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A lognormal model for evaluating maximum residue levels of pesticides in crops Full text
2021
Guo, Yuan | Li, Zijian
To evaluate pesticide regulatory standards in agricultural crops, we introduced a regulatory modeling framework that can flexibly evaluate a population’s aggregate exposure risk via maximum residue levels (MRLs) under good agricultural practice (GAP). Based on the structure of the aggregate exposure model and the nature of variable distributions, we optimized the framework to achieve a simplified mathematical expression based on lognormal variables including the lognormal sum approximation and lognormal product theorem. The proposed model was validated using Monte Carlo simulation, which demonstrates a good match for both head and tail ends of the distribution (e.g., the maximum error = 2.01% at the 99th percentile). In comparison with the point estimate approach (i.e., theoretical maximum daily intake, TMDI), the proposed model produced higher simulated daily intake (SDI) values based on empirical and precautionary assumptions. For example, the values at the 75th percentile of the SDI distributions simulated from the European Union (EU) MRLs of 13 common pesticides in 12 common crops were equal to the estimated TMDI values, and the SDI values at the 99th percentile were over 1.6-times the corresponding TMDI values. Furthermore, the model was refined by incorporating the lognormal distributions of biometric variables (i.e., food intake rate, processing factor, and body weight) and varying the unit-to-unit variability factor (VF) of the pesticide residues in crops. This ensures that our proposed model is flexible across a broad spectrum of pesticide residues. Overall, our results show that the SDI is significantly reduced, which may better reflect reality. In addition, using a point estimate or lognormal PF distribution is effective as risk assessments typically focus on the upper end of the distribution.
Show more [+] Less [-]Uptake of nicotine from discarded cigarette butts – A so far unconsidered path of contamination of plant-derived commodities Full text
2018
Selmar, Dirk | Radwan, Alzahraa | Abdalla, Neama | Taha, Hussein | Wittke, Carina | El-Henawy, Ahmed | Alshaal, Tarek | Amer, Megahed | Kleinwächter, Maik | Nowak, Melanie | El-Ramady, Hassan
This study aimed to elucidate the origin of the widespread nicotine contamination of plant-derived commodities, by conducting field experiments with various herbs and spice plants. By scattering tobacco and cigarette butts on the field and subsequent nicotine analyses of the acceptor plants, we verified that the alkaloid is leached out into the soil and is taken up by the crop plants. This path of contamination pertains even when there is only one cigarette butt per square meter. Even such minor pollution results - at least in the case of basil and peppermint - in considerable high nicotine contaminations, which exceed the maximum residue level by more than 20-fold.The data reported here clearly outline the large practical relevance of this soil-borne contamination path and imply that unthoughtful disposal of cigarette butts in the field by farm workers may be the reason for the widespread occurrence of nicotine contamination in plant-derived commodities. Therefore, such misbehavior needs to be prevented using education and sensitization, and by including this issue into the guidelines of good agricultural practice.
Show more [+] Less [-]Comparative analysis of modeled nitrogen removal by shellfish farms Full text
2015
Rose, Julie M. | Bricker, Suzanne B. | Ferreira, Joao G.
The use of shellfish aquaculture for nutrient removal and reduction of coastal eutrophication has been proposed. Published literature has indicated that nitrogen contained in harvested shellfish can be accurately estimated from shell length:nitrogen content ratios. The range of nitrogen that could be removed by a typical farm in a specific estuarine or coastal setting is also of interest to regulators and planners. Farm Aquaculture Resource Management (FARM) model outputs of nitrogen removal at the shellfish farm scale have been summarized here, from 14 locations in 9 countries across 4 continents. Modeled nitrogen removal ranged from 105lbsacre−1year−1 (12gm−2year−1) to 1356lbsacre−1year−1 (152gm−2year−1). Mean nitrogen removal was 520lbsacre−1year−1 (58gm−2year−1). These model results are site-specific in nature, but compare favorably to reported nitrogen removal effectiveness of agricultural best management practices and stormwater control measures.
Show more [+] Less [-]Reactive Modeling of Denitrification in Soils with Natural and Depleted Organic Matter Full text
2011
Mastrocicco, Micòl | Colombani, Nicolò | Salemi, Enzo | Castaldelli, Giuseppe
Nitrogen fertilizers used in agriculture often cause nitrate leaching towards shallow groundwater, especially in lowland areas where the flat topography minimize the surface run off. In order to introduce good agricultural practices that reduce the amount of nitrate entering the groundwater system, it is important to quantify the kinetic control on nitrate attenuation capacity. With this aim, a series of anaerobic batch experiments, consisting of loamy soils and nitrate-contaminated groundwater, were carried out using acetate and natural dissolved organic matter as electron donors. Acetate was chosen because it is the main intermediate species in many biodegradation pathways of organic compounds, and it is a suitable carbon source for denitrification. Sorption of acetate was also determined, fitting a Langmuir isotherm in both natural and artificially depleted organic matter soils. Experiments were performed in quadruplicate to account for the spatial variability of soil parameters. The geochemical code PHREEQC (version 2) was used to simulate kinetic denitrification using Monod equation, equilibrium Langmuir sorption of acetate, and equilibrium reactions of gas and mineral phases (calcite). The reactive modeling results highlighted a rapid acetate and nitrate mineralization rate, suggesting that the main pathway of nitrate attenuation is through denitrification while calcite acted as a buffer for pH. However, in the absence of acetate, the natural content of organic matter did not allow to complete the denitrification process leading to nitrite accumulation. Reactive modeling is thought to be an efficient and robust tool to quantify the complex biogeochemical reactions which can take place in underground environments.
Show more [+] Less [-]Perceived outcomes of Good Agricultural Practices (GAPs) technologies adoption in citrus farms of Iran (reflection of environment-friendly technologies) Full text
2019
Razzaghi Borkhani, Fatemeh | Mohammadi, Yaser
The main purpose of this study was to analyze the perceived outcomes of Good Agricultural Practices (GAPs) technologies adoption in order to sustain citrus farms in Mazandaran province, Iran. Study population consisted of all citrus growers in the villages of 12 counties of Mazandaran province, which a sample of 290 orchardmen were selected through a proportional random sampling technique. A questionnaire was designed to collect data which was both valid and reliable according to expert opinion and Cronbach’s alpha coefficient respectively. The results of the factor analysis showed that “market access and safe product exports,” “consumer’ health and environment-friendly behavior,” “safe production and public demand,” and “information sharing and strengthening local associations” were the four perceived outcomes of GAPs technologies adoption in citrus farms of Iran. These factors explained 65.02% of the total variance. These four perceived outputs of GAPs support economic, environmental, and social sustainability dimensions respectively.
Show more [+] Less [-]Systemic insecticides (neonicotinoids and fipronil): trends, uses, mode of action and metabolites Full text
2015
Simon-Delso, N. | Amaral-Rogers, V. | Belzunces, L. P. | Bonmatin, J. M. | Chagnon, M. | Downs, C. | Furlan, L. | Gibbons, D. W. | Giorio, C. | Girolami, V. | Goulson, D. | Kreutzweiser, D. P. | Krupke, C. H. | Liess, M. | Long, E. | McField, M. | Mineau, P. | Mitchell, E. A. D. | Morrissey, C. A. | Noome, D. A. | Pisa, L. | Settele, J. | Stark, J. D. | Tapparo, A. | Van Dyck, H. | Praagh, Jaap van | Van der Sluijs, J. P. | Whitehorn, P. R. | Wiemers, M.
Systemic insecticides (neonicotinoids and fipronil): trends, uses, mode of action and metabolites Full text
2015
Simon-Delso, N. | Amaral-Rogers, V. | Belzunces, L. P. | Bonmatin, J. M. | Chagnon, M. | Downs, C. | Furlan, L. | Gibbons, D. W. | Giorio, C. | Girolami, V. | Goulson, D. | Kreutzweiser, D. P. | Krupke, C. H. | Liess, M. | Long, E. | McField, M. | Mineau, P. | Mitchell, E. A. D. | Morrissey, C. A. | Noome, D. A. | Pisa, L. | Settele, J. | Stark, J. D. | Tapparo, A. | Van Dyck, H. | Praagh, Jaap van | Van der Sluijs, J. P. | Whitehorn, P. R. | Wiemers, M.
Since their discovery in the late 1980s, neonicotinoid pesticides have become the most widely used class of insecticides worldwide, with large-scale applications ranging from plant protection (crops, vegetables, fruits), veterinary products, and biocides to invertebrate pest control in fish farming. In this review, we address the phenyl-pyrazole fipronil together with neonicotinoids because of similarities in their toxicity, physicochemical profiles, and presence in the environment. Neonicotinoids and fipronil currently account for approximately one third of the world insecticide market; the annual world production of the archetype neonicotinoid, imidacloprid, was estimated to be ca. 20,000 tonnes active substance in 2010. There were several reasons for the initial success of neonicotinoids and fipronil: (1) there was no known pesticide resistance in target pests, mainly because of their recent development, (2) their physicochemical properties included many advantages over previous generations of insecticides (i.e., organophosphates, carbamates, pyrethroids, etc.), and (3) they shared an assumed reduced operator and consumer risk. Due to their systemic nature, they are taken up by the roots or leaves and translocated to all parts of the plant, which, in turn, makes them effectively toxic to herbivorous insects. The toxicity persists for a variable period of time—depending on the plant, its growth stage, and the amount of pesticide applied. A wide variety of applications are available, including the most common prophylactic non-Good Agricultural Practices (GAP) application by seed coating. As a result of their extensive use and physicochemical properties, these substances can be found in all environmental compartments including soil, water, and air. Neonicotinoids and fipronil operate by disrupting neural transmission in the central nervous system of invertebrates. Neonicotinoids mimic the action of neurotransmitters, while fipronil inhibits neuronal receptors. In doing so, they continuously stimulate neurons leading ultimately to death of target invertebrates. Like virtually all insecticides, they can also have lethal and sublethal impacts on non-target organisms, including insect predators and vertebrates. Furthermore, a range of synergistic effects with other stressors have been documented. Here, we review extensively their metabolic pathways, showing how they form both compound-specific and common metabolites which can themselves be toxic. These may result in prolonged toxicity. Considering their wide commercial expansion, mode of action, the systemic properties in plants, persistence and environmental fate, coupled with limited information about the toxicity profiles of these compounds and their metabolites, neonicotinoids and fipronil may entail significant risks to the environment. A global evaluation of the potential collateral effects of their use is therefore timely. The present paper and subsequent chapters in this review of the global literature explore these risks and show a growing body of evidence that persistent, low concentrations of these insecticides pose serious risks of undesirable environmental impacts.
Show more [+] Less [-]Systemic insecticides (neonicotinoids and fipronil): trends, uses, mode of action and metabolites Full text
2014 | 2015
Simon-Delso, Noa | Amaral-Rogers, Vanessa | Belzunces, Luc P | Bonmatin, Jean-Marc | Chagnon, Madeleine | Downs, Craig | Furlan, Lorenzo | Gibbons, David W | Giorio, Chiara | Girolami, Vincenzo | Goulson, Dave | Kreutzweiser, David P | Krupke, Christian H | Liess, Matthias | Whitehorn, Penelope R | Utrecht University | Buglife | French National Institute for Agricultural Research (INRA) | The National Center for Scientific Research (CNRS) | University of Quebec in Montreal (UQAM) | Haereticus Environmental Laboratory | Veneto Agricoltura | Royal Society for the Protection of Birds (RSPB) | University of Cambridge | University of Padua | University of Sussex | Natural Resources Canada | Purdue University | Helmholtz Centre for Environmental Research-UFZ, Germany | Biological and Environmental Sciences | 0000-0001-9852-1012
Since their discovery in the late 1980s, neonicotinoid pesticides have become the most widely used class of insecticides worldwide, with large-scale applications ranging from plant protection (crops, vegetables, fruits), veterinary products, and biocides to invertebrate pest control in fish farming. In this review, we address the phenyl-pyrazole fipronil together with neonicotinoids because of similarities in their toxicity, physicochemical profiles, and presence in the environment. Neonicotinoids and fipronil currently account for approximately one third of the world insecticide market; the annual world production of the archetype neonicotinoid, imidacloprid, was estimated to be ca. 20,000tonnes active substance in 2010. There were several reasons for the initial success of neonicotinoids and fipronil: (1) there was no known pesticide resistance in target pests, mainly because of their recent development, (2) their physicochemical properties included many advantages over previous generations of insecticides (i.e., organophosphates, carbamates, pyrethroids, etc.), and (3) they shared an assumed reduced operator and consumer risk. Due to their systemic nature, they are taken up by the roots or leaves and translocated to all parts of the plant, which, in turn, makes them effectively toxic to herbivorous insects. The toxicity persists for a variable period of time-depending on the plant, its growth stage, and the amount of pesticide applied. A wide variety of applications are available, including the most common prophylactic non-Good Agricultural Practices (GAP) application by seed coating. As a result of their extensive use and physicochemical properties, these substances can be found in all environmental compartments including soil, water, and air. Neonicotinoids and fipronil operate by disrupting neural transmission in the central nervous system of invertebrates. Neonicotinoids mimic the action of neurotransmitters, while fipronil inhibits neuronal receptors. In doing so, they continuously stimulate neurons leading ultimately to death of target invertebrates. Like virtually all insecticides, they can also have lethal and sublethal impacts on non-target organisms, including insect predators and vertebrates. Furthermore, a range of synergistic effects with other stressors have been documented. Here, we review extensively their metabolic pathways, showing how they form both compound-specific and common metabolites which can themselves be toxic. These may result in prolonged toxicity. Considering their wide commercial expansion, mode of action, the systemic properties in plants, persistence and environmental fate, coupled with limited information about the toxicity profiles of these compounds and their metabolites, neonicotinoids and fipronil may entail significant risks to the environment. A global evaluation of the potential collateral effects of their use is therefore timely. The present paper and subsequent chapters in this review of the global literature explore these risks and show a growing body of evidence that persistent, low concentrations of these insecticides pose serious risks of undesirable environmental impacts. | Additional co-authors: E. Long, M. McField, P. Mineau, E. A. D. Mitchell, C. A. Morrissey, D. A. Noome, L. Pisa, J. Settele, J. D. Stark, A. Tapparo, H. Van Dyck, J. Van Praagh, J. P. Van der Sluijs, M. Wiemers
Show more [+] Less [-]Systemic insecticides (neonicotinoids and fipronil): trends, uses, mode of action and metabolites Full text
2015
Amaral-Rogers, V. | Belzunces, Luc | Bonmatin, J-M. | Chagnon, M. | Downs, C. | Furlan, L. | Gibbons, D.W. | Giorio, C. | Girolami, V. | Goulson, D. | Kreutzweiser, D.P. | Krupke, C. | Liess, M. | Long, E. | McField, M. | Mineau, P. | Mitchell, E.A.D. | Morrissey, C.A. | Noome, D.A. | Pisa, L | Settele, J. | Stark, J. D. | Tapparo, A. | Van Dyck, H. | van Praagh, J.P. | Van der Sluijs, J. P. | Whitehorn, P.R. | Wiemers, M.
Since their discovery in the late 1980s, neonicotinoid pesticides have become the most widely used class of insecticides worldwide, with large-scale applications ranging from plant protection (crops, vegetables, fruits),veterinary products, and biocides to invertebrate pest control in fish farming. In this review, we address the phenyl-pyrazole fipronil together with neonicotinoids because of similarities in their toxicity, physicochemical profiles, and presence in the environment. Neonicotinoids and fipronil currently account for approximately one third of the world insecticide market; the annual world production of the archetype neonicotinoid, imidacloprid, was estimated to be ca. 20,000 tonnes active substance in 2010. There were several reasons for the initialsuccess of neonicotinoids and fipronil: (1) there was no known pesticide resistance in target pests, mainly because of their recent development, (2) their physicochemical properties included many advantages over previous generations of insecticides (i.e., organophosphates, carbamates, pyrethroids, etc.), and (3) they shared an assumed reduced operator and consumer risk. Due to their systemic nature, they are taken up by the roots or leaves and translocated to all parts of the plant, which, in turn, makes them effectively toxic to herbivorous insects. The toxicity persists for a variable period of time—depending on the plant, its growth stage, and the amount of pesticide applied. Awide variety of applications are available, including the most common prophylactic non-Good Agricultural Practices (GAP) application by seed coating. As a result of their extensive use and physicochemical properties, these substances can be found in all environmental compartments including soil, water, and air. Neonicotinoids and fipronil operate by disrupting neural transmission in the central nervous system of invertebrates. Neonicotinoids mimic the action of neurotransmitters, while fipronil inhibits neuronal receptors. In doing so, they continuously stimulate neuronsleading ultimately to death of target invertebrates. Like virtually all insecticides, they can also have lethal and sublethal impacts on non-target organisms, including insect predators and vertebrates. Furthermore, a range of synergistic effects with other stressors have been documented. Here, we review extensively their metabolic pathways, showing how they form both compound-specific and common metabolites which can themselves be toxic. These may result in prolonged toxicity. Considering their wide commercial expansion, mode of action, the systemic properties in plants, persistence and environmental fate, coupled with limited information about the toxicity profiles of these compounds and their metabolites, neonicotinoids and fipronil may entail significant risks to the environment. A global evaluation of the potential collateral effects of their use is therefore timely. The present paper and subsequent chapters in this review of the global literature explore these risks and show a growing body of evidence that persistent, low concentrations of these insecticides pose serious risks of undesirable environmental impacts.
Show more [+] Less [-]Systemic insecticides (neonicotinoids and fipronil): trends, uses, mode of action and metabolites | Pesticides néonicotinoïdes. Tendances, usages et modes d’action des métabolites Full text
2014
Simon-Delso, N. | Amaral-Rogers, V. | Belzunces, L.P. | Bonmatin, Jean-Marc | Chagnon, M. | Downs, C. | Furlan, L. | Gibbons, D. W. | Giorio, C. | Girolami, V. | Goulson, D. | Kreutzweiser, D. P. | Krupke, C. H. | Liess, M. | Long, E. | Mcfield, M. | Mineau, P. | Mitchell, E. A. D. | Morrissey, C. A. | Noome, D. A. | Pisa, L. | Settele, J. | Stark, J. D. | Tapparo, A. | van Dyck, H. | van Praagh, J. | van Der Sluijs, J. P. | Whitehorn, P. R. | Wiemers, M. | Copernicus Institute of Sustainable Development [Utrecht] ; Universiteit Utrecht / Utrecht University [Utrecht] | Beekeeping Research and Information Center | Buglife | Abeilles et environnement (AE) ; Institut National de la Recherche Agronomique (INRA) | Centre de biophysique moléculaire (CBM) ; Université d'Orléans (UO)-Université de Tours (UT)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Chimie - CNRS Chimie (INC-CNRS)-Centre National de la Recherche Scientifique (CNRS)
. | Depuis leur découverte dans les années 1980, les pesticides néonicotinoïdes sont devenus la classe la plus largement utilisée des insecticides, dans le monde entier, avec des applications à grande échelle allant de la protection des plantes (cultures, légumes, fruits), aux produits vétérinaires et aux biocides pour le contrôle des invertébrés parasites en pisciculture. Dans cette revue, nous joignons la fipronil, un phénylpyrazole, aux néonicotinoïdes en raison de la similitude de leur toxicité, des profils physico-chimiques, et de leur présence dans l'environnement. Les néonicotinoïdes et le fipronil représentent actuellement environ un tiers du marché mondial des insecticides ; la production mondiale annuelle de l'archétype des néonicotinoïdes, l'imidaclopride, a été estimée au total à 20 000 tonnes de substance active en 2010. Le succès initial des néonicotinoïdes et du fipronil est dû à plusieurs raisons : (1) il n'y avait pas de résistance connue à ces pesticides chez les ravageurs cibles, principalement en raison de leur développement récent, (2) leurs propriétés physico-chimiques rassemblaient de nombreux avantages par rapport à celles des générations précédentes d’insecticides (c’est-à-dire, les organophosphorés, les carbamates, les pyréthrinoïdes, etc.), et,(3) ils partagent et supposent des risques réduits pour l’opérateur et le consommateur. En raison de leur nature systémique, ils sont absorbés par les racines ou les feuilles et transloqués à toutes les parties de la plante, laquelle, à son tour, est effectivement toxique pour les insectes herbivores. La toxicité persiste pendant une période de temps variable en fonction de la plante, de son stade de croissance, et de la quantité de pesticide appliquée. Une grande variété d'applications sont disponibles, y compris la NON Bonne Pratique Agricole(GAP)prophylactique d’application courante en enrobage de semences. En conséquence de leur utilisation extensive et de leurs propriétés physico-chimiques, ces substances peuvent être trouvés dans tous les compartiments environnementaux, y compris le sol, l'eau et l'air. Les néonicotinoïdes et le fipronil fonctionnent en perturbant la transmission nerveuse dans le système nerveux central des invertébrés.Les néonicotinoïdes imitent l'action des neurotransmetteurs, tandis que le fipronil inhibe les récepteurs neuronaux. Ce faisant, les premiers stimulent en permanence les neurones conduisant finalement les invertébrés cibles à la mort. Comme pratiquement tous les insecticides, ils peuvent également avoir des effets létaux et sublétaux sur les organismes non cibles, y compris les vertébrés prédateurs d'insectes. En outre, une gamme d’effets synergiques avec d'autres facteurs de stress a été documentée. Ici, nous passons en revue de façon extensive leurs voies métaboliques, montrant comment les composés spécifiques et les métabolites communs, lesquels peuvent eux-mêmes être toxiques, forment ensemble deux cas. Ceux-ci peuvent entraîner une toxicité prolongée. Compte tenu de leur large expansion commerciale, leur mode d'action, leurs propriétés systémiques chez les plantes, leur persistance et leur devenir environnemental, couplés avec des informations limitées sur les profils de toxicité de ces composés et de leurs métabolites, les néonicotinoïdes et le fipronil peuvent entraîner des risques importants pour l'environnement. Une évaluation globale des effets collatéraux potentiels de leur utilisation est donc opportune. Le présent document, et les chapitres suivants dans cette revue de la littérature mondiale, explorent ces risques et montrent une quantité croissante de preuves qui, sur la base de la persistance et de faibles concentrations de ces pesticides, posent de sérieux risques d’impacts environnementaux indésirables.
Show more [+] Less [-]Systemic insecticides (neonicotinoids and fipronil): trends, uses, mode of action and metabolites Full text
2015
Simon-Delso, N | Amaral-Rogers, V. | Belzunces, Luc | Bonmatin, J-M. | Chagnon, M. | Downs, C. | Furlan, L. | Gibbons, D.W. | Giorio, C. | Girolami, V. | Goulson, D. | Kreutzweiser, D.P. | Krupke, C. | Liess, M. | Long, E. | Mcfield, M. | Mineau, P. | Mitchell, E.A.D. | Morrissey, C.A. | Noome, D.A. | Pisa, L | Settele, J. | Stark, J. D. | Tapparo, A. | van Dyck, H. | van Praagh, J.P. | van Der Sluijs, J. P. | Whitehorn, P.R. | Wiemers, M. | Universiteit Utrecht / Utrecht University [Utrecht] | Centre Apicole de Recherche et Information ; Partenaires INRAE | Buglife | Abeilles et environnement (AE) ; Institut National de la Recherche Agronomique (INRA) | Centre de biophysique moléculaire (CBM) ; Université d'Orléans (UO)-Université de Tours (UT)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Chimie - CNRS Chimie (INC-CNRS)-Centre National de la Recherche Scientifique (CNRS) | Département des Sciences Biologiques ; Université du Québec à Montréal = University of Québec in Montréal (UQAM) | Haereticus Environmental Laboratory ; Partenaires INRAE | Veneto Agricoltura | Centre for Conservation Science | Department of Chemistry ; University of Cambridge [UK] (CAM) | Università degli Studi di Padova = University of Padua (Unipd) | School of Life Sciences ; University of Sussex | Canadian Forest Service ; Natural Resources Canada (NRCan) | Department of Entomology ; Michigan State University [East Lansing] ; Michigan State University System-Michigan State University System | Helmholtz Zentrum für Umweltforschung = Helmholtz Centre for Environmental Research (UFZ) | Smithsonian Institution | Pierre Mineau Consulting ; Partenaires INRAE | Laboratory of Soil Biology ; Université de Neuchâtel = University of Neuchatel (UNINE) | Jardin Botanique de Neuchâtel | University of Saskatchewan [Saskatoon, Canada] (U of S) | Kijani ; Partenaires INRAE | Department of Community Ecology ; Helmholtz Zentrum für Umweltforschung = Helmholtz Centre for Environmental Research (UFZ) | German Centre for Integrative Biodiversity Research (iDiv) | Washington State University (WSU) | Université Catholique de Louvain = Catholic University of Louvain (UCL) | Scientific Advisor ; Partenaires INRAE | University of Bergen (UiB) | School of Natural Sciences ; University of Stirling
International audience | Since their discovery in the late 1980s, neonicotinoid pesticides have become the most widely used class of insecticides worldwide, with large-scale applications ranging from plant protection (crops, vegetables, fruits), veterinary products, and biocides to invertebrate pest control in fish farming. In this review, we address the phenyl-pyrazole fipronil together with neonicotinoids because of similarities in their toxicity, physicochemical profiles, and presence in the environment. Neonicotinoids and fipronil currently account for approximately one third of the world insecticide market; the annual world production of the archetype neonicotinoid, imidacloprid, was estimated to be ca. 20,000 tonnes active substance in 2010. There were several reasons for the initial success of neonicotinoids and fipronil: (1) there was no known pesticide resistance in target pests, mainly because of their recent development, (2) their physicochemical properties included many advantages over previous generations of insecticides (i.e., organophosphates, carbamates, pyrethroids, etc.), and (3) they shared an assumed reduced operator and consumer risk. Due to their systemic nature, they are taken up by the roots or leaves and translocated to all parts of the plant, which, in turn, makes them effectively toxic to herbivorous insects. The toxicity persists for a variable period of time—depending on the plant, its growth stage, and the amount of pesticide applied. Awide variety of applications are available, including the most common prophylactic non-Good Agricultural Practices (GAP) application by seed coating. As a result of their extensive use and physicochemical properties, these substances can be found in all environmental compartments including soil, water, and air. Neonicotinoids and fipronil operate by disrupting neural transmission in the central nervous system of invertebrates. Neonicotinoids mimic the action of neurotransmitters, while fipronil inhibits neuronal receptors. In doing so, they continuously stimulate neurons leading ultimately to death of target invertebrates. Like virtually all insecticides, they can also have lethal and sublethal impacts on non-target organisms, including insect predators and vertebrates. Furthermore, a range of synergistic effects with other stressors have been documented. Here, we review extensively their metabolic pathways, showing how they form both compound-specific and common metabolites which can themselves be toxic. These may result in prolonged toxicity. Considering their wide commercial expansion, mode of action, the systemic properties in plants, persistence and environmental fate, coupled with limited information about the toxicity profiles of these compounds and their metabolites, neonicotinoids and fipronil may entail significant risks to the environment. A global evaluation of the potential collateral effects of their use is therefore timely. The present paper and subsequent chapters in this review of the global literature explore these risks and show a growing body of evidence that persistent, low concentrations of these insecticides pose serious risks of undesirable environmental impacts.
Show more [+] Less [-]Determination of thiamethoxam and its metabolite clothianidin residue and dissipation in cowpea by QuEChERS combining with ultrahigh-performance liquid chromatography–tandem mass spectrometry Full text
2021
Chen, Li | Li, Fugen | Jia, Chunhong | Yu, Pingzhong | Zhao, Ercheng | He, Min | Jing, Junjie
The dissipation and residue levels of thiamethoxam and its metabolite clothianidin in cowpea were investigated under field conditions. Samples of cowpea were analyzed using a QuEChERS technique with ultra-performance liquid chromatography tandem mass spectrometry. The recoveries were 86.5–118.9% for thiamethoxam and 75.6–104.1% for clothianidin, with the coefficient of variation of < 13%. The water dispersible granule formulation of thiamethoxam was applied on cowpea at 30 and 45 g active ingredient ha⁻¹ in accordance with good agricultural practice. The half-life of thiamethoxam in cowpea was 0.8–1.6 days. The cowpea samples were gathered at 3, 7, and 10 days after the last application, and the residues of thiamethoxam in cowpea were < 0.005–0.054 mg kg⁻¹, while those of clothianidin were < 0.005–0.008 mg kg⁻¹. The final residues of thiamethoxam and clothianidin were below the European Union (EU) maximum residue level (0.3 mg kg⁻¹ for thiamethoxam; 0.2 mg kg⁻¹ for clothianidin) in cowpea after a preharvest interval (PHI) of 7 days. This study provided basic data on the use and safety of thiamethoxam and clothianidin in cowpea to help the Chinese government formulate a maximum residue level for thiamethoxam in cowpea.
Show more [+] Less [-]Risks of large-scale use of systemic insecticides to ecosystem functioning and services Full text
2015
Chagnon, Madeleine | Kreutzweiser, David | Mitchell, Edward A.D. | Morrissey, Christy A. | Noome, Dominique A. | Van der Sluijs, Jeroen P.
Large-scale use of the persistent and potent neonicotinoid and fipronil insecticides has raised concerns about risks to ecosystem functions provided by a wide range of species and environments affected by these insecticides. The concept of ecosystem services is widely used in decision making in the context of valuing the service potentials, benefits, and use values that well-functioning ecosystems provide to humans and the biosphere and, as an endpoint (value to be protected), in ecological risk assessment of chemicals. Neonicotinoid insecticides are frequently detected in soil and water and are also found in air, as dust particles during sowing of crops and aerosols during spraying. These environmental media provide essential resources to support biodiversity, but are known to be threatened by long-term or repeated contamination by neonicotinoids and fipronil. We review the state of knowledge regarding the potential impacts of these insecticides on ecosystem functioning and services provided by terrestrial and aquatic ecosystems including soil and freshwater functions, fisheries, biological pest control, and pollination services. Empirical studies examining the specific impacts of neonicotinoids and fipronil to ecosystem services have focused largely on the negative impacts to beneficial insect species (honeybees) and the impact on pollination service of food crops. However, here we document broader evidence of the effects on ecosystem functions regulating soil and water quality, pest control, pollination, ecosystem resilience, and community diversity. In particular, microbes, invertebrates, and fish play critical roles as decomposers, pollinators, consumers, and predators, which collectively maintain healthy communities and ecosystem integrity. Several examples in this review demonstrate evidence of the negative impacts of systemic insecticides on decomposition, nutrient cycling, soil respiration, and invertebrate populations valued by humans. Invertebrates, particularly earthworms that are important for soil processes, wild and domestic insect pollinators which are important for plant and crop production, and several freshwater taxa which are involved in aquatic nutrient cycling, were all found to be highly susceptible to lethal and sublethal effects of neonicotinoids and/or fipronil at environmentally relevant concentrations. By contrast, most microbes and fish do not appear to be as sensitive under normal exposure scenarios, though the effects on fish may be important in certain realms such as combined fish-rice farming systems and through food chain effects. We highlight the economic and cultural concerns around agriculture and aquaculture production and the role these insecticides may have in threatening food security. Overall, we recommend improved sustainable agricultural practices that restrict systemic insecticide use to maintain and support several ecosystem services that humans fundamentally depend on.
Show more [+] Less [-]Environmental fate and exposure; neonicotinoids and fipronil Full text
2015
Bonmatin, J.-M. | Giorio, C. | Girolami, V. | Goulson, D. | Kreutzweiser, D. P. | Krupke, C. | Liess, M. | Long, E. | Marzaro, M. | Mitchell, E. A. D. | Noome, D. A. | Simon-Delso, N. | Tapparo, A.
Systemic insecticides are applied to plants using a wide variety of methods, ranging from foliar sprays to seed treatments and soil drenches. Neonicotinoids and fipronil are among the most widely used pesticides in the world. Their popularity is largely due to their high toxicity to invertebrates, the ease and flexibility with which they can be applied, their long persistence, and their systemic nature, which ensures that they spread to all parts of the target crop. However, these properties also increase the probability of environmental contamination and exposure of nontarget organisms. Environmental contamination occurs via a number of routes including dust generated during drilling of dressed seeds, contamination and accumulation in arable soils and soil water, runoff into waterways, and uptake of pesticides by nontarget plants via their roots or dust deposition on leaves. Persistence in soils, waterways, and nontarget plants is variable but can be prolonged; for example, the half-lives of neonicotinoids in soils can exceed 1,000 days, so they can accumulate when used repeatedly. Similarly, they can persist in woody plants for periods exceeding 1 year. Breakdown results in toxic metabolites, though concentrations of these in the environment are rarely measured. Overall, there is strong evidence that soils, waterways, and plants in agricultural environments and neighboring areas are contaminated with variable levels of neonicotinoids or fipronil mixtures and their metabolites (soil, parts per billion (ppb)-parts per million (ppm) range; water, parts per trillion (ppt)-ppb range; and plants, ppb-ppm range). This provides multiple routes for chronic (and acute in some cases) exposure of nontarget animals. For example, pollinators are exposed through direct contact with dust during drilling; consumption of pollen, nectar, or guttation drops from seed-treated crops, water, and consumption of contaminated pollen and nectar from wild flowers and trees growing near-treated crops. Studies of food stores in honeybee colonies from across the globe demonstrate that colonies are routinely and chronically exposed to neonicotinoids, fipronil, and their metabolites (generally in the 1–100 ppb range), mixed with other pesticides some of which are known to act synergistically with neonicotinoids. Other nontarget organisms, particularly those inhabiting soils, aquatic habitats, or herbivorous insects feeding on noncrop plants in farmland, will also inevitably receive exposure, although data are generally lacking for these groups. We summarize the current state of knowledge regarding the environmental fate of these compounds by outlining what is known about the chemical properties of these compounds, and placing these properties in the context of modern agricultural practices.
Show more [+] Less [-]Policy responses
2018
Mateo-Sagasta, Javier | Turral, Hugh