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Organophosphate pesticides such as malathion are the most widely used pesticides. Despite endocrine-disrupting effects, there is a paucity of information regarding chronic exposure to non-persistent organopesticides such as malathion. The purpose of this study is to describe the exposure burden among U.S. residents as well as possible impacts on fertility. Population-based data collected by the National Health and Nutrition Examination Survey (NHANES) between 2015 and 2016 were used to perform a retrospective analysis on urinary concentrations of malathion diacid. Samples were assessed from 1703 adult participants, statistically weighted to represent over 231 million individuals. General linear models were used to examine associations between exposure and reproductive health measures among pre-menopausal women. Detectable concentrations of malathion diacid were identified in 16.1 % (n = 254) of samples. Concentrations were higher among women who reported seeing a physician due to difficulties becoming pregnant (P < 0.001; r2 = 0.12) as well as among women who reported trying for at least a year to become pregnant (P < 0.001; r2 = 0.06). Exposure to malathion is associated with a history of reproductive health challenges among women. [ABSTRACT FROM AUTHOR]

The application of malathion, an insecticide derived from organophosphates, raises substantial apprehensions over human health in the context of pest management in agricultural produce. The presence of a lack of specialized knowledge and the intricate nature of traditional diagnostic methods have further intensified these symptoms, resulting in significant and persistent damage to the human body. The present study aims to synthesis a gold-nanobipyramids (AuNBPs) for identifying malathion and other organophosphate pollutants, even at exceedingly low levels of detection. The AuNBPs is synthesis by the utilization of the seed-mediated growth (SMG) method. The UV-Vis spectroscopy analysis has identified 2 unique absorption peaks, specifically transverse surface plasmon resonance (t-SPR) occurring between 550 and 600 nm, and longitudinal surface plasmon resonance (l-SPR) occurring within the wavelength range of 750 to 850 nm. Additional analysis of AuNBPs reveals its capacity for notable and distinctive optical resonance, particularly in the visible and near-infrared regions of the electromagnetic spectrum. This characteristic renders AuNBPs very appropriate for the development of localized surface plasmon resonance (LSPR) sensors. The sensitivity experiments conducted on the LSPR sensor based on AuNBPs have shown compelling evidence of its capability to detect malathion and other pollutants in the AuNBPs growth solution across different concentrations. These findings highlight the sensor's potential for efficient residue detection of malathion. This discovery underscores the significant importance of its function in safeguarding food safety and reducing the potential hazards linked to the utilization of malathion and other insecticides based on organophosphates in agricultural practices. [ABSTRACT FROM AUTHOR]

Aedes albopictus, also known as the Asian tiger mosquito, is indigenous to the tropical forests of Southeast Asia. Ae. albopictus is expanding across the globe at alarming rates, raising concern over the transmission of mosquito-borne diseases, such as dengue, West Nile fever, yellow fever, and chikungunya fever. Since Ae. albopictus was reported in Houston (Harris County, Texas) in 1985, this species has rapidly expanded to at least 32 states across the United States. Public health efforts aimed at controlling Ae. albopictus, including surveillance and adulticide spraying operations, occur regularly in Harris County. Despite rotation of insecticides to mitigate the development of resistance, multiple mosquito species including Culex quinquefasciatus and Aedes aegypti in Harris County show organophosphate and pyrethroid resistance. Aedes albopictus shows relatively low resistance levels as compared to Ae. aegypti, but kdr-mutation and the expression of detoxification genes have been reported in Ae. albopictus populations elsewhere. To identify potential candidate detoxification genes contributing to metabolic resistance, we used RNA sequencing of field-collected malathion-resistant and malathion-susceptible, and laboratory-maintained susceptible colonies of Ae. albopictus by comparing the relative expression of transcripts from three major detoxification superfamilies involved in malathion resistance due to metabolic detoxification. Between these groups, we identified 12 candidate malathion resistance genes and among these, most genes correlated with metabolic detoxification of malathion, including four P450 and one alpha esterase. Our results reveal the metabolic detoxification and potential cuticular-based resistance mechanisms associated with malathion resistance in Ae. albopictus in Harris County, Texas. Author summary: The Asian tiger mosquito, Aedes albopictus, is an invasive species rapidly expanding worldwide. It is the main vector for several arboviruses, including dengue virus, Zika virus, and chikungunya virus. These viral diseases pose a substantial threat to global public health. Ae. albopictus has developed resistance to insecticides such as malathion, making its control more challenging. To uncover the genetic basis of this resistance, we conducted a study using RNA sequencing-based transcriptome profiling. In this study, we obtained gene expression patterns in malathion-resistant and susceptible mosquitoes. The transcriptomic information allowed us to identify potential key genes in detoxification gene families associated with metabolic resistance to malathion. Our discovery provides insights into the molecular mechanisms behind malathion resistance in Ae. albopictus. Our research not only contributes to the understanding of mosquito biology and control but also highlights the future direction for continued efforts in developing innovative strategies to mitigate rapid development of insecticide resistance in Ae. albopictus. [ABSTRACT FROM AUTHOR]

Malathion® is a persistent organophosphate pesticide used against biting and chewing insects on vegetables. It is a difficult-to-remove surface contaminant of vegetables and contaminates surface and ground water and soils. Malathion® is only partially water soluble, but use of detergent carriers makes adhering Malathion® residues difficult to subsequently remove. Magnetically treated water (MTW) successfully removed Malathion® from Chinese Kale (Brassica oleracea L.), meeting Maximum Residue Load (MRL) standards. Samples were soaked in MTW for 30 min prior to detection with GC/MS/MS, 98.5±3.02% of Malathion® was removed after washing by MTW. Removal by simple washing was only ≈42±1.2% which was not nearly sufficient to meet MRL criteria. [ABSTRACT FROM AUTHOR]

Simple Summary: The tiger mosquito, Aedes albopictus, spreads the virus causing dengue fever, notably in Southeast Asian countries. To stop the spread of this disease, the Aedes mosquitoes are killed with chemicals known as pyrethroids. However, despite pyrethroids being highly effective insecticides, tiger mosquitoes are becoming resistant and surviving exposure to these chemicals. We have measured that tiger mosquitoes from two regions in Cambodia (the capital, Phnom Penh, and rural Pailin province) are highly resistant to pyrethroids. To determine what causes resistance, we have implicated unusually high activity of enzymes, known as P450 monooxygenases, which break down pyrethroids and thus render them harmless in the resistant mosquitoes. We have ruled out another common mechanism of pyrethroid resistance, which is changes in the mosquitoes' DNA sequence, which prevents pyrethroids from binding to a protein known as the voltage-gated sodium channel, thereby disrupting signals being sent throughout the nervous system. Overall, our findings describe an important survey monitoring the prevalence of insecticide resistance in disease-spreading mosquitoes in Cambodia, and with the increased understanding of what causes resistance, we are in a strong position to advise that mosquito control methods alternative to pyrethroids should be implemented as soon as possible to ensure continuing management of dengue fever. (1) Background: In Cambodia, Aedes albopictus is an important vector of the dengue virus. Vector control using insecticides is a major strategy implemented in managing mosquito-borne diseases. Resistance, however, threatens to undermine the use of insecticides. In this study, we present the levels of insecticide resistance of Ae. albopictus in Cambodia and the mechanisms involved. (2) Methods: Two Ae. albopictus populations were collected from the capital, Phnom Penh city, and from rural Pailin province. Adults were tested with diagnostic doses of malathion (0.8%), deltamethrin (0.03%), permethrin (0.25%), and DDT (4%) using WHO tube assays. Synergist assays using piperonyl butoxide (PBO) were implemented before the pyrethroid assays to detect the potential involvement of metabolic resistance mechanisms. Adult female mosquitoes collected from Phnom Penh and Pailin were tested for voltage-gated sodium channel (VGSC) kdr (knockdown resistance) mutations commonly found in Aedes sp.-resistant populations throughout Asia (S989P, V1016G, and F1534C), as well as for other mutations (V410L, L982W, A1007G, I1011M, T1520I, and D1763Y). (3) Results: The two populations showed resistance against all the insecticides tested (<90% mortality). The use of PBO (an inhibitor of P450s) strongly restored the efficacy of deltamethrin and permethrin against the two resistant populations. Sequences of regions of the vgsc gene showed a lack of kdr mutations known to be associated with pyrethroid resistance. However, four novel non-synonymous mutations (L412P/S, C983S, Q1554STOP, and R1718L) and twenty-nine synonymous mutations were detected. It remains to be determined whether these mutations contribute to pyrethroid resistance. (4) Conclusions: Pyrethroid resistance is occurring in two Ae. albopictus populations originating from urban and rural areas of Cambodia. The resistance is likely due to metabolic resistance specifically involving P450s monooxygenases. The levels of resistance against different insecticide classes are a cause for concern in Cambodia. Alternative tools and insecticides for controlling dengue vectors should be used to minimize disease prevalence in the country. [ABSTRACT FROM AUTHOR]

Pesticide contamination of aquatic ecosystems poses a significant threat to humans and can adversely affect fungal-driven processes in these understudied habitats. Here, we investigated the effects of four pesticides on detritus-inhabiting and plant root-associated fungi from streams, peatlands, and saltwater marshes. Additionally, we assessed the isolates' capacities to degrade three carbon sources to understand the impact of pesticides on fungal-driven processes. Pesticide assays were conducted in 96-well glass-coated plates, with fungal growth measured using a UV-Vis spectrophotometer set to 595 nm. Assays included technical replication (n = 6), replication over time (n = 2), negative controls, and carry-over controls. In total, we assayed more than 153 isolates, representing up to 97 fungal genera. Results showed that 1.9%, 49.7%, 3.1%, and 5.6% of the isolates exhibited consistently lower growth when exposed to atrazine, mancozeb, cypermethrin, and malathion, respectively. Furthermore, 101 isolates, comprising 87 genera, were tested for cellulase, starch degradation, and tannase activity, with 41.6%, 28.7%, and 30.7% of the isolates testing positive, respectively. These findings suggest that while many species demonstrate functional redundancy, some fungal species are sensitive to current environmental pesticide levels, which affects their growth and may have broader implications on ecosystem health. [ABSTRACT FROM AUTHOR]

The study aims to synthesize a selective matrix imprinted sorbent for the extraction of parathion and malathion. The structural unit of the polymeric framework was 2-methylpropanoic acid, the intermolecular crosslinker was ethylene glycol dimethacrylate, the polymerization initiator was azobisisobutyronitrile, the porogen was xylene, and the analyte was parathion. The synthesis was carried out under conditions of heating the reaction mixture to 65 °C, after which the matrix was washed with methanol to remove the analyte. For comparison purposes, non-imprinted control polymer was used as a negative control, which was prepared similarly, but without the addition of the analyte. The identification and quantification of organophosphates were performed by gas chromatography, and the morphological characteristics of the sorbents were evaluated by scanning electron microscopy. The optimal buffer for the purification of organophosphates was acetate buffer with a pH of 4; the optimal organic eluent was methanol. The limit of detection for para- and malathion was 0.1 μg/ml; the limit of quantification was 0.3 μg/ml. Linearity in the extraction conditions was observed in the range of 0.1–1 μg/ml for parathion and 0.1–2 μg/ml for malathion. The developed method will enable quick, selective, and cost-effective extraction of organophosphates from various substrates. [ABSTRACT FROM AUTHOR]

The African fig fly (AFF) Zaprionus indianus Gupta, 1970, is an invasive species that has caused significant damage to several monoculture crops since its introduction in the Brazilian territory, resulting losses for farmers and decrease of fruit productions. A way to manage fruit pests is the chemical control, which could act as a selective pressure against genetic variation in the insect populations. The esterases are detoxifying enzymes that can respond to the selection by insecticides, they are conserved in evolution, and are involved in the hydrolysis of esters, including insecticide degradation. Esterases can be identified by isoenzyme electrophoresis, which is a valuable tool for genetic, biochemical, and ecological studies, particularly in approaches with pest species. This experimental study aimed to evaluate survival and esterase polymorphisms at the Est2 and Est3 loci in three different geographical populations of Z. indianus from Brazil (Aracaju, Uberaba and Florianópolis) after exposition to organophosphate malathion. We identified patterns of sex‐specific genetic variation that indicate a response to insecticide exposition. These results indicated that the insecticide biological response in this species is sex‐dependent, providing relevant information about the AFF‐malathion interaction. This study may contribute to the development of more effective and sustainable management strategies for AFF control in Brazil using genetic and ecological approaches. [ABSTRACT FROM AUTHOR]

Insecticides are widely used in agriculture, horticulture, medicine, and industry, as well as domestically. Increased insecticide application has been attributed to higher agricultural productivity and lower infield and postharvest crop loss in the twentieth century. Malathion is a very commonly used organophosphorus (OP) insecticide applied in over 100 food crops in agriculture and post-harvest storage. Different species of Aspergillus have shown their efficiency to degrade OP chemicals. A malathion tolerant Aspergillus niger MRU01, developed by prolonged malathion exposure, was tested for its efficiency to remove malathion as well as three other commonly used OP insecticides, viz., parathion, chlorpyrifos and dimethoate. The tolerant strain showed growth efficiency as well as enhanced production of phosphatases and esterase enzyme as compared to untreated and treated wild type (A. niger ATCC16404). The removal of malathion was 29% and 68%, in the wild type and the tolerant strain, respectively during five days. The tolerant strain was also able to remove dimethoate (63%) and chlorpyrifos (54%) with high efficiency while a low rate of removal of parathion (33%) was observed. The strain can be tested in the microcosms more specifically for bioremediation of other OP insecticides before its application in the field. The malathion tolerant Aspergillus niger MRU01 grew efficiently in the presence of 500 μM malathion. Treatment of the fungus with malathion and other OP insecticides – parathion, chlorpyrifos, and dimethoate – caused enhanced expression of phosphatases and esterases. The tolerant A. niger MRU01 strain had significantly lower mycelia concentrations of insecticides than of the wild type A. niger ATCC16404. Degradation of insecticides by the tolerant strain was significantly higher than by the wild type indicating its broad spectrum of tolerance. [ABSTRACT FROM AUTHOR]

Current study evaluated the effect of four plant oils, four plant powders, two inert dusts compared to Malation against one of the major stored product insects (cowpea beetle). Based on percent of reduction obtained after five months of Callosobruchus maculatus treatment, results showed that plant oils and clove oil were achieved the strongest effect for reducing the number of emerged adults of the tested insect followed by spearmint and orange depending on LC50 values. For inert dusts and malathion, malathion showed the highest effect. While the two inert dusts, silica and katelsous had nearly equal action. For plant powders, the results had the same trend with plant oils where the clove powder had the first order for reducing the number of emerged adults followed by spearmint and orange. [ABSTRACT FROM AUTHOR]

Current study was conducted to evaluate some plant oils (clove, spearmint and orange); plant powders (clove, spearmint and orange); two inert dusts (silica and katelsous) and the insecticide (malathion) as recommended standard reference against one of the most important stored grain insects, Rhizopertha dominica. Three methods of application, mixing with medium, residual and repellent activity were used to determine some criteria (toxicity, emergence, progeny reduction, which measure the susceptibility of the tested insect). In addition, the study included the damage of grains (% wheat loss) and the side effect on the germination. Results showed that toxicity of the tested materials were depending on insect species and bioassay methods. This variation may be regarding to feeding habit of tested insects and the vapor pressure and molecular weight of each compound, which influence the level of toxicity. Moreover, insecticidal activity in the tested materials was related to their chemical composition, and activity decreased with the time depends on the component volatility for oils. Moreover, clove oil showed to has the best effects among the oils in the present study, where it reduced the emerged adults, the percent of weight loss and increased the percent of reduction. However, the clove oil inhibited the percent of germination of R. dominica. Results also showed that the percent of germination did not influence by the method of mixing. [ABSTRACT FROM AUTHOR]

Maize weevil, Sitophilus zeamais Motschulsky, is one of the most common and destructive postharvest pests in the world, damaging stored cereal crops. Several ecological alternatives have been studied to control S. zeamais, including use of plant extracts. The objective of the study was to use qualitative phytochemical tests to evaluate insecticidal effect are acetone extract of Dysphania ambrosioides leaves against adults of S. zeamais in native Raton maize. Seven treatments were used at concentrations of 10, 50, 100, 200, and 300 g liter-1, a negative check of 100% acetone, and a positive check of 5% malathion with five replications in a completely randomized design. Numbers of dead and emerged F1 adults of S. zeamais, weight loss, and germination of maize grain of Raton race were evaluated. Results showed that acetone extract of D. ambrosioides leaves was effective against S. zeamais in native maize Raton race; this effect could be attributed to coumarins, flavonoids, triterpenes, and steroids in D. ambrosioides that have potential to suppress development of S. zeamais and be an environmentally friendly alternative to frequent use of synthetic chemical insecticides. El gorgojo del maíz, Sitophilus zeamais Motschulsky, es una de las plagas postcosecha más comunes y destructivas del mundo, que daña de cereales almacenados. Se han estudiado varias alternativas ecológicas para controlar a S. zeamais , incluido el uso de extractos de plantas. El objetivo del estudio fue utilizar pruebas fitoquímicas cualitativas para evaluar el efecto insecticida del extracto acetónico de hojas de Dysphania ambrosioides contra adultos de S. zeamais en maíz nativo Ratón. Se utilizaron siete tratamientos en concentraciones de 10, 50, 100, 200 y 300 g litro-1, un control negativo de 100% acetona y un control positivo de 5% malatión con cinco repeticiones en un diseño completamente al azar. Se evaluó el número de adultos F1 muertos y emergidos de S. zeamais, la pérdida de peso y la germinación de grano. Los resultados mostraron que el extracto de acetona de hojas de D. ambrosioides fue efectivo contra S. zeamais en maíz nativo raza Ratón; Este efecto podría atribuirse a las cumarinas, flavonoides, triterpenos y esteroides en D. ambrosioides que tienen potencial para suprimir el desarrollo de S. zeamais y ser una alternativa respetuosa con el medio ambiente al uso frecuente de insecticidas químicos sintéticos. [ABSTRACT FROM AUTHOR]

Detection of pesticide residues in soil samples was conducted using UHPLC-MS/MS. Non-dietary health risk assessment was conducted using calculate chronic daily intake (CDI) from ingestion, inhalation and dermal contact pathways and following non-carcinogenic and carcinogenic risks in the adults and adolescent. The rank order of pesticide in soil based on their concentration was malathion (0.082 mg kg−1)> cyproconazole (0.019 mg kg−1)> propargite (0.018 mg kg−1)> butachlor (0.016 mg kg−1) > chlorpyrifos (0.0067 mg kg−1)> diazinon (0.0014 mg kg−1)> imidacloprid (0.0007 mg kg−1). Hazard index (HI) values obtained of exposure to pesticides in soil in adults and adolescent were 0.0012 and 0.0035, respectively. Hence, exposed population are at the acceptable range of non-carcinogenic risk (HI < 1). Cancer risk (CR) values due to propargite in soil via ingestion pathway in adults and adolescent were 2.03E–09 and 2.08E–09, respectively; therefore, carcinogenic risk due to the exposure to pesticide contaminated soil was safe range (CR < 1E–06). [ABSTRACT FROM AUTHOR]

Resistance to preemergence (PRE) soil-applied herbicides, such as inhibitors of very-long-chain fatty acid (VLCFA) elongases, was documented in two waterhemp [Amaranthus tuberculatus (Moq.) J.D. Sauer] populations (SIR and CHR) from Illinois, USA. To limit the spread of resistant weed populations, rapid detection measures are necessary. Soil-based resistance assays are limited by edaphic factors, application timing, variable seeding depth and rainfall amount. Therefore, cost-effective techniques mitigating effects of edaphic factors that are appropriate for small- to large-scale assays are needed. Our research goal was to identify and quantify resistance to the VLCFA-inhibiting herbicides, S-metolachlor and pyroxasulfone, using a soilless greenhouse assay. Dose-response experiments were conducted under greenhouse conditions with pre-germinated waterhemp seeds planted on the vermiculite surface, which had been saturated with S-metolachlor (0.015–15 μM), pyroxasulfone (0.0005–1.5 μM), or S-metolachlor plus the cytochrome P450 (P450) inhibitor, malathion. Lethal dose estimates of 50% (LD50) and growth reduction of 50% (GR50) were calculated for S-metolachlor and pyroxasulfone PRE and used to determine resistance indices (RI) for resistant populations (CHR and SIR) relative to sensitive populations, SEN and ACR. RI values for S-metolachlor using LD50 values calculated relative to SEN and ACR were 17.2 and 15.2 (CHR) or 11.5 and 10.1 (SIR), while RI values for pyroxasulfone using LD50 values calculated relative to SEN and ACR were 3.8 and 3.1 (CHR) or 4.8 and 3.8 (SIR). Malathion decreased the GR50 of S-metolachlor to a greater degree in CHR compared to ACR, consistent with P450 involvement in S-metolachlor resistance in CHR. Results from these soilless assays are in accord with previous findings in soil-based systems that demonstrate CHR and SIR are resistant to S-metolachlor and pyroxasulfone. This method provides an effective, reproducible alternative to soil-based systems for studying suspected PRE herbicide-resistant populations and will potentially assist in identifying non-target-site resistance mechanisms. [ABSTRACT FROM AUTHOR]

The species Ceratitis capitata (Weidemann, 1824), known as Mediterranean fruit fly, is an important pest for fruit trees worldwide. The control of this pest is carried out mainly by the chemical method, using organophosphorus, pyrethroid, and spinosyn pesticides. The lethality of doses of malathion, deltamethrin, and spinetoram on immature and adult stages of C. capitata was evaluated under laboratory conditions. The egg, larval, pupal, and adult stages were exposed to doses of pesticides through contact and ingestion. The doses were obtained by decreasing the recommended doses (malathion: 200 mL L−1, deltamethrin: 50 mL L−1, and spinetoram: 120 g ha−1) with intervals of 20%, this being the minimum dose used. The variables evaluated were: viability of eggs and pupae and mortality of larvae and adults. Application of spinetoram and malathion through contact caused high mortality of adults, with LD90 at the sub‐doses of 43.74% (52.48 g c.p. ha−1) and 68.81% (137.62 mL c.p. 100 L−1), respectively. The mortality of adults by ingestion of deltamethrin and malathion allowed us to estimate only the LD50. Only the pesticide deltamethrin presented LD50 for the egg stage. The larval and pupal stages the effect of the pesticides on larvae treated through contact resulted in 52% mortality with spinetoram and 62% with malathion. The mortality of larvae and pupae treated through ingestion was below 20% for the three pesticides. Sub‐doses of spinetoram (43.74%; 52.48 g c.p. ha−1) and malathion (68.81%; 137.62 mL c.p. 100 L−1) can be used since they present a 90% efficiency on C. capitata adult when applied by contact under laboratory conditions. [ABSTRACT FROM AUTHOR]

The capabilities of pure bacterial strains and their consortia isolated from agricultural soil were evaluated during a bioremediation process of the organophosphate pesticide malathion. The pure bacterial strains efficiently degraded 50.16–68.47% of the pesticide within 15 days of incubation, and metabolites were observed to accumulate in the soil. The consortia of three bacterial species [Micrococcus aloeverae (MAGK3) + Bacillus cereus (AGB3) + Bacillus paramycoides (AGM5)] degraded the malathion more effectively, and complete malathion removal was observed by the 15th day in soils inoculated with that consortium. In contrast, the combined activity of any two of these strains was lower than the mixed consortium of all of the strains. Individual mixed consortia of Micrococcus aloeverae (MAGK3) + Bacillus cereus (AGB3); Micrococcus aloeverae (MAGK3) + Bacillus paramycoides (AGM5); and Bacillus cereus (AGB3) + Bacillus paramycoides (AGM5) caused 76.58%, 70.95%, and 88.61% malathion degradation in soil, respectively. Several intermediate metabolites like malaoxon, malathion monocarboxylic acid, diethyl fumarate, and trimethyl thiophosphate were found to accumulate and be successively degraded during the bioremediation process via GC–MS detection. Thus, inoculating with a highly potent bacterial consortium isolated from in situ soil may result in the most effective pesticide degradation to significantly relieve soils from pesticide residues, and could be considered a prospective approach for the degradation and detoxification of environments contaminated with malathion and other organophosphate pesticides. This study reports the use of a mixed culture of Indigenous bacterial species for successful malathion degradation. [ABSTRACT FROM AUTHOR]

In this study, we measured the enzymatic activity of acetylcholinesterase (AChE) using the Light Addressable Amperometric Sensor (LAAS), an electrochemical sensor that can easily measure redox current values of multiple samples. Acetylthiocholine (ATCh) was used as a substrate. ATCh is hydrolyzed by AChE and releases electrons, making it possible to measure current values in accordance with the amount of substrate using LAAS. When KCl solution was used as the supporting electrolyte and an Ag/AgCl reference electrode as the counter electrode, a correlation between substrate concentration and reaction was confirmed in the range of 1 μM–10 mM. Malathion was then used as an inhibitor of AChE. Malathion phosphorylates and inactivates AChE, which prevents substrate hydrolysis and is expected to decrease the current value. Experimental results showed a decrease in sensor response correlated with inhibitor concentration. [ABSTRACT FROM AUTHOR]

Super-sensitive malathion detection was achieved using a nonenzymatic electrochemical sensor based on a CuO/ZnO-modified glassy carbon electrode (GCE). Due to the high affinity between the Cu element and the sulfur groups in malathion, the developed CuO-ZnO/GCE sensor may bond malathion with ease, inhibiting the redox signal of the Cu element when malathion is present. In addition to significantly increasing the ability of electron transfer, the addition of 3D-flower-like ZnO enhances active sites of the sensor interface for the high affinity of malathion, giving the CuO-ZnO/GCE composite an exceptional level of sensitivity and selectivity. This enzyme-free CuO-ZnO/GCE malathion sensor demonstrates outstanding stability and excellent detection performance under optimal operating conditions with a wide linear range of malathion from 0 to 200 nM and a low detection limit of 1.367 nM. A promising alternative technique for organophosphorus pesticide (OP) determination is offered by the analytical performance of the proposed sensor, and this method can be quickly and sensitively applied to samples that have been contaminated with these pesticides. [ABSTRACT FROM AUTHOR]

The "Integrated Wastewater Discharge Standard" was implemented for water pollutant discharge in China's pesticide industry, which has no control requirements for particular wastewater pollutants in the industry. In the standard, certain pollutants discharge limits are limited strictly or loosely, resulting in practical management implementation difficulties. In view of the highly selective targeting characteristics of organic pesticide active ingredients in fungicides, insecticides, and herbicides, a method for deriving discharge limits based on the water quality criteria for pesticides for the protection of nonsensitive species is established based on the idea of fully protecting aquatic organisms beyond sensitive objects. Through the use of malathion as an example, by screening its toxicity data in different species of aquatic organisms, the sequence point with the most significant change in the acute toxicity sensitivity of the species is taken as the variation point in the cumulative frequency of the sensitive and nonsensitive species to derive the water quality criteria, using the species sensitivity distribution method as the scientific basis for determining the discharge limits. After a comparative analysis of different simulation models, the sigmoid model, with the best fit, is selected to determine that the sensitive species hazard concentration (HCs) of malathion to aquatic organisms in China is 46.4 µg/L, and the discharge limit derived from the HCs based on the relationship between the environmental capacity and emissions is rounded to 250 µg/L. Studies showed that the relationship between the emissions limit derived from the water quality criteria for protecting nonsensitive species and malathion limit stipulated in the "Environmental Quality Standards for Surface Water" conforms to the corresponding relationship of the quality standard and discharge standard, which can be achieved by current pollution control technology, combined with water quality improvement. The discharge limit offers the advantages of technical accessibility and economic rationality. [ABSTRACT FROM AUTHOR]

Pesticides registered with the U.S. EPA for mosquito control are called adulticides and are released directly into the atmosphere as aerosols to target flying mosquitos. This adulticide application approach is different from traditional (agricultural) pesticide applications, yet the fate and transport of adulticides in large metropolitan areas is largely unknown. The Houston Metropolitan Area encompasses eight counties, many of which require county-level mosquito control programs that utilize adulticides. Malathion and permethrin are the primary adulticides used by Harris County (HC) in Houston, TX, USA. Houston, like many other metropolitan areas, has an urban atmosphere supporting the oxidation of both gas and particle phase pollutants. During the summer mosquito season of 2016, we collected atmospheric total suspended particulate matter (PM) samples at Jones Forest (JF), located in Montgomery County (directly north of HC) to investigate the atmospheric transport and oxidation of adulticides in an urban atmosphere. Despite HC alternating the adulticide treatment schedule, we measured permethrin, malathion, and malaoxon (oxidation product of malathion), throughout the sampling campaign. These consistent measurements, in conjunction with 12 h backward trajectories, support the conclusion that JF is influenced by other county-level mosquito-control programs and agricultural pesticide use. This cross-county transport may impact adulticide effectiveness by supporting pesticide resistance in mosquito populations due to repeated exposures to pesticides. This study highlights the need for mosquito control collaborations between counties, especially in areas of urban expansion overlapping with agricultural activities. [ABSTRACT FROM AUTHOR]

Malathion is one of the commonly used organophosphate pesticides known to attack the central nervous system, posing a risk to humans and other animals upon exposure. The surface enhanced Raman spectroscopy (SERS) has been identified as an indispensable tool for chemical and biomolecular sensing. In this work, the facile fabrication of activated carbon (AC)‐based colloidal SERS active substrate dubbed AC@AgNPs was designed by trapping AgNPs on the surface of AC for detection of varying concentrations of malathion. Apart from the higher concentrations of malathion, the rest of the normal Raman spectra of malathion standard solutions exhibited weak Raman signals. The intensity of peaks for 0.47 mg L−1 were nearly non‐existent which is an indication that the malathion pesticide could only be detected up to 0.95 mg L−1 when using silica wafer. On the contrary, all the SERS spectra of malathion in wheat extracts adsorbed on AC@AgNPs substrate exhibited strong Raman signals. Quantitative analysis of malathion was performed by regression models developed using PLSR built with the raw spectra (no pretreatment), SNV‐PLSR, and SNV‐CARS‐PLSR. The model with the most remarkable performance was established by using SNV‐PLSR with r = 0.9869 and RPD = 4.61. This research shows that the proposed method can rapidly detect malathion residues in wheat, suggesting that it could be adopted for production process monitoring of other related food products to guarantee their safety for human and animal consumption. [ABSTRACT FROM AUTHOR]

Malathion and diazinon are pesticides commonly used in agriculture to avoid insects that damage crops; however, they may cause impairment to the male genital system of exposed humans. The present work carried out a systematic review of the literature concerning the primary studies that assessed the reproductive effects resulting from male rats and mice exposed to malathion or diazinon. The search for articles was performed on the databases PubMed, LILACS, Scopus, and SciELO, using different combinations of the search terms "malathion," "diazinon," "mice," "rats," "male reproduction," "fertility," and "sperm," followed by the Boolean operators AND or OR. The results obtained indicate that both pesticides act as reproductive toxicants by reducing sperm quality, diminishing hormonal concentrations, inducing increased oxidative stress, and provoking histopathological damage in reproductive organs. Then, the exposure to malathion and diazinon may provoke diminished levels of testosterone by increasing acetylcholine stimulation in the testis through muscarinic receptors, thus, providing a reduction in steroidogenic activity in Leydig cells, whose effect is related to lower levels of testosterone in rodents, and consequently, it is associated with decreased fertility. Considering the toxic effects on the male genital system of rodents and the possible male reproductive toxicity in humans, it is recommended the decreased use of these pesticides and their replacement for others that show no or few toxic effects for non-target animals. [ABSTRACT FROM AUTHOR]

This study evaluates the single and combined effects of dimethoate (DI) and malathion (MA) on oxidative stress biomarkers in the freshwater mussel Dreissena polymorpha, estimating the potential harm of these pesticides on aquatic ecosystems. Superoxide dismutase (SOD) and catalase (CAT) activities, and glutathione (GSH) and lipid peroxidation (TBARS) levels were determined in D. polymorpha exposed to sublethal concentrations of DI, MA and a combination of the two during 24 and 96 h periods. The results showed that the GSH levels were decreased but the TBARS levels were increased in all the exposure groups after 24 and 96 h compared to the control. It was observed that SOD activity decreased but CAT activity increased in all the DI exposure groups after 24 h compared to the control. At the end of 96 hours, it was observed that CAT and SOD activities increased again in some exposure groups compared to the control. Exposure time also had an effect on biomarkers in different levels. According to the results, the cytotoxicity of DI and MA combination depended on their concentrations. DI or/ and MA, in sub-lethal concentrations, induced oxidative damages in D. polymorpha. Combined exposure of the pesticides can alter their toxicity and may be evidence of increased toxicity and oxidative stress. [ABSTRACT FROM AUTHOR]

Exposure of aquatic organisms to organophosphorus pollutants is a subject of keen interest to biologists and environmental scientists. Examining histopathological changes in the tissues of exposed animals can provide great insights to understand the health condition of the organisms. This study examined the effects of malathion concentration and exposure time on the liver and gill tissues of the rainbow trout (Oncorhynchus mykiss) in a laboratory condition and tried to provide a quantitative assessment for the analysis of these effects. The experiment was conducted in three treatments including 0.025, 0.05, and 0.075 mg/L of malathion for 1, 5, and 9 days with a nonexposed group as control, in three replicates. The liver and gill samples were fixed in buffered formalin. About 5 µ tissue sections were prepared using the conventional histological methods and stained using the hematoxylin–eosin method. Histopathological changes in the liver and gill tissues were quantified by grading and the resulting data were analyzed by rank-based estimation. The results showed that histopathological changes in the liver and gill tissues are more affected by the malathion concentration than by the duration of the exposure. However, longer exposure had an intensifying effect on the tissue damage caused by the malathion at higher concentrations. The presence of melanomacrophages as an indicator of malathion toxicity was determined. The fish exposed to 0.075 mg/L malathion for 9 days showed atrophy in the liver and gill tissues, indicating cell death and functional inactivation. Histopathological changes in the liver and gills confirmed the dose-dependent effect of malathion on the rainbow trout. [ABSTRACT FROM AUTHOR]

Aedes aegypti transmits major arboviruses of public health importance, including dengue, chikungunya, Zika, and yellow fever. The use of insecticides represents the cornerstone of vector control; however, insecticide resistance in Ae. aegypti has become widespread. Understanding the molecular basis of insecticide resistance in this species is crucial to design effective resistance management strategies. Here, we applied Illumina RNA-Seq to study the gene expression patterns associated with resistance to three widely used insecticides (malathion, alphacypermethrin, and lambda-cyhalothrin) in Ae. aegypti populations from two sites (Manatí and Isabela) in Puerto Rico (PR). Cytochrome P450s were the most overexpressed detoxification genes across all resistant phenotypes. Some detoxification genes (CYP6Z7, CYP28A5, CYP9J2, CYP6Z6, CYP6BB2, CYP6M9, and two CYP9F2 orthologs) were commonly overexpressed in mosquitoes that survived exposure to all three insecticides (independent of geographical origin) while others including CYP6BY1 (malathion), GSTD1 (alpha-cypermethrin), CYP4H29 and GSTE6 (lambda-cyhalothrin) were uniquely overexpressed in mosquitoes that survived exposure to specific insecticides. The gene ontology (GO) terms associated with monooxygenase, iron binding, and passive transmembrane transporter activities were significantly enriched in four out of six resistant vs. susceptible comparisons while serine protease activity was elevated in all insecticide-resistant groups relative to the susceptible strain. Interestingly, cuticular-related protein genes (chinase and chitin) were predominantly downregulated, which was also confirmed in the functional enrichment analysis. This RNA-Seq analysis presents a detailed picture of the candidate detoxification genes and other pathways that are potentially associated with pyrethroid and organophosphate resistance in Ae. aegypti populations from PR. These results could inform development of novel molecular tools for detection of resistance-associated gene expression in this important arbovirus vector and guide the design and implementation of resistance management strategies. [ABSTRACT FROM AUTHOR]

Malathion, one of the oldest and probably most widely used organophosphate insecticides worldwide, is used to prevent ectoparasite insects on fruits and vegetables, mainly on agricultural crops. Our study was designed to observe the effects of malathion on some enzymes like catalase and glutathione, on some hormones like folicle Stimulating Hormone (FSH), Luteinizing Hormone (LH), and testosterone, on Matrix Metalloproteinases (MMP) like MMP1, MMP2, and on blood cells in rats. We had used some techniques like spectrophotometry to study catalase and glutathione activity. ELISA for FSH, LH, and testosterone activity studies; protein zymography for MMP activity and haemocytometry for total and differential counts of blood cells It was observed that all hormones and enzymes expression was decreased, as was the total and differential count of blood cells. But in the case of MMP activity, both MMP1 and MMP2 expression were considerably increased under the effect of malathion. As most of the agricultural crops and fruits are consumed by humans, and as both rats and humans share one-fourth of the human genome, this study could help with research on the effects of malathion in the environment as well as on the restriction or dosage estimation for malathion use in both ecological and agricultural aspects. [ABSTRACT FROM AUTHOR]

Cowpea beetle, Callosobruchus maculatus (Fabricius) (Coleoptera: Chrysomelidae) is one of the most dangerous insect pests in field and storage. It causes a high damage to the legumes by decreased dietary values, germination and seed weights. Using synthetic insecticides for controlling stored grain pests have a lot of problems for humans and environment. Therefore, the mixing seeds laboratory experiments were conducted to study the efficacy of certain alternative safety compounds against C. maculatus such as Beauveria bassiana, Metarhizium anisopliae, ascorbic acid, boric acid, talc powder and kaolin compared with an organophosphorus nervous insecticide, malathion 1% dust, that recommended in Egypt for controlling stored grain pests. The present results showed that the malathion was the highest toxicity effect against cowpea beetle adults with LC50(3.89 ppm) after 3-day post treatment. However, the boric acid was the lowest toxicity effect with LC50 (72855 ppm) after 6 days post treatment. The other tested materials showed moderate effects. These results indicate that malathion is still having high effect against cowpea beetle. The toxicity of bio-insecticides (M. anisopliae and B. bassiana) after 6days were more than toxicity malathion 1%dust after 1day.Wheraes, the toxicity of bio-insecticides (M. anisopliae and B. bassiana) increased with increase of period of exposure from 2 to 6 days high rates about 28 times, 31 times, respectively. The findings showed that the tested compounds have a promising insecticidal activity against C. maculatus and can be used as possible alternatives to synthetic chemical insecticides such as malathion for the control of stored product insects. [ABSTRACT FROM AUTHOR]

A study was carried out to determine the ALS (acetolactate synthase)-inhibitor herbicide resistance in the Mexican grass Ixophorus unisetus, a troublesome weed in corn crops in Mexico. First, the resistance was confirmed in field screening assays. Eight populations that survived nicosulfuron treatment at a field rate of 40 g ai ha−1 were labeled as putative-resistant. Dose–response trials demonstrated a high resistance in the eight populations (GR50 from 140.33 to 245.46 g ai ha−1). The synergism of malathion plus nicosulfuron demonstrated that the non-target-site resistance (NTSR) mechanism based on cytochrome P450 (Cyt-P450) was involved in five populations of I. unisetus. Molecular studies revealed that a single-nucleotide change occurs in the amino acid at position 376 (from GAT to GAG), which codifies from Asp-376 to Glu-376. This is the first time that Asp-376-Glu has been reported in this species. Assays in vitro and in vivo demonstrated I. unisetus cross-resistance to flucarbazone, penoxsulam, bispyribac-Na, and imazamox. No multiple resistance was found in two resistant populations exposed to different herbicides. Our results indicate that the lack of good control over Mexican grass in corn with ALS inhibitors is due to target-site mutation and NTSR mechanisms (Cyt-P450-mediated metabolism). A strategy should be established in Mexican fields to continue controlling this weed, including mechanical control practices and a good combination of the available pre- and post-emergence herbicides. [ABSTRACT FROM AUTHOR]

Northeast region (NER) states of India remain highly malarious due to their geographical and ecotype diversity. Furthermore, rapid urbanization and change in climate are also affecting the vector biology and behavior of the existing species. Hence, a study is conducted in the states of Tripura and Meghalaya to generate data on the bionomics of the prevalent malaria vector species. The data from this study show that primary vectors of malaria An. minimus and An. baimaii were anthropophagic. However, An. baimaii showed a behavioral shift towards zoophagicity (∼14%). Insecticide bioassays confirm that these two major vector species are reportedly susceptible to DDT, Malathion, and indicate that intervention by DDT-IRS is effective. Thus, the implementation of appropriate strategies based on this recent information on the bionomics of malaria vectors in NE region of India will provide an opportunity to achieve malaria elimination by date in these states. [ABSTRACT FROM AUTHOR]

The indiscriminate and rampant use of pesticides has raised serious concerns regarding their toxic impact on non-target organisms which underlines need for the development of an effective antidote. Metabolic activation of organophosphate pesticides by the phase I enzyme, cytochrome P450 plays a key role in influencing pesticide-toxicity. In this study, we have investigated the effect of environmentally relevant malathion concentration (100 μg/L) alone and in combination with vitamin B12 on the expression of genes related to xenobiotic metabolism such as CYP enzymes, PgP and the key oxidative stress responsive transcription factor, Nrf2 in zebra fish liver and brain. Expressions of Nrf2-trasncribed antioxidant genes and their activities were also measured. Administration of vitamin B12 successfully revived motor functions by modulation of AchE activity. Mechanistically, vitamin B12 was demonstrated to alleviate oxidative stress which was accompanied by decreased phase-I enzyme cyp3c1 and increased pgp expressions. [ABSTRACT FROM AUTHOR]

Complex diseases are associated with the effects of multiple genes, proteins, and biological pathways. In this context, the tools of Network Medicine are compatible as a platform to systematically explore not only the molecular complexity of a specific disease but may also lead to the identification of disease modules and pathways. Such an approach enables us to gain a better understanding of how environmental chemical exposures affect the function of human cells, providing better perceptions about the mechanisms involved and helping to monitor/prevent exposure and disease to chemicals such as benzene and malathion. We selected differentially expressed genes for exposure to benzene and malathion. The construction of interaction networks was carried out using GeneMANIA and STRING. Topological properties were calculated using MCODE, BiNGO, and CentiScaPe, and a Benzene network composed of 114 genes and 2415 interactions was obtained. After topological analysis, five networks were identified. In these subnets, the most interconnected nodes were identified as: IL-8, KLF6, KLF4, JUN, SERTAD1, and MT1H. In the Malathion network, composed of 67 proteins and 134 interactions, HRAS and STAT3 were the most interconnected nodes. Path analysis, combined with various types of high-throughput data, reflects biological processes more clearly and comprehensively than analyses involving the evaluation of individual genes. We emphasize the central roles played by several important hub genes obtained by exposure to benzene and malathion. [ABSTRACT FROM AUTHOR]

Organophosphorus pesticides (OP) have extensive applications in agriculture, while their overuse causes inevitable residues in food, soil, and water, ultimately being harmful to human health and even causing diverse dysfunctions. Herein, a novel colorimetric platform was established for quantitative determination of malathion based on peroxidase mimic AuPt alloy decorated on CeO2 nanorods (CeO2@AuPt NRs). The synthesized nanozyme oxidized colorless 3,3′,5,5′-tetramethylbenzidine (TMB) in the presence of H2O2. Besides, the oxidized TMB was inversely reduced by ascorbic acid (AA), which were originated from hydrolysis of L-ascorbic acid-2-phosphate (AA2P) with the assistance of acid phosphatase (ACP). Based upon this observation ACP analysis was explored by colorimetry, showing a wid linear range of 0.2 ~ 3.5 U L−1 and a low limit of detection (LOD = 0.085 U L−1, S/N = 3). Furthermore, malathion present in the colorimetric system inhibited the activity of ACP and simultaneously affected the generation of AA, in turn promoting the recovery of the chromogenic reaction. Based on this, the LOD was decreased to 1.5 nM (S/N = 3) for the assay of malathion with a wide linear range of 6 ~ 100 nM. This simple colorimetric platform provides some informative guidelines for determination of other pesticides and disease markers. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this study was to investigate the applicability of the adsorption process of a persistent organophosphorus pesticide (malathion) from aqueous solutions by using titanium dioxide- polypropylene nanocomposite (Nano-PP/TiO2). Methods: The structure of Nano-PP/TiO2 was specified by field emission scanning electron microscopes (FE-SEM), fourier-transform infrared spectroscopy (FTIR), brunauer-emmett-teller (BET), and transmission electron microscope (TEM) technologies. Response surface methodology (RSM) was applied to optimize the adsorption of malathion onto Nano-PP/TiO2 and investigates the effects of various experimental parameters including contact time (5-60 min), adsorbent dose (0.5-4 g/l) and initial malathion concentration (5-20000 mg/l). Extraction and analysis of malathion were performed by dispersive liquid-liquid microextraction (DLLME) coupled with a gas chromatography, coupled with flame ionization detector (GC/FID). Results: The isotherms obtained for Nano-PP/TiO2 revealed that it was a mesoporous material with a total pore volume of 2.06 cm3/g, average pore diameters of 2.48 nm and a surface area of 51.52 m2/g. The obtained results showed that the Langmuir type 2 was the best-fitted model for delegating the equilibrium data of isotherm studies with adsorption capacity of 7.43 mg/g, and pseudo-second-order type 1 for kinetic model. The optimized conditions to achieve the maximum removal (96%) were at a malathion concentration of 7.13 mg/L, contact time of 52 min and adsorbent dose of 0.5 g/L. Conclusion: Due to its efficient and appropriate function in adsorbing malathion from aqueous solutions, it was revealed that Nano-PP/TiO2 can be used as an effective adsorbent as well as in further studies. Highlights: • Novel application of polypropylene and titanium dioxide nanocomposite, Nano-PP/TiO2. • Removal of organophosphorus malathion using Nano-PP/TiO2. • Optimizing the process conditions for adsorption of malathion from aqueous based on the response surface model •Identifying monolayer adsorption of malathion onto Nano-PP/Tio2 surfaces [ABSTRACT FROM AUTHOR]

A hairpin DNA-enabled ratiometric electrochemical aptasensor is reported for sensitive and reliable detection of malathion (MAL). The approach employs hairpin DNA (ferrocene-labeled, Fc-hDNA) as a carrier to hybridize MAL aptamers (methylene blue-labeled, MB-Apt) to form double-stranded DNA structures on an electrode. The presence of MAL induces the removal of aptamers, and hDNA re-forms hairpin structures, causing a decrease in the oxidation current of MB (IMB) and an increase in the oxidation current of Fc (IFc). The ratiometric signal of IFc/IMB responds quantitatively to MAL concentrations. To compare analytical performances, a linear single-stranded DNA (ssDNA) is also used to construct the ssDNA-based aptasensor. We demonstrate that hairpin DNA possessing a rigid two-dimensional structure can improve the assembly efficiency of aptamers and the stability of redox probes. The approach combines the advantages of the ratiometric electrochemical method with hairpin DNA-based conformational switching probes, enabling hDNA-based aptasensor with enhanced sensitivity and reliability, offering a linear range of 0.001 to 1.0 ng mL−1. The platform was applied to detect MAL in lettuce, and the statistical analysis indicated that no significant differences were found between the developed platform and HPLC-MS. [ABSTRACT FROM AUTHOR]

The decline of insect pollinators is a significant concern within the current biodiversity crisis. The paradox between the benefits that these animals represent to humans and the evidence of human activities driving their extinction calls for the urgent protection of bees. To address the role of chemical pollution in this scenario, we assessed the acute toxicity as well as four biomarker responses (cholinesterase [ChE], glutathione S‐transferase, catalase, and lipid peroxidation [LPO]) elicited by dietary 24‐h exposure to three insecticides (malathion, imidacloprid, and fipronil) on the stingless neotropical bee Tetragonisca angustula and the honeybee Apis mellifera. Malathion was the most toxic substance to both species, with 48‐h median lethal doses (LD50s) of 0.25 ng/bee to A. mellifera and 0.02 ng/bee to T. angustula. Fipronil was also highly toxic and presented a similar toxicity to both species, with 48‐h LD50s of 0.5 ng/bee (A. mellifera) and 0.4 ng/bee (T. angustula). Imidacloprid had the lowest acute toxicity with a 48‐h LD50 of 29 ng/bee for A. mellifera, whereas T. angustula tolerated exposure higher than 35 ng/bee. Apparent biomarker responses were observed in bees of both species that survived exposure to higher concentrations of malathion (ChE inhibition) and fipronil (increased LPO). Our results suggest that specific sensitivity to insecticides varies greatly among compounds and pollinator species, but the use of different representative species can facilitate the prioritization of substances regarding their risk to pollinators. Further research is necessary to better characterize the risk that pesticides represent in neotropical agricultural landscapes. Environ Toxicol Chem 2023;42:1022–1031. © 2023 SETAC [ABSTRACT FROM AUTHOR]

Background: Since 2000, Burkina Faso has experienced regular dengue cases and outbreaks, making dengue an increasingly important health concern for the country. Previous studies in Burkina Faso reported that resistance of Aedes aegypti to pyrethroid insecticides was associated with the F1534C and V1016I kdr mutations. The current study reports high resistance of Ae. aegypti populations to pyrethroid insecticides, likely supported by mutations in the voltage-gated sodium channel, here evidenced by genotyping the kdr SNPs V410L, V1016I and F1534C. We also describe a new multiplex PCR-based diagnostic of F1534C and V1016I kdr SNPs. Methods: Larvae of Ae. aegypti were collected from three health districts of Ouagadougou in 2018. The resistance status of Ae. aegypti to permethrin (15 μg/ml) and deltamethrin (10 μg/ml) was tested using bottles and to malathion (5%) using WHO tube tests. All bioassays used 1-h exposure and mortality recorded 24 h post-exposure. Bioassay results were interpreted according to WHO thresholds for resistance diagnosis. The kdr mutations were screened using AS-PCR and TaqMan methods in exposed and non-exposed Aedes mosquitoes. Results: Females from all health districts were resistant to permethrin and deltamethrin (< 20% mortality) but were fully susceptible to 5% malathion. The F1534C and V1016I kdr mutations were successfully detected using a newly developed multiplex PCR in perfect agreement with TaqMan method. The 1534C/1016I/410L haplotype was correlated with permethrin resistance but not with deltamethrin resistance; however, the test power was limited by a low frequency of dead individuals in deltamethrin exposure. Conclusions: Resistance to pyrethroid insecticides is associated with kdr mutant haplotypes, while the absence of substantial resistance to malathion suggests that it remains a viable option for dengue vector control in Ouagadougou. [ABSTRACT FROM AUTHOR]

Malathion is one of the most well-known pesticides which is widely used for controlling insects and pests. Slow degradation and extensive and/or inappropriate use of malathion have resulted in the contamination of the environment inflicting hazardous damages to the ecosystems and human health. This systematic study along with meta-analysis is aimed at reviewing a vast number of reports on the application of the above-mentioned methods used for the extraction and detection of malathion in a wide variety of samples. Initially, the relevant articles over the last decade (2011-2020) were selected for the meta-analysis and subsequently systematically reviewed. The major key points of each article were extracted by a predefined data template. In addition, the statistical analyses were performed by the R software. Following a thorough screening, 812 articles were found to be suitable. Of which, 68 were finally selected which met the required quantitative criteria for the meta-analysis. Meta-analysis was conducted by the random-effects model with a high heterogeneity (I2 = 99.99%). The pooled results on the selected articles revealed that the solid phase-based methods in combination with gas chromatography-mass spectroscopy (GC-MS) have gained lots of interest among the researchers. Within the mentioned articles, the respective recoveries, LODs and LOQs were reported to fall in the range of 95.43-139%, 0.000026-100 µg/l, 0.000078-300 µg/l and 97.20-136%, 0.00001-1.3 µg/g, 0.00005-4.2 µg/g for the aqueous and solid matrices. The results also revealed that the maximum recovery was affiliated to the SPE method (139%) for the aqueous matrices, while the corresponding value for the solid matrices was 134%. According to the pooled data, the mean recoveries varied in the ranges of 92.11-102.50 % and 92.21-102.91% in the aqueous and solid matrices, respectively. The maximum recovery of malathion was assigned to the extraction by SPE (101.46%, 95% CI= 94.66-108.27). [ABSTRACT FROM AUTHOR]

An electrochemical sensor based on polyaniline‐ZnO−NiO (PANI‐ZnO−NiO) nanocomposite was developed for the non‐enzymatic detection of malathion. The structure, surface morphology, and optical properties of the as‐prepared nanocomposite were studied by XRD, FTIR, SEM, and UV‐Vis spectroscopy. The electrochemical behavior of the nanocomposite based sensor was first evaluated through cyclic voltammetry (CV). Under optimum conditions, differential pulse voltammetry (DPV) was further utilized for malathion detection, which proved the PANI‐ZnO−NiO/GCE electrode as an effective electrochemical sensor. The developed electrochemical sensor showed a low detection limit of 1.0×10−8 M with a wider linear range of 10 to 70 nM for malathion. [ABSTRACT FROM AUTHOR]

Background: Unintentional exposure to pesticides can occur during an occupational or non-occupational situation. Occupational exposures in Texas are reported by law. In contrast, non-occupational exposures are sometimes overlooked, and very little information on these exposures is available. This study describes the magnitude and characteristics of acute non-occupational pesticide exposures reported in Texas during 2015-2021. Methods: Data were obtained from the Texas Department of Agriculture's internal database to establish geographic and temporal distributions of the cases. Cases were classified based on the strength of evidence following Centers for Disease Control and Prevention (CDC) guidelines. Descriptive statistics were used to characterize the attributes of the reported cases and the reported health effects. Results: A total of 313 non-occupational pesticide exposure incidents were identified; 228 cases had enough strength of evidence to support an association between exposure and the health effects. Insecticides were the type of pesticide with the most reports (50.4%, n=115). Cameron and Hidalgo counties had the highest incidences of pesticide exposure cases, 0.58 and 0.48 per 100,000 population, respectively, and among these counties, malathion was the active ingredient with the most reports. However, overall, naphthalene was the most reported active ingredient, involved in 12.3% (n=28) of the incidents. Most of the cases were classified as low illness severity (82.9%, n=189), with headaches, eye irritation, and dyspnea being the most reported symptoms, and only 21% (n=49) of the people exposed seeking medical attention after the incidents. Conclusions: Texas had a low incidence (0.16 per 100,000 population) of acute nonoccupational pesticide exposure cases during 2015-2021. Incidence of exposures was three times higher for residents of Cameron and Hidalgo counties, compared with the incidence for the entire state from 2015-2021. Findings of this study highlight areas where interventions could be focused to reduce pesticide exposure. [ABSTRACT FROM AUTHOR]

The evidence supporting the biological plausibility of the association of permethrin and malathion with hematological cancer is limited and contradictory; thus, further studies are needed. This study aimed to investigate whether in vitro exposure to 0.1 μM permethrin and malathion at 0, 24, 48 and 72 h after cell culture initiation induced changes in the gene expression and DNA methylation in mononuclear cells from bone marrow and peripheral blood (BMMCs, PBMCs). Both pesticides induced several gene expression modifications in both tissues. Through gene ontology analysis, we found that permethrin deregulates ion channels in PBMCs and BMMCs and that malathion alters genes coding proteins with nucleic acid binding capacity, which was also observed in PBMCs exposed to permethrin. Additionally, we found that both insecticides deregulate genes coding proteins with chemotaxis functions, ion channels, and cytokines. Several genes deregulated in this study are potentially associated with cancer onset and development, and some of them have been reported to be deregulated in hematological cancer. We found that permethrin does not induce DNA hypermethylation but can induce hypomethylation, and that malathion generated both types of events. Our results suggest that these pesticides have the potential to modify gene expression through changes in promoter DNA methylation and potentially through other mechanisms that should be investigated. [ABSTRACT FROM AUTHOR]

As an abundant source of antioxidants and diet flavor enhancers, the plant essential oils can have positive effects on fish growth, and resistance against environmental stressors. In this study, garden thyme (Thymus vulgaris) essential oil (TEO) was used in the diet of rainbow trout, Oncorhynchus mykiss, to evaluate its protective effect against malathion pesticide exposure. Tested fish (19.99±0.01 g) were divided into six groups (three replicates), namely: T1: control diet; T2: control diet + 0.025 mg L−1 malathion; T3: control diet + 0.075 mg L−1 malathion; T4: control diet + 1% TEO; T5: control diet + 0.025 mg L−1 malathion + 1% TEO and T6: control diet + 0.075 mg L−1 malathion + 1% TEO. After 21 days, T4 fish had the highest final body weight (FW), weight gain (WG), specific growth rate (SGR), and the lowest feed conversion ratio (FCR) among experimental treatments (P<0.05). The blood parameters including the red blood cells (RBC), white blood cell count (WBC), hematocrit (Hct), and hemoglobin (Hb) values were the highest in T4 treatment, displaying a significant difference with T1 treatment (P<0.05). Fish in the T4 groups had the highest total protein (TP) and albumin (ALB), while fish of T3 showed the lowest levels of these parameters (P<0.05) and also had the highest level of triglycerides (TRG), cholesterol (CHOL), lactate dehydrogenase (LDH), and urea (Ur). Alanine aminotransferase (ALT), aspartate aminotransferase (AST), and alkaline phosphatase (ALP) enzymes recorded the lowest levels in T4 treatment, which showed a significant difference with T1 group. The catalase (CAT) and superoxide dismutase (SOD) showed the highest activities in T4 treatment, while the lowest SOD and the highest malondialdehyde (MDA) levels occurred in T3 group (P<0.05). Total immunoglobulin (total Ig) level, alternative complement (ACH50) and lysozyme in the serum and skin mucus of T4 treatment of rainbow trout showed the highest activities with a significant difference from groups (P<0.05). From the results of the present study, it can be concluded that 1% of T. vulgaris as a supplement to the diet of rainbow trout can stimulate and improve the immune system of the fish. TEO can have a protective effect against unfavorable effects of malathion and improves the growth of the fish. [ABSTRACT FROM AUTHOR]

Background: Metabolic detoxification is one of the major mechanisms contributing to the development of resistance in mosquitoes, including the southern house mosquito, Culex quinquefasciatus. The three major detoxification supergene families, cytochrome P450s, glutathione S-transferases and general esterases, have been demonstrated to play an important role in metabolic resistance. In this study, we performed differential gene expression analysis based on high-throughput transcriptome sequencing on samples from four experimental groups to give insight into key genes involved in metabolic resistance to malathion in Cx. quinquefasciatus. We conducted a whole transcriptome analysis of field captured wild Cx. quinquefasciatus from Harris County (WI), Texas and a malathion susceptible laboratory-maintained Sebring colony (CO) to investigate metabolic insecticide resistance. Field captured mosquitoes were also phenotypically classified into the malathion resistant and malathion susceptible groups following a mortality response measure conducted using a Centers for Disease Control and Prevention (CDC) bottle assay. The live (MR) and dead (MS) specimens from the bottle assay, along with an unselected WI sample and a CO sample were processed for total RNA extraction and subjected to whole-transcriptome sequencing. Results: We demonstrated that the genes coding for detoxification enzymes, particularly cytochrome P450s, were highly up-regulated in the MR group compared to the MS group with similar up-regulation observed in the WI group compared to the CO group. A total of 1,438 genes were differentially expressed in comparison between MR and MS group, including 614 up-regulated genes and 824 down-regulated genes. Additionally, 1,871 genes were differentially expressed in comparison between WI and CO group, including 1,083 up-regulated genes and 788 down-regulated genes. Further analysis on differentially expressed genes from three major detoxification supergene families in both comparisons resulted in 16 detoxification genes as candidates potentially associated with metabolic resistance to malathion. Knockdown of CYP325BC1 and CYP9M12 using RNA interference on the laboratory-maintained Sebring strain significantly increased the mortality of Cx. quinquefasciatus after exposure to malathion. Conclusion: We generated substantial transcriptomic evidence on metabolic detoxification of malathion in Cx. quinquefasciatus. We also validated the functional roles of two candidate P450 genes identified through DGE analysis. Our results are the first to demonstrate that knockdown of CYP325BC1 and CYP9M12 both significantly increased malathion susceptibility in Cx. quinquefasciatus, indicating involvement of these two genes in metabolic resistance to malathion. [ABSTRACT FROM AUTHOR]

Simple Summary: Due to the global increase in pesticide applications, aquatic animals are constantly subjected to their action in natural reservoirs. Terbuthylazine and malathion, two commonly detected pesticides in water and soil samples elsewhere, have been shown to have a significant negative impact on zebrafish, even at environmentally realistic concentrations. They can induce oxidative stress, mitochondrial and lysosomal destabilization, leading to immune toxicity, cytotoxicity, and DNA damage. All of these adverse outcomes might severely impact the health status of fish before being translated into an effect on the population. The present study should emphasize the importance of paying attention to pesticide traces in the environment, which can have devastating effects on biota even at low concentrations. Our research sought to determine the molecular and biochemical effects of environmentally relevant exposure to commonly used chloro-s-triazine herbicide terbuthylazine and organophosphate insecticide malathion on zebrafish. To this aim, mature zebrafish were exposed to 2 and 30 µg L−1 terbuthylazine and 5 and 50 µg L−1 malathion alone and in combination for 14 days. Aside from the accumulation of TBARS and protein carbonyls, a decrease in antioxidants and succinate dehydrogenase activity, an increase in oxidized glutathione, and enhanced apoptosis via Caspase-3 and BAX overexpression were observed. Furthermore, terbuthylazine and malathion induced mitochondrial swelling (up to 210% after single exposure and up to 470% after co-exposure) and lactate dehydrogenase leakage (up to 268% after single exposure and up to 570% after co-exposure) in a concentration-dependent manner. Significant upregulation of ubiquitin expression and increased cathepsin D activity were characteristics that appeared only upon terbuthylazine exposure, whereas the induction of IgM was identified as the specific characteristic of malathion toxicity. Meanwhile, no alterations in the zebrafish hypothalamic-pituitary-thyroid axis was observed. Co-exposure increased the adverse effects of individual pesticides on zebrafish. This study should improve the understanding of the mechanisms of pesticide toxicity that lead to fish impairment and biodiversity decline. [ABSTRACT FROM AUTHOR]

Introduction: Malathion (MAL), a kind of organophosphate pesticide (OPs), is one of the oldest phosphoric pesticides used for both domestic and commercial agricultural purposes. However, it possesses adverse effects and organ-specific toxicity for the heart, kidney, and other vertebrate organs. The exact effects of the short-term toxicity of MAL on lipid peroxidation, antioxidant activity, and pro-inflammatory cytokines have not been sufficiently elucidated yet. Methods: We evaluated lipid peroxidation (MDA level), antioxidant activity [superoxide dismutase (SOD) and catalase (CAT)], tumor necrosis factor alpha (TNF-α), and Interleukin-1 beta (IL-1β) in different tissues of MAL-treated Wistar rats, at doses of 50, 100, and 200 mg/kg. Results: After 14 days of exposure, CAT and SOD activities and MDA level increased in most tissues. Based on the histopathological results, the liver, kidney, and heart were the most affected, while the testes and lungs showed no damage. Also, increased TNF-α was measured as an inflammatory cytokine compared to untreated rats. IL-1β levels showed a dual response to the toxic effects of MAL, such as an increase in testis, kidney, and lung tissues and reduced in liver, heart, and blood tissues. Conclusion: The present findings reinforce the concept that MAL can cause tissue-specific damage while enhancing the activity of antioxidant enzymes and reducing cytokine levels. [ABSTRACT FROM AUTHOR]

En Nayarit, México, desde el 2003 se ha aplicado malatión dentro de las acciones del manejo integrado de plagas para controlar a las moscas de la fruta del género Anastrepha, lo que hace necesario conocer el estado de susceptibilidad intrínseca de estos insectos al insecticida. Se probó la susceptibilidad de hembras, machos, y la combinatoria 50:50 hembras/machos de Anastrepha obliqua (Macquart) sin presión de selección por cuatro años. La menor susceptibilidad fue a 1,000 y 10,000 mg de malatión por litro, siendo más susceptibles las hembras que los machos, y la combinatoria de hembras/machos 50:50. Los datos obtenidos pueden funcionar como comparativo en ensayos de susceptibilidad de especímenes a los que actualmente se les ha manejado con concentraciones aproximadas de malatión de 8,300 ppm en el campo. At Nayarit, Mexico, since 2003 malathion has been applied in integrated pest management to control Anastrepha flies. It is necessary to know the susceptibility of these pests to the insecticide. We tested Anastrepha obliqua (Macquart) females, males, and 50:50 female/males that had selection pressure from this insecticide. The lower susceptibility was 1,000 and 10,000 mg of malathion per liter. The females were more susceptible than males or the 50:50 combination. These data are comparative for susceptibility tests of field specimens sprayed with 8,300 ppm of malathion. [ABSTRACT FROM AUTHOR]

Pesticide use is indispensable for combating diseases occurring during olive cultivation. However, this has led to challenges of pesticide residues in consumer products as a result of pesticide application errors and the methods used during processing and preservation. This work aimed to identify the effects of table olive processing and preservation techniques on the concentrations of malathion and its degradation product malaoxon. For this purpose, olive trees in an experimental olive orchard were sprayed homogeneously with malathion at a dose of 975 mg L−1 and processed as (i) vacuum-packed, (ii) alkali treated and (iii) directly brined for natural fermentation. The changes in microbial growth, pH-acidity and pesticide (malathion and malaoxon) concentrations were monitored regularly during the experiment. Lactic acid bacteria, yeast and mould growth were not detected in any of the treatments. Mesophilic aerobic bacteria and enterobacteria were the dominant microbial groups in all non-sprayed treatments, but no enterobacteria growth was detected in sprayed treatments. Lower pH values were observed in the brines of natural fermentation treatments of both sprayed and non-sprayed olives. The independent effects of time and processing method and their interactions on malathion and malaoxon concentrations were found significant (p <.05). During the experiments, the highest reduction in malathion concentration was observed in alkali treated samples (95–99%), followed by naturally fermented (77–88%) and vacuum-packed samples (74–76%). Processing factors for all treatments were lower than 1. [ABSTRACT FROM AUTHOR]

This is the first description of OP-induced behavioural alterations for juvenile P. dentata Aggression and inactivity were induced by the OPs The insecticides reduced feeding (e.g. eating) in exposed crabs Impacts were also associated with vulnerability and hampered survivorship Behavioural alterations induced by xenobiotics, like pesticides, have not been assessed for many Neotropical crab species. This study sought to evaluate such effects on juvenile Poppiana dentata, exposed to two organophosphate (OP) pesticides under laboratory conditions. Treatments involved a control, solvent control (xylene), malathion and diazinon commercial insecticides, with the OPs administered in three logarithmically increasing concentrations of 0.1, 1 and 10 µg/L. A pre-established ethogram was used to document behavioural acts for treatments; foraging, eating, grooming, locomotion, quiescence (inactive), prolonged agonism, non-agonistic contact and moulting. Each treatment cohort was continuously recorded over a 72 hr period. The time durations for each act were determined from the video footage (n = 2,304 hr) and used to determine time spent on each behavioural act, over a 24 hr time period. Time spent by OP-exposed crabs on each act differed significantly from those of the controls. Diazinon-exposed crabs spent most of their daily time in heightened agonistic behaviour (43.4–71.6%). Malathion-exposed crabs spent the majority of their time being inactive (46.7–79.0%) and xylene-exposed crabs exhibited similar behavioural alterations of heightened aggression (53.6%) and inactivity (39.3%). OP-induced changes in essential behaviours of juvenile P. dentata can increase vulnerability, hamper survival and increase risk to predators via impaired locomotion, induced inactivity and limited energy availability, through reduced food intake. These findings provide a better understanding of OP-induced behavioural alterations in juvenile P. dentata and the long-term consequences for essential processes like growth, reproduction and survival. [ABSTRACT FROM AUTHOR]

The desert locust upsurge in the Horn of Africa over 2019–2021 led to a total of 1.6 million ha being treated with broad-spectrum organophosphate and pyrethroid insecticides in Ethiopia and Kenya, while insect growth regulators and the entomopathogenic fungus Metarhizium acridum were applied in Somalia. Environmental monitoring was largely absent, with limited surveys conducted in Kenya and Ethiopia. Overdosing of fenitrothion of a 960 g/L formulation in Kenya led to non-target mortality, including birds and honeybees. In Ethiopia, chlorpyrifos and malathion applications coincided with a honey production decline of 78% in 2020 compared to pre-upsurge levels. The use of M. acridum on nearly 253,000 ha was a breakaway from previous campaigns, in which its successful application in Somalia against both hopper bands and swarms shows that the persistent and pervasive use of organophosphate insecticides can no longer be justified. Furthermore, future procurement of organophosphate insecticides and possibly insect growth regulators could become increasingly problematic due to measures enacted by the European Union. It is recommended that the complementary impact of M. acridum and bird predation on locusts should be considered in an integrated management approach for both swarm and hopper control. [ABSTRACT FROM AUTHOR]

The automobile catalytic converter (ACC) contains a huge number of precious metals as catalysts. When an ACC fails to meet standards, it is removed from the exhaust of an automobile but retains some catalytic activity. However, the recovery and/or activation of this waste is a high-cost process and includes several chemical treatments. Catalytic wet air oxidation (CWAO) has been reported as an effective wastewater treatment method. The most important disadvantage of CWAO is cost-nonefficiency. Herein, to overcome these problems, the simple recovery of catalysts from waste ACC for reuse in CWAO was investigated. The optimum conditions of reaction were investigated through response surface methodology (RSM). The optimum removal efficiency was 88% when the reaction conditions were set on the 20 bar of pressure at 111.5 °C over 77 min and using 0.41 g of recovered catalyst. In addition, toxicity testing was performed on a model of malathion-contaminated wastewater before and after CWAO treatment. Final product identification was performed which showed that CWAO eliminated the toxicity of wastewater and was determined to be malaoxon, present at acceptable concentrations, and tributyl phosphate. In conclusion, there may be important potential for the use of recovered ACC catalyst in the treatment of toxic wastewater. [Display omitted] • A UACC was used as catalyst in wet air oxidation. • Catalyst was simply recovered through a simple grounding and washing. • The WACC is able to remove malathion from aqueous solution through the CWAO. • Malathion completely was degraded and non-toxic intermediates were generated. [ABSTRACT FROM AUTHOR]