The Experts below are selected from a list of 249 Experts worldwide ranked by ideXlab platform
James R Wheeler - One of the best experts on this subject based on the ideXlab platform.
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an evaluation of fish early life stage tests for predicting reProductive and longer term toxicity from Plant Protection Product active substances
Environmental Toxicology and Chemistry, 2014Co-Authors: James R Wheeler, Samuel K Maynard, Mark CraneAbstract:The chronic toxicity of chemicals to fish is routinely assessed by using fish early life stage (ELS) test results. Fish full life cycle (FLC) tests are generally required only when toxicity, bioaccumulation, and persistence triggers are met or when there is a suspicion of potential endocrine-disrupting properties. This regulatory approach is based on a relationship between the results of fish ELS and FLC studies first established more than 35 yrs ago. Recently, this relationship has been challenged by some regulatory authorities, and it has been recommended that more substances should undergo FLC testing. In addition, a project proposal has been submitted to the Organisation for Economic Cooperation and Development (OECD) to develop a fish partial life cycle (PLC) test including a reProductive assessment. Both FLC and PLC tests are animal- and resource-intensive and technically challenging and should therefore be undertaken only if there is clear evidence that they are necessary for coming to a regulatory decision. The present study reports on an analysis of a database of paired fish ELS and FLC endpoints for Plant Protection Product active substances from European Union draft assessment reports and the US Environmental Protection Agency Office of Pesticide Programs Pesticide Ecotoxicity Database. Analysis of this database shows a clear relationship between ELS and FLC responses, with similar median sensitivity across substances when no-observed-effect concentrations (NOECs) are compared. There was also no indication that classification of a substance as a mammalian reProductive toxicant leads to more sensitive effects in fish FLC tests than in ELS tests. Indeed, the response of the ELS tests was generally more sensitive than the most sensitive reProduction NOEC from a FLC test. This analysis indicates that current testing strategies and guidelines are fit for purpose and that there is no need for fish full or partial life cycle tests for most Plant Protection Product active substances. Environ Toxicol Chem 2014;33:1874–1878. © 2014 SETAC
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saving two birds with one stone using active substance avian acute toxicity data to predict formulated Plant Protection Product toxicity
Environmental Toxicology and Chemistry, 2014Co-Authors: Samuel K Maynard, Peter Edwards, James R WheelerAbstract:Environmental safety assessments for exposure of birds require the provision of acute avian toxicity data for both the pesticidal active substance and formulated Products. As an example, testing on the formulated Product is waived in Europe using an assessment of data for the constituent active substance(s). This is often not the case globally, because some countries require acute toxicity tests with every formulated Product, thereby triggering animal welfare concerns through unnecessary testing. A database of 383 formulated Products was compiled from acute toxicity studies conducted with northern bobwhite (Colinus virginianus) or Japanese quail (Coturnix japonica) (unpublished regulatory literature). Of the 383 formulated Products studied, 159 contained only active substances considered functionally nontoxic (median lethal dose [LD50] > highest dose tested). Of these, 97% had formulated Product LD50 values of >2000 mg formulated Product/kg (limit dose), indicating that no new information was obtained in the formulated Product study. Furthermore, defined (point estimated) LD50 values for formulated Products were compared with LD50 values predicted from toxicity of the active substance(s). This demonstrated that predicted LD50 values were within 2-fold and 5-fold of the measured formulated Product LD50 values in 90% and 98% of cases, respectively. This analysis demonstrates that avian acute toxicity testing of formulated Products is largely unnecessary and should not be routinely required to assess avian acute toxicity. In particular, when active substances are known to be functionally nontoxic, further formulated Product testing adds no further information and unnecessarily increases bird usage in testing. A further analysis highlights the fact that significant reductions (61% in this dataset) could be achieved by using a sequential testing design (Organisation for Economic Co-operation and Development test guideline 223), as opposed to established single-stage designs. Environ Toxicol Chem 2014;33:1578–1583. © 2014 The Authors. Published on behalf of SETAC by Wiley Periodicals, Inc.
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environmental toxicology saving two birds with one stone using active substance avian acute toxicity data to predict formulated Plant Protection Product toxicity
2014Co-Authors: Samuel K Maynard, Peter Edwards, James R WheelerAbstract:Environmental safety assessments for exposure of birds require the provision of acute avian toxicity data for both the pesticidal active substance and formulated Products. As an example, testing on the formulated Product is waived in Europe using an assessment of data for the constituent active substance(s). This is often not the case globally, because some countries require acute toxicity tests with everyformulatedProduct,therebytriggeringanimal welfareconcernsthroughunnecessarytesting.Adatabaseof383formulatedProducts was compiled from acute toxicity studies conducted with northern bobwhite (Colinus virginianus) or Japanese quail (Coturnix japonica) (unpublished regulatory literature). Of the 383 formulated Products studied, 159 contained only active substances considered functionally nontoxic (median lethal dose (LD50)>highest dose tested). Of these, 97%had formulated ProductLD50 values of>2000mg formulated Product/kg (limit dose), indicating that no new information was obtained in the formulated Product study. Furthermore, defined (point estimated) LD50 values for formulated Products were compared with LD50 values predicted from toxicity of the active substance(s). This demonstrated that predicted LD50 values were within 2-fold and 5-foldof the measured formulated Product LD50 values in 90% and 98% ofcases,respectively.ThisanalysisdemonstratesthatavianacutetoxicitytestingofformulatedProductsislargelyunnecessaryandshould notberoutinelyrequiredtoassessavianacutetoxicity.Inparticular,whenactivesubstancesareknowntobefunctionallynontoxic,further formulated Product testing adds no further information and unnecessarily increases bird usage in testing. A further analysis highlights the fact that significant reductions (61% in this dataset) could be achieved by using asequential testing design (Organisation forEconomic
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Reducing the number of fish in bioconcentration studies for Plant Protection Products by reducing the number of test concentrations.
Chemosphere, 2012Co-Authors: Stuart Creton, Lennart Weltje, Hannah Hobson, James R WheelerAbstract:Abstract Fish bioconcentration tests are time consuming, expensive, and use many animals. Alternative methods that replace, reduce or refine the use of fish for BCF testing would therefore be of value. Test guidelines generally require that bioconcentration factors (BCFs) are determined at two exposure concentrations. However, recent revisions to the OECD Test Guideline for BCF testing (TG 305) provide the option to use only one exposure concentration, when justification is provided, although two concentrations may still be required for some regulatory purposes. Analysis of 55 studies on Plant Protection Products demonstrates that BCF values do not significantly differ between the two exposure concentrations. This analysis therefore provides evidence to support the revision of OECD TG 305, and in particular provides justification for using the one test concentration approach for Plant Protection Product active substances.
Samuel K Maynard - One of the best experts on this subject based on the ideXlab platform.
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an evaluation of fish early life stage tests for predicting reProductive and longer term toxicity from Plant Protection Product active substances
Environmental Toxicology and Chemistry, 2014Co-Authors: James R Wheeler, Samuel K Maynard, Mark CraneAbstract:The chronic toxicity of chemicals to fish is routinely assessed by using fish early life stage (ELS) test results. Fish full life cycle (FLC) tests are generally required only when toxicity, bioaccumulation, and persistence triggers are met or when there is a suspicion of potential endocrine-disrupting properties. This regulatory approach is based on a relationship between the results of fish ELS and FLC studies first established more than 35 yrs ago. Recently, this relationship has been challenged by some regulatory authorities, and it has been recommended that more substances should undergo FLC testing. In addition, a project proposal has been submitted to the Organisation for Economic Cooperation and Development (OECD) to develop a fish partial life cycle (PLC) test including a reProductive assessment. Both FLC and PLC tests are animal- and resource-intensive and technically challenging and should therefore be undertaken only if there is clear evidence that they are necessary for coming to a regulatory decision. The present study reports on an analysis of a database of paired fish ELS and FLC endpoints for Plant Protection Product active substances from European Union draft assessment reports and the US Environmental Protection Agency Office of Pesticide Programs Pesticide Ecotoxicity Database. Analysis of this database shows a clear relationship between ELS and FLC responses, with similar median sensitivity across substances when no-observed-effect concentrations (NOECs) are compared. There was also no indication that classification of a substance as a mammalian reProductive toxicant leads to more sensitive effects in fish FLC tests than in ELS tests. Indeed, the response of the ELS tests was generally more sensitive than the most sensitive reProduction NOEC from a FLC test. This analysis indicates that current testing strategies and guidelines are fit for purpose and that there is no need for fish full or partial life cycle tests for most Plant Protection Product active substances. Environ Toxicol Chem 2014;33:1874–1878. © 2014 SETAC
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saving two birds with one stone using active substance avian acute toxicity data to predict formulated Plant Protection Product toxicity
Environmental Toxicology and Chemistry, 2014Co-Authors: Samuel K Maynard, Peter Edwards, James R WheelerAbstract:Environmental safety assessments for exposure of birds require the provision of acute avian toxicity data for both the pesticidal active substance and formulated Products. As an example, testing on the formulated Product is waived in Europe using an assessment of data for the constituent active substance(s). This is often not the case globally, because some countries require acute toxicity tests with every formulated Product, thereby triggering animal welfare concerns through unnecessary testing. A database of 383 formulated Products was compiled from acute toxicity studies conducted with northern bobwhite (Colinus virginianus) or Japanese quail (Coturnix japonica) (unpublished regulatory literature). Of the 383 formulated Products studied, 159 contained only active substances considered functionally nontoxic (median lethal dose [LD50] > highest dose tested). Of these, 97% had formulated Product LD50 values of >2000 mg formulated Product/kg (limit dose), indicating that no new information was obtained in the formulated Product study. Furthermore, defined (point estimated) LD50 values for formulated Products were compared with LD50 values predicted from toxicity of the active substance(s). This demonstrated that predicted LD50 values were within 2-fold and 5-fold of the measured formulated Product LD50 values in 90% and 98% of cases, respectively. This analysis demonstrates that avian acute toxicity testing of formulated Products is largely unnecessary and should not be routinely required to assess avian acute toxicity. In particular, when active substances are known to be functionally nontoxic, further formulated Product testing adds no further information and unnecessarily increases bird usage in testing. A further analysis highlights the fact that significant reductions (61% in this dataset) could be achieved by using a sequential testing design (Organisation for Economic Co-operation and Development test guideline 223), as opposed to established single-stage designs. Environ Toxicol Chem 2014;33:1578–1583. © 2014 The Authors. Published on behalf of SETAC by Wiley Periodicals, Inc.
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environmental toxicology saving two birds with one stone using active substance avian acute toxicity data to predict formulated Plant Protection Product toxicity
2014Co-Authors: Samuel K Maynard, Peter Edwards, James R WheelerAbstract:Environmental safety assessments for exposure of birds require the provision of acute avian toxicity data for both the pesticidal active substance and formulated Products. As an example, testing on the formulated Product is waived in Europe using an assessment of data for the constituent active substance(s). This is often not the case globally, because some countries require acute toxicity tests with everyformulatedProduct,therebytriggeringanimal welfareconcernsthroughunnecessarytesting.Adatabaseof383formulatedProducts was compiled from acute toxicity studies conducted with northern bobwhite (Colinus virginianus) or Japanese quail (Coturnix japonica) (unpublished regulatory literature). Of the 383 formulated Products studied, 159 contained only active substances considered functionally nontoxic (median lethal dose (LD50)>highest dose tested). Of these, 97%had formulated ProductLD50 values of>2000mg formulated Product/kg (limit dose), indicating that no new information was obtained in the formulated Product study. Furthermore, defined (point estimated) LD50 values for formulated Products were compared with LD50 values predicted from toxicity of the active substance(s). This demonstrated that predicted LD50 values were within 2-fold and 5-foldof the measured formulated Product LD50 values in 90% and 98% ofcases,respectively.ThisanalysisdemonstratesthatavianacutetoxicitytestingofformulatedProductsislargelyunnecessaryandshould notberoutinelyrequiredtoassessavianacutetoxicity.Inparticular,whenactivesubstancesareknowntobefunctionallynontoxic,further formulated Product testing adds no further information and unnecessarily increases bird usage in testing. A further analysis highlights the fact that significant reductions (61% in this dataset) could be achieved by using asequential testing design (Organisation forEconomic
Helena Basa Cesnik - One of the best experts on this subject based on the ideXlab platform.
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validation of the multiresidual gc ms method for determining Plant Protection Product residues in strawberries
Acta Agriculturae Slovenica, 2018Co-Authors: Helena Basa CesnikAbstract:Gas chromatography coupled with mass spectrometry was used for the introduction and validation of the multiresidual method for determining of Plant Protection Product residues in strawberries. During the validation procedure, limits of quantification were set and the method was checked for its recovery, linearity, repeatability, reproducibility and measurement uncertainty. An interlaboratory comparison was also performed to check the accuracy of the method. The method was proven to be fit for purpose. Afterwards 19 strawberry samples were analysed for the presence of Plant Protection Product residues using the validated method. In the strawberries 5 active substances, all fungicides, were found: chlorothalonil, cyprodinil, fludioxonil, metalaxyl+metalaxyl-M and pyrimethanil. Residues of these active substances were in range 0.01 – 0.44 mg/kg. No cases exceeding the maximum residue levels were measured.
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Plant Protection Product residues in white grapes and wines of malvasia istriana produced in istria
Food Additives & Contaminants Part B-surveillance, 2016Co-Authors: Helena Basa Cesnik, Spela Velikonja Bolta, Dejan Bavcar, Sanja Radeka, Klemen LisjakAbstract:ABSTRACTMonitorting of Plant Protection Product residues was performed in 12 grape and 66 wine samples of “Malvasia Istriana” variety, produced in Istria winegrowing region of Croatia and Slovenia. The samples were analysed for the presence of 169 different active compounds using two multiresidual analytical methods: gas chromatography coupled with mass spectrometry and liquid chromatography coupled with tandem mass spectrometry. Residues were found in 58.3% of all the inspected grape samples and in 28.8% of all the inspected wine samples. Beside that contents of residues in grapes were below 10% of maximum residue level values and they should not represent any risk for “Malvasia Istriana” grape or wine consumers.
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Plant Protection Product residues in white grapes and wines of malvasia istriana produced in istria part b surveillance
Food Additives and Contaminants Part A-chemistry Analysis Control Exposure & Risk Assessment, 2016Co-Authors: Helena Basa Cesnik, Spela Velikonja Bolta, Dejan Bavcar, Sanja Radeka, Klemen LisjakAbstract:Monitorting of Plant Protection Product residues was performed in 12 grape and 66 wine samples of “Malvasia Istriana” variety, produced in Istria winegrowing region of Croatia and Slovenia. The samples were analysed for the presence of 169 different active compounds using two multiresidual analytical methods: gas chromatography coupled with mass spectrometry and liquid chromatography coupled with tandem mass spectrometry. Residues were found in 58.3% of all the inspected grape samples and in 28.8% of all the inspected wine samples. Beside that contents of residues in grapes were below 10% of maximum residue level values and they should not represent any risk for “Malvasia Istriana” grape or wine consumers.
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Plant Protection Product residues in red grapes and teran ptp wine
Food Additives & Contaminants Part B-surveillance, 2015Co-Authors: Helena Basa Cesnik, Spela Velikonja Bolta, Klemen LisjakAbstract:Between 2011 and 2013, a total of 73 grape and 82 wine samples from winegrowing district Kras (Karst) were analysed for Plant Protection Product (PPP) residues. The samples were analysed for the presence of 215 different active compounds using two multiresidual analytical methods: gas chromatography coupled with mass spectrometry and liquid chromatography coupled with tandem mass spectrometry. Residues were found in 91.8% of all grape samples and in 67.1% of all wine samples. In all grape samples, residues were below maximum residue levels (MRLs) and 58.9% of all grape samples contained active substances at a level of less then 10% of the MRL. Nearly 33% of all Teran PTP wines did not contain PPP residues at all. Residues diminish during processing of grapes to wine, so their content in wine was low. Therefore, it could be concluded that grapes and wine in the winegrowing district Kras are safe for consumers.
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Plant Protection Product residues in agricultural Products of slovene origin found in 2008
Journal of Central European Agriculture, 2011Co-Authors: Helena Basa Cesnik, Spela Velikonja Bolta, A GregorcicAbstract:In the year 2008, 166 apple, bean, carrot, cucumber, lettuce, pear, potato and spinach samples from Slovene producers were analysed for Plant Protection Product residues. The samples were analysed for the presence of 158 different active compounds using three analytical methods. In two samples (1.2%) exceeded maximum residue levels (MRLs) were determined which is better than the results of the monitoring of pesticide residues in the Products of Plant origin in the 27 European Union, Member States (EU MS) and 2 European Free Trade Association (EFTA) States: Norway and Iceland in 2008 (2.2%). The most frequently found active substance in agricultural Products was dithiocarbamates. Products which contained 4 or more active substances per sample were apples and pears.
Marco Vighi - One of the best experts on this subject based on the ideXlab platform.
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Year-round behaviour of soil microarthropod communities under Plant Protection Product application
Ecotoxicology, 2014Co-Authors: Cornelis A M Gestel, Marco VighiAbstract:The use of Plant Protection Products (PPPs) in agro-environments can lead to undesired exposure of non-target organisms in non-target compartments. A year-round field survey was conducted in a vineyard in Northern Italy, for monitoring the changes in the structure of soil microarthropod communities under the application of PPPs, focusing on springtails and mites, both inside and 4 and 10 m outside the vineyard. Exposure to PPPs was estimated as time-weighted average soil concentrations. The fluctuations in the abundances of the different organisms after the application of PPPs, especially insecticides, were recorded. A recovery in abundances was observed at the end of the Productive season outside the field and at the beginning of the next spring within the vineyard. Using multivariate statistical tools, the behaviour of each taxon in relation to the stressors was assessed. Some organisms were affected by the stressors, while others were favoured because of low vulnerability to PPPs and the indirect effect of the absence of other taxa. The principal response curves (PRC) method was the most sensitive tool for assessing PPP effects on soil arthropod communities. Strong differences were evident in the structure of the communities inside and outside the vineyard, with the communities sampled 4 and 10 m outside the vineyard being fairly similar, the latter considered as control. The role of physical stressors on community composition is recognised. However, chemical stressors, and in particular PPP exposure seemed to have larger effects on structural and functional characteristics of soil arthropod communities than physical stressors.
Konstantinos A Aliferis - One of the best experts on this subject based on the ideXlab platform.
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untargeted metabolomics as a hypothesis generation tool in Plant Protection Product discovery highlighting the potential of trehalose and glycerol metabolism of fungal conidiospores as novel targets
Metabolomics, 2020Co-Authors: Ioannis F Kalampokis, Konstantinos A Aliferis, Alexander Erban, Sotirios Amillis, George Diallinas, Joachim KopkaAbstract:INTRODUCTION The Production of high quality and safe food represents a main priority for the agri-food sector in the effort to sustain the exponentially growing human population. Nonetheless, there are major challenges that require the discovery of new, alternative, and improved Plant Protection Products (PPPs). Focusing on fungal Plant pathogens, the dissection of mechanisms that are essential for their survival provides insights that could be exploited towards the achievement of the aforementioned aim. In this context, the germination of fungal spores, which are essential structures for their dispersal, survival, and pathogenesis, represents a target of high potential for PPPs. To the best of our knowledge, no PPPs that target the germination of fungal spores currently exist. OBJECTIVES Within this context, we have mined for changes in the metabolite profiles of the model fungus Aspergillus nidulans FGSC A4 conidiospores during germination, in an effort to discover key metabolites and reactions that could potentially become targets of PPPs. METHODS Untargeted GC/EI-TOF/MS metabolomics and multivariate analyses were employed to monitor time-resolved changes in the metabolomes of germinating A. nidulans conidiospores. RESULTS Analyses revealed that trehalose hydrolysis plays a pivotal role in conidiospore germination and highlighted the osmoregulating role of the sugar alcohols, glycerol, and mannitol. CONCLUSION The ineffectiveness to introduce active ingredients that exhibit new mode(s)-of-action as fungicides, dictates the urge for the discovery of PPPs, which could be exploited to combat major Plant Protection issues. Based on the crucial role of trehalose hydrolysis in conidiospore dormancy breakage, and the subsequent involvement of glycerol in their germination, it is plausible to suggest their biosynthesis pathways as potential novel targets for the next-generation antifungal PPPs. Our study confirmed the applicability of untargeted metabolomics as a hypothesis-generation tool in PPPs' research and discovery.
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metabolomics in Plant Protection Product research and development discovering the mode s of action and mechanisms of toxicity
2020Co-Authors: Konstantinos A AliferisAbstract:Abstract In order to address the challenges that the agri-food sector is facing, the implementation of advanced, high-throughput tools is required for the discovery and assessment of new sources of bioactivity as Plant Protection Products (PPPs). The discovery of the mode(s)-of-action (MoA) of bioactive compounds and the assessment of their toxicological profiles represent the most challenging steps in their research and development (RD however, the potential of such approach is largely unexploited. Additionally, metabolomics could greatly contribute toward gaining insights into the MoA of the next-generation PPPs such as nano-PPPs and endophyte-based PPPs. The presentation of the current state-of-the-art in the above topics and future perspectives is the aim of this chapter.