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International Journal of Environmental... May 2017Flowers are frequently treated with pesticides and, as a result, florists handling daily a large number of flowers can be exposed to pesticide residues. A study was...
Flowers are frequently treated with pesticides and, as a result, florists handling daily a large number of flowers can be exposed to pesticide residues. A study was conducted among twenty volunteer florists located in Namur Province and in the Brussels Capital Region of Belgium in order to assess their potential dermal exposure to dislodgeable pesticide residues transferred from flowers to hands. Two pairs of cotton gloves were worn during two consecutive half days while handling flowers and preparing bouquets (from min 2 h to max 3 h/day). The residual pesticide deposits on the glove samples were extracted with a multi-residue Quick Easy Cheap Effective Rugged Safe (QuEChERS) method and analyzed by a combination of gas and liquid chromatography tandem mass spectrometry (GC-MS/MS and LC-MS/MS) by an accredited laboratory. A total of 111 active substances (mainly insecticides and fungicides) were detected, with an average of 37 active substances per sample and a total concentration per glove sample of 22.22 mg/kg. Several predictive levels of contamination were considered to assess the risk. The potential dermal exposures (PDE) of florists were estimated at the average, for different percentiles, and at the maximum concentration of residues in samples. At the PDE P90 and at the PDE (or worst case) values, three and five active substances respectively exceed the Acceptable Operator Exposure Level (AOEL), indicating risk situations. For the systemic exposure (SE), one active substance (clofentezine) exceeds the AOEL at the P90 predictive level. In the worst case, SE (at the maximum concentrations), four active substances (clofentezine, famoxadone, methiocarb, and pyridaben) exceed their respective AOEL values. Among the 14 most frequently detected active substances, two have SE values exceeding the AOEL. Exposure could be particularly critical for clofentezine with an SE value four times higher than the AOEL (393%). The exposure of florists appeared to be an example of a unique professional situation in which workers are exposed regularly to both a very high number of toxic chemicals and rather high concentration levels. Therefore the priority should be to raise the level of awareness among the florists who must change their habits and practices if they want to minimize their exposure.
Topics: Adult; Belgium; Chromatography, Liquid; Environmental Monitoring; Flowers; Gas Chromatography-Mass Spectrometry; Humans; Occupational Exposure; Pesticide Residues; Risk Assessment; Tandem Mass Spectrometry
PubMed: 28505067
DOI: 10.3390/ijerph14050526 -
The Science of the Total Environment Mar 2024The presence of pesticides in aquatic ecosystems poses significant risks to non-target organisms, necessitating monitoring and environmental risk assessment. This study...
The presence of pesticides in aquatic ecosystems poses significant risks to non-target organisms, necessitating monitoring and environmental risk assessment. This study aimed to evaluate the dynamics and environmental risk of pesticides in a hydro-agricultural area with intensive agricultural practices, in the Mediterranean region (South of Portugal). Seasonality and location influenced pesticide numbers and concentrations, with the highest levels observed during the dry season. Triazines, phenylureas, and organophosphates were the predominant pesticide classes, with terbuthylazine, bentazone, terbutryn, diazinon, and metolachlor exhibiting the highest detection frequencies (68 % to 72 %). Notably, 44 % of the quantified pesticides are no longer authorized in Portugal, with 33 % posing a high environmental risk. Some insecticides, including imidacloprid, methiocarb, and malathion, were occasionally detected at concentrations that posed high risks to the aquatic ecosystem (RQ ≥ 1). Irgarol, an algicide used in irrigation canals, presented a high risk in 91 % of the analysed samples. The study's distribution profile of pesticides revealed a significant transportation of these compounds from reservoirs to irrigation hydrants, establishing them as a secondary source of crop and environmental contamination. Additionally, the assessment of spatial distribution and environmental risk allowed for the identification of specific pollutants in different locations, prioritizing them based on their ecotoxicological risk to aquatic ecosystems. These findings reinforce the importance of implementing management measures at the level of hydro-agricultural areas, helping to stop the cycle of pesticide contamination. Only this type of strategy will make it possible to protect water quality, biodiversity and the health of citizens, contributing to the European Union's objectives of improving the condition of freshwater bodies and promoting the sustainable use of pesticides.
Topics: Pesticides; Ecosystem; Environmental Monitoring; Water Pollutants, Chemical; Agriculture; Water Supply
PubMed: 38278229
DOI: 10.1016/j.scitotenv.2024.170304 -
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 -
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 -
Environmental Health Perspectives Nov 2012Many pesticides in current use have recently been revealed as in vitro androgen receptor (AR) antagonists, but information about their combined effects is lacking.
BACKGROUND
Many pesticides in current use have recently been revealed as in vitro androgen receptor (AR) antagonists, but information about their combined effects is lacking.
OBJECTIVE
We investigated the combined effects and the competitive AR antagonism of pesticide mixtures.
METHODS
We used the MDA-kb2 assay to test a combination of eight AR antagonists that did not also possess AR agonist properties ("pure" antagonists; 8 mix: fludioxonil, fenhexamid, ortho-phenylphenol, imazalil, tebuconazole, dimethomorph, methiocarb, pirimiphos-methyl), a combination of five AR antagonists that also showed agonist activity (5 mix: cyprodinil, pyrimethanil, vinclozolin, chlorpropham, linuron), and all pesticides combined (13 mix). We used concentration addition (CA) and independent action (IA) to formulate additivity expectations, and Schild plot analyses to investigate competitive AR antagonism.
RESULTS
A good agreement between the effects of the mixture of eight "pure" AR antagonists and the responses predicted by CA was observed. Schild plot analysis revealed that the 8 mix acted by competitive AR antagonism. However, the observed responses of the 5 mix and the 13 mix fell within the "prediction window" boundaries defined by the predicted regression curves of CA and IA. Schild plot analysis with these mixtures yielded anomalous responses incompatible with competitive receptor antagonism.
CONCLUSIONS
A mixture of widely used pesticides can, in a predictable manner, produce combined AR antagonist effects that exceed the responses elicited by the most potent component alone. Inasmuch as large populations are regularly exposed to mixtures of antiandrogenic pesticides, our results underline the need for considering combination effects for these substances in regulatory practice.
Topics: Androgen Receptor Antagonists; Cell Line, Tumor; Dihydrotestosterone; Dose-Response Relationship, Drug; Female; Humans; Pesticides; Receptors, Androgen; Risk Assessment
PubMed: 23008280
DOI: 10.1289/ehp.1205391 -
Journal of Nematology Dec 1999The effects of abamectin B1, diazinon, and methiocarb insecticides on Aphelenchoides fragariae and Ditylenchus dipsaci in Lamium maculatum, Phlox subulata, Rhododendron...
The effects of abamectin B1, diazinon, and methiocarb insecticides on Aphelenchoides fragariae and Ditylenchus dipsaci in Lamium maculatum, Phlox subulata, Rhododendron indicum, and Begonia x tuberhybrida were determined in a series of greenhouse experiments. Abamectin at 0.005 or 0.011 g a.i./liter (0.3 or 0.6 ml/liter Avid 0.15 EC), diazinon at 0.62 or 1.87 g a.i./liter (2.6 or 7.8 ml/liter KnoxOut GH), or methiocarb at 3.5 g a.i./liter (4.7 g/liter Mesurol) were applied in two to six weekly or biweekly applications to foliage until runoff. Diazinon and abamectin reduced both A. fragariae and D. dipsaci populations in Lamium and Phlox, especially after repeated applications. Diazinon was generally more effective than abamectin. While methiocarb reduced A. fragariae densities in Lamium, it was not as efficacious as diazinon or abamectin. Nematode populations varied widely between host plant species and over time. Management of high nematode populations was difficult, and none of the materials tested was effective against A. fragariae in azalea or begonia. Both abamectin and diazinon are currently registered for insect control in ornamentals and may be combined with cultural control tactics to manage foliar nematodes.
PubMed: 19270930
DOI: No ID Found -
Journal of Chromatography. A Jun 2007We report on the development and validation under ISO 17025 criteria of a multi-residue confirmatory method to identify and quantify 17 widely chemically different...
Development and validation of a multi-residue method for pesticide determination in honey using on-column liquid-liquid extraction and liquid chromatography-tandem mass spectrometry.
We report on the development and validation under ISO 17025 criteria of a multi-residue confirmatory method to identify and quantify 17 widely chemically different pesticides (insecticides: Carbofuran, Methiocarb, Pirimicarb, Dimethoate, Fipronil, Imidacloprid; herbicides: Amidosulfuron, Rimsulfuron, Atrazine, Simazine, Chloroturon, Linuron, Isoxaflutole, Metosulam; fungicides: Diethofencarb) and 2 metabolites (Methiocarb sulfoxide and 2-Hydroxytertbutylazine) in honey. This method is based on an on-column liquid-liquid extraction (OCLLE) using diatomaceous earth as inert solid support and liquid chromatography (LC) coupled to mass spectrometry (MS) operating in tandem mode (MS/MS). Method specificity is ensured by checking retention time and theoretical ratio between two transitions from a single precursor ion. Linearity is demonstrated all along the range of concentration that was investigated, from 0.1 to 20 ng g(-1) raw honey, with correlation coefficients ranging from 0.921 to 0.999, depending on chemicals. Recovery rates obtained on home-made quality control samples are between 71 and 90%, well above the range defined by the EC/657/2002 document, but in the range we had fixed to ensure proper quantification, as levels found in real samples could not be corrected for recovery rates. Reproducibility is found to be between 8 and 27%. Calculated CCalpha and CCbeta (0.0002-0.943 ng g(-1) for CCalpha, and 0.0002-1.232 ng g(-1) for CCbeta) show the good sensitivity attained by this multi-residue analytical method. The robustness of the method has been tested in analyzing more than 100 raw honey samples collected from different areas in Belgium, as well as some wax and bee samples, with a slightly adapted procedure.
Topics: Chromatography, Liquid; Honey; Pesticide Residues; Reproducibility of Results; Sensitivity and Specificity; Tandem Mass Spectrometry
PubMed: 17416380
DOI: 10.1016/j.chroma.2007.03.035 -
Environmental Health Perspectives Apr 2016There are concerns that diminished prostaglandin action in fetal life could increase the risk of congenital malformations. Many endocrine-disrupting chemicals have been...
Effects of Common Pesticides on Prostaglandin D2 (PGD2) Inhibition in SC5 Mouse Sertoli Cells, Evidence of Binding at the COX-2 Active Site, and Implications for Endocrine Disruption.
BACKGROUND
There are concerns that diminished prostaglandin action in fetal life could increase the risk of congenital malformations. Many endocrine-disrupting chemicals have been found to suppress prostaglandin synthesis, but to our knowledge, pesticides have never been tested for these effects.
OBJECTIVES
We assessed the ability of pesticides that are commonly used in the European Union to suppress prostaglandin D2 (PGD2) synthesis.
METHODS
Changes in PGD2 secretion in juvenile mouse Sertoli cells (SC5 cells) were measured using an ELISA. Coincubation with arachidonic acid (AA) was conducted to determine the site of action in the PGD2 synthetic pathway. Molecular modeling studies were performed to assess whether pesticides identified as PGD2-active could serve as ligands of the cyclooxygenase-2 (COX-2) binding pocket.
RESULTS
The pesticides boscalid, chlorpropham, cypermethrin, cyprodinil, fenhexamid, fludioxonil, imazalil (enilconazole), imidacloprid, iprodione, linuron, methiocarb, o-phenylphenol, pirimiphos-methyl, pyrimethanil, and tebuconazole suppressed PGD2 production. Strikingly, some of these substances-o-phenylphenol, cypermethrin, cyprodinil, linuron, and imazalil (enilconazole)-showed potencies (IC50) in the range between 175 and 1,500 nM, similar to those of analgesics intended to block COX enzymes. Supplementation with AA failed to reverse this effect, suggesting that the sites of action of these pesticides are COX enzymes. The molecular modeling studies revealed that the COX-2 binding pocket can accommodate most of the pesticides shown to suppress PGD2 synthesis. Some of these pesticides are also capable of antagonizing the androgen receptor.
CONCLUSIONS
Chemicals with structural features more varied than previously thought can suppress PGD2 synthesis. Our findings signal a need for in vivo studies to establish the extent of endocrine-disrupting effects that might arise from simultaneous interference with PGD2 signaling and androgen action.
CITATION
Kugathas S, Audouze K, Ermler S, Orton F, Rosivatz E, Scholze M, Kortenkamp A. 2016. Effects of common pesticides on prostaglandin D2 (PGD2) inhibition in SC5 mouse Sertoli cells, evidence of binding at the COX-2 active site, and implications for endocrine disruption. Environ Health Perspect 124:452-459; http://dx.doi.org/10.1289/ehp.1409544.
Topics: Androgen Receptor Antagonists; Animals; Arachidonic Acid; Catalytic Domain; Cyclooxygenase 2; Endocrine Disruptors; Male; Mice; Models, Molecular; Pesticides; Prostaglandin D2; Protein Binding; Sertoli Cells
PubMed: 26359731
DOI: 10.1289/ehp.1409544 -
Journal of Food Protection Nov 2004A rapid multiresidue method has been developed for the analysis of N-methylcarbamate insecticides (oxamyl, methomyl, propoxur, carbofuran, carbaryl, and methiocarb) in...
A rapid multiresidue method has been developed for the analysis of N-methylcarbamate insecticides (oxamyl, methomyl, propoxur, carbofuran, carbaryl, and methiocarb) in fruit and vegetable juices. The method is based on the adsorption of the N-methyl carbamates in Florisil and the subsequent extraction of pesticides using a low volume of acetone. Residue levels in juice were determined by reversed-phase high-performance liquid chromatography with fluorescence detection after postcolumn derivatization. The separation of carbamates is performed on a C8 column with water-methanol as mobile phase. Recovery studies were performed at 500-, 100-, and 10-ng/ml fortification levels, and average recoveries obtained for carbamates ranged from 79 to 109%, with relative standard deviations between 1.4 and 9.9%. The method was found to be linear over the range assayed from 10 to 1,000 ng/ml, and the detection limits for carbamates varied from 0.8 to 1.9 ng/ml.
Topics: Beverages; Chromatography, High Pressure Liquid; Consumer Product Safety; Dose-Response Relationship, Drug; Drug Residues; Fluorescence; Food Contamination; Fruit; Insecticides; Sensitivity and Specificity; Vegetables
PubMed: 15553643
DOI: 10.4315/0362-028x-67.11.2565