the effluents from wastewater treatment plants (WWTP). The objectives of this study were to determine the geochemical quality of a French river subject to strong urban pressure (the Jalle River in the Bordeaux area) and to examine the bioavailability of natural and anthropogenic REEs in a model species of freshwater bivalve, the Asian clam Corbicula fluminea. To this end, two fractions (dissolved and total) of the water from the Jalle River were sampled and the bivalves were exposed by in situ caging during a three-month monitoring period. The REE patterns obtained showed the presence of Gadolinium (Gd) anomalies in the dissolved and total fractions as well as in Corbicula fluminea. The apparent bioavailability of natural REEs was in the following order for the dissolved fraction: Medium REEs (MREEs) > Light REEs (LREEs) > Heavy REEs (HREEs) and for the particulate fraction: MREEs > LREEs = HREEs. These results highlight the importance of the particulate fraction in the study of the bioavailability of REEs in bivalves. An increase of anthropogenic Gd (Gdanth) was observed in the dissolved fraction between the upstream site (3.4 ng.Lâ1) and the WWTP Downstream site (48.4 ng.Lâ1). The Gd anomaly observed in the water was also observed in Corbicula fluminea with a significant increase in the bioaccumulation of Gdanth, from 1.5 ± 1 ng.gDWâ1 upstream to 4.1 ± 0.7 ng.gDWâ1 downstream of the WWTP effluents, thus confirming the enhanced bioavailability of medical-origin Gd to freshwater bivalves. This study strongly suggests that Corbicula fluminea can be used as a sentinel species in the monitoring of Gd contamination of medical origin. It would thus appear important to consider the potential entry of this contaminant into the human food chain via other, commercially exploited bivalve species
Impacts of highway runoff on metal contamination including rare earth elements in a small urban watershed: case study of Bordeaux Metropole (SW France)
International audienceHigh temporal resolution sampling of runoff (15 samples/4 h) and river water (24 samples/24 h) was performed during a major rainstorm (41 mm/4 h) in the Bordeaux Metropole, after a dry and high vehicle-density period. Runoff was sampled at the outlet of one collector draining Northern Bordeaux Highway (NBH; 80,000â93,000 vehicles/day) and river water in the downstream Jalle River. The studied metals, including priority and emergent (Rare Earth Elements [REEs]) contaminants, showed major temporal and spatial variations in the dissolved and particulate concentrations. Hierarchical cluster analyses distinguished metal groups, reflecting different: (i) sources (i.e., automotive traffic: ZnâCuâCe and wastewater treatment plant: CdâAgâGd) and/or (ii) processes (i.e., groundwater dilution by rainwater and sorption processes). The contribution of the particulate fraction to total metal fluxes was predominant in the NBH collector (except for Sr and Mo) and highly variable in the Jalle River, where the highest particulate metal loads were due to the export of road dusts exported by the NBH collector. Metal fluxes from the NBH collector represented highly variable fractions of daily fluxes into the Gironde Estuary at the outlet of the Jalle River, depending on elements and partitioning. The resulting relative contributions ranged from: 5% (Sr) to 40% (Cu) for dissolved phases and 30% (As) to 88% (Cu) for particulate phases. The first 40 min of the event accounted for 65% of the suspended particulate matter flux (and associated particulate metals) exported by the NBH collector, whereas the respective water flux contribution was 35%. This finding clearly demonstrates the importance of monitoring the first minutes of rainy events when establishing mass balances in urban systems
Rare Earth Element fluxes over 15âŻyears into a major European Estuary (Garonne-Gironde, SW France): Hospital effluents as a source of increasing gadolinium anomalies
International audienceNew and rapidly developing technologies imply the emission of emerging potentially toxic contaminants such as Rare Earth Elements (REEs). Yet, the lithology-derived quantities and anthropogenic contributions, especially from urban areas, to annual REE fluxes into fluvial-estuarine systems remain widely unknown. The Garonne River drains water from ~20% of the French land surface hosting about 5,200,000 inhabitants and two large cities. Based on long-term monitoring (2003â2017) of water discharges and dissolved REEs concentrations at the outlet of the Garonne Watershed upstream from Bordeaux, this study aims at assessing REE anomalies and evaluating temporal evolution of annual dissolved REE fluxes into the Gironde Estuary. Additionally, potential urban sources (e.g. domestic, medical) in the urban area of Bordeaux (1,190,000 inhab.) were analyzed to evaluate respective signatures and contributions. Gadolinium (Gd) showed clear anomalies in all samples, with annual average anthropogenic concentrations ranging from 1.8 to 7.2âŻng·Lâ1 (0.011 to 0.046âŻnmol·Lâ1) in the Garonne River. If variations in annual Gd fluxes depend on hydrology, anthropogenic Gd fluxes have shown an overall increasing trend from 32âŻkg·yearâ1 (204âŻmol·yearâ1) in 2003 to 75âŻkg·yearâ1 (475âŻmol·yearâ1) in 2017. Sewer waters from the third largest hospital complex of France, the hospital group Pellegrin, contributed 25% to the incoming daily Gd flux into Bordeaux major Waste Water Treatment Plant (WWTP), owed to Gd use as contrast agent for Magnetic Resonance Imaging (MRI). Due to weak removal efficiency in the WWTP, the Bordeaux Metropole significantly contributes (>27âŻkg·yearâ1; 172âŻmol·yearâ1) to Gd fluxes in the Gironde Estuary. The temporal evolution of anthropogenic Gd fluxes in the Garonne River may be related with the growing regional population and the increasing number of MRI instruments, highlighting the importance of new high-tech applications in urban areas on contaminant fluxes and their potential harmful effects in fluvial-estuarine systems in the future
Calpain activation by hepatitis C virus proteins inhibits the extrinsic apoptotic signaling pathway
International audienc