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Environmental Pollution (Barking, Essex... Jun 2024Diazinon is an organophosphorus pesticide widely used in agriculture and household pest control, and its use also poses several environmental and health hazards. In this...
Diazinon is an organophosphorus pesticide widely used in agriculture and household pest control, and its use also poses several environmental and health hazards. In this study, we investigated the spatial and temporal distribution of diazinon in Baiyangdian, evaluated its potential ecological risk and toxicity to aquatic organisms based on RQ (Risk quotient) and TU (Toxic unit) analysis, and assessed the potential effects of diazinon accumulation on probiotics and pathogens based on statistical analysis of high-throughput sequencing data. The results showed that diazinon in Baiyangdian posed a low to moderate chronic risk to sediment-dwelling organisms and a low toxicity effect on aquatic invertebrates, which was mainly concentrated in October and human-intensive areas. Meanwhile, increases in sediment electrical conductivity (EC), amorphous iron oxides content and phenol oxidase activity favored diazinon accumulation in sediments, whereas the opposite was the case for sediment organic carbon, β-1,4-glucosidase, phosphatase, catalase and pH, suggesting that environmental indicators play a key role in the behavior and distribution of diazinon. In addition, diazinon in heavily contaminated areas seem to inhibit the rare probiotics (Bifidobacterium adolescentis and Serratia sp.), while promoted dominant pathogens (e.g., Burkholderia cenocepacia), which can lead to increased disease risk to humans and ecosystems, disruption of ecological balance and potential health problems. However, probiotic Streptomyces xiamenensis resist to diazinon would be a potential degrader for diazinon remove. In conclusion, this study unveiled the effects of diazinon pollution on wetland ecosystems, emphasizing ecological impacts and potential health concerns. In addition, the discovery of diazinon resistant probiotics provided new insights into wetland ecological restoration.
PubMed: 38906403
DOI: 10.1016/j.envpol.2024.124408 -
Ecotoxicology and Environmental Safety Jun 2024Diazinon, an organophosphorus insecticide, is predominantly removed through photodegradation and biodegradation in the environment. However, photodegradation can...
Diazinon, an organophosphorus insecticide, is predominantly removed through photodegradation and biodegradation in the environment. However, photodegradation can generate diazoxon, a highly toxic oxidation byproduct, while biodegradation is hard to complete mineralize diazinon, showing limitations in both methods. In this study, we provided an efficient strategy for the complete and harmless removal of diazinon by synergistically employing biodegradation and photodegradation. The diazinon-degrading strain X1 was capable of completely degrading 200 μM of diazinon into 2-isopropyl-6-methyl-4-pyrimidinol (IMP) within 6 h without producing the highly toxic diazoxon. IMP was the only intermediate metabolite in biodegradation process, which cannot be further degraded by strain X1. Through RT-qPCR and prokaryotic expression analyses, the hydrolase OpdB was pinpointed as the key enzyme for diazinon degradation in strain X1. Photodegradation was further used to degrade IMP and a pyridazine ring-opening product of IMP was identified via high resolution mass spectrometry. The acute toxicity of this product to aquatic organisms were 123 times and 6630 times lower than that of diazinon and IMP, respectively. The stepwise application of biodegradation and photodegradation was proved to be a successful approach for the remediation of diazinon and its metabolite IMP. This integrated method ensures the harmless and complete elimination of diazinon and IMP within only 6 h. The research provides a theoretical basis for the efficient and harmless remediation of organophosphorus insecticide residuals in the environment.
PubMed: 38901169
DOI: 10.1016/j.ecoenv.2024.116599 -
Talanta Jun 2024Stable detection of diazinon (DZN) residues in vegetables is important for food safety. In this work, an electrochemiluminescence (ECL) aptasensor with dual-catalytic...
Stable detection of diazinon (DZN) residues in vegetables is important for food safety. In this work, an electrochemiluminescence (ECL) aptasensor with dual-catalytic glucose in-situ production of HO was constructed for the stable detection of DZN in vegetables. Firstly, MWCNTs@MB was prepared using π-π stacking interactions between methylene blue (MB) and multi-walled carbon nanotubes (MWCNTs) to enhance the loading of MB on an electrode and thus catalyze the generation of HO from glucose. Secondly, CuO@AuNPs was formed by loading AuNPs on the surface of CuO through spontaneous reduction reaction, which improved the interfacial charge transfer, CuO nano-enzyme had glucose oxidase mimicking activity and could further catalyze the production of more HO from glucose. MWCNTs@MB and CuO@AuNPs played a key role in the in-situ generation of co-reacting reagent HO, which solved the problem of unstable detection caused by the easy decomposition of the HO solution added to the luminescence system. In addition, the aptamer was immobilized on the electrode surface by forming Au-S bonds with CuO@AuNPs. As a result, the ECL aptasensor performed good linearity in 1.00 pg mL-1.00 μg mL and a low limit of detection (LOD) to 0.39 pg mL (S/N = 3). This work provided an effective method for the accurate and stable detection of DZN residues in vegetables, which was of great significance in ensuring food safety and assessing the environmental risk of DZN.
PubMed: 38897007
DOI: 10.1016/j.talanta.2024.126443 -
Chemosphere Jun 2024In the last years, issues related to intensive agriculture have been found in protected areas potentially harming wildlife. This study aimed to analyze a wide range of...
In the last years, issues related to intensive agriculture have been found in protected areas potentially harming wildlife. This study aimed to analyze a wide range of pesticides in water and sediments of two protected areas namely Doñana Natural Park (DNP) and Tablas de Daimiel National Park (TDNP) performing an environmental risk assessment in order to highlight potential risks to living organisms derived from pesticide burden. Higher pesticide load was found in DNP than TDNP with similar distribution profiles, with pyrethroid insecticides (PYRs) the main detected class. Particularly problematic are two PYRs, cyhalothrin and fenvalerate, which were detected at high concentrations that can pose a high risk to aquatic organisms. In addition, despite being detected at lower concentrations, the presence of chlorpyrifos, cypermethrin, and permethrin in water, and of chlorpyrifos, dicofol, and diflufenican in sediments, must be taken into account due to their potential risks for aquatic organisms. Moreover, some banned pesticides such as dimethoate, terbutryn, diazinon, and tricyclazol were detected in water at levels which deserve further investigation to assess their potential sources, including potential illegal practices.
PubMed: 38885764
DOI: 10.1016/j.chemosphere.2024.142628 -
Bioorganic Chemistry Jun 2024In this review, the current progress in the research and development of butyrylcholinesterase (BChE) reactivators is summarised and the advantages or disadvantages of... (Review)
Review
In this review, the current progress in the research and development of butyrylcholinesterase (BChE) reactivators is summarised and the advantages or disadvantages of these reactivators are critically discussed. Organophosphorus compounds such as nerve agents (sarin, tabun, VX) or pesticides (chlorpyrifos, diazinon) cause irreversible inhibition of acetylcholinesterase (AChE) and BChE in the human body. While AChE inhibition can be life threatening due to cholinergic overstimulation and crisis, selective BChE inhibition has presumably no adverse effects. Because BChE is mostly found in plasma, its activity is important for the scavenging of organophosphates before they can reach AChE in the central nervous system. Therefore, this enzyme in combination with its reactivator can be used as a pseudo-catalytic scavenger of organophosphates. Three structural types of BChE reactivators were found, i.e. bisquaternary salts, monoquaternary salts and uncharged compounds. Although the reviewed reactivators have certain limitations, the promising candidates for BChE reactivation were found in each structural group.
PubMed: 38878749
DOI: 10.1016/j.bioorg.2024.107526 -
Frontiers in Genetics 2024Toxicological risk assessment increasingly utilizes transcriptomics to derive point of departure (POD) and modes of action (MOA) for chemicals. One essential biological...
Toxicological risk assessment increasingly utilizes transcriptomics to derive point of departure (POD) and modes of action (MOA) for chemicals. One essential biological process that allows a single gene to generate several different RNA isoforms is called alternative splicing. To comprehensively assess the role of splicing dysregulation in toxicological evaluation and elucidate its potential as a complementary endpoint, we performed RNA-seq on A549 cells treated with five oxidative stress modulators across a wide dose range. Differential gene expression (DGE) showed limited pathway enrichment except at high concentrations. However, alternative splicing analysis revealed variable intron retention events affecting diverse pathways for all chemicals in the absence of significant expression changes. For instance, diazinon elicited negligible gene expression changes but progressive increase in the number of intron retention events, suggesting splicing alterations precede expression responses. Benchmark dose modeling of intron retention data highlighted relevant pathways overlooked by expression analysis. Systematic integration of splicing datasets should be a useful addition to the toxicogenomic toolkit. Combining both modalities paint a more complete picture of transcriptomic dose-responses. Overall, evaluating intron retention dynamics afforded by toxicogenomics may provide biomarkers that can enhance chemical risk assessment and regulatory decision making. This work highlights splicing-aware toxicogenomics as a possible additional tool for examining cellular responses.
PubMed: 38846964
DOI: 10.3389/fgene.2024.1389095 -
Food Chemistry Oct 2024Accurate and rapid monitoring of organophosphorus pesticides (OPs) residues is crucial for regulating food safety. Herein, dual-emission carbon dots (de-CDs) were...
Accurate and rapid monitoring of organophosphorus pesticides (OPs) residues is crucial for regulating food safety. Herein, dual-emission carbon dots (de-CDs) were fabricated for the ratiometric detection of OPs and Hg. The de-CDs exhibited two emission peaks at 678 and 485 nm when excited with visible light. Interestingly, the fluorescence at 678 nm was significantly quenched by Hg mainly because of the static quenching effect, whereas that at 485 nm exhibited a slight change. More significantly, the quenched fluorescence of the de-CDs recovered remarkably after introducing omethoate, diazinon and malathion. Accordingly, the ratiometric detection of the three OPs and Hg was achieved with high selectivity and robust performance. In addition, the OPs residues assay in Brassica chinensis was successfully performed with satisfactory results. This study not only provides an attractive tool for the simple and rapid assay of OPs but also offers new insights into the fabrication of multi-functional carbon dots.
Topics: Brassica; Carbon; Mercury; Quantum Dots; Organophosphorus Compounds; Hydrogen-Ion Concentration; Pesticides; Spectrometry, Fluorescence; Food Contamination; Water Pollutants, Chemical; Pesticide Residues
PubMed: 38810445
DOI: 10.1016/j.foodchem.2024.139755 -
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 -
Aquatic Toxicology (Amsterdam,... Jul 2024Human impacts on ecological communities are pervasive and species must either move or adapt to changing environmental conditions. For environments polluted by...
Human impacts on ecological communities are pervasive and species must either move or adapt to changing environmental conditions. For environments polluted by contaminants, researchers have found hundreds of target pest species evolving increased tolerance, but we have substantially fewer cases of evolved tolerance in non-target species. When species do evolve increased tolerance, inducible tolerance can provide immediate protection and favor the evolution of increased tolerance over generations via genetic assimilation. Using a model larval amphibian (wood frogs, Rana sylvatica), we examined the tolerance of 15 populations from western Pennsylvania and eastern New York (USA), when first exposed to no pesticide or sublethal concentrations and subsequently exposed to lethal concentrations of three common insecticides (carbaryl, chlorpyrifos, and diazinon). We found high variation in naïve tolerance among the populations for all three insecticides. We also discovered that nearly half of the populations exhibited inducible tolerance, though the degree of inducible tolerance (magnitude of tolerance plasticity; MoTP) varied. We observed a cross-tolerance pattern of the populations between chlorpyrifos and diazinon, but no pattern of similar MoTP among the pesticides. With populations combined from two regions, increased tolerance was not associated with proximity to agricultural fields, but there were correlations between proximity to agriculture and MoTP. Collectively, these results suggests that amphibian populations possess a wide range of naïve tolerance to common pesticides, with many also being able to rapidly induce increased tolerance. Future research should examine inducible tolerance in a wide variety of other taxa and contaminants to determine the ubiquity of these responses to anthropogenic factors.
Topics: Animals; Insecticides; Chlorpyrifos; Diazinon; Carbaryl; Water Pollutants, Chemical; Larva; Ranidae; Pennsylvania; New York; Drug Tolerance
PubMed: 38759526
DOI: 10.1016/j.aquatox.2024.106945 -
Journal of Agricultural and Food... May 2024Compound-specific isotope analysis stands as a promising tool for unveiling the behavior of pesticides in agricultural environments. Using the commercial formulations of...
Compound-specific isotope analysis stands as a promising tool for unveiling the behavior of pesticides in agricultural environments. Using the commercial formulations of persistent fungicide procymidone (PRO) and less persistent insecticide diazinon (DIA), respectively, we analyzed the concentration and carbon isotope composition (δC) of the residual pesticides through soil incubation experiments in a greenhouse (for 150 days) and lab conditions (for 50-70 days). Our results showed that the magnitude of δC variation depends on pesticide specificity, in which PRO in the soil exhibited little variation in δC values over the entire incubation times, while DIA demonstrated an increased δC value, with the extent of δC variability affected by different spiking concentrations, plant presence, and light conditions. Moreover, the pesticides extracted from soils were isotopically overlapped with those from crop lettuce. Ultimately, the isotope composition of pesticides could infer the degradation and translocation processes and might contribute to identifying the source(s) of pesticide formulation in agricultural fields.
Topics: Diazinon; Carbon Isotopes; Soil; Pesticide Residues; Soil Pollutants; Fungicides, Industrial; Insecticides; Bridged Bicyclo Compounds
PubMed: 38758169
DOI: 10.1021/acs.jafc.4c00640