Search Results (153)

Organophosphorus pesticides (OPs) are widely used in agriculture, but prospective studies on their chronic exposure and risk of type 2 diabetes (T2D) and glucose metabolism disorders are scarce. Most previous studies focused on agricultural workers and relied on questionnaires or urinary metabolites for exposure assessment. We conducted a nested case–control study with 1006 pairs of participants based on the Dongfeng–Tongji cohort to investigate the association between serum OP levels, T2D risk, and fasting blood glucose (FBG) changes over a 5-year follow-up. Serum OP concentrations were measured by gas chromatography–triple quadrupole mass spectrometry. Among the 29 types of OPs detected, Chlorpyrifos and Fenitrothion had detection rates of 99.9% and 87.9%, respectively. Etrimfos and Parathion were detected in 75.8% and 64.5% of participants. Four types of OPs—Ethoprophos, Phorate, Diazinon, and Malathion, categorized into ≤LOD and >LOD groups—had detection rates ranging from 20% to 60%. OP exposure was not associated with T2D risk in the overall population. Among participants with baseline FBG ≥ 6.1 mmol/L, OP exposure showed a positive association with incident T2D and with increases in FBG during a 5-year follow-up. In contrast, OP exposure was associated with decreased FBG in the overall population. Moreover, significant interactions were observed between OP exposure and baseline FBG levels (P_interaction < 0.05), suggesting that baseline glucose levels may modify the metabolic effects of chronic OP exposure. These findings highlight the importance of considering basal glucose status when evaluating the long-term metabolic effects of OP exposure. Full article

Malathion (MLT) is an organophosphate pesticide widely used worldwide. Due to its environmental persistence and accumulation in living organisms, concerns have been raised regarding its potential health effects beyond the classical mechanism of cholinergic inhibition, particularly its impact on immune function. In this study, we aimed to systematically evaluate the immunotoxicity of MLT in mice and identify the lowest-observed-adverse-effect level (LOAEL) for immunotoxic effects. Key parameters assessed included body and organ weights, hematological and clinical chemistry profiles, histopathological changes, and immune function indicators. The results showed that exposure to MLT, particularly at low and intermediate doses, led to a significant increase in thymus weight, along with marked reductions in interleukin-10 (IL-10) levels, neutrophils, polychromatic erythroblasts, and monocyte lineage cells. Histological examination revealed atrophy of splenic white pulp, indicating immunopathological alterations predominantly at these dose levels. In contrast, immunoglobulin G (IgG) levels increased in a dose-dependent manner, possibly reflecting a compensatory humoral response to the observed suppression of cellular immune components. Meanwhile, the plaque-forming cell (PFC) response exhibited a dose-dependent trend but was significantly inhibited only at the highest dose, suggesting a complex, non-linear effect on humoral immunity. Based on significant alterations in thymus weight, cellular immune parameters, and splenic histopathology observed at the lowest dose tested (16 mg/kg bw), this value was preliminarily identified as the LOAEL for MLT-induced immunotoxicity in mice. Full article

In on-site rapid detection, the electrochemical method boasts high sensitivity and rapid response capabilities, while the colorimetric method can provide intuitive visual readings suitable for on-site screening. Therefore, this study developed an innovative dual-mode electrochemical/colorimetric aptasensor for the accurate detection of malathion (MAL) in vegetables. The sensor combines magnetic Fe₃O₄@ZIF-8-DNA composites and CuZr-MOF-cDNA probes, enabling simultaneous detection of the target through electrochemical reactions and colorimetric changes. The introduction of CuZr-MOF not only enhances the sensor’s conductivity but also significantly amplifies the electrochemical signal through its catalytic properties. The magnetic Fe₃O₄@ZIF-8-DNA composite facilitates solid–liquid separation under an external magnetic field. When the target MAL is present, the aptamer binds to the target, causing the CuZr-MOF-cDNA probes to release from the composite, altering the number of free probes in the supernatant and generating varying intensities of colorimetric signals. Meanwhile, the MAL captured in the precipitate by the aptamer is quantitatively detected through electrochemical methods. Experimental results demonstrate that as the target concentration increases, the colorimetric signal intensifies while the electrochemical signal weakens, showing a good linear relationship between the two. The aptasensor’s limit of detection (LOD) for colorimetric and electrochemical modes was 1.57 × 10⁻¹¹ M and 4.76 × 10⁻¹¹ M, respectively, with recoveries ranging from 87.71% to 107.68% and relative standard deviations between 3.23% and 10.75%. This method exhibits high sensitivity, excellent selectivity, and strong reliability, providing a novel technique for the accurate quantification of MAL in vegetables, particularly suited for on-site rapid detection. Full article

Spodoptera frugiperda is a major agricultural pest both in Brazil and worldwide, with widespread resistance to synthetic insecticides. This study evaluated the toxicity and residual activity of toxic bait formulations combining 17 insecticides with the plant-based kairomone attractant Noctovi^® 43SB against S. frugiperda adults. Bioassays were conducted with 48 h-old, food-deprived adults. Toxicity was assessed by incorporating insecticides at 2% concentration into Noctovi^® 43SB. Residual activity was measured by applying toxic baits on cotton leaves and testing at 3, 7, 15, 21, and 30 days after application (DAA). Insecticides based on methomyl, spinetoram, spinosad, indoxacarb, malathion, and zeta-cypermethrin induced over 95% mortality. Methomyl showed the greatest toxicity (LC₅₀ = 322 mg a.i. L⁻¹; LC₉₀ = 1160 mg a.i. L⁻¹). Eleven insecticides maintained residual activity (≥70%) after 30 DAA, except malathion. Overall, toxic bait formulations combining Noctovi^® 43SB with methomyl, spinosad, spinetoram, or indoxacarb proved highly effective, offering both rapid and prolonged control of S. frugiperda adults. These findings highlight attract-and-kill as a promising tool for sustainable management of this pest. Full article

Organophosphate pesticides are among the most persistent and toxic contaminants in aquatic environments, requiring effective strategies for detection and remediation. In this work, density functional theory (DFT) calculations were employed to investigate the adsorption of nine representative organophosphates (glyphosate, malathion, diazinon, azinphos-methyl, fenitrothion, parathion-methyl, disulfoton, tokuthion, and ethoprophos) on mercaptobenzothiazole disulfide (MBTS) and MBTS-functionalized graphene (G–MBTS). All simulations were performed in aqueous solution using the SMD solvation model with dispersion corrections and counterpoise correction for basis set superposition error. MBTS alone displayed a range of affinities, suggesting potential selectivity across the organophosphates, with adsorption energies ranging from 0.27 to 1.05 eV, malathion being the strongest binder and glyphosate the weakest. Anchoring of MBTS to graphene was found to be highly favorable (1.26 eV), but the key advantage is producing stable adsorption platforms that promote planar orientations and $\pi$–$\pi$/dispersive interactions. But the key advantage is not stronger binding but the tuning of interfacial electronic properties: all G–MBTS–OP complexes show uniform, narrow HOMO-LUMO gaps (∼0.79 eV) and systematically larger charge redistribution. These features are expected to enhance electrochemical readout even when adsorption strength was comparable or slightly lower (0.47–0.88 eV) relative to MBTS alone. A Quantum Theory of Atoms in Molecules (QTAIM) analysis of the G–MBTS–malathion complex revealed a dual stabilization mechanism: multiple weak C–H⋯$\pi$ interactions with graphene combined with stronger S⋯O and hydrogen-bonding interactions with MBTS. These results advance the molecular-level understanding of pesticide–surface interactions and highlight MBTS-functionalized graphene as a promising platform for the selective detection of organophosphates in water. Full article

The relative efficacy of amorphous silica dusts, malathion, and pirimiphos methyl was assessed against S. oryzae and T. castaneum in stored wheat under laboratory conditions. Insecticidal performance was influenced by physical properties such as particle size, surface area, bulk density, and oil/water adsorption capacity. Fumed silicas showed the highest toxicity, particularly Wacker HDK H20 (LC₅₀ = 19.4 mg/100 g at 12% moisture). Precipitated silica, Sipernat 22, though less potent (LC₅₀ = 46.6 mg/100 g), displayed consistent efficacy across different moisture levels, making it a suitable inert carrier. Increasing grain moisture to 15% significantly reduced the effectiveness of all dusts. When insecticides were combined with silica, their toxicity increased markedly. Malathion on silica (0.2%) reduced LC₅₀ values to 21.5 and 23.3 µg a.i./100 g for T. castaneum and S. oryzae, respectively, compared to 52.3 and 84.7 µg a.i./100 g on talc. Pirimiphos methyl on silica (0.1%) was the most effective, achieving LC₅₀ values of 13.4 and 15.5 µg a.i./100 g. Long-term bioassays over 25 weeks showed declining mortality rates, particularly at 15% moisture. However, pirimiphos methyl on silica maintained over 90% mortality at 12% moisture throughout the period, indicating strong residual efficacy. The results highlight the synergistic potential of combining silica with chemical insecticides and the crucial role of environmental humidity in stored grain pest management. Full article

Organochlorine insecticides (DDTs), organophosphate insecticides (malathion), carbamate insecticides (carbaryl and thiram), pyrethroid (cypermethrin and fenvalarate) insecticides, and herbicides (glyphosate and atrazine) were selected for this study because they disrupt cervical and myometrial function in the bovine oestrous cycle. However, their potential to affect reproductive success in cattle during pregnancy has not been directly confirmed. The aim of this study was to determine the effects of the investigated pesticides on cervical contractions in pregnant cows. Cervical strips from cows at 4–6 months of gestation were treated with the eight singular pesticides (used at non-toxic, environmental dose) or oestradiol (E2) under two different conditions (37.5 °C for 24 h and 4 °C for 48 h), which were applied to assess pesticide effects under both physiological and prolonged-exposure settings. The strength of the contractions was then measured. The findings of the study demonstrated that both the carbamates and glyphosate increased the force of cervical strip contractions to a greater extent than cypermethrin. In contrast, fenvalerate was observed to induce a state of cervical relaxation, analogous to the effects of E2, while DDT, malathion and atrazine exerted no effect on cervical motor function during the period of pregnancy under investigation. These preliminary findings indicate a potential impact of pesticides on cervical function during pregnancy, but should be interpreted with caution as they are based on isolated tissue at a single concentration. Further in vivo and dose–response studies are needed to confirm their biological and clinical relevance. Full article

Insecticide resistance monitoring is essential for effective mosquito control. This study compared CDC Bottle Bioassays (BBAs) using technical and formulated insecticides (deltamethrin/Deltagard and malathion/Fyfanon EW) against the Culex pipiens complex (Fogg Rd) and Culex tarsalis Coquillett (Vic Fazio). BBAs indicated resistance to deltamethrin and emerging resistance to malathion in Fogg Rd, as well as resistance to both in Vic Fazio. Field trials, however, showed high efficacy: Deltagard caused 97.7% mortality in Fogg Rd and 99.4% in Vic Fazio. Fyfanon EW produced 100% mortality in Fogg Rd but only 47% in Vic Fazio. Extended BBA endpoints at 120 and 180 min aligned better with field outcomes. Deltagard achieved 100% mortality at 120 min in both populations; technical deltamethrin reached 85.7% (Fogg Rd) and 83.5% (Vic Fazio) at 180 min. Fyfanon EW and malathion showed similar performance: 100% mortality was achieved in Fogg Rd by 120 min but was lower in Vic Fazio; malathion reached 55%; and Fyfanon EW reached 58.6% by 180 min. Statistical analysis confirmed that BBAs using formulated products better reflected field performance, particularly when proprietary ingredients were involved. These findings support the use of formulated products and extended observation times in BBAs to improve operational relevance and resistance interpretation in addition to detecting levels of insecticide resistance. Full article

The widespread presence of pesticides—especially malathion—in aquatic environments presents a major obstacle to conventional remediation strategies, while the ongoing global energy crisis underscores the urgency of developing renewable energy sources such as hydrogen. In this context, photocatalytic water splitting emerges as a promising approach, though its practical application remains limited by poor charge carrier dynamics and insufficient visible-light utilization. Herein, we report the design and evaluation of a series of TiO₂-based ternary nanocomposites comprising commercial P25 TiO₂, reduced graphene oxide (rGO), and molybdenum disulfide (MoS₂), with MoS₂ loadings ranging from 1% to 10% by weight. The photocatalysts were fabricated via a two-step method: hydrothermal integration of rGO into P25 followed by solution-phase self-assembly of exfoliated MoS₂ nanosheets. The composites were systematically characterized using X-ray diffraction (XRD), Raman spectroscopy, transmission electron microscopy (TEM), UV-Vis diffuse reflectance spectroscopy (DRS), and photoluminescence (PL) spectroscopy. Photocatalytic activity was assessed through two key applications: the degradation of malathion (20 mg/L) under simulated solar irradiation and hydrogen evolution from water in the presence of sacrificial agents. Quantification was performed using UV-Vis spectroscopy, gas chromatography–mass spectrometry (GC-MS), and thermal conductivity detection (GC-TCD). Results showed that the integration of rGO significantly enhanced surface area and charge mobility, while MoS₂ served as an effective co-catalyst, promoting interfacial charge separation and acting as an active site for hydrogen evolution. Nearly complete malathion degradation (~100%) was achieved within two hours, and hydrogen production reached up to 6000 µmol g⁻¹ h⁻¹ under optimal MoS₂ loading. Notably, photocatalytic performance declined with higher MoS₂ content due to recombination effects. Overall, this work demonstrates the synergistic enhancement provided by rGO and MoS₂ in a stable P25-based system and underscores the viability of such ternary nanocomposites for addressing both environmental remediation and sustainable energy conversion challenges. Full article

The present study focuses on the sources and spatial distribution of potentially toxic elements (PTEs) and organic pollutants in water, canal bed sediment, and soil in the Versiliana urban park, an inclusive green area near the coast in the densely populated Versilia Plain of Tuscany. Surface water and bed sediments from canals crossing the urban park were collected at 10 stations during four different surveys to account for hydrological seasonality. Groundwater was collected in a survey through 10 piezometers. Eleven shallow soil samples were also collected, with the aim of evaluating the potential release of pollutants. Groundwater ranged from Ca-HCO₃, to NaCl, CaCl₂, and Na-HCO₃ water types, indicating conservative mixing and cation exchange processes during seawater intrusion. Most waters from canals belonged to the Ca-HCO₃ hydrofacies; a salinization shift, due to hydraulic connection with saline groundwater and soil sea salt dissolution, is observed. The concentration of most PTEs in groundwater and canal water is below Italian regulatory thresholds, with the only exception being As, which exceeds the legal limit in some samples. In most sediments, Ni, Cr, Zn, and As exceed the threshold effect concentration, and in some cases, the probable effect concentration. Geogenic PTE sources are attributed to metalliferous mineralization that characterizes the upstream Versilia River basin catchment. However, local PTE inputs from vehicular emissions and local industrial activities have been highlighted. Arsenic in sediments originated from geogenic sources and from arsenical pesticides, as indicated by the analysis of organic compounds, highlighting the legacy of the use of organic pesticides that have settled in bed sediments, in particular malathion and metalaxyl. The arsenic risk-based screening level in soil is lower compared with the regulatory threshold and with the measured concentration. Full article

Organophosphate pesticides (OPs) enter the environment through various avenues, posing significant health risks. This highlights the need to monitor OPs in food and environmental samples. This study introduces an enzyme inhibition-mediated distance-based paper (EIDP) biosensor designed for naked-eye visual detection of OPs in food samples. We synthesized a copper alginate (Cu-Alg) hydrogel that traps water within the gel and restricts water flow on pH paper. When incubated with acetylcholinesterase (AChE) and acetylthiocholine (ATCh), the enzyme activity of AChE on ATCh generates thiocholine, which interacts with the Cu²⁺ ions in the gel. This interaction alters the gel’s 3D structure, releasing the trapped water onto the pH paper. Conversely, when AChE is exposed to OPs, its activity is inhibited, limiting the water flow from the gel. As a result, OPs are quantified by measuring the reduction in water flow distance within a linear range of 18 to 105 ng/mL, with a lower detection limit of 18 ng/mL. The EIDP biosensor exhibits high selectivity for OP detection and successfully analyzes OPs in pumpkin and rice samples, achieving percent recoveries ranging from 93% to 103%. This method offers a straightforward, portable, instrument-free, and cost-effective solution for detecting OPs in food samples. Full article

In soybean fields across Northeast China, Thrips flavus Schrank (Thysanoptera, Thripidae) populations are increasing, posing a significant threat to soybean production. The aim of this study was to evaluate the toxicity, insecticide efficacy, and field performance of thirty insecticides against T. flavus. Laboratory bioassays revealed that fenthion (LC₅₀ = 2.26 mg/L), sulfoxaflor (LC₅₀ = 4.28 mg/L), cyetpyrafen (LC₅₀ = 4.94 mg/L), and imidacloprid (LC₅₀ = 6.16 mg/L) exhibited the highest toxicity against T. flavus. Pot experiments were subsequently conducted to assess insecticide efficacy. Seven days after application at the highest tested concentration, the insecticide efficacy of fenthion, sulfoxaflor, chlorantraniliprole, bifenazate, and malathion achieved 100% control efficacy. The four insecticides were selected for field trials based on their high toxicity and insecticide efficacy. Seven days after application, the field efficacy of fenthion at 11.25 g a.i.·hm⁻², sulfoxaflor at 1.19 g a.i.·hm⁻², cyetpyrafen at 8.10 g a.i.·hm⁻², and imidacloprid at 11.25 g a.i.·hm⁻² exceeded 80%. Thus, these four insecticides hold strong potential for integrated management of T. flavus. Overall, the findings provide a valuable reference for developing chemical control strategies against this pest. Full article

In this work, OP- and OC-degrading bacteria were isolated from agricultural soil samples taken in the department of Bolivar, Colombia. The objective of this research was to degrade organochlorine and organophosphorus pesticides using bacterial colonies native to agricultural soils. Two bacterial colonies were isolated from the soil samples, which showed a higher degree of adaptation to media contaminated with the pesticide mixtures. They were identified by biochemical tests using BBL Crystal kits, and, subsequently, their 16S rDNA was sequenced using the PCR technique. Bacterial growth was studied by the OD index, taking absorbance readings on a UV-VIS spectrophotometer at 600 nm, at the 0.5 McFarland scale, and quantification of pesticide degradation was studied by GC–MS. The colonies identified were Bacillus cereus and Paenibacillus lautus. B. cereus isolates were exposed to the OPs malathion, chlorpyrifos, and coumaphos [80 mg·L⁻¹], degrading at rates of 52.4%, 78.8% and 79.5%, respectively, after 12 days of incubation in liquid medium at pH = 7.0 ± 0.2 and 37 °C. Furthermore, P. lautus isolates exposed to the OCs lindane, metolachlor, endrin, and p,p′-DDT [80 mg·L⁻¹] degraded at rates of 64.0%, 60.8%, 55.7% and 65.1% under the same conditions of temperature, pH, and incubation time. These results show that B. cereus and P. lautus might be useful for cleaning up environments that have been polluted by OPs and OCs. Full article

The widespread use of pesticides, such as atrazine and malathion, in agricultural systems raises significant concerns regarding the contamination of groundwater, which serves as a critical resource for drinking water. This study applies machine learning techniques to predict the concentrations of atrazine and malathion in groundwater across Georgia, USA, using 2019 data. A Random Forest classifier was employed to integrate various environmental and demographic factors, including pesticide application rates, precipitation, lithology, and population density, to predict pesticide contamination in groundwater. The models demonstrated high training accuracies of 100% and moderate average testing accuracy of 55% for atrazine and 60% for malathion across five iterations. The low test accuracy of the model, ranging from 50% to 75%, is likely due to overfitting, which can be attributed to the small dataset size and the complex nature of pesticide-contamination patterns, making it challenging for the model to generalize to unseen data. Feature importance analysis revealed that average pesticide usage emerged as the most influential factor for atrazine, while aquifer lithology and precipitation played crucial roles in both models. These results provide valuable insights into the dynamics of pesticide contamination, highlighting areas at greater risk of contamination. The findings underscore the importance of integrating environmental, geological, and agricultural variables for more effective groundwater management and sustainable agricultural practices, contributing to the protection of water resources and public health. Full article

Aedes aegypti mosquitoes are established throughout Nouakchott, Mauritania, where its insecticide resistance status is unknown and dengue has become endemo-epidemic since 2014. Eggs were collected using ovitraps at 12 sites in five districts of Nouakchott, in August 2024. Adult females and larvae of the F1 generation were used for bioassays. Permethrin, deltamethrin, bendiocarb, and malathion were evaluated at discriminating concentrations. Larval assays were carried out at seven concentrations with Bacillus thuriengensis var israelensis (Bti) and temephos. The presence of knockdown resistance (kdr) mutations known to be associated with pyrethroid resistance was assessed by polymerase chain reaction and amplicons sequencing. Adults showed high levels of resistance to all insecticides tested. Larvae were susceptible to Bti (LD50 < 50 µg/L) and temephos (LD50% = 6.8 ± 0.7 µg/L). Only three kdr point mutations, S989P, V1016G, and F1534C, were found. The tri-locus genotypes SP/VG/FC were significantly associated with pyrethroid survival while only the tri-locus genotypes PP/GG/FF showed significant association with deltamethrin resistance. Given their level of insecticide resistance, there is an urgent need to control Ae. aegypti populations by several methods, including the use of biological larvicides, physical elimination of peridomestic breeding sites, water drainage, and public education to prevent arbovirus transmission. Full article