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EFSA Journal. European Food Safety... May 2024In accordance with Article 43 of Regulation (EC) 396/2005, EFSA received a request from the European Commission to propose fall-back maximum residue levels (MRLs) for...
Assessment of fall-back MRLs for revoked CXLs previously implemented in the EU legislation and review of the JMPR evaluation of the toxicological data related to pyrasulfotole, pyraziflumid, spiropidion and tetraniliprole.
In accordance with Article 43 of Regulation (EC) 396/2005, EFSA received a request from the European Commission to propose fall-back maximum residue levels (MRLs) for recently revoked Codex MRLs that have been previously implemented in the EU legislation. Overall, MRLs for 12 a.s. are concerned, i.e. chlormequat, diazinon, bifenthrin, fludioxonil, indoxacarb, difenoconazole, famoxadone, azoxystrobin, mandipropamid, emamectin benzoate, flutriafol and afidopyropen. In addition, EFSA was requested to evaluate the toxicological data assessed by JMPR related to pyrasulfotole, pyraziflumid, spiropidion and tetraniliprole. These are active substances have not been assessed previously at EU level. The assessment should allow to take a decision, if the CXLs adopted for these four a.s. can be implemented in the EU MRL legislation.
PubMed: 38774114
DOI: 10.2903/j.efsa.2024.8693 -
Scientific Reports May 2024In this study, a sensitive and selective fluorescent chemosensor was developed for the determination of pirimicarb pesticide by adopting the surface molecular imprinting...
In this study, a sensitive and selective fluorescent chemosensor was developed for the determination of pirimicarb pesticide by adopting the surface molecular imprinting approach. The magnetic molecularly imprinted polymer (MIP) nanocomposite was prepared using pirimicarb as the template molecule, CuFeO nanoparticles, and graphene quantum dots as a fluorophore (MIP-CuFeO/GQDs). It was then characterized using X-ray diffraction (XRD) technique, Fourier transforms infrared (FT-IR) spectroscopy, scanning electron microscope (SEM), and transmission electron microscopy (TEM). The response surface methodology (RSM) was also employed to optimize and estimate the effective parameters of pirimicarb adsorption by this polymer. According to the experimental results, the average particle size and imprinting factor (IF) of this polymer are 53.61 nm and 2.48, respectively. Moreover, this polymer has an excellent ability to adsorb pirimicarb with a removal percentage of 99.92 at pH = 7.54, initial pirimicarb concentration = 10.17 mg/L, polymer dosage = 840 mg/L, and contact time = 6.15 min. The detection of pirimicarb was performed by fluorescence spectroscopy at a concentration range of 0-50 mg/L, and a sensitivity of 15.808 a.u/mg and a limit of detection of 1.79 mg/L were obtained. Real samples with RSD less than 2 were measured using this chemosensor. Besides, the proposed chemosensor demonstrated remarkable selectivity by checking some other insecticides with similar and different molecular structures to pirimicarb, such as diazinon, deltamethrin, and chlorpyrifos.
Topics: Pesticides; Carbamates; Quantum Dots; Molecularly Imprinted Polymers; Polymers; Spectrometry, Fluorescence; Graphite; Molecular Imprinting; Adsorption; Limit of Detection; Spectroscopy, Fourier Transform Infrared; Nanocomposites; Pyrimidines
PubMed: 38704412
DOI: 10.1038/s41598-024-60748-6 -
Human & Experimental Toxicology 2024Organophosphate pesticides (Ops) like diazinon (DZN) have well-known neurotoxic effects and low-level chronic exposure has been linked to detrimental neurobehavioral...
Persistent diazinon induced neurotoxicity: The effect on inhibitory avoidance memory performance, amyloid precursor proteins, and TNF-α levels in the prefrontal cortex of rats.
INTRODUCTION
Organophosphate pesticides (Ops) like diazinon (DZN) have well-known neurotoxic effects and low-level chronic exposure has been linked to detrimental neurobehavioral impairments and memory deficits. However, it's not entirely clear how DZN-induced biological changes, particularly in the prefrontal cortex (PFC) contribute to these effects. The purpose of this study is to investigate the impact of DZN exposure on inhibitory avoidance (IA) memory function, amyloid precursor expression (APP), and proinflammatory tumor necrosis factor-α (TNF-α) levels in the rat cortex.
MATERIALS AND METHODS
Rats were divided into 4 groups and recived 2 mg/kg DZN for 5-days or 12-weeks and two control groups recived the same volume of vehicle. IA memory was assesed using the shuttle box apparatus. Rats were sacrificed and the prefrontal cortex PFC were removed. Real-time PCR and Western blotting were used to messure TNF-α, and amyloid protein precursors gene expression and protein levels.
RESULTS
Our findings indicated that DZN caused body weight loss and a notable decline in performance on the IA memory. Additionally, 5-days exposure increased APP and APLP2 protein levels in the PFC, while 12-weeks exposure decreased these levels. Furthermore, expression of APP and APLP2 gens were decreased in PFC. TNF-α levels increased as a result of 5-days exposure to DZN, but these levels dropped to normal after 12-weeks administration, and this observation was significant.
CONCLUSION
Taken together, exposure to low doses of DZN leads to disturbances in IA memory performance and also alternations in amyloid beta precursors that can be related to increased risk of Alzheimer's disease.
Topics: Rats; Animals; Diazinon; Tumor Necrosis Factor-alpha; Amyloid beta-Peptides; Oxidative Stress; Insecticides; Prefrontal Cortex
PubMed: 38472141
DOI: 10.1177/09603271241235408 -
Journal of Pesticide Science Feb 2024The objective of this study was to assess the long-term stability of pesticide residues in brown rice and soybean. The long-term stability of pesticide residues in brown...
The objective of this study was to assess the long-term stability of pesticide residues in brown rice and soybean. The long-term stability of pesticide residues in brown rice and soybean was assessed for 5415 days (over 14 years) and 1801 days (about 5 years), respectively. The samples-certified reference materials (CRMs) 7504-a (brown rice) and 7509-a (soybean) -were prepared by freeze-pulverization. Two target pesticides (etofenprox and fenitrothion) were selected for brown rice and four (chlorpyrifos, diazinon, fenitrothion, and permethrin) for soybean. Our analytical results for long-term stability based on highly reliable isotope dilution mass spectrometry were in the range of expanded uncertainty (=2) for the certified values of each CRM. The concentration showed a decreasing trend in none of the target pesticides when the samples were stored at temperatures between -20 °C and -30 °C, which indicated that the target pesticides were stable for the tested long terms.
PubMed: 38450090
DOI: 10.1584/jpestics.D23-047 -
Heliyon Feb 2024The realm of diazinon reduction from polluted water has witnessed a surge in the significance of advanced oxidation processes (AOPs) in recent times. However, there is a...
The realm of diazinon reduction from polluted water has witnessed a surge in the significance of advanced oxidation processes (AOPs) in recent times. However, there is a dearth of research focusing on the mitigation of its toxicity through AOPs. Thus, the primary objective of this study was to evaluate the effectiveness of the Electro-Fenton process (EFP) in the eradication and detoxification of diazinon in aqueous solutions. Synthetic wastewater samples with concentrations of 2, 2.5 and 3 mg/L were prepared. A total of 27 samples were determined using Box Behnken Design. Reaction time, pH and iron to hydrogen peroxide ratio (Fe/HO) were examined as operational parameters under a constant current of 5.4 amps. The quantification of diazinon concentration was performed using High-Performance Liquid Chromatography (HPLC). To evaluate the detoxification of diazinon, the Daphnia magna bioassay was employed as a methodology in this study. According to the results, the EFP could reduce the diazinon to zero and the LC values are increased by applying the process. The LC values for diazinon were determined using the Daphnia magna bioassay, considering initial concentrations of 2, 2.5, and 3 mg/L at a pH of 5, a reaction time of 15 min, and an iron to hydrogen peroxide molar ratio of 2. The recorded LC50 values were 3.039, 3.076, and 3.106, respectively, indicating the lowest frequency of cumulative death in Daphnia magna. In this case, after 96 h, only 3 cases (30%) of Daphnia magna death were observed. However, for all the mentioned concentrations of diazinon, after 96 h of exposure to samples without applying the Daphnia Magna death process, it was observed between 60 and 100%. Reducing the diazinon concentration and increasing the 96-h LC showed that the EFP can reduce the toxicity of diazinon on Daphnia Magna at the same time. Therefore, EFP can be considered a superior method with low ecotoxicity.
PubMed: 38380001
DOI: 10.1016/j.heliyon.2024.e25928 -
Stress Biology Feb 2024Organophosphate compounds are widely used in agricultural activities to optimize food production. Contamination of field soil by these compounds may result in...
Organophosphate compounds are widely used in agricultural activities to optimize food production. Contamination of field soil by these compounds may result in detrimental effects on soil biota. The aim of the present study was to isolate microorganisms from field soils and evaluate the strains on ability to degrade organophosphates as single isolate and as a consortium. Isolated strains were identified using both biochemical and molecular techniques. Results revealed that, out of the 46 isolated strains, three isolates herein referred to as S6, S36 and S37 showed an average diazinon degradation rate of 76.4%, 76.7% and 76.8% respectively, of the initial dose (50 ppm) within 11 days of incubation in mineral medium. Notably, isolates S36 and S37 were more effective than S6 in degrading diazinon by 40% in soil aliquot after 11 days and therefore were evaluated on biochemical reactions and molecular identification. The isolates showed variable biochemical characteristics. However, both isolates possessed catalase enzyme, but lacked oxidase enzyme. Molecular characterization showed that, the closest species for S36 and S37 were Priestia megaterium and P. arybattia, respectively, based on 16S rRNA gene similarity (> 99%). Combination of the strains increased diazinon degradation ability by 45% compared to single strain treatment. Chlorpyrifos was the most highly degraded organophosphate, compared to phorate and cadusafos. Therefore it is expected that the pesticide-degrading bacteria could be a solution to soil health improvement and contribution to the production of safe agricultural products.
PubMed: 38319394
DOI: 10.1007/s44154-023-00138-6 -
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 -
Environmental Science and Pollution... Feb 2024Pharmaceuticals and pesticides can be considered hazardous compounds for Mediterranean coastal wetland ecosystems. Although many of these compounds co-occur in...
Pharmaceuticals and pesticides can be considered hazardous compounds for Mediterranean coastal wetland ecosystems. Although many of these compounds co-occur in environmental samples, only a few studies have been dedicated to assessing the ecotoxicological risks of complex contaminant mixtures. We evaluated the occurrence of 133 pharmaceuticals and pesticides in 12 sites in a protected Mediterranean wetland, the Albufera Natural Park (ANP), based on conventional grab sampling and polar organic chemical integrative samplers (POCIS). We assessed acute and chronic ecological risks posed by these contaminant mixtures using the multi-substance Potentially Affected Fraction (msPAF) approach and investigated the capacity of a constructed wetland to reduce chemical exposure and risks. This study shows that pharmaceuticals and pesticides are widespread contaminants in the ANP, with samples containing up to 75 different compounds. POCIS samplers were found to be useful for the determination of less predictable exposure profiles of pesticides occurring at the end of the rice cultivation cycle, while POCIS and grab samples provide an accurate method to determine (semi-)continuous pharmaceutical exposure. Acute risks were identified in one sample, while chronic risks were determined in most of the collected samples, with 5-25% of aquatic species being potentially affected. The compounds that contributed to the chronic risks were azoxystrobin, ibuprofen, furosemide, caffeine, and some insecticides (diazinon, imidacloprid, and acetamiprid). The evaluated constructed wetland reduced contaminant loads by 45-73% and reduced the faction of species affected from 25 to 6%. Our study highlights the need of addressing contaminant mixture effects in Mediterranean wetlands and supports the use of constructed wetlands to reduce contaminant loads and risks in areas with high anthropogenic pressure.
Topics: Pesticides; Wetlands; Ecosystem; Environmental Monitoring; Organic Chemicals; Pharmaceutical Preparations; Water Pollutants, Chemical
PubMed: 38277107
DOI: 10.1007/s11356-024-31968-0 -
Iranian Journal of Biotechnology Oct 2023Organophosphate pesticides are one of the most extensively applied insecticides in agriculture. These insecticides persist in the environs and thereby cause severe...
Green Synthesis of Polylactic acid/FeO@β-Cyclodextrin Nanofibrous Nanocomposite Loaded with Extract as a Novel Nano-biosorbent: Evaluation of Diazinon Removal and Antibacterial Activity.
BACKGROUND
Organophosphate pesticides are one of the most extensively applied insecticides in agriculture. These insecticides persist in the environs and thereby cause severe pollution problems. Iron oxide polymer nanocomposites are wastewater remediation agents synthesized by various methods. When compared to chemical processes, green synthesis using plant extract is thought to be more cost- and environmentally-friendly.
OBJECTIVES
This study aimed to evaluate the green synthesis of FeO@β-Cyclodextrin (FeO@β-CD) nanoparticles using () methanol extract. These nanoparticles are loaded on polylactic acid (PLA) nanofibrous nanocomposite along with extract (2, 4, and, 6wt %) to produce PLA/FeO@β-CD/ extract nanofibrous nanocomposite as a new nano biosorbent. Furthermore, the antibacterial properties of this compound and its activity in diazinon removal have been evaluated.
MATERIALS AND METHODS
FeO@β-CD nanoparticles synthesis was performed via co-precipitation method using FeCl.6HO and FeCl.4HO and β-cyclodextrin, and Ferulago angulata extract. Then polylactic acid/ FeO@β-CD / F. angulate.extract nanofibrous nanocomposite was prepared by the electrospinning method. Energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction analysis (XRD), vibrating sample magnetometer (VSM), and Fourier transform infrared spectroscopy (FTIR) were used to analyze the structure of the nanocomposite. The antibacterial activity of this nanocomposite against several fish and human bacterial pathogens, as well as its effectiveness in diazinon elimination, have been evaluated in the sections that follow.
RESULTS
The nanocomposite structure demonstrated that FeO nanoparticles were produced and put into the polylactic acid matrix with an average particle size of 40 nm. Furthermore, the results showed that this nanocomposite exhibited removal efficiency of diazinon over 80% after 120 minutes under pH=7 and 2.5 gr.L nanocomposite concentration. Also, this structure showed above 70% antibacterial ability against Bacillus cereus, and 60% antibacterial ability against and .
CONCLUSION
FeO nanocomposite synthesis may be accomplished in a delicate and efficient manner by using Ferulago angulata to produce FeO@-CD nanoparticles. The stability of the nanoparticles was enhanced by combining extract with polylactic acid nanofibers to create an antibacterial homocomposition nanocomposite. This device may be used to remove and disinfect diazinon from aqueous media in an environmentally friendly manner.
PubMed: 38269202
DOI: 10.30498/ijb.2023.392864.3682 -
ACS Omega Jan 2024Herein, a nonenzymatic detection of paraoxon-ethyl was developed by modifying a glassy carbon electrode (GCE) with gold-silver core-shell (Au-Ag) nanoparticles combined...
Electrochemical Sensors based on Gold-Silver Core-Shell Nanoparticles Combined with a Graphene/PEDOT:PSS Composite Modified Glassy Carbon Electrode for Paraoxon-ethyl Detection.
Herein, a nonenzymatic detection of paraoxon-ethyl was developed by modifying a glassy carbon electrode (GCE) with gold-silver core-shell (Au-Ag) nanoparticles combined with the composite of graphene with poly(3,4-ethylenedioxythiophene)/poly(styrenesulfonate) (PEDOT:PSS). These core-shell nanoparticles (Au-Ag) were synthesized using a seed-growth method and characterized using UV-vis spectroscopy and high-resolution transmission electron microscopy (HR-TEM) techniques. Meanwhile, the structural properties, surface morphology and topography, and electrochemical characterization of the composite of Au-Ag core-shell/graphene/PEDOT:PSS were analyzed using infrared spectroscopy, field emission scanning electron microscopy (FE-SEM), atomic force microscopy (AFM), and electrochemical impedance spectroscopy (EIS) techniques. Moreover, the proposed sensor for paraoxon-ethyl detection based on Au-Ag core-shell/graphene/PEDOT:PSS modified GCE demonstrates good electrochemical and electroanalytical performance when investigated with cyclic voltammetry (CV), differential pulse voltammetry (DPV), and chronoamperometry techniques. It was found that the synergistic effect between Au-Ag core-shell nanoparticles and the composite of graphene/PEDOT:PSS provides a higher conductivity and enhanced electrocatalytic activity for paraoxon-ethyl detection at an optimum pH of 7. At pH 7, the proposed sensor for paraoxon-ethyl detection shows a linear range of concentrations from 0.2 to 100 μM with a limit of detection of 10 nM and high sensitivity of 3.24 μA μM cm. In addition, the proposed sensor for paraoxon-ethyl confirmed good reproducibility, with the possibility of being further developed as a disposable electrode. This sensor also displayed good selectivity in the presence of several interfering species such as diazinon, carbaryl, ascorbic acid, glucose, nitrite, sodium bicarbonate, and magnesium sulfate. For practical applications, this proposed sensor was employed for the determination of paraoxon-ethyl in real samples (fruits and vegetables) and showed no significant difference from the standard spectrophotometric technique. In conclusion, this proposed sensor might have a potential to be developed as a platform of electrochemical sensors for pesticide detection.
PubMed: 38250352
DOI: 10.1021/acsomega.3c08349