Potential risks of metal toxicity in contaminated sediments of Deûle river in Northern France

International audienceThe aim of this paper was to evaluate the potential sediment cumulative damage and toxicity due to metal contamination in a polluted zone of Deûle river (in northern France) from nearby two smelters. Metal-enrichment factors and geoaccumulation indices measured with sediment depth revealed that - compared to background levels either in local reference soils or in world rivers sediments/suspended particulate matter - Cd contributed to the highest pollution levels, followed by Zn, Pb and to a much lesser extent Cu and Ni. A comparison of the vertical distribution of AVS (acid volatile sulfides), SEM (simultaneously extracted metals), TMC (total metal concentrations), TOC (total organic carbon) and interstitial water-metal concentrations in the sediment allowed us to highlight the extent of toxicity caused by Cd, Pb, Zn, Ni and Cu and to raise the possibility of their association with certain geochemical phases. To assess the actual environmental impacts of these metals in Deûle river, numerical sediment quality guidelines were further used in the present work. Sedimentary Pb, Zn, and Cd contents largely exceeded PEC (probable effect concentration) values reported as consensus-based sediment quality guidelines for freshwater ecosystems. As for risks of toxicity from pore waters, metal concentrations reached their maxima at the surficial layers of the sediment (1-3. cm) and IWCTU (Interstitial Water Criteria Toxicity Unit) observed for Pb and to a lesser extent Cd, violated the corresponding water quality data recommended by USEPA

Genome-wide association analyses identify new Brugada syndrome risk loci and highlight a new mechanism of sodium channel regulation in disease susceptibility.

Brugada syndrome (BrS) is a cardiac arrhythmia disorder associated with sudden death in young adults. With the exception of SCN5A, encoding the cardiac sodium channel Na1.5, susceptibility genes remain largely unknown. Here we performed a genome-wide association meta-analysis comprising 2,820 unrelated cases with BrS and 10,001 controls, and identified 21 association signals at 12 loci (10 new). Single nucleotide polymorphism (SNP)-heritability estimates indicate a strong polygenic influence. Polygenic risk score analyses based on the 21 susceptibility variants demonstrate varying cumulative contribution of common risk alleles among different patient subgroups, as well as genetic associations with cardiac electrical traits and disorders in the general population. The predominance of cardiac transcription factor loci indicates that transcriptional regulation is a key feature of BrS pathogenesis. Furthermore, functional studies conducted on MAPRE2, encoding the microtubule plus-end binding protein EB2, point to microtubule-related trafficking effects on Na1.5 expression as a new underlying molecular mechanism. Taken together, these findings broaden our understanding of the genetic architecture of BrS and provide new insights into its molecular underpinnings

Géochimie des métaux et du soufre dans les sédiments des estuaires de la Seine et de l'Authie

L'étude de la spéciation des métaux et du soufre dans trois carottes sédimentaires de la baie d'Authie et de la vasière nord de l'estuaire de la Seine a été réalisée afin de mieux comprendre le comportement des contaminants métalliques au cours de la diagenèse précoce (qui est considérée par les géochimistes comme l'ensemble des transformations biogéochimiques ayant lieu dans les premiers centimètres de la colonne sédimentaire). Grâce à l'activité bactérienne dans le sédiment, le carbone organique est décomposé et parallèlement, l'oxygène, les nitrates, les oxydes de fer et de manganèse puis les sulfates sont réduits. Pour notre part, nous avons pu mettre en évidence que ces réactions d'oxydoréduction induisent une redistribution des métaux au sein du sédiment par des réactions de complexation et de précipitation/redissolution qui les rendent plus ou moins réactifs. De plus, à travers notre travail concernant le marquage anthropique, nous avons montré que le sédiment peut se comporter comme un réservoir mais également comme un puits pour de nombreux polluants métalliques (Cd, Cu, Ni, Pb, Zn). Enfin, les résultats d'analyses des eaux interstitielles et ceux issus de la spéciation du soufre dans les phases liquide et solide (au sein de laquelle sont présents des sulfures peu stables comme FeS et des composés plus réfractaires, comme la pyrite) nous ont conduit à réaliser des calculs d'équilibres thermodynamiques. Ces derniers nous ont permis de prédire et en partie de vérifier (par analyses RX, micro-Raman, RPE) la formation de phases discrètes et de solutions solides.LILLE1-BU (590092102) / SudocSudocFranceF

Submillimetric pH measurement in interstitial water using a DET method based on an anion exchange resin coupled with pH indicators in a binding gel

International audienc

Impact des remises en suspension du sédiment liées au trafic fluvial en rivières canalisées sur l'état des masses d'eau (application au bassin Artois-Picardie)

La canalisation et la création de canaux de liaison, destinées à faciliter le développement industriel et les échanges commerciaux ont entraîné une forte pollution historique ainsi qu une artificialisation de milieux naturels, désormais soumis aux objectifs de bon potentiel. La remise en suspension par le trafic fluvial des sédiments pose la question de son impact sur la qualité des eaux et sur l atteinte des objectifs d état. L étude de la qualité chimique des sédiments et de l eau de trois canaux du Nord de la France, la Deûle, la Sensée (naviguées) et la Scarpe (non naviguée) montre que ceux-ci présentent des concentrations variables en P et en ETM (globalement Deûle ~ Scarpe > Sensée), ces derniers restant globalement bien piégés par les sulfures dans les sédiments. Même si les concentrations en ETM dissous restent relativement faibles par rapport aux concentrations enregistrées dans les sédiments, elles peuvent parfois excéder les normes de qualité environnementales de la DCE. La labilité de ces ETM estimée par les DGT s avère faible y compris pour Pb qui est cependant accumulé de façon importante par les gammares encagés déployés sur les trois sites. La navigation ne semble jouer qu un rôle limité sur l enrichissement de la colonne d eau en métaux et en phosphore dissous, ainsi que sur l oxygénation des eaux de surface. Le phytoplancton apparaît avoir une influence plus importante que la navigation sur l évolution de ces milieux. Finalement, l impact de la navigation sur la qualité chimique de l eau reste limité en raison de la géochimie singulière du bassin Artois-Picardie.Rivers channelization and creation of linking channels to facilitate industrial development and trade have led to a strong historical pollution and artificialization of aquatic environments that are now subjected to good potential status objectives. Sediment resuspension by navigation, its impact on water quality and the achievement of status are the main concern of this thesis. Sediment and water chemical quality of three channels of Northern France have been studied: the Deûle River, the Sensée River (both navigated) and the Scarpe River (not navigated). The rivers have varying concentrations of P and ETM (overall Deûle ~ Scarpe > Sensée), which are generally well trapped with sulfides in sediments. Although the concentrations of dissolved ETM remain relatively low compared to the levels recorded in the sediment, they can sometimes exceed the environmental quality standards of the WFD. Lability of these ETM estimated by DGT is weak, even for Pb which is however significantly accumulated by caged gammarids deployed on the three sites. The navigation seems to play a limited role in the enrichment of the water column in dissolved metals and phosphorus, as well as the oxygenation of surface waters. Phytoplankton appears to have a greater influence on the evolution of these environments. Finally, the impact of navigation on the chemical quality of the water remains limited due to the peculiar geochemistry of the Artois-Picardie basin.LILLE1-Bib. Electronique (590099901) / SudocSudocFranceF

Gold and silver micro-wire electrodes for trace analysis of metals

International audienc

Separation of microplastics and sediments: a comparative analysis of extracting methods

International audienc

Direct determination of rare earth elements in natural water and digested sediment samples by inductively coupled plasma quadrupole mass spectrometry using collision cell

International audienceThe present study is based on the use of a conventional quadrupole ICP-MS for determining directly rare earth elements (REEs) in both fresh or slightly saline waters and digested sediments. The development of a robust method using a collision reaction cell (different collision gases and fluxes have been tested) and kinetic energy discrimination is proposed for the accurate quantification of REEs without any mathematical corrections and preconcentration steps. The choice of He gas over H2 and its flow in the collision reaction cell as well as the isotopes studied are thoroughly discussed with the aim of reducing drastically interferences. The exhaustive list of interferences (argides, chlorides, oxides, hydroxides, hydrides and doubly charged) has been investigated for the first time at different concentration levels, relevant with those found in environmental matrices based on the FORum of European Geological Surveys (FOREGS) database. The interference equivalent concentrations (IECs) have been determined and summarized. Although the impact of barium interferences onto europium and the impossibility to measure Sc have been pointed out, this method has been validated for all the other REEs in aquatic environmental matrices by studying the recoveries of spiked natural waters (5 commercially available mineral waters with dry residues ranging from 22 to 2,513 mg L−1 and a filtrated natural river water from Northern France) with relevant concentrations of REEs. Standard reference materials (i.e. three waters (AQUA-1, SLRS-6 and SLEW-3) and four sediments (BCR-667, HISS-1, Metranal-1 and PACS-3)) were also analysed to ensure the robustness of the method