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Sediment pollution: An assessment of anthropogenic and geogenic trace element contributions along the central Algerian coast
2023
Aroua, Mohamed | Boulahdid, Mostefa | Radakovitch, Olivier | Benhalima, Moustafa | Guendouzi, Yassine | Fowler, Scott | Ambrosi, Jean-Paul | Ecole Nationale Supérieure des Sciences de la Mer et de l'Aménagement du Littoral (ESSMAL) | Laboratoire de recherche sur les transferts des radionucléides dans les écosystèmes aquatiques (IRSN/PSE-ENV/SRTE/LRTA) ; Service de recherche sur les transferts et les effets des radionucléides sur les écosystèmes (IRSN/PSE-ENV/SRTE) ; Institut de Radioprotection et de Sûreté Nucléaire (IRSN)-Institut de Radioprotection et de Sûreté Nucléaire (IRSN) | Stony Brook University [SUNY] (SBU) ; State University of New York (SUNY) | Centre européen de recherche et d'enseignement des géosciences de l'environnement (CEREGE) ; Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Collège de France (CdF (institution))-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE) | This research work was financiallysupported by the French program METMAR-MERMEX as part of the PHCTASSILI project (Code PHC: 17MDU986; Title: Inputs, accumulationsand trace metal contamination in Algiers and Marseille coastal areas).
International audience | Sediment cores from the central Algerian coast were collected to investigate the distribution, sources and risk oftrace metals. The local geochemical background of metals was defined from the core S collected in an uncontaminatedarea of the coast. The anthropogenic inputs in Algiers Bay elevated Ag, Cd, Pb and Zn concentrationsas their maximum were 3.1, 3, 2.1 and 1.8 times the background values, respectively. Meanwhile, increasedcontents of Arsenic (up to 21.1 mg/kg) were detected in all sites. Correlations and PCA suggest that lithogenicsources controlled metal deposition, while most sediment arsenic was agriculture-derived. Organic matter actedas a sink or source for some trace metals. According to EFs, the study area showed slight to moderate enrichmentwith respect to Ag, As, Pb, Cd, Zn and Cu, whereas they remained uncontaminated with Cr, V, Co and Ni. Thisstudy provides a needed baseline for future environmental investigations.
Show more [+] Less [-]Insights on the particle-attached riverine archaeal community shifts linked to seasons and to multipollution during a Mediterranean extreme storm event
2023
Noyer, Mégane | Bernard, Maria | Verneau, Olivier | Palacios, Carmen | Centre de Formation et de Recherche sur les Environnements Méditérranéens (CEFREM) ; Université de Perpignan Via Domitia (UPVD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS) | Université de Perpignan Via Domitia (UPVD) | Génétique Animale et Biologie Intégrative (GABI) ; AgroParisTech-Université Paris-Saclay-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE) | Système d'Information des GENomes des Animaux d'Elevage (SIGENAE) ; Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)
International audience | Rivers are representative of the overall contamination found in their catchment area. Contaminant concentrations in watercourses depend on numerous factors including land use and rainfall events. Globally, in Mediterranean regions, rainstorms are at the origin of fluvial multipollution phenomena as a result of Combined Sewer Overflows (CSOs) and floods. Large loads of urban-associated microorganisms, including faecal bacteria, are released from CSOs which place public health - as well as ecosystems - at risk. The impacts of freshwater contamination on river ecosystems have not yet been adequately addressed, as is the case for the release of pollutant mixtures linked to extreme weather events. In this context, microbial communities provide critical ecosystem services as they are the only biological compartment capable of degrading or transforming pollutants. Through the use of 16S rRNA gene metabarcoding of environmental DNA at different seasons and during a flood event in a typical Mediterranean coastal river, we show that the impacts of multipollution phenomena on structural shifts in the particle-attached riverine bacteriome were greater than those of seasonality. Key players were identified via multivariate statistical modelling combined with network module eigengene analysis. These included species highly resistant to pollutants as well as pathogens. Their rapid response to contaminant mixtures makes them ideal candidates as potential early biosignatures of multipollution stress. Multiple resistance gene transfer is likely enhanced with drastic consequences for the environment and human-health, particularly in a scenario of intensification of extreme hydrological events.
Show more [+] Less [-]Potential of fluorescent tracers to appraise biochar amendment strategies for pesticide mitigation — insights from comparative sorption
2023
Sene, Seynabou | Dollinger, Jeanne | Hammecker, Claude | Lagacherie, Manon | Negro, Sandrine | Samouëlian, Anatja | Laboratoire d'étude des Interactions Sol - Agrosystème - Hydrosystème (UMR LISAH) ; Institut de Recherche pour le Développement (IRD)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut Agro Montpellier ; Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro) | The study was funded by the Carbonex Company in the framework of a research and development project.
Mitigation of pesticide dispersion in soil and water is required to protect ecosystem health and the anthropic uses of water bodies. Biochar amendments have been suggested to reduce pesticide dispersion due to their high sorption potentials. Nevertheless, appraisals at different scales have been limited by the costs of pesticide analyses. The aim of this study was to evaluate the potential of two fluorescent tracers, uranine (UR) and sulforhodamine B (SRB), for use as pesticide proxies in the context of biochar amendments used for mitigation purposes. Therefore, we compared the sorption processes of both fluorescent tracers and those of three pesticides, glyphosate, 2,4-D, and difenoconazole for soils; three wood biochars (pine, oak, and beech/charm blend); and soil/biochar mixtures representing agricultural usages. The results showed that the sorption of glyphosate by soil was unaffected by amendment with the tested pine, oak, and wood blend biochars. In contrast, the sorption coefficients of UR, SRB, 2,4-D, and difenoconazole were significantly increased with these biochar amendments. SRB, in particular, exhibited sorption behavior similar to that of the hydrophobic fungicide difenoconazole. This indicates promise for the use of SRB as a proxy for hydrophobic pesticides, in testing biochar amendments.
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