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Physical limitation of pesticides (chlordecone) decontamination in volcanic soils: Fractal approach and numerical simulation
2020
Woignier, Thierry | Rangon, Luc | Clostre, Florence | Mottes, Charles | Cattan, Philippe | Primera, Philippe | Jannoyer, Magalie
In the French West Indies, the chlordecone (organochloride pesticide) pollution is now diffuse becoming new contamination source for crops and environment (water, trophic chain). Decontamination by bioremediation and chemical degradation are still under development but the physical limitations of these approaches are generally not taken into account. These physical limitations are related to the poor physical accessibility to the pesticides in soils because of the peculiar structural properties of the contaminated clays (pore volume, transport properties, permeability, and diffusion). Some volcanic soils (andosols), which represent the half of the contaminated soils in Martinique, contain nanoclay (allophane) with a unique structure and porous properties. Andosols are characterized by pore size distribution in the mesoporous range, a high specific surface area, a large pore volume, and a fractal structure. Our hypothesis is that the clay microstructure characteristics are crucial physico-chemical factors strongly limiting the remediation of the pesticide. Our results show that allophane microstructure (small pore size, hierarchical microstructure, and tortuosity) favors accumulation of chlordecone, in andosols. Moreover, the clay microporosity limits the accessibility of microorganisms and chemical species able to decontaminate because of poor transport properties (permeability and diffusion). We model the transport properties by two approaches: (1) we use a numerical model to simulate the structure of allophane aggregates. The algorithm is based on a cluster–cluster aggregation model. From the simulated data, we derived the pore volume, specific surface area, tortuosity, permeability, and diffusion. We show that transport properties strongly decrease because of the presence of allophane. (2) The fractal approach. We characterize the fractal features (size of the fractal aggregate, fractal dimension, tortuosity inside allophane aggregates) and we calculate that transport properties decrease of several order ranges inside the clay aggregates. These poor transport properties are important parameters to explain the poor accessibility to pollutants in volcanic soils and should be taken into account by future decontamination process. We conclude that for andosols, this inaccessibility could render inefficient some of the methods proposed in the literature.
Afficher plus [+] Moins [-]Do constructed wetlands in grass strips reduce water contamination from drained fields?
2015
Vallée, Romain | Dousset, Sylvie | Schott, François-Xavier | Pallez, Christelle | Ortar, Agnès | Cherrier, Richard | Munoz, Jean-François | Benoît, Marc | Laboratoire Interdisciplinaire des Environnements Continentaux (LIEC) ; Institut Ecologie et Environnement (INEE) ; Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Terre et Environnement de Lorraine (OTELo) ; Institut national des sciences de l'Univers (INSU - CNRS)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS) | Chambre Régionale d'Agriculture de Lorraine (CRA Lorraine [Laxou]) ; Chambre Régionale d'Agriculture Grand Est | Laboratoire d'hydrologie de Nancy (LHN) ; Agence nationale de sécurité sanitaire de l'alimentation, de l'environnement et du travail (ANSES) | Agro-Systèmes Territoires Ressources Mirecourt (ASTER Mirecourt) ; Institut National de la Recherche Agronomique (INRA) | Agence de l'Eau Rhin-Meuse [09A54015]; Zone Atelier Moselle
International audience | This study evaluates the efficiency of two small constructed wetlands installed in the regulatory grass strips between a drained plot and a river. The observed nitrate removal efficiencies were independent of the season or type of constructed wetland and ranged from 5.4 to 10.9% of the inlet amounts. The pesticide mass budgets ranged from −618.5 to 100%, depending on the molecule. The negative efficiencies were attributed to runoff and remobilization. In contrast, the highest efficiencies were associated with pesticides with high Koc and low DT50 (half-life) values, suggesting sorption and degradation. However, the effectiveness of these wetlands is limited for pesticides with low Koc or high DT50 values; thus, the use of these molecules must be reduced. Increasing the number of these small, inexpensive and low-maintenance wetlands in the agricultural landscape would reduce the level of water pollution whilst preserving the extent of cultivated land, but their long-term effectiveness should be evaluated.
Afficher plus [+] Moins [-]Synthèse des connaissances sur le transfert des pesticides vers l’atmosphère par volatilisation depuis les plantes
2015
Lichiheb, Nebila | Bedos, Carole | Personne, Erwan | Barriuso, Enrique
Les niveaux de concentration des pesticides dans l’atmosphère méritent une attention particulière de la part de la recherche compte tenu de leurs impacts potentiels sur la population et les écosystèmes. L’activité agricole constitue la principale source de contamination de l’atmosphère par les pesticides. Bien que la volatilisation depuis la plante soit reconnue plus intense et plus rapide que la volatilisation depuis le sol, cette voie de transfert est à ce jour la moins bien renseignée avec peu de modèles disponibles pour sa description. Le manque de connaissances est lié essentiellement à la complexité des interactions entre les processus ayant lieu à la surface de la feuille et qui sont en compétition avec la volatilisation, notamment la pénétration foliaire et la photodégradation. Cet article présente une synthèse bibliographique sur l’état des lieux des connaissances sur le processus de volatilisation des pesticides depuis un couvert végétal, de la pénétration foliaire et de la photodégradation, ainsi que les facteurs de contrôle de ces processus. Les méthodes de mesure ainsi que les modèles existants décrivant ces processus sont également présentés et analysés | The agricultural activity presents the main source of the atmospheric contamination by pesticides. The occurrence of pesticides in the atmosphere concerns the research community due to their potential impacts on population and ecosystems. The volatilization from plants is higher and faster than the volatilization from soil. However, this transfer pathway is difficult to assess with few available models. The lack of knowledge on pesticide volatilization from plants is essentially linked to the complex interactions between processes occurring at the leaf surface and competing with volatilization, such as leaf penetration and photodegradation. This article presents a bibliographic synthesis of the state of knowledge on pesticide volatilization from plants, leaf penetration, photodegradation and control factors of these processes. Measuring methods and existing models describing these processes are also presented and analyzed
Afficher plus [+] Moins [-]Identification and characterization of tebuconazole transformation products in soil by combining suspect screening and molecular typology
2016
Storck, Veronika | Lucini, Luigi | Mamy, Laure | Ferrari, Federico | Papadopoulou, Evangelina | Nikolaki, Sofia | Karas, Panagiotis | Servien, Rémi | Karpouzas, Dimitrios | Trevisan, Marco | Benoit, Pierre | Martin-Laurent, Fabrice | Agroécologie [Dijon] ; Institut National de la Recherche Agronomique (INRA)-Université de Bourgogne (UB)-AgroSup Dijon - Institut National Supérieur des Sciences Agronomiques, de l'Alimentation et de l'Environnement | Università cattolica del Sacro Cuore [Milano] (Unicatt) | Spinoff universita cattolica del sacro cuore | Ecologie fonctionnelle et écotoxicologie des agroécosystèmes (ECOSYS) ; Institut National de la Recherche Agronomique (INRA)-AgroParisTech | University of Thessaly [Volos] (UTH) | University of Patras | ToxAlim (ToxAlim) ; Institut National de la Recherche Agronomique (INRA)-Université Toulouse III - Paul Sabatier (UT3) ; Université de Toulouse (UT)-Université de Toulouse (UT)-Ecole Nationale Vétérinaire de Toulouse (ENVT) ; Institut National Polytechnique (Toulouse) (Toulouse INP) ; Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National Polytechnique (Toulouse) (Toulouse INP) ; Université de Toulouse (UT)-Ecole d'Ingénieurs de Purpan (INP - PURPAN) ; Institut National Polytechnique (Toulouse) (Toulouse INP) ; Université de Toulouse (UT)-Université de Toulouse (UT) | European Project: 324349,EC:FP7:PEOPLE,FP7-PEOPLE-2012-IAPP,LOVE-TO-HATE(2013)
International audience | Once released into the environment, pesticides generate transformation products (TPs) which may be of (eco-)toxicological importance. Past studies have demonstrated the difficulty to predict pesticide TP occurrence and their environmental risk by monitoring-driven approaches mostly used in current regulatory frameworks targeting only known toxicologically relevant TPs. We present a novel combined approach which identifies and categorizes known and unknown pesticide TPs in soil by combining suspect screening time-of-flight mass spectrometry with in silico molecular typology. This approach applies an empirical and theoretical pesticide TP library for compound identification by both non-target and target time-of-flight (tandem) mass spectrometry and structural elucidation through a molecular structure correlation program. In silico molecular typology was then used to group the detected TPs according to common molecular descriptors and to indirectly elucidate their environmental properties by analogy to known pesticide compounds having similar molecular descriptors. This approach was evaluated via the identification of TPs of the triazole fungicide tebuconazole occurring in a field dissipation study. Overall, 22 empirical and 12 yet unknown TPs were detected and categorized into three groups with defined environmental properties. This approach combining suspect screening time-of-flight mass spectrometry with molecular typology could be extended to other organic pollutants and used to rationalize the choice of TPs to be intensively studied towards a more comprehensive environmental risk assessment scheme.
Afficher plus [+] Moins [-]Integrated modeling of agricultural scenarios (IMAS) to support pesticide action plans: the case of the Coulonge drinking water catchment area (SW France)
2017
Vernier F. | Leccia-Phelpin O. | Lescot J.M. | Minette S. | Miralles A. | Barberis D. | Scordia C. | Kuentz-Simonet V. | Tonneau J.P.
Non-point source pollution is a cause of major concern within the European Union. This is reflected in increasing public and political focus on a more sustainable use of pesticides, as well as a reduction in diffuse pollution. Climate change will likely to lead to an even more intensive use of pesticides in the future, affecting agriculture in many ways. At the same time, the Water Framework Directive (WFD) and associated EU policies called for a “good” ecological and chemical status to be achieved for water bodies by the end of 2015, currently delayed to 2021–2027 due to a lack of efficiency in policies and timescale of resilience for hydrosystems, especially groundwater systems. Water managers need appropriate and user-friendly tools to design agro-environmental policies. These tools should help them to evaluate the potential impacts of mitigation measures on water resources, more clearly define protected areas, and more efficiently distribute financial incentives to farmers who agree to implement alternative practices. At present, a number of reports point out that water managers do not use appropriate information from monitoring or models to make decisions and set environmental action plans. In this paper, we propose an integrated and collaborative approach to analyzing changes in land use, farming systems, and practices and to assess their effects on agricultural pressure and pesticide transfers to waters. The integrated modeling of agricultural scenario (IMAS) framework draws on a range of data and expert knowledge available within areas where a pesticide action plan can be defined to restore the water quality, French “Grenelle law” catchment areas, French Water Development and Management Plan areas, etc. A so-called “reference scenario” represents the actual soil occupation and pesticide-spraying practices used in both conventional and organic farming. A number of alternative scenarios are then defined in cooperation with stakeholders, including socio-economi
Afficher plus [+] Moins [-]Effects of glyphosate and a commercial formulation Roundup® exposures on maturation of Xenopus laevis oocytes
2019
Slaby, Sylvain | Titran, Pauline | Marchand, Guillaume | Hanotel, Julie | Lescuyer, Arlette | Lepretre, Alain | Bodart, Jean-Francois | Marin, Matthieu | Lemiere, Sebastien | Laboratoire de Génie Civil et Géo-Environnement (LGCgE) - ULR 4515 (LGCgE) ; Université d'Artois (UA)-Université de Lille-Ecole nationale supérieure Mines-Télécom Lille Douai (IMT Lille Douai) ; Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)-JUNIA (JUNIA) ; Université catholique de Lille (UCL)-Université catholique de Lille (UCL) | Unité de Glycobiologie Structurale et Fonctionnelle UMR 8576 (UGSF) ; Université de Lille-Centre National de la Recherche Scientifique (CNRS) | Unité de Recherches Animal et Fonctionnalités des Produits Animaux (URAFPA) ; Institut National de la Recherche Agronomique (INRA)-Université de Lorraine (UL)
International audience | Pesticides are often found at high concentrations in small ponds near agricultural field where amphibians are used to live and reproduce. Even if there are many studies on the impacts of phytopharmaceutical active ingredients in amphibian toxicology, only a few are interested in the earlier steps of their life cycle. While their populations are highly threatened with extinction. The aim of this work is to characterize the effects of glyphosate and its commercial formulation Roundup® GT Max on the Xenopus laevis oocyte maturation which is an essential preparation for the laying and the fertilization. Glyphosate is an extensively used herbicide, not only known for its effectiveness but also for its indirect impacts on non-target organisms. Our results showed that exposures to both forms of glyphosate delayed this hormone-dependent process and were responsible for spontaneous maturation. Severe and particular morphogenesis abnormalities of the meiotic spindle were also observed. The MAPK pathway and the MPF did not seem to be affected by exposures. The xenopus oocyte is particularly affected by the exposures and appears as a relevant model for assessing the effects of environmental contamination.
Afficher plus [+] Moins [-]Effect of drying on the desorption of diuron and terbuthylazine from natural soils
2007
Lennartz, Bernd | Louchart, Xavier | University of Rostock | Laboratoire d'étude des Interactions Sol - Agrosystème - Hydrosystème (UMR LISAH) ; Institut de Recherche pour le Développement (IRD)-Institut National de la Recherche Agronomique (INRA)-Centre international d'études supérieures en sciences agronomiques (Montpellier SupAgro)-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro)
Corresponding author. fax: +49 381 498 2159. E-mail address: bernd.lennartz@uni-rostock.de (B. Lennartz). | International audience | This work was initiated to study the effects of climate induced soil water status variations which can reach extreme values under natural conditions on the sorption process of hydrophobic organic compounds. Based on the classical slurry batch methodology an approach is developed that allows the fast and careful complete drying of soil suspensions (microwave technique). Classical adsorption experiments were followed by three desorption steps with and without drying cycles. Drying and re-wetting enhanced the sorption-desorption hysteresis and Freundlich adsorption coefficients increased from 5.9 to 16 and 5.2 to 21 over three drying cycles for diuron and terbuthylazine respectively. Assuming the validity of a dual stage adsorption process, model evaluation suggests that drying is as a shrinking-like process leading to conformational changes of the dominant sorbent (soil organic matter) which restrict the intra-micro-particle diffusion. Rewetting only leads to a partial recovery of the diffusional pore space.
Afficher plus [+] Moins [-]Measurement of trifluralin volatilization in the field: relation to soil residue and effect of soil incorporation
2006
Bedos, Carole | Rousseau Djabri, M-France | Gabrielle, Benoit | Flura, Dominique, D. | Durand, Brigitte, B. | Barriuso, Enrique | Cellier, Pierre | Environnement et Grandes Cultures (EGC) ; Institut National de la Recherche Agronomique (INRA)-AgroParisTech
International audience
Afficher plus [+] Moins [-]Effect of grass cover on water and pesticide transport through undisturbed soil columns, comparison with field study (Morcille watershed, Beaujolais)
2010
Dousset, S. | Thevenot, M. | Schrack, D. | Gouy, V. | Carluer, N. | Laboratoire des Interactions Microorganismes-Minéraux-Matière Organique dans les sols (LIMOS) ; Université Henri Poincaré - Nancy 1 (UHP)-Centre National de la Recherche Scientifique (CNRS) | Université de Lille, Sciences et Technologies | Unité expérimentale SAD - Station de Mirecourt (MIRECOURT) ; Institut National de la Recherche Agronomique (INRA) | Milieux aquatiques, écologie et pollutions (UR MALY) ; Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)
[Departement_IRSTEA]Eaux [TR1_IRSTEA]ARCEAU | The purpose of this work is to assess the effectiveness of two grass covers (buffer zone and grass-covered inter-row), to reduce pesticide leaching, and subsequently to preserve groundwater quality. Lower amounts of pesticides leached through grass-cover soil columns (2.7e24.3% of the initial amount) than the bare soil columns (8.0e55.1%), in correspondence with their sorption coefficients. Diuron was recovered in higher amounts in leachates (8.9e32.2%) than tebuconazole (2.7e12.9%), in agreement with their sorption coefficients. However, despite having a sorption coefficient similar to that of diuron, more procymidone was recovered in the leachates (10.2e55.1%), probably due to its facilitated transport by dissolved organic matter. Thus even in this very permeable soil, higher organic matter contents associated with grass-cover reduce the amount of pesticide leaching and limit the risk of groundwater contamination by the pesticides. The results of diuron and tebuconazole transfer through undisturbed buffer zone soil columns are in agreement with field observations on the buffer zone.
Afficher plus [+] Moins [-]Evaluation of temperature corrections for pesticide half-lives in tropical and temperate soils
2022
Campan, Pauline | Samouëlian, Anatja | Voltz, Marc | Laboratoire d'étude des Interactions Sol - Agrosystème - Hydrosystème (UMR LISAH) ; Institut de Recherche pour le Développement (IRD)-AgroParisTech-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) | This work was funded by the Guadeloupe region and the European Regional Development Fund (FEDER) (grant 410–00160),and the senior author was awarded a doctoral scholarship by the Institut Agro Montpellier.
International audience | Temperature is a key factor that influences pesticide degradation. Extrapolating degradation half-lives (DT50) measured at a given temperature to different temperatures remains challenging, especially for tropical conditions with high temperatures. In this study, the use of the standard Arrhenius equation for correcting temperature effects on pesticide degradation in soils was evaluated and its performance was compared with that of alternative Arrhenius-based equations. To do so, a database of 509 DT50 values measured between 5 and 35 °C for 32 pesticides on tropical and temperate soils was compiled for the first time through an extensive literature search. The temperature correction models were fitted to the database using linear mixed regression approaches that included soil type and compound effects. No difference in the temperature dependence of DT50 between tropical and temperate soils was detected, regardless of the model. A comparison of the prediction performances of the models showed that constant activation energy (Ea) cannot be considered valid for the whole range of temperatures. The classical Arrhenius equation with an Ea of 65.4 kJ.mol−1, as recommended by the European Food Safety Authority (EFSA), was shown to be valid for correcting the DT50 only for temperatures ranging from 5 to 20 °C. However, for temperatures greater than 20 °C, which are common in tropical environments, the median Ea was significantly lower at 10.3 kJ.mol−1. These findings suggest the need to adapt the standard temperature correction of the European pesticide risk assessment temperature procedure when it is applied in tropical settings
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