Carbon and suspended sediment transport in an impounded alpine river (Isère, France)
Carbon and total suspended sediment (TSS) loads were investigated from April 2006 to March 2008 in the mountainous watershed of the Isère River, French Alps (5570 km2). The river bed has been highly impounded for hydroelectricity production during the last century. Hydraulic flushes are managed every year to prevent TSS storage within upstream dams. The Isère River has been instrumented for high-frequency monitoring of water, TSS by turbidity and carbon (organic, inorganic, dissolved and particulate) in order to evaluate the impact of natural floods and hydraulic flushes on annual loads. Annual TSS load which was estimated between 1.3 and 2.3 MT y−1 (i.e. 233 to 413 T km−2 y−1) highlighted the high erodibility of the Isère watershed. Annual carbon load was estimated between 173 103 T y−1 and 199 103 T y−1 (i.e 31 to 36 T km−2 y−1). About 80% of the annual carbon loads were inorganic. The impact of hydraulic flushes on annual loads appeared limited (less than 3% for annual TSS load and about 1.5% for annual carbon load), whereas the most important natural flood event contributed to 20% of the annual TSS load and 10% of the annual carbon load.
(Hydrological Processes. vol. 27, n° 0885-6087, pp. 2498-2508, 25/06/2026)
LTHE, OSUG, UJF, Grenoble INP, INSU - CNRS, IRSTEA, USMB [Université de Savoie] [Université de Chambéry], CNRS, IRD, INSU - CNRS, INPG, CNRS, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, ISTO, BRGM, INSU - CNRS, UO, CNRS, SISYPHE, UPMC, EPHE, PSL, PSL, CNRS, EDF [E.D.F.]
UPLC MS/MS Quantification of Primary Metabolites of Benzo[a]pyrene and Fluoranthene Produced In Vitro by Sole (Solea sola) Liver Microsomal Activation
Biotransformation pathways of PAHs in a flat fish, Solea solea, living in nurseries close to coastal areas and estuaries constitute a great challenge for the environmental risk. Among PAHs, Fluoranthene (Fluo) has a different chemical structure than benzo[a]pyrene (BaP), and can influence its biotransformation pathways and genotoxic potential. The aim of this study was to bring some response elements about the in vitro metabolic activation of Fluo and BaP by sole liver microsomes. The quantification of several primary metabolites of BaP and Fluo produced in vitro, following a sole liver microsomal activation, was conducted using a sensitive analytical UPLC MS/MS method. Four types of BaP metabolites (dihydrodiols, diones, OH-BaP, and 7,8-dihydroepoxide), and three types of Fluo metabolites (2,3-dihydrodiol, 2,3-dione, and sum of OH-Fluo) were quantified. The concentration for which the metabolite production was maximal was of 40 μM and 100 μM for BaP and Fluo, respectively. The biotransformation rate was higher for Fluo (9.97%) than for BaP (6.69%).Whatever the PAH, dihydrodiols and phenols were the major metabolites produced accounting for, respectively, 50% and 30–40% for BaP, and 40 and 60% for Fluo. Despite some differences in conformation, both PAHs seem to be activated by similar pathways and the diol-epoxide appears as a predominant one.
(Polycyclic Aromatic Compounds. vol. 33, n° 1040-6638, pp. 52-71, 25/06/2026)
BE, IFREMER, LPTC, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Use of integrative samplers for the determination of the efficiency of wastewater advanced treatments: case of pharmaceuticals compounds
Introduction. The general objective of the ECHIBIOTEB research program (“Innovating tools for sampling, chemical and biological analyses for the diagnosis of wastewater advanced tertiary treatments and sludge treatments”, 2011-2014, financed by the French National Research Agency) is introduced in a previous presentation. Briefly it consists in developing new tools for the determination of the efficiency of advanced treatments, especially for the sampling. This presentation will describe the potential of Polar Organic Chemical Integrative Sampler (POCIS) for the monitoring of pharmaceuticals in water, compared to grab sampling. Analytical methodology. Until today, two campaigns were performed in order to follow the efficiency of ozone (O3) treatment, alone and coupled with Granular Activated Carbon (GAC) by exposing 20 POCIS before and after the wastewater treatment during 28 days. Each triplicate, associated to a field blank, is dedicated to a kind of analysis (pharmaceuticals, alkylphenols, and biological analysis, for example). In parallel, grab samplings were achieved after 0, 14 and 28 days of POCIS exposition in order to compare these two approaches. 104 molecules belonging to several therapeutic classes such as antibiotics, -blockers, antineoplastics, antivirals, phosphodiesterase type 5 inhibitor (PDE 5), analgesics, broncholidators, non-steroidal anti-inflammatory and psychiatric drugs, lipid regulators and stimulants, were analysed. Therefore, in order to determine the in-situ rate constants of exposed POCIS, 3 Reference Performance Compounds (PRC) were previously added in the adsorbant phase: salbutamol-d3, caffeine-13C and desisopropylatrazin-d5 (DIA d5) and laboratory calibration on pharmaceuticals were performed. Solid Phase Extractions (SPE) were carried out on the different samples depending on compound classes and, then, analyses were performed by liquid phase chromatography coupled with tandem mass spectrometry (LC-MS/MS). Results. Among targeted compounds, 39 molecules were not detected in any samples of wastewater, in the dissolved phase and 32 molecules in any POCIS samplers. As illustrated in Figure 1a, concentrations upstream from the treatments are higher than those downstream; whatever is the nature of wastewater process. Betablockers, macrolides, psychiatric drugs, fluoroquinolones and quinolones are the most abundant compounds upstream these processes and downstream, only two classes (Betablockers and stimulants) remain present as relatively high concentrations. Therefore, it seems that GAC and GAC+O3 treatments involve a drastic reduction of micropollutant concentrations in wastewaters. Regarding concentrations determined in the adsorbant phase of passive samplers (Figure 1b), the tendency between upstream and downstream coincides well with the one of wastewater samples, in terms of pharmaceutical abundances and between samples too. Figure 2 shows that the number of detected targeted compounds depends on the place of sampling (up or downstream) and on the way of sampling (POCIS vs. grab sampling). For the process using granular activated carbon, based on the measurements of 103 molecules, 13 extra compounds are detected in the adsorbant phase of POCIS compared to the dissolved phase, upstream and downstream the process. Until today, regarding the analysis of 93 molecules for ozone+GAC process, the trend is also observed with the detection of 23 and 17 extra compounds, upstream and downstream respectively. These results show the real interest of this sampling mode by the improvement of methodology sensitivity. Laboratory calibration of passive samplers allow to determine rate constants for more than 25 of target compounds and so, to compare directly the results between integrative and grab sampling in terms of concentrations. This methodology of sampling reveals its interest for the quantification of targeted compounds and has been also applied to the analysis of non-targeted compounds in order to complete the knowledge on the efficiency of such process. The presence of pharmaceuticals and non-targeted compounds could explain the potential toxicity of these samples (wastewater and POCIS extracts). Acknowledgements. The authors wish to thank the program ECOTECH-ECHIBIOTEB, the Aquitaine Region and the European Union (CPER A2E project) for financial support. Europe is moving in Aquitaine with the European Regional Development Fund.
(pp. 36, 25/06/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, UR MALY, IRSTEA
Biodiversité marine : chapitre 6
A l'échelle du golfe de Gascogne et de ses zones côtières et littorales, les suivis de la biodiversité montrent d'importantes variations annuelles d'abondance e de répartition géographique des espèces en relation avec le climat. Les tendances actuelles montrent que la biodiversité va évoluer vers une augmentation de représentativité des espèces tempérées chaudes, une modification de la phénologies des espèces et de la productivité des écosystèmes.
(pp. 173-188, 25/06/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, UR EPBX, IRSTEA, LERAR, COAST, IFREMER, IRSTEA, IFREMER, MNHN, UPMC
Devenir des micropolluants dans les traitements tertiaires et traitements des boues
(pp. 22, 25/06/2026)
UR MALY, IRSTEA, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Zebrafish: A model animal for analyzing the impact of environmental pollutants on muscle and brain mitochondrial bioenergetics.
Mercury, anthropogenic release of uranium (U), and nanoparticles constitute hazardous environmental pollutants able to accumulate along the aquatic food chain with severe risk for animal and human health. The impact of such pollutants on living organisms has been up to now approached by classical toxicology in which huge doses of toxic compounds, environmentally irrelevant, are displayed through routes that never occur in the lifespan of organisms (for instance injecting a bolus of mercury to an animal although the main route is through prey and fish eating). We wanted to address the effect of such pollutants on the muscle and brain mitochondrial bioenergetics under realistic conditions, at unprecedented low doses, using an aquatic model animal, the zebrafish Danio rerio. We developed an original method to measure brain mitochondrial respiration: a single brain was put in 1.5mL conical tube containing a respiratory buffer. Brains were gently homogenized by 13 strokes with a conical plastic pestle, and the homogenates were immediately used for respiration measurements. Skinned muscle fibers were prepared by saponin permeabilization. Zebrafish were contaminated with food containing 13μg of methylmercury (MeHg)/g, an environmentally relevant dose. In permeabilized muscle fibers, we observed a strong inhibition of both state 3 mitochondrial respiration and cytochrome c oxidase activity after 49 days of MeHg exposure. We measured a dramatic decrease in the rate of ATP release by skinned muscle fibers. Contrarily to muscles, brain mitochondrial respiration was not modified by MeHg exposure although brain accumulated twice as much MeHg than muscles. When zebrafish were exposed to 30μg/L of waterborne U, the basal mitochondrial respiratory control ratio was decreased in muscles after 28 days of exposure. This was due to an increase of the inner mitochondrial membrane permeability. The impact of a daily ration of food containing gold nanoparticles of two sizes (12 and 50nm) was investigated at a very low dose for 60 days (40ng gold/fish/day). Mitochondrial dysfunctions appeared in brain and muscle for both tested sizes. In conclusion, at low environmental doses, dietary or waterborne heavy metals impinged on zebrafish tissue mitochondrial respiration. Due to its incredible simplicity avoiding tedious and time-consuming mitochondria isolation, our one-pot method allowing brain respiratory analysis should give colleagues the incentive to use zebrafish brain as a model in bioenergetics. This article is part of a Directed Issue entitled: Bioenergetic dysfunction, adaptation and therapy.
(International Journal of Biochemistry and Cell Biology. vol. 45, n° 1357-2725, pp. 16-22, 25/06/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, IBGC, UB, CNRS
Effects of environmental realistic mixture of pesticides on natural biofilms communities with different exposure history
The Morcille River located in the Beaujolais vineyard area (Eastern France), is subjected to strong wine-growing pressure leading to the contamination by a range of herbicides and fungicides of the surrounding fresh water environment. The objective of this study was to evaluate the potential use of passive samplers extracts in order to highlight effects of representative pesticide mixtures on natural biofilm communities with diverse exposure history. Chronic and acute impacts of pesticides in mixture were evaluated using POCIS (Polar Organic Chemical Integrative Sampler) extracts on natural biofilm communities originated from a pesticide contaminated site (downstream site) or a reference site (upstream site). Biofilms were exposed in an artificial channel system to POCIS extracts (PE) or placed in clean water during 13 days in order to model different levels of toxic pressure in relation with a realistic pesticide mixture directly isolated from the field. After 13 days of exposure, significant impacts of PE treatment on growth related parameters and on physiological endpoints were observed. A significant decrease of diatoms density was observed on biofilms exposed to PE compared to non exposed biofilms undependably of biofilm origin. Moreover DW and AFDM were lower for downstream biofilms exposed to PE compared to non exposed biofilms. Taxonomic analyses revealed impacts of mixture of pesticides on diatom composition. Upstream communities exposed or not to PE presented different diatom composition with higher proportion of Nitzschia palea and Eolimna minima for contaminated treatment. Downstream communities exposed or not to PE showed very similar composition at the end of the experiment highlighting the importance of immigration processes in the recovery of diatom assemblages (Morin et al., 2012). In order to evaluate initial tolerance of biofilms to pesticide mixture; acute toxicity tests were realized before the beginning of the channel experiment. Acute exposures revealed a significant higher tolerance for biofilm originated from downstream site compared to biofilms originated from upstream site. This difference of tolerance to PE was related to very different taxonomic compositions in regards to biofilm origin; it reflects adaptation of communities by species selection processes and is an illustration of the PICT concept (Blanck et al., 1988).Our results underline impacts of mixture of pesticides on growth (DW, AFDM and diatoms density), diatom composition, and community tolerance of natural biofilms. This study highlights the potential use of passive sampler extracts combined with acute toxicity tests and chronic exposure experiment in order to evaluate effects of more realistic pesticide mixtures on natural biofilms communities, and then the future and likely applications of such approaches for ecological risk assessment.
(pp. 2, 25/06/2026)
UR REBX, IRSTEA, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, UR MALY, IRSTEA
Ecological resistance to Acer negundo invasion in a European riparian forest: relative importance of environmental and biotic drivers
Question: The relative importance of environmental vs. biotic resistance of recipient ecological communities remains poorly understood in invasion ecology. Acer negundo, a North American tree, has widely invaded riparian forests throughout Europe at the ecotone between early- (Salix spp. and Populus spp.) and late-successional (Fraxinus spp.) species. However, it is not present in the upper part of the Rhone River, where native Alnus incana occurs at an intermediate position along the successional riparian gradient. Is this absence of the invasive tree due to environmental or biotic resistance of the recipient communities, and in particular due to the presence of Alnus? Location: Upper Rhone River, France. Methods: We undertook a transplant experiment in an Alnus-dominated community along the Upper Rhone River, where we compared Acer negundo survival and growth, with and without biotic interactions (tree and herb layer effects), to those of four native tree species from differing successional positions in the Upper Rhone communities (P. alba, S. alba, F. excelsior and Alnus incana). Results: Without biotic interactions Acer negundo performed similarly to native species, suggesting that the Upper Rhone floodplain is not protected from Acer invasion by a simple abiotic barrier. In contrast, this species performed less well than F. excelsior and Alnus incana in environments with intact tree and/or herb layers. Alnus showed the best growth rate in these conditions, indicating biotic resistance of the native plant community. Conclusions: We did not find evidence for an abiotic barrier to Acer negundo invasion of the Upper Rhone River floodplain communities, but our results suggest a biotic resistance. In particular, we demonstrated that (i) additive competitive effects of the tree and herb layer led to Acer negundo suppression and (ii) Alnus incana grew more rapidly than Acer negundo in this intermediate successional niche.
(Applied Vegetation Science. vol. 16, n° 1402-2001, pp. 184-192, 25/06/2026)
UGA [2016-2019], UR EMGR, IRSTEA, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
On the numerical investigation of cardiovascular balloon-expandable stent using finite element method
(Computational Materials Science. vol. 79, n° 0927-0256, pp. 326-335, 25/06/2026)
CRP Henri Tudor, CRP Henri-Tudor, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, LEME, UPN
Innovative chemical and biological tools for the evaluation of the efficiency of wastewater advanced treatments and sludge treatments
Introduction. The general objective of the ECHIBIOTEB research program (“Innovating tools for sampling, chemical and biological analyses for the diagnostic of wastewater advanced treatments and sludge treatments”, 2011-2014, financed by the French National Research Agency, coordinated by Irstea) is to use innovative and complementary tools to better assess the efficiency of wastewater advanced treatments and sludge treatments. To achieve this goal, various strategies were combined: chemical analysis of a large panel of selected priority and emerging contaminants, non-target chemical analysis, in vitro and in vivo biological analysis and integrative samplers. Through various examples, our presentation will focus on the interest and also the limit of these tools to evaluate the efficiency of wastewater advanced treatments and sludge treatments. The chemical and biological tools tested in the program. -Chemical analysis of targeted contaminants: 14 traces metal and 170 organic molecules belonging to pharmaceuticals, oestrogenic hormones, alkylphenols (AkP), Endocrine Disruptor Compounds (EDC), Polycyclic Aromatic Hydrocarbons (PAH), pesticides, PolyChloroBiphenyl (PCB) and PolyBrominated DiphenylEthers (PBDE) were selected. According to their physico-chemical properties, they are measured in the dissolved phase of water and/or in sludge samples. After extractions by methods such as Solid Phase Extraction or Solid Phase MicroExtraction (SPME) for waters, and Accelerated Solvent Extraction or microwave extraction for sludge, molecules are analysed by gas (GC) or liquid phase chromatography (LC) coupled with single or tandem mass spectrometry. In fine, the aim is to select the relevant compounds to characterize such water and sludge treatment processes. -Non-target chemical analysis: Various instrumental strategies such as GC-2D-MS/TOF (two-dimensional gas phase chromatography coupled to Time Of Flight mass spectrometer), SPME-GC/TOF, HRMS/TOF (High Resolution Mass Spectrometry) are applied to identify new organic contaminants or degradation products. -In vitro and in vivo biological analysis: they are used to link the presence of contaminants to their effects on biological receptors (in vitro assays) or on living organisms (in vivo assays). Receptors studied by in vitro bioassays are estrogen, androgen, glucocorticoid, thyroid and dioxin receptors. Cytotoxicity and genotoxicity are also evaluated. In vivo bioassays are performed either in laboratory on effluents, fresh sludge samples and sludge eluates, or in a modified in situ approach with wastewaters deviated and flow controlled. In vivo laboratory bioassays include aquatic and terrestrial tests: bacteria (acute toxicity, Microtox®), micro-algae (growth), rotifers (reproduction), micro-crustaceans (reproduction) and plants (root elongation and early growth). In vivo modified in situ bioassays are realised on gasteropod (survival, growth, reproduction), crustacean (survival, alimentation rate, reproduction), insect (survival, growth) and fish embryos (survival, hatching, developmental abnormalities). -Integratives samplers: POCIS (Polar Organic Chemical Integrative Sampler) and SPMD (Semi-Permeable Membrane Device), dedicated to water sampling of hydrophilic and hydrophobic organic molecules respectively, are used to increase the samples representativeness1. Their use are combined with target and non target chemical analysis and with in vitro biological tests. -Effect directed analysis (EDA): whose principle is based on a combination of biotesting (by in vitro bioassays), fractionation procedure and chemical analytical methods. The toxic response guide the chemical fractionation and identification of compound responsible for the observed toxic effects. -Interaction of Dissolved Organic Matter (DOM) with micropollutants: the influence of the DOM onto toxicity and bioavailability of contaminants is studied through fast and small microplate tests, based on inhibitive competition of fluorescence. Sampling campaigns. From March 2011 to October 2012, 13 sampling campaigns (10 for water and 3 for sludge) were conducted. Water campaigns were organized either on a short (1 day) or on a long period (1 month). During short campaigns, chemical analysis of targeted contaminants, non-target chemical analysis, in vitro bioassays, in vivo bioassays praticed in laboratory and DOM tests were implemented. During long campaigns, every ECHIBIOTEB tools were used, including integrative samplers and in vivo in situ bioassays. Moreover, global parametres like phosphorus, nitrate, pH and suspended particles were controlled in order to give an indication on the operational conditions of the treatment studied. The treatments used for advanced (or tertiary) water treatments were adsorbants like Granular Activated Carbon (GAC), zeolites or expanded clay, and advanced oxidation processes (AOP) like ozone (O3), ozone peroxide (H2O2), UV/H2O2 , O3 + GAC, and polishing pond ; they were studied in full scale or large scale pilot design, located at the outlet of secondary biological treatments. For sludge treatments, solar dryer, compost and reed-bed filter were tested. First results. - Chemical analysis of targeted contaminants: For most of the compounds and whatever the type of treatment, targeted analysis showed a significant reduction in contaminant concentration in the dissolved phase of water after treatment. Pharmaceuticals concentrations, as example, were reduced in effluents about 100 times lower than in influents. The evaluation and discussion on removal rates are presented in a parallel study (ARMISTIQ research program) and detailed in the abstract “Occurrence of selected micropollutants in treated wastewater and removal with optimised tertiary treatments”. In our presentation, we will discuss on the pertinence of these compounds and more precisely on the selection of a shorter list of targeted compounds to characterize water and sludge treatment processes. -Non-target chemical analysis of 3 different sludge samples allowed to obtain a list of 190 molecules of interest, among which some nitrogen heterocyclic compounds as potential new contaminants. Further investigations are needed, especially combining chemical with biological analysis (EDA), to determine which compounds among these 190 would be the most relevant to be considered for water or sludge treatment characterization. -With in vitro biological analysis, an oestrogenic activity was detected in the aqueous influent of various advanced treatments, whereas it was poorly or not detected in the effluent. Compounds responsible for this toxic activity seem to be efficiently removed by GAC. Moreover, low PAH-like activity was detected in aqueous influent and effluent of wastewater tertiary treament in link to the low PAH concentrations measured in water samples. No dioxin-like or thyroid activity was detected in wastewaters. Genotoxic and cytotoxic activities were detected in some aqueous influents. Genotoxicity was no longer detected in effluents whereas cytotoxic activites are still detected at significant level in the ozone effluent. -With in vivo biological tests, low toxicity was measured in situ and in the laboratory before and after the studied treatment (O3+GAC and O3). Nevertheless, the size of the Japanese Medaka larvae and the hatching efficiency were reduced before those advanced treatments. Regarding the reproduction of Ceriodaphnia dubia, atypical dose-response curves were observed before the O3+GAC treatment showing inhibitory effects at low concentrations and reproduction rates significantly higher than the control at high concentrations. No difference was observed on the sludge toxicity before and after the solar dryer. On the contrary, the composting of sludge reduces the toxicity of the samples in terrestrials tests and tests performed on sludge water extracts, Furthermore, the root elongation test on oat in contact with fresh sludge sample seems suitable for routine analyses because of this simplicity and fastness. -The use of POCIS as integrative samplers allowed us to detect and quantify more -blockers, as an example, than with grab sampling. Nevertheless, the decrease of -blockers concentrations after advanced water treatment is in the same order of magnitude with grab and passive sampling. Compared to grab sampling, POCIS allowed to detect 7 more pharmaceuticals in influent of tertiary treatments and 4 more in effluents. The detection of a greater number of compounds thanks to integrative samplers (i.e. concentration effect) should be helpful to explain some toxicity results.
(pp. 48, 25/06/2026)
UR MALY, IRSTEA, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, INERIS, ESE, UP11, CNRS