Trajectories of legacy and emerging metal contaminants in French river sediments
Trace metals and metalloids (TMMs) are substancesdisseminated in the critical zone (CZ) as a result of i. mechanicalerosion processes or chemical alteration of bedrocks anduncontaminated soils, and ii. releases from multiple sourcesrelated to anthropogenic activities during several millennia. Inrivers, legacy and emerging TMMs, including Rare EarthElements (REEs), are predominantly or partially adsorbed onsuspended particulate matter. Therefore, riverine transport ofnatural and anthropogenic TMMs depends on hydraulicconditions, and storage occurs in depositional zones (e.g.reservoirs, floodplains, ponds). As rivers are the receptacle formany substances released into the CZ, analysing temporal trendsof TMMs in dated sediment cores can reflect the trajectory ofcontaminant pressure in watersheds, as sediments are consideredas testimonies of past and current anthropogenic activities, andmay provide information about the potential future impacts ofemerging pollutants.This study aims at establishing regional geochemicalbackgrounds (RGB) and the trajectories of legacy and emergingTMMs in dated sediment cores at the outlets of the main Frenchriver watersheds (Rhône, Loire, Eure-Seine, Lot-Garonne).These investigations are supported by temporal TMM and REEtrends in watersheds characterized by contrasting geologicalfeatures. Preliminary results showed that mean REEconcentrations are approximatively twice higher in sedimentdeposits collected in the Loire River than in the Seine and RhoneRivers for which mean REE contents are relatively similar.Moreover, European Shale (EUS)-normalized concentrations ofREEs highlighted positive anomalies of light- and medium-REEsas Cerium (Ce), Samarium (Sm), and Europium (Eu). Theseanomalies determined in the Rhône and Loire Rivers, and in theEure-Seine continuum have not been systematically measured inthe most recent deposits as expected. As REE anomalies are notexclusively due to anthropogenic signals, but may also derivefrom lithology (calcareous versus crystalline rocks) andbiogeochemical processes, it appears essential to discriminate thecontributions of anthropogenic signals and RGB to totalconcentrations. Based on these results, we discuss the potentialof increasingly used Technology-Critical Elements (TCEs),recorded in sediment archives, as markers of the beginning of the4th industrial revolution.
(10/07/2022)
M2C, UNICAEN, NU, INSU - CNRS, UNIROUEN, NU, CNRS, COBRA, IRCOF, UNIROUEN, NU, INSA Rouen Normandie, INSA, NU, CNRS, UNIROUEN, NU, INSA Rouen Normandie, INSA, NU, INC3M, UNICAEN, NU, ENSICAEN, NU, ULH, NU, UNIROUEN, NU, INSA Rouen Normandie, INSA, NU, INC-CNRS, CNRS, INC-CNRS, CNRS, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, IRSN/PSE-ENV/SRTE/LRTA, IRSN/PSE-ENV/SRTE, IRSN, IRSN/PSE-ENV/SAME/LMRE, IRSN/PSE-ENV/SAME, IRSN, LEHNA, UCBL, ENTPE, CNRS, GéHCO, UT, NEOLAiA, IRSN/PSE-ENV/STAAR/LRTA, IRSN/PSE-ENV/STAAR, IRSN
Genetic improvement of shoreline evolution forecasting models
(pp. 1916-1923, 09/07/2022)
LEGOS, IRD, UT3, Comue de Toulouse, INSU - CNRS, CNES, CNRS, ISAE-SUPAERO, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, IRD, CNES
Machine-Learning Functional Zonation Approach for Characterizing Terrestrial–Aquatic Interfaces: Application to Lake Erie
Ecosystems at coastal terrestrial–aquatic interfaces play a significant role in global biogeochemical cycles. In this study, we aimed to characterize coastal wetlands with particular focus on the co-variability between plant dynamics, topography, soil, and other environmental factors. We proposed a functional zonation approach based on machine learning clustering to identify the spatial regions, i.e., zones that capture these co-varied properties. This approach was applied to publicly available datasets along Lake Erie, in the Great Lakes Region. We investigated the heterogeneity of coastal ecosystem structures as a function of along-shore distance and transverse distance, based on the spatial data layers, including topography, wetland vegetation cover, and the time series of Landsat’s enhanced vegetation index (EVI) between 1990 and 2020. Results showed that the topographic metrics (elevation and slope), soil texture, and plant productivity influence the spatial distribution of wetland land-covers (emergent and phragmites). These results highlight a natural organization along the transverse axis, where the elevation and the EVI increase further away from the coastline. In addition, the clustering analysis allowed us to identify regions with distinct environmental characteristics, as well as the ones that are more sensitive to interannual lake-level variations.
(Remote Sensing. vol. 14, n° 2072-4292, 08/07/2022)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
What are the key factors influencing sediment quality along Western European rivers?
The composition of sediments in rivers and large streams provides indicators on many processes in the critical zone such as chemical pollution. Since 1945, a large amount of data was produced in Europe by managers and researchers to assess and monitor the quality of water bodies. Within the framework of the Interpol project, a database of 12,000 samples was implemented to study the key factors involved in the variability of metal concentrations in sediments between 1945 and 2020 along 7 European river corridors (Rhone, Seine, Lot-Garonne, Loire, Scheldt, Meuse and Rhine). The exploitation of these data allowed us to determine that spatial (location) and temporal (critical pollution period) factors were the most significant. At this scale, factors such as the analytical protocol or the type of matrix have a secondary influence on the variability of concentrations. Trend analysis of Cd, Pb and Zn showed that the middle and downstream sections of the corridors are affected by urban and industrial hotspots, while upstream contamination is mostly influenced by historical mining areas. This work has made all the data compiled available to the scientific community and managers and provides new results concerning the effectiveness of regulations.
(04/07/2022)
LEHNA, UCBL, ENTPE, CNRS, LEHNA IAPHY, LEHNA, UCBL, ENTPE, CNRS, GEDI, LSCE, UVSQ, INSU - CNRS, CNRS, DRF (CEA), CEA, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, M2C, UNICAEN, NU, INSU - CNRS, UNIROUEN, NU, CNRS, OFB - DRAS, OFB, GéHCO, UT, NEOLAiA
Approche optique et moléculaire non-ciblée pour caractériser et tracer les sources naturelles et anthropiques de matière organique dissoute (MOD) à l'échelle d'un bassin versant péri-urbain Auteurs
Les activités anthropiques à l’échelle d’un bassin-versant peuvent être très nombreuses (e.g. pratiques agricoles, industrielles, transport, tourisme). Ces activités engendrent des pressions qui se manifestent par l’apport de polluants vers les cours d’eau (e.g. micropolluants organiques, métaux traces). Il reste encore difficile d’identifier l’ensemble de ces sources de polluants au niveau d’un bassin versant péri-urbain. Du fait de son ubiquité, la matière organique dans sa fraction dissoute (MOD) constitue un complexe de molécules originaire à la fois ces activités mais également de sources plus naturelles (e.g. lixiviation de sols non-anthropisé, production autochtone). Ainsi, cette étude vise à déterminer si la MOD à travers ses propriétés optiques et moléculaires peut constituer un marqueur de sources naturelles et anthropiques. Pour cela, différentes sources typiques d’occupations de sols forestières, agricoles, mais également issues de rejets de stations de traitement des eaux usées et de ruissellements urbains ont été identifiées et prélevées à l’échelle d’un bassin-versant périurbain (Bassin de l’Yzeron, Observatoire de terrain en hydrologie urbaine). La MOD des échantillons a été caractérisée par une série de techniques analytiques optiques (UV-Vis, fluorescence 3D et HPSEC/UV-fluo) et moléculaire (LC-HRMS). Des analyses statistiques ont étaient appliquées sur le jeu de données généré pour identifier des marqueurs de sources échantillonnées a priori. Les résultats montrent qu’une combinaison pertinente d’indicateurs optiques permet de différencier les types de sources naturelles et anthropiques de MOD. Les données issues des analyses moléculaires ont permis de mettre en évidence un ensemble de molécules communes à toutes les sources de MOD mais surtout des ensembles de molécules typique de chaque type de source. Ces empreintes moléculaires typiques sont caractérisées par des classes de polarité et de masse de molécules.
(04/07/2022)
RiverLy, INRAE, LPTC, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Copper contamination in vineyard soils of Bordeaux: spatial risk assessment for the replanting of vines and crops
Copper (Cu) is widely and historically used in viticulture as a fungicide against mildew. Cu has a strong affinity for soil organic matter and accumulates in topsoil horizons. Thus, Cu may negatively affect soil organisms and plants, consequently reducing soil fertility and productivity. The Bordeaux vineyards have the largest vineyard surfaces (26%) within French controlled appellation and a great proportion of French wine production (around 5 million hl per year). Considering the local context of vineyard surfaces decreasing (vine uprooting) and possible new crop plantation, the issue of Cu potential toxicity rises. Therefore, the aims of this work are firstly to evaluate the Cu contamination in vineyard soils of Bordeaux, secondly to produce a risk assessment map for new vine or crop plantation. We used soil analyses from several local studies to build a database with 4496 soil horizon samples. The database was enhanced by means of pedotransfer functions in order to estimate the bioaccessible (EDTA-extractable) Cu in soils of samples without measurements. From this database, 1797 georeferenced samples with CuEDTA concentrations in the topsoil (0-50 cm depth) were used for kriging interpolation in order to produce the spatial distribution map of CuEDTA in vineyard soils. Then, the spatial distribution of Cu was crossed with vine uprooting surfaces and municipality boundaries. CuEDTAconcentrations ranged from 0.52 to 459 mg/kg and showed clear anomalies. Our results from spatial analysis showed that almost 50% of vineyard soil surfaces have CuEDTA concentrations higher than 30 mg/kg (moderate risk for new plantation) and 20% with concentrations higher than 50 mg/kg (high risk for new plantation). A decision-support map based on municipalities was realised to provide a simple tool to stakeholders concerned by land use management.
(03/07/2022)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, Bordeaux Sciences Agro
Giant deep submarine depressions: A combined dissolution-mechanical process along carbonate margins
Abstract Submarine depressions are common features on the eastern Bahamian seafloor but the genesis of the deepest ones (>4000 m in water depth) is not well understood. We conducted a morphometric analysis and compared them to a worldwide database of rounded depressions, whatever their genesis is. The deep Bahamian depressions are large elongated structures, among the largest on Earth, with a width greater than 1000 m and a depth sometimes greater than 200 m. They extend at the toe of the Blake Bahama Escarpment (BBE), one of the tallest escarpments on Earth. Some of them align parallel to the BBE. Other depressions align along large submarine canyon axes. When aligned along canyon axes, the depressions closest to the canyon head are flanked by a topographic high interpreted as a slope-break deposit, i.e., sediment deposited after flow expansion following a hydraulic jump. Turbidity currents in the carbonate canyon system are not permanent processes, but are rather triggered during sea-level highstands when the carbonate platform is flooded. In addition, some depressions are not located in canyon axes. Consequently, the size and location of the depressions are not likely explained by a simple plunge pool mechanical erosion. Rather, our data suggest that all depressions could be initiated by giant karstic dissolution structures (dolines or sinkholes). Under interpretation, those located in canyon axes are sporadically refreshed by carbonate-laden turbidity currents. The height of the outsized chutes marking the crossing of the BBE by the canyon mouth generates a hydraulic jump allowing sediment deposition toward the bottom of the depression. Large depressions observed at this location in the Bahamas were the result of an initial dissolution phase related to retreat of the BBE and the more recent sediment-laden flow activity. The depressions orientated along canyon axes facilitated the regressive erosion that formed the canyons. At present, the depressions located at canyon mouths act as regular plunge pools.
(Geological Society of America Bulletin. vol. 135, n° 0016-7606, pp. 743-752, 02/07/2022)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Metal contamination and heat stress impair swimming behavior and acetylcholinesterase activity in embryo-larval stages of the Mediterranean mussel, Mytilus galloprovincialis
Behavioral parameters are increasingly considered sensitive and early bioindicators of toxicity in aquatic organisms. A video-tracking tool was specifically developed to monitor the swimming behaviour of D-larvae of the Mediterranean mussel, Mytilus galloprovincialis, in controlled laboratory conditions. Both maximum and average swimming speeds and trajectories were recorded. We then investigated the impact of copper and silver with or without a moderate rise of temperature on swimming behavior and acetylcholinesterase (AChE) activity of mussel D-larvae and the possible mechanistic link between both biological responses. Our results showed that copper and/or silver exposure, as well as temperature increase, disrupts the swimming behavior of mussel larvae which could compromise their dispersal and survival. In addition, the combined effect of temperature and metals significantly (p < 0.05) increased AChE activity in mussel larvae. Pearson's correlation analysis was performed and results showed that the AChE activity is positively correlated with maximum speeds (r = 0.71, p < 0.01). This study demonstrates the value of behavioral analyzes of aquatic invertebrates as a sensitive and integrate marker of the effects of stressors.
(Marine Environmental Research. vol. 179, n° 0141-1136, 01/07/2022)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Correction: Gasperi et al. Micropollutants in Urban Runoff from Traffic Areas: Target and Non-Target Screening on Four Contrasted Sites. Water 2022, 14, 394
In the original publication [...]
(Water. vol. 14, n° 2073-4441, pp. 2215, 01/07/2022)
GERS-LEE, LEESU, ENPC, UPEC UP12, LSCE, UVSQ, INSU - CNRS, CNRS, DRF (CEA), CEA, GEDI, LSCE, UVSQ, INSU - CNRS, CNRS, DRF (CEA), CEA, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, LUT, Cerema, ENPC
Role of iron in gene expression and in the modulation of copper uptake in a freshwater alga: Insights on Cu and Fe assimilation pathways.
Metal uptake and toxicity can generally be related to its aqueous speciation and to the presence of competitive ions as described by the biotic ligand model. Beyond these simple chemical interactions at the surface of aquatic organisms, several internal biological feedback mechanisms can also modulate metal uptake. This is particularly important for essential elements for which specific transport systems were developed over the course of evolution. Based on the results of short-term Cu2+ uptake experiments and on the analysis of the expression of certain genes involved in Cu and Fe homeostasis, we studied the effects of Fe3+ on Cu2+ uptake by the freshwater green alga Chlamydomonas reinhardtii. We observed a significant increase in Cu2+ uptake rate in algal cells acclimated to a low Fe3+ medium up to 4.7 times greater compared to non-acclimated algal cells. The overexpression of the ferroxidase FOX1 and permease FTR1 genes suggests an activation of the high affinity Fe3+ assimilation system, which could constitute a plausible explanation for the increase in Cu2+ uptake rate in acclimatized algae. We show that Fe availability can have a significant impact on Cu uptake. Our observations reinforce the importance of considering physiological factors to better predict metal bioavailability.
(Environmental Pollution. vol. 305, n° 0269-7491, pp. 119311, 01/07/2022)
BOREA, UNICAEN, NU, MNHN, IRD, SU, CNRS, UA, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS