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Environmental Science and Pollution... Nov 2018Pesticide residues (112 compounds) were quantified by GC-MS/MS or LC-MS/MS in 85 bee bread samples and 154 pollen samples obtained from five apiaries each with three or...
Pesticide residues (112 compounds) were quantified by GC-MS/MS or LC-MS/MS in 85 bee bread samples and 154 pollen samples obtained from five apiaries each with three or four colonies (genotype Buckfast) in Luxembourg over the period 2011-2013. Thiacloprid, chlorfenvinphos, tebuconazole, and methiocarb were found most frequently in bee bread while thiacloprid, permethrin-cis, and permethrin-trans were detected most frequently in the pollen samples. Three neonicotinoid insecticides (clothianidin, imidacloprid, and thiamethoxam) that were restricted by an EU regulation in 2013 after our sampling campaign was finished were each found in less than 8% of the pollen or bee bread samples. The maximum concentrations of thiacloprid, metazachlor, and methiocarb measured in the pollen collected by a group of honeybee colonies (n = 5) without survivors within the 3-year period of observation were 86.20 ± 10.74 ng/g, 2.80 ± 1.26 ng/g, and below the limit of quantification, respectively. The maximum concentrations of the same compounds measured in the pollen collected by a group of honeybee colonies with significantly (P = 0.02) more survivors (7 out of 9) than expected, if the survivors had been distributed randomly among the groups of colonies, were 11.98 ± 2.28 ng/g, 0.44 ± 0.29 ng/g, and 8.49 ± 4.13 ng/g, respectively. No honeybee colony that gathered pollen containing more than 23 ng/g thiacloprid survived the 3-year project period. There was no statistically significant association between pesticide residues in the bee bread and the survival of the colonies. Actions already taken or planned and potential further actions to protect bees from exposure to pesticides are discussed.
Topics: Animals; Bees; Chromatography, Gas; Chromatography, Liquid; Environmental Monitoring; Guanidines; Insecticides; Luxembourg; Neonicotinoids; Nitro Compounds; Pesticide Residues; Pesticides; Pollen; Propolis; Tandem Mass Spectrometry; Thiazines; Thiazoles
PubMed: 30220063
DOI: 10.1007/s11356-018-3187-4 -
Chemosphere Nov 2019This study was a follow-up of a previous study that investigated a set of selected fatty acids (FAs; 12 of 56 pools) in Helix pomatia L. as biomarkers of chemical stress...
This study was a follow-up of a previous study that investigated a set of selected fatty acids (FAs; 12 of 56 pools) in Helix pomatia L. as biomarkers of chemical stress induced by applying micro-doses of molluscicides. Here, the potential of rarely used peroxidation (PI) and unsaturation (UI) coefficients were tested as biomarkers. These indices were calculated based on the FA profiles of foot and hepatopancreas tissues of H. pomatia L. Snails were treated with three molluscicides: metaldehyde, methiocarb, and potassium chloride, in three doses each (5, 10, or 15 μl, 0.01% w/v concentration), for 12 weeks, under laboratory conditions. Correlations were evaluated between frequently used oxidation status indicators (catalase, glutathione peroxidase, selenium-dependent peroxidase, superoxide dismutase, glutathione transferase, glutathione reductase, glutathione, carbonyl protein, and thiobarbituric acid reactive substances, in the form of MDA) and UI and PI ratios. These results confirmed that fatty acids could be directly used as biomarkers of exposure and oxidative physiological status in snails. Moreover, the UI and PI, calculated based on FAs, clearly reflected the current oxidation status in snails. These indices changed with the application of micro-doses of molluscicides. In conclusion, these indices could serve as sensitive biomarkers of chemical stress in snails.
Topics: Animals; Biomarkers; Environmental Exposure; Fatty Acids; Helix, Snails; Hepatopancreas; Lipid Peroxidation; Molluscacides; Oxidation-Reduction; Oxidative Stress
PubMed: 31229720
DOI: 10.1016/j.chemosphere.2019.06.026 -
Journal of Agricultural and Food... Apr 2020The goal of this study was to perform in silico identification of bioinsecticidal potential of 42 monoterpenes against and Snyder. Quantitative structure-activity...
The goal of this study was to perform in silico identification of bioinsecticidal potential of 42 monoterpenes against and Snyder. Quantitative structure-activity relationship (QSAR) modeling was performed for both organisms, while docking and molecular dynamics were used only for . Neryl acetate has the lowest interaction energy (-87 kcal/mol) against active site of acetylcholinesterase, which is comparable to the ones of methiocarb and pirimicarb (-90 kcal/mol) and reported PDB binder 9-(3-iodobenzylamino)-1,2,3,4-tetrahydroacridine (-112.67 kcal/mol). Interaction stability was verified by molecular dynamics simulations and showed that the stability of ACHE active site complexes with three selected terpenes is comparable to the one of the pirimicarb and methiocarb. Overall, our results suggest that pulegone, citronellal, carvacrol, linalyl acetate, neryl acetate, citronellyl acetate, and geranyl acetate may be considered as a potential pesticide candidates.
Topics: Acetylcholinesterase; Animals; Drosophila melanogaster; Insect Proteins; Insecticides; Isoptera; Molecular Docking Simulation; Molecular Dynamics Simulation; Monoterpenes; Quantitative Structure-Activity Relationship
PubMed: 32251592
DOI: 10.1021/acs.jafc.0c00272 -
Environmental Pollution (Barking, Essex... Mar 2017Two stages of selection from a pool of 56 fatty acids analyzed in Helix pomatia yielded a set of 12 biomarker acids undergoing significant changes in contact with three...
Two stages of selection from a pool of 56 fatty acids analyzed in Helix pomatia yielded a set of 12 biomarker acids undergoing significant changes in contact with three microdoses of toxic substances, i.e. three molluscicides containing metaldehyde, methiocarb, and potassium chloride (PC). The proposed palette of acids, including saturated fatty acids (SFA), monounsaturated fatty acids (MUFA), and polyunsaturated fatty acids (PUFA), determined separately in the foot tissues and hepatopancreas of Gastropoda, can be used in ecotoxicological research as a reliable test of the effect of trace doses of stressors. The final set of the biomarker FA comprised C16:0; C18:0; C23:0; C18:1 n-9; C20:1 n-9; C18:2 n-6; C18:3 n-3; C20:2; C20:4 n-6; C20:5 n-3; C22:4 n-6; and C22:5 n-3. A clear physiological response manifested as changes in the content of fatty acids (FA) was observed in the snails even in the case of the lowest doses of the pollutants. All experimental factors analyzed, i.e., the dose (5, 10, or 15 μl 0.01% w/v concentration) and the type of preparation (metaldehyde, methiocarb or PC), had a significant (p ≤ 0.01) impact on the FA composition of the foot and hepatopancreas. Limitation of the analysis to a narrow pool of reactive FA meets the requirements of parameters of biomarkers of exposure and facilitates and accelerates visualization of the bioindicator organism's response to the presence of the stressor in the environment.
Topics: Animals; Biomarkers; Environmental Exposure; Fatty Acids; Lipid Metabolism; Molluscacides; Poland; Snails
PubMed: 28043742
DOI: 10.1016/j.envpol.2016.12.068 -
Toxicology and Applied Pharmacology Aug 2016In humans, the ATP-binding cassette efflux transporter ABCG2 contributes to the fetoprotective barrier function of the placenta, potentially limiting the toxicity of...
In humans, the ATP-binding cassette efflux transporter ABCG2 contributes to the fetoprotective barrier function of the placenta, potentially limiting the toxicity of transporter substrates to the fetus. During testing of chemicals including pesticides, developmental toxicity studies are performed in rabbit. Despite its toxicological relevance, ABCG2-mediated transport of pesticides in rabbit placenta has not been yet elucidated. We therefore generated polarized MDCK II cells expressing the ABCG2 transporter from rabbit placenta (rbABCG2) and evaluated interaction of the efflux transporter with selected insecticides, fungicides, and herbicides. The Hoechst H33342 accumulation assay indicated that 13 widely used pesticidal active substances including azoxystrobin, carbendazim, chlorpyrifos, chlormequat, diflufenican, dimethoate, dimethomorph, dithianon, ioxynil, methiocarb, propamocarb, rimsulfuron and toclofos-methyl may be rbABCG2 inhibitors and/or substrates. No such evidence was obtained for chlorpyrifos-methyl, epoxiconazole, glyphosate, imazalil and thiacloprid. Moreover, chlorpyrifos (CPF), dimethomorph, tolclofos-methyl and rimsulfuron showed concentration-dependent inhibition of H33342 excretion in rbABCG2-transduced MDCKII cells. To further evaluate the role of rbABCG2 in pesticide transport across the placenta barrier, we generated polarized MDCKII-rbABCG2 monolayers. Confocal microscopy confirmed correct localization of rbABCG2 protein in the apical plasma membrane. In transepithelial flux studies, we showed the time-dependent preferential basolateral to apical (B>A) directed transport of [(14)C] CPF across polarized MDCKII-rbABCG2 monolayers which was significantly inhibited by the ABCG2 inhibitor fumitremorgin C (FTC). Using this novel in vitro cell culture model, we altogether showed functional secretory activity of the ABCG2 transporter from rabbit placenta and identified several pesticides like the insecticide CPF as potential rbABCG2 substrates.
Topics: ATP Binding Cassette Transporter, Subfamily G, Member 2; Animals; Biological Transport; Dogs; Female; Madin Darby Canine Kidney Cells; Pesticides; Placenta; Pregnancy; Rabbits
PubMed: 27288731
DOI: 10.1016/j.taap.2016.06.007 -
Australian Veterinary Journal Jun 2017A 7-year-old female spayed Labrador Retriever was managed for suspected carbamate toxicosis after confirmed ingestion of a large amount of methiocarb. Therapy included...
CASE REPORT
A 7-year-old female spayed Labrador Retriever was managed for suspected carbamate toxicosis after confirmed ingestion of a large amount of methiocarb. Therapy included decontamination, supportive care and management for aspiration pneumonia. On the third day of hospitalisation, after an initial clinical improvement, the dog developed respiratory muscle weakness, inspiratory dyspnoea and pronounced cervical muscle weakness. These delayed clinical signs were consistent with the 'intermediate syndrome' described in some cases of organophosphate and carbamate toxicoses in humans and also described in one case of organophosphate toxicosis in the dog. Intermediate syndrome has not been reported in carbamate toxicosis in the dog.
CONCLUSION
This case report highlights the necessity for veterinarians to monitor for additional complications not commonly considered in acute carbamate toxicoses.
Topics: Animals; Carbamates; Dog Diseases; Dogs; Female; Insecticides; Methiocarb; Nervous System Diseases; Treatment Outcome; Victoria
PubMed: 28555948
DOI: 10.1111/avj.12589 -
Chemosphere Aug 2015The application of molluscicides baits on the soil surface is the most common practice to control terrestrial gastropods. There seems to be a gap in the accurate...
The application of molluscicides baits on the soil surface is the most common practice to control terrestrial gastropods. There seems to be a gap in the accurate evaluation of molluscicidal baits effects to soil arthropods, since their hazard to non-target organisms has been considered low after mixing baits into soil. In this work the ecotoxicological effects of two molluscicide baits (metaldehyde and methiocarb) to the collembolan Folsomia candida were evaluated using two different approaches: (1) molluscicidal baits were applied to the top soil once and only at the beginning of the exposure and avoidance behaviour and reproduction were evaluated; and (2) baits were replaced by new ones after 14-d of exposure, simulating the recommended application rate recommended by the manufacturer and reproduction was assessed (repeated/pulse exposure). A preference for the side contaminated for methiocarb was observed but the distribution of collembolans in the avoidance test with metaldehyde was random. Exposure to metaldehyde resulted in a significant increase in mortality. For methiocarb, a reduction in the juveniles produced but no acute effects were observed. In the bait pulse test, the toxic effects of each chemical was significantly increased compared with the single exposure test, for all treatments used (both reproduction and mortality). In summary, molluscicides have an adverse effect on F. candida, with severe effects on their behaviour (only for methiocarb), reproduction and survival (for both), which can lead to population collapse with time.
Topics: Animals; Arthropods; Molluscacides; Reproduction; Soil; Soil Pollutants
PubMed: 25769136
DOI: 10.1016/j.chemosphere.2015.02.035 -
In Silico Pharmacology 2017Molecular descriptors (including quantum chemical, topological and physicochemical descriptors) were calculated for five -tolyl derivatives insecticides [namely,...
Molecular descriptors (including quantum chemical, topological and physicochemical descriptors) were calculated for five -tolyl derivatives insecticides [namely, carbosulfan (CBS), carbofuran (CBF), isoprocab (IFP), methiocarb (MTC) and isocarbophos (ICP)]. Calculated quantum chemical parameters included the total energy, the electronic energy, the binding energy, the core-core repulsion energy, the heat of formation, the dipole moment and the frontier molecular orbital energies. All the calculated quantum chemical parameters (except dipole moment) exhibited strong correlation with the experimental LD values of the studied insecticides (at various Hamiltonians). Calculated topological parameters included the molecular topological index (MTI), polar surface area (PSA), total connectivity (TC), total valence connectivity (TVC), Wiener index (WI), topological diameter (TD) and Balaban index (BI). However, only MTI, PSA, WI and BI exhibited excellent correlation with the toxicological activity of the insecticides. Also among all the calculated physicochemical parameters [logP, surface area (SA), surface volume (SV), hydration energy (E), polarizability (PLZ) and refractivity (RFT)], only SV, E, PLZ and RFT were useful in establishing quantitative structure activity relationship (QSAR). Application of QSAR indicated that the calculated theoretical LD values for the studied insecticides displayed excellent correlation with experimentally derived LD values. However, best results were obtained from quantum chemical descriptors under modified neglect of atomic overlap (MNDO). The toxicity profile of the insecticides also correlated strongly with ionization energy, electron affinity, global softness and global harness. Reactive sites of each of the insecticides were established using Fukui function, Huckel charges and HOMO/LUMO diagrams. Six new molecules were proposed and their theoretical activities were estimated. The proposed molecules included 2-methyl-2-(methylthio)-2,3-dihydrobenzofuran-7-yl methylcarbamate, -methyl -2-((methylaminooxy)carbonyl)phenyl phosphoramidothioate, 2-((methylaminooxy)carbonyl)phenyl methylcarbamate, 2-(1-(methylthio)ethyl)phenyl methylcarbamate, -methyl--(2-(methylthiooxy) benzoyl) hydroxyl amine and 4-methyl naphthalen-2-yl methylcarbamate. Some of the proposed molecules exhibited negative values of LD (indicating extreme toxicity) while two of them exhibited values that are comparable to existing insecticides.
PubMed: 29308350
DOI: 10.1007/s40203-017-0036-y -
Journal of Pharmaceutical and... Aug 2024Pesticides play an important role in forensic toxicology and are usually classified as a single class of chemicals. Despite their commonly perceived unity, pesticides...
Development and validation of a multi-substance method for routine analysis of pesticides in post-mortem samples by Ultra-High Performance Liquid Chromatography-Tandem Mass Spectrometry.
Pesticides play an important role in forensic toxicology and are usually classified as a single class of chemicals. Despite their commonly perceived unity, pesticides encompass a spectrum of compounds, including organophosphates, carbamates, pyrethroids or organochlorines, among others, each with varying degrees of toxicity. Pesticide analysis in post-mortem samples can be difficult due to the complexity of the samples and to the high toxicity of these compounds. The aim of this study was to develop and validate an easy to use, sensitive, and robust method, using ultra-performance liquid chromatography-tandem mass spectrometry to be incorporated in the routine flow for pesticide analysis in post-mortem blood samples. Described herein is a streamlined, expeditious, yet highly efficient method facilitating the screening, qualitative assessment, and quantitative confirmation of 15 pesticides, including acetamiprid, azinphos-ethyl, bendiocarb, carbofuran, chlorfenvinphos, dimethoate, imidaclopride, malathion, methiocarb, methomyl, parathion, pirimicarb, strychnine, tetrachlorvinphos, and thiacloprid in post-mortem blood, recognizing the pivotal role blood plays in forensic investigations. The developed method was linear from 10 to 200 ng/mL; limits of detection were between 1 and 10 ng/mL, depending on the compound; it was successfully evaluated a dilution ratio of 1-2, 5 and 10; and 8 substances showed maximum stability for the time interval studied. This UHPLC-MS/MS method is useful and a powerful tool in a toxicology lab because it is fast, simple, effective, and trustworthy. The results of this validation highlight the robustness of the analytical method, providing a valuable tool for the accurate and sensitive detection of pesticides in post-mortem blood. Poised for routine implementation, this method has already found success in suspected intoxication cases, promising to elevate the standards of forensic pesticide analysis.
Topics: Tandem Mass Spectrometry; Chromatography, High Pressure Liquid; Humans; Pesticides; Forensic Toxicology; Reproducibility of Results; Autopsy; Limit of Detection
PubMed: 38701535
DOI: 10.1016/j.jpba.2024.116176 -
Monitoring of the 17 EU Watch List contaminants of emerging concern in the Ave and the Sousa Rivers.The Science of the Total Environment Feb 2019The occurrence of micropollutants in the environment is a matter of high concern. Some regulations have been published in the last years and a Watch List of contaminants...
The occurrence of micropollutants in the environment is a matter of high concern. Some regulations have been published in the last years and a Watch List of contaminants of emerging concern (CECs) for European Union monitoring of surface water was launched in the Decision 2015/495, including three estrogens (estrone, E1; 17-β-estradiol, E2; and 17-α-ethinylestradiol, EE2), four pharmaceuticals (diclofenac and the macrolide antibiotics azithromycin, clarithromycin and erythromycin), an anti-oxidant (2,6-ditert-butyl-4-methylphenol, BHT), an UV filter (2-ethylhexyl 4-methoxycinnamate, EHMC), some pesticides (methiocarb and the neonicotinoids imidacloprid, thiacloprid, thiamethoxam, clothianidin and acetamiprid) and two herbicides (oxadiazon and triallate). This study provides the first spatial and seasonal monitoring campaign in the Ave and the Sousa Rivers for the all set of the 17 Watch List CECs (not reported yet for any country), in order to assess their occurrence, distribution, frequency and risk assessment. It also highlights the need of extend the study to other regions and environmental matrices to investigate the occurrence and possible sources of contamination of CECs, aiming to give insights for decision makers to define mitigation strategies for a more sustainable water policy.
PubMed: 30308880
DOI: 10.1016/j.scitotenv.2018.08.309