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Introduction: Currently, although there have been a few reports on the endocrine-disrupting effects of neonicotinoids, the effect on Chironomidae during long-term exposure remains unknown. Methods: Ecdysis and sex ratio, along with ecdysone-relevant gene expressions of representative neonicotinoid dinotefuran on Chironomus kiinensis were investigated at different environmental concentrations by long-term exposure. Results: A low dose of dinotefuran delayed pupation and emergence via inhibiting ecdysis. Sex ratios of adults shifted toward male-dominated populations with the concentration of dinotefuran increasing. The corresponding transcriptions of ecdysis genes ecr, usp, E74, and hsp70 were significantly downregulated in the midge. For estrogen effects, the vtg gene expression was upregulated, but there was no significant change for the err gene. Discussion: These results would improve our understanding of the endocrine-disrupting mechanisms of neonicotinoid insecticides to Chironomidae and provide data support for assessing their potential environmental risks.
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Chironomidae , Disruptores Endócrinos , Guanidinas , Neonicotinoides , Nitrocompostos , Razão de Masculinidade , Animais , Neonicotinoides/toxicidade , Chironomidae/efeitos dos fármacos , Chironomidae/genética , Chironomidae/metabolismo , Masculino , Nitrocompostos/toxicidade , Disruptores Endócrinos/toxicidade , Feminino , Guanidinas/toxicidade , Muda/efeitos dos fármacos , Inseticidas/toxicidade , Larva/efeitos dos fármacos , Exposição Ambiental/efeitos adversosRESUMO
Pesticide use is a major factor contributing to the global decline in bee populations. Sublethal effects, such as behavior alterations, are neglected in pesticide regulation for pollinators. However, these effects can bring important information to understanding the impacts of pesticides on bees' daily activities. In this study, we aimed to investigate the effects of the insecticide acetamiprid (7 ng/µL) and the fungicide azoxystrobin (10 ng/µL) on the behavior of the Neotropical solitary bee Centris analis. Female and male bees were exposed to these chemicals continuously for 48 h, followed by an additional 48 h without contaminated food, totaling 96 h of observation. We used five experimental groups: control, solvent control, insecticide, fungicide, and pesticide mixture (insecticide + fungicide). Behavioral alterations based on locomotion and light response were assessed by video tracking at 48 (end of pesticide exposure) and 96 h (end of bioassay). In addition, after recording bees at 96 h, the individuals were anesthetized for brain collection and histological evaluation of mushroom bodies to evaluate if pesticides can damage their neurons and impair the cognitive processes and responses of bees to sensory stimuli. Bees exposed to acetamiprid and pesticide mixture showed lethargic movements and impaired locomotion at 48 h. Notably, these behavioral effects were no longer evident after the bees consumed uncontaminated food for an additional 48 h, totaling 96 h from the start of pesticide exposure. Only fungicide exposure did not result in any behavioral or brain histological changes. Therefore, our study showed that acetamiprid at an estimated residual concentration, despite being classified as having low toxicity for bees, can cause significant initial locomotion disruption in solitary bees. These findings highlight the importance of considering sublethal effects in environmental risk assessment.
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Fungicidas Industriais , Inseticidas , Locomoção , Neonicotinoides , Pirimidinas , Estrobilurinas , Animais , Abelhas/efeitos dos fármacos , Abelhas/fisiologia , Neonicotinoides/toxicidade , Estrobilurinas/toxicidade , Fungicidas Industriais/toxicidade , Locomoção/efeitos dos fármacos , Inseticidas/toxicidade , Pirimidinas/toxicidade , Metacrilatos/toxicidade , Masculino , Feminino , Comportamento Animal/efeitos dos fármacosRESUMO
The widespread application of neonicotinoid insecticides (NNIs) has attracted widespread attention to their potential ecotoxicological effects. In this study, we systematically evaluated the toxic effects of thiamethoxam (TMX) and its metabolite clothianidin (CLO) on earthworms (Eisenia fetida). Specifically, the antioxidant system responses and endogenous metabolite metabolism responses in earthworms were analyzed in the temporal dimension after 7, 14, 21 and 28 days of exposure to TMX and CLO. The results found that TMX and CLO could inhibit the growth phenotype of earthworms and cause significant changes in antioxidant system related indicators. More importantly, we found that TMX and CLO could cause significant changes in the metabolic profiles of earthworms through NMR-based metabolomics. From the changes in endogenous metabolites, the toxicity effects of TMX on earthworms gradually increases with prolonged exposure time. Differently, the toxicity effects of CLO on earthworms is significantly higher than that of TMX in the early stages of exposure. Meanwhile, these impacts will not weaken with prolonged exposure time. Furthermore, the results of KEGG enrichment pathway analysis indicated that TMX and CLO could significantly interfere with energy homeostasis, redox homeostasis, osmotic regulation, amino acid metabolism and protein synthesis in earthworms. These findings further deepen our understanding of the ecotoxicological effects of NNIs on soil organism.
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Guanidinas , Inseticidas , Neonicotinoides , Oligoquetos , Tiametoxam , Tiazóis , Oligoquetos/efeitos dos fármacos , Oligoquetos/metabolismo , Animais , Tiametoxam/toxicidade , Neonicotinoides/toxicidade , Tiazóis/toxicidade , Guanidinas/toxicidade , Inseticidas/toxicidade , Nitrocompostos/toxicidade , Oxazinas/toxicidade , Antioxidantes/metabolismo , MetabolômicaRESUMO
Controlling crop pests while conserving pollinators is challenging, particularly when prophylactically applying broad-spectrum, systemic insecticides such as neonicotinoids. Systemic insecticides are often used in conventional agriculture in commercial settings, but the conditions that optimally balance pest management and pollination are poorly understood. We investigated how insecticide application strategies control pests and expose pollinators to insecticides with an observational study of cucurbit crops in the Midwestern United States. To define the window of protection and potential pollinator exposure resulting from alternative insecticide application strategies, we surveyed 62 farms cultivating cucumber, watermelon, or pumpkin across 2 yr. We evaluated insecticide regimes, abundance of striped and spotted cucumber beetles (Acalymma vittatum [Fabricius] and Diabrotica undecimpunctata Mannerheim), and insecticide residues in leaves, pollen, and nectar. We found that growers used neonicotinoids (thiamethoxam and imidacloprid) at planting in all cucumber and pumpkin and approximately half of watermelon farms. In cucumber, foliar thiamethoxam levels were orders of magnitude higher than the other crops, excluding nearly all beetles from fields. In watermelon and pumpkin, neonicotinoids applied at planting resulted in 4-8 wk of protection before beetle populations increased. Floral insecticide concentrations correlated strongly with foliar concentrations across all crops, resulting in high potential exposure to pollinators in cucumber and low-moderate exposure in pumpkin and watermelon. Thus, the highest-input insecticide regimes maintained cucumber beetles far below economic thresholds while also exposing pollinators to the highest pollen and nectar insecticide concentrations. In cucurbits, reducing pesticide inputs will likely better balance crop protection and pollination, reduce costs, and improve yields.
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The silverleaf whitefly, Bemisia tabaci Gennadius (Hemiptera: Aleyrodidae), is a significant agricultural pest worldwide, impacting a variety of crop yields. Since the introduction of B. tabaci Mediterranean (MED) species in Brazil, limited research has measured the relative efficacy of the primary insecticides used in whitefly management. This study evaluated the susceptibility of three distinct B. tabaci MED populations to 11 insecticide active ingredients and characterized the bacterial endosymbionts within each population. The insecticides tested were acetamiprid, bifenthrin, cyantraniliprole, diafenthiuron, spiromesifen, imidacloprid, pymetrozine, pyriproxyfen, sulfoxaflor, and thiamethoxam. Results showed varying LC50 and LC90 values among tested insecticides and populations. Notably, populations varied in response to imidacloprid and thiamethoxam with some populations having a 6× higher tolerance. Sequencing data of endosymbionts revealed that individuals from the most susceptible B. tabaci population harbored Rickettsia and Arsenophonus, whereas these bacteria were not detected in the resistant populations. These findings highlight the need for frequent insecticide toxicity bioassays of distinct B. tabaci populations and the adoption of integrated pest management strategies to preserve the efficacy of insecticides for B. tabaci control. Additionally, the role of infection by endosymbionts to alter susceptibility should be further explored.
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Neonicotinoids (NEOs), despite their widespread use as insecticides, exhibit a notable knowledge deficit in regards to their presence in wastewater treatment plants (WWTPs) and their surrounding environments. This study delves into the presence and disposition of 5 NEOs: Thiamethoxam (THM), Clothianidin (CLO), Imidacloprid (IMD), Acetamiprid (ACE), and Thiacloprid (THA) across 3 domestic WWTPs and their receiving waters. Notably, THM, CLO, and ACE were consistently detected in all water and sludge samples, with THM emerging as the most abundant compound in both influent and effluent. Among the 3 WWTPs, WWTP 2, employing a fine bubble oxidation process, achieved the highest removal efficiency, surpassing 68%, in contrast to WWTP 1 (CAST) at 37% and WWTP 3 (A/A/O) at 7%. Biodegradation played a pivotal role in NEO removal, accounting for 36.7% and 68.2% of the total removal in WWTP 1 and WWTP 2, respectively. Surprisingly, in WWTP 3, biotransformation process inadvertently increased ACE and CLO concentrations by approximately 4.1% and 4.5%, respectively. The total NEO concentration in the receiving surface waters ranged from 72.7 to 155.5 ng/L, while sediment concentrations were significantly lower, spanning between 0.10 and 1.53 ng/g. WWTPs serve as both a removal and concentration point for NEOs, thereby significantly influencing their transportation. Additionally, the concentration of most NEOs in the receiving waters progressively increased from upstream to downstream, highlighting the substantial impact of WWTP discharges on natural water environments. This research offers valuable insights into NEO pollution surrounding WWTPs in the Pearl River Delta, ultimately aiding in pollution control and environmental protection decisions.
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There is growing concern that some managed and wild insect pollinator populations are in decline, potentially threatening biodiversity and sustainable food production on a global scale. In recent years, there has been increasing evidence that sub-lethal exposure to neurotoxic, neonicotinoid pesticides can negatively affect pollinator immunocompetence and could amplify the effects of diseases, likely contributing to pollinator declines. However, a direct pathway connecting neonicotinoids and immune functions remains elusive. In this study we show that haemocytes and non-neural tissues of the honeybee Apis mellifera express the building blocks of the nicotinic acetylcholine receptors that are the target of neonicotinoids. In addition, we demonstrate that the haemocytes, which form the cellular arm of the innate immune system, actively express choline acetyltransferase, a key enzyme necessary to synthesize acetylcholine. In a last step, we show that the expression of this key enzyme is affected by field-realistic doses of clothianidin, a widely used neonicotinoid. These results support a potential mechanistic framework to explain the effects of sub-lethal doses of neonicotinoids on the immune function of pollinators.
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Acetilcolina , Guanidinas , Hemócitos , Inseticidas , Neonicotinoides , Animais , Abelhas/efeitos dos fármacos , Abelhas/imunologia , Inseticidas/toxicidade , Neonicotinoides/toxicidade , Acetilcolina/metabolismo , Hemócitos/efeitos dos fármacos , Hemócitos/imunologia , Hemócitos/metabolismo , Guanidinas/toxicidade , Tiazóis , Receptores Nicotínicos/metabolismo , Receptores Nicotínicos/efeitos dos fármacos , Colina O-Acetiltransferase/metabolismoRESUMO
Neonicotinoid insecticides (NEOs) are a widely used type of insecticide found globally, leading to broad human exposure. However, there is limited research on how internal exposure levels of NEOs and their metabolites impact in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) outcomes. A study was conducted at the Sixth Affiliated Hospital of Sun Yat-sen University between 2017 and 2020 involving 436 women undergoing IVF/ICSI treatment. Data on demographics and clinical history were collected from medical records. The concentrations of 11 NEOs and 4 NEO metabolites in follicular fluid and serum were measured using a salting-out assisted liquid-liquid extraction method and liquid chromatography-tandem mass spectrometry. Our findings indicated that NEOs were prevalent in women with infertility. One NEO metabolite, N-dm-ACE, was detected in all samples with median concentrations of 0.221 ng/mL in follicular fluid and 0.228 ng/mL in serum. The study showed a decrease in the number of retrieved oocytes, mature oocytes, 2 PN zygotes, and high-quality embryos as the number of exposed NEOs in follicular fluid increased. Women in the highest tertile of N-dm-ACE exposure had fewer mature oocytes, 2 PN zygotes, and lower oocyte maturity rates compared to those in the lowest tertile. The findings suggest that exposure to NEOs may negatively impact reproductive outcomes in IVF/ICSI pregnancies, particularly affecting oocyte retrieval and embryo quality. This study highlights the potential adverse effects of environmental NEO exposure on IVF/ICSI outcomes, emphasizing the importance of considering such exposures in preconception care.
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Neonicotinoid insecticides (NNIs) are extensively utilized globally because of their efficient and broad-spectrum properties. However, their residues are also extensively distributed in the environment. Herein, MIL-101-SO3Na with abundant -NH- and sulfonate groups was synthesized via chloromethylation and nucleophilic substitution postmodification strategies and used to extract NNIs via solid-phase extraction. MIL-101-SO3Na was enhanced by introducing C-H···N hydrogen bonds to strengthen interaction forces and -SO3Na groups to adjust surface charge and enhance electrostatic attraction. This modification and the substantial specific surface area (998 m2·g-1) of the metal-organic framework markedly enhanced the enrichment efficiency of MIL-101. The proposed method based on MIL-101-SO3Na exhibited a minimal detection threshold (0.04-0.87 ng·L-1), an extensive linear spectrum (1-2000 ng·L-1), and notable accuracy (a variation of 3.02-11.8%) in water and drink samples. NNI concentrations between 0.25 and 24.2 ng·L-1 in fruit juice and tea samples were accurately identified using the proposed method, demonstrating its feasibility in practical applications. The postmodification of MIL-101-SO3Na is an exceptional and promising approach for the sensitive detection of ultratrace NNI levels in complex matrices.
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Microbial degradation is acknowledged as a viable and eco-friendly approach for diminishing residues of neonicotinoid insecticides. This study reports the dominant strain of Md2 that degrades acetamiprid was screened from soil and identified as Aspergillus heterochromaticus, and the optimal degradation conditions were determined. Research indicated that the degradation of Md2 to 100 mg/L acetamiprid was 55.30%. Toxicological analyses of acetamiprid and its metabolites subsequently revealed that acetamiprid and its metabolites inhibited the germination of cabbage seed, inhibited the growth of Escherichia coli, and induced the production of micronuclei in the root tip cells of faba beans. Based on the analysis of metabolic pathways, it has been determined that the primary metabolic routes of acetamiprid include N-demethylation to form IM-2-1 and oxidative cleavage of the cyanoimino group to produce IM-1-3. Using 16S rRNA high-throughput sequencing, the results showed that acetamiprid and Md2 elevated the relative abundance of Acidithiobacillus, Ascomycetes, and Stramenobacteria, with increases of 10~12%, 6%, and 9%, respectively, while reducing the relative abundance of Acidobacteria, Chlorobacteria, Ascomycetes, and Sporobacteria, with decreases of 15%, 8%, 32%, and 6%, respectively. The findings will facilitate the safety evaluation of the toxicological properties of neonicotinoid insecticides, their biodegradable metabolites, and associated research on their degradation capabilities.
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Plant protection products (PPPs), which are frequently used in agriculture, can be major stressors for honeybees. They have been found abundantly in the beehive, particularly in pollen. Few studies have analysed effects on honeybee larvae, and little is known about effects of insecticide-fungicide-mixtures, although this is a highly realistic exposure scenario. We asked whether the combination of a frequently used insecticide and fungicides would affect developing bees. Honeybee larvae (Apis mellifera carnica) were reared in vitro on larval diets containing different PPPs at two concentrations, derived from residues found in pollen. We used the neonicotinoid acetamiprid, the combined fungicides boscalid/dimoxystrobin and the mixture of all three substances. Mortality was assessed at larval, pupal, and adult stages, and the size and weight of newly emerged bees were measured. The insecticide treatment in higher concentrations significantly reduced larval and adult survival. Interestingly, survival was not affected by the high concentrated insecticide-fungicides-mixture. However, negative synergistic effects on adult survival were caused by the low concentrated insecticide-fungicides-mixture, which had no effect when applied alone. The lower concentrated combined fungicides led to significantly lighter adult bees, although the survival was unaffected. Our results suggest that environmental relevant concentrations can be harmful to honeybees. To fully understand the interaction of different PPPs, more combinations and concentrations should be studied in social and solitary bees with possibly different sensitivities.
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Fungicidas Industriais , Inseticidas , Larva , Neonicotinoides , Animais , Abelhas/efeitos dos fármacos , Abelhas/crescimento & desenvolvimento , Fungicidas Industriais/toxicidade , Neonicotinoides/toxicidade , Larva/efeitos dos fármacos , Larva/crescimento & desenvolvimento , Inseticidas/toxicidade , Inseticidas/farmacologia , Compostos de Bifenilo , Niacinamida/análogos & derivadosRESUMO
Neonicotinoids are ubiquitous in global surface waters and pose a significant risk to aquatic organisms. However, information is lacking on the variations in sensitivity of organisms at different developmental stages to the neurotoxic neonicotinoids. We established a spectrum of toxicity to zebrafish embryos at four neurodevelopmental stages (1, 3, 6, and 8 h post fertilization [hpf]) and dechorionated embryos at 6 hpf based on external and internal exposure to imidacloprid as a representative neonicotinoid. Embryos at the gastrula stage (6 and 8 hpf) were more sensitive to imidacloprid than embryos at earlier developmental stages. Dechorionated embryos were more sensitive to imidacloprid than embryos with a chorion, suggesting that the chorion offers protection against pollutants. Nine sublethal effects were induced by imidacloprid exposure, among which uninflated swim bladder (USB) was the most sensitive. Water depth and air availability in the exposure chambers were critical factors influencing the occurrence of USB in zebrafish larvae. Internal residues of metabolites accounted for <10% of imidacloprid, indicating that imidacloprid was metabolized in a limited fashion in the embryos. In addition, acute toxicity of the main metabolite 5-hydroxy-imidacloprid was significantly lower than that of imidacloprid, indicating that the observed toxicity in embryos exposed to imidacloprid was mainly induced by the parent compound. Our research offers a fresh perspective on choosing the initial exposure time in zebrafish embryo toxicity tests, particularly for neurotoxicants. Environ Toxicol Chem 2024;00:1-11. © 2024 SETAC.
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Novel insecticides were recently introduced to counter pyrethroid resistance threats in African malaria vectors. To prolong their effectiveness, potential cross-resistance from promiscuous pyrethroid metabolic resistance mechanisms must be elucidated. Here, we demonstrate that the duplicated P450s CYP6P9a/-b, proficient pyrethroid metabolizers, reduce neonicotinoid efficacy in Anopheles funestus while enhancing the potency of chlorfenapyr. Transgenic expression of CYP6P9a/-b in Drosophila confirmed that flies expressing both genes were significantly more resistant to neonicotinoids than controls, whereas the contrasting pattern was observed for chlorfenapyr. This result was also confirmed by RNAi knockdown experiments. In vitro expression of recombinant CYP6P9a and metabolism assays established that it significantly depletes both clothianidin and chlorfenapyr, with metabolism of chlorfenapyr producing the insecticidally active intermediate metabolite tralopyril. This study highlights the risk of cross-resistance between pyrethroid and neonicotinoid and reveals that chlorfenapyr-based control interventions such as Interceptor G2 could remain efficient against some P450-based resistant mosquitoes.
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Anopheles , Sistema Enzimático do Citocromo P-450 , Guanidinas , Resistência a Inseticidas , Inseticidas , Malária , Neonicotinoides , Piretrinas , Tiazóis , Animais , Tiazóis/farmacologia , Guanidinas/farmacologia , Resistência a Inseticidas/genética , Anopheles/efeitos dos fármacos , Anopheles/genética , Piretrinas/farmacologia , Piretrinas/metabolismo , Neonicotinoides/farmacologia , Inseticidas/farmacologia , Sistema Enzimático do Citocromo P-450/metabolismo , Sistema Enzimático do Citocromo P-450/genética , Especificidade por Substrato , Mosquitos Vetores/efeitos dos fármacos , Mosquitos Vetores/genética , Proteínas de Insetos/metabolismo , Proteínas de Insetos/genéticaRESUMO
Neonicotinoid pesticides are a relatively new class of pesticides that have garnered significant attention owing to their potential ecological risks to nontarget organisms. A method combining solid phase extraction with liquid chromatography-tandem mass spectrometry (SPE-LC-MS/MS) was developed for the rapid and accurate detection of eight neonicotinoid pesticides (dinotefuran, E-nitenpyram, thiamethoxam, clothianidin, imidacloprid, imidaclothiz, acetamiprid, and thiacloprid) in wastewater. The chromatographic mobile phase and MS parameters were selected, and a single-factor method was used to determine the optimal column type, extraction volume, sample loading speed, and pH for SPE. The optimal parameters were as follows: column type, HLB column (500 mg/6 mL); sample extraction volume, 500 mL; sample loading speed, 10 mL/min; and sample pH, 6-8. The matrix effects of the wastewater samples were reduced by optimizing the chromatographic gradient-elution program, examining the dilution factor of the samples, and using the isotope internal standard calibration method. Prior to analysis, the wastewater samples were diluted 5-fold with ultrapure water for pretreatment. Subsequently, 2 mmol/L ammonium acetate aqueous solution containing 0.1% (v/v) formic acid and methanol was used as mobile phases for gradient elution on a ZORBAX Eclipse Plus C18 column (100 mm×2.1 mm, 1.8 µm). The samples were quantified using positive-ion multiple reaction monitoring (MRM) mode for 10 min. Imidacloprid-d4 was used as the isotope internal standard. The SPE process was further optimized by applying response surface methodology to select the type and mass of rinsing and elution solvents. The optimal pretreatment of the SPE column included rinsing with 10% methanol aqueous solution and elution with methanol-acetonitrile (1â¶1, v/v) mixture (7 mL). The eight neonicotinoid pesticides showed satisfactory linearity within the relevant range, with linear correlation coefficients (r) all greater than 0.9990. The method detection limits (MDLs) ranged from 0.2 to 1.2 ng/L, and the method quantification limits (MQLs) ranged from 0.8 to 4.8 ng/L. The average recoveries of the eight neonicotinoid pesticides were in the range of 82.6%-94.2% at three spiked levels, with relative standard deviations (RSDs) ranging from 3.9% to 9.4%. Finally, the optimized method was successfully applied to analyze wastewater samples collected from four sewage treatment plants. The results indicated that the eight neonicotinoid pesticides could be generally detected at concentrations ranging from not detected (ND) to 256 ng/L. The developed method has a low MDL and high accuracy, rendering it a suitable choice for the trace detection of the eight neonicotinoid pesticides in wastewater when compared with other similar methods. The proposed method can be utilized to monitor the environmental impact and assess the potential risks of neonicotinoid pesticides in wastewater, thus promoting the protection of nontarget organisms and the sustainable use of these pesticides in agriculture.
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Neonicotinoides , Nitrocompostos , Extração em Fase Sólida , Espectrometria de Massas em Tandem , Águas Residuárias , Poluentes Químicos da Água , Espectrometria de Massas em Tandem/métodos , Extração em Fase Sólida/métodos , Águas Residuárias/química , Águas Residuárias/análise , Neonicotinoides/análise , Poluentes Químicos da Água/análise , Cromatografia Líquida/métodos , Nitrocompostos/análise , Tiametoxam/análise , Guanidinas/análise , Tiazóis/análise , Praguicidas/análise , Tiazinas/análise , Oxazinas/análiseRESUMO
Although the potential effects of neonicotinoids (NEOs) in early life have received considerable attention, data on the exposure of mothers and infants to NEOs are scarce. In this study, four parent NEOs and one metabolite were widely detected in paired maternal serum (MS), umbilical cord serum (UCS) and breast milk (BM) samples, with median total NEO concentrations (ΣNEOs) of 113, 160 and 69 ng/L, respectively. Decreasing trends were observed for N-desmethyl-acetamiprid (30 %/year), acetamiprid (22 %/year) and ΣNEOs (15 %/year) in breast milk between 2014 and 2022, whereas increasing trends were seen for clothianidin (17 %/year) and thiamethoxam (30 %/year). N-desmethyl-acetamiprid was the predominant compound in all matrices. However, the contributions of N-desmethyl-acetamiprid (35 %) and thiamethoxam (36 %) in breast milk were similar in 2022. Moreover, thiamethoxam has become the predominant contributor to the estimated daily intake of ΣNEOs since 2018, with the highest contribution of 71 % in 2022, suggesting the effects of NEOs continue to evolve and more attention should be paid to the new NEOs. Notably, the correlations and ratios of NEOs between paired UCS and MS were more significant and higher than those between paired BM and MS, respectively, indicating that NEO exposure was largely affected by the prenatal period.
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Leite Humano , Neonicotinoides , Leite Humano/química , Humanos , Neonicotinoides/análise , Feminino , Gravidez , Inseticidas/análise , Exposição Materna/estatística & dados numéricos , Recém-Nascido , Tiametoxam , AdultoRESUMO
As a member of the neonicotinoid group, imidaclothiz has garnered increasing attention due to its possible health risks. This study investigated the metabolism and distribution of imidaclothiz in mice. Seven imidaclothiz metabolites were found, four of which are known, and three are unknown. The metabolic reactions observed were hydroxylation, nitrate ester hydrolysis, methylation, urea formation, and reduction to NO. Precise quantification revealed that after 2 h of oral administration, imidaclothiz rapidly dispersed into various organs and tissues, peaking at 4 h, and was then swiftly eliminated. No propensity for accumulation in the body, particularly in the liver, was observed. Toxicity data from the T.E.S.T prediction indicated that imidaclothiz had moderate toxicity to rats, and a majority of its metabolites were more toxic than the parent compound. These findings complement the existing knowledge of the imidaclothiz environmental fate in mammals and offer a reference point for its application in agriculture and industry.
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Inseticidas , Neonicotinoides , Animais , Camundongos , Inseticidas/metabolismo , Neonicotinoides/metabolismo , Masculino , Fígado/metabolismo , Fígado/efeitos dos fármacos , Ratos , FemininoRESUMO
Bees play a crucial role as pollinating insects in both natural and cultivated areas. However, the use of pesticides, such as thiamethoxam, has been identified as a contributing factor compromising bee health. The current risk assessment primarily relies on the model species Apis mellifera, raising concerns about the applicability of these assessments to other bee groups, including stingless bees. In this study, we investigated the acute toxicity of thiamethoxam on the stingless bee Frieseomelitta varia by determining the average lethal concentration (LC50) and mean lethal time (LT50). Additionally, we evaluated the enzymatic profile of Acetylcholinesterase (AChE), Carboxylesterase-3 (CaE-3), and Glutathione S-Transferase (GST), in the heads and abdomens of F. varia after exposure to thiamethoxam (LC50/10). The LC50 of thiamethoxam was determined to be 0.68 ng ai/µL, and the LT50 values were 37 days for the control group, 25 days at LC50/10, and 27 days at LC50/100. The thiamethoxam significantly decreased the survival time of F. varia. Furthermore, the enzymatic profile exhibited differences in CaE3 activity within one day in the heads and ten days in the abdomen. GST activity showed differences in the abdomen after one and five days of thiamethoxam exposure. These findings suggests that the abdomen is more affected than the head after oral exposure to thiamethoxam. Our study provides evidence of the toxicity of thiamethoxam at both the cellular and organismal levels, reinforcing the need to include non-Apis species in pollinator risk assessments. and provide solid arguments for bee protection.
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Biomarcadores , Glutationa Transferase , Inseticidas , Tiametoxam , Abelhas/efeitos dos fármacos , Abelhas/fisiologia , Animais , Tiametoxam/toxicidade , Biomarcadores/metabolismo , Glutationa Transferase/metabolismo , Inseticidas/toxicidade , Acetilcolinesterase/metabolismo , Dose Letal Mediana , Carboxilesterase/metabolismo , Neonicotinoides/toxicidadeRESUMO
This study analyzed neonicotinoid insecticides (NEOs) and metabolite (m-NEOs) residues in 136 Panax notoginseng samples via ultra-performance liquid chromatography-tandem mass spectrometry. Imidacloprid was the most detected NEO (88.24% of samples), ranging from 1.50 to 2850 µg/kg. To the best of our knowledge, some novel NEOs were detected in P. notoginseng for the first time. NEO clustering patterns varied among plant parts, with higher contamination in leaves and flowers. Fourteen NEO/m-NEOs, including cycloxaprid and acetamiprid, showed site-specific behavior, indicating the possibility of using multiple NEOs simultaneously during planting, resulting in formation of distinct metabolites in different plant parts. Transfer rates in decoction and infusion ranged from 10.06 to 32.33%, reducing residues postprocessing. Dietary risk assessment showed low hazard quotients (HQa: 7.05 × 10-7 to 2.09 × 10-2; HQc: 3.74 × 10-7 to 2.38 × 10-3), but risk-ranking scores indicated potential hazards with imidacloprid and acetamiprid in flowers and leaves. The findings are expected to promote safety assessment and distribution research of NEOs in plants.
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Contaminação de Alimentos , Inseticidas , Neonicotinoides , Panax notoginseng , Resíduos de Praguicidas , Folhas de Planta , Inseticidas/análise , Neonicotinoides/análise , Panax notoginseng/química , Resíduos de Praguicidas/análise , Contaminação de Alimentos/análise , Folhas de Planta/química , Medição de Risco , Espectrometria de Massas em Tandem , Flores/química , Nitrocompostos/análise , Cromatografia Líquida de Alta PressãoRESUMO
The stingless bee Frieseomelitta varia Lepeletier 1836 (Hymenoptera: Apidae) is an essential pollinator in natural and agricultural ecosystems in the Neotropical region. However, these bees may be exposed to pesticides during foraging, which can affect both individuals and their colonies. One example comes from the use of pyraclostrobin (a fungicide) and thiamethoxam (an insecticide) for pest control in pepper crops, which F. varia visits. This study aimed to evaluate the isolated and combined sublethal effects of thiamethoxam (TMX) (0.000543 ng a.i./µL) and pyraclostrobin (PYR) (1.5 ng i.a./µL) on the morphology of the midgut and Malpighian tubules of F. varia workers. Results showed that both pesticides, regardless of the exposure time (through feeding during 48 h or 96 h), disturbed the morphology of the analyzed organs. Specifically, F. varia exposed orally to sublethal concentrations of thiamethoxam and pyraclostrobin, either alone or in combination, exhibited a higher rate of damage to the midgut (e.g., vacuolization, apocrine secretion, and cellular elimination) compared to the bees in the control groups, both after 48 h and 96 h of exposure. In Malpighian tubules, vacuolation is the only damage present. As the observed morphological alterations likely compromise the excretion and absorption functions, exposure to pyraclostrobin and thiamethoxam may lead to disturbances at both the individual and colony levels. These results highlight the urgent need for a future reassessment of the safety of fungicides and insecticides regarding their potential effects on bee populations.
Assuntos
Inseticidas , Túbulos de Malpighi , Estrobilurinas , Tiametoxam , Animais , Abelhas/efeitos dos fármacos , Abelhas/fisiologia , Tiametoxam/toxicidade , Estrobilurinas/toxicidade , Inseticidas/toxicidade , Túbulos de Malpighi/efeitos dos fármacos , Fungicidas Industriais/toxicidade , Neonicotinoides/toxicidade , Nitrocompostos/toxicidadeRESUMO
The toxicity of neonicotinoids and many of their replacement insecticides to nontarget soil invertebrates such as earthworms has previously been established. However, the long-term effects of these substances on these organisms are largely unknown. In the field of soil ecotoxicology, lumbricid earthworms such as Eisenia andrei are used extensively due to the availability of standardized test methods and their adaptability to laboratory culture and testing. Multigenerational studies have gained popularity and attention in recent years, with a shift toward the use of long-term assays and lower concentrations of test chemicals. The use of exposure concentrations that include those measured in a monitoring program carried out by the Government of Ontario presents a realistic exposure scenario that may not show significant effects in contemporary, shorter term studies. We used current standardized test methods as a basis for the development of multigenerational studies on E. andrei. The effects of exposure to a single application of the insecticides thiamethoxam and cyantraniliprole on the survival and reproduction of E. andrei were observed over three (thiamethoxam) or two (cyantraniliprole) generations using consecutive reproduction tests. No significant impacts on adult survival were reported in any generation for either insecticide, whereas reproduction decreased between the first and second generations in the thiamethoxam test, with median effective concentration (EC50) values of 0.022 mg/kg dry weight reported for the first generation compared with 0.002 mg/kg dry weight in the second generation. For cyantraniliprole, an EC50 of 0.064 was determined for the first generation compared with 0.016 mg/kg dry weight in the second generation. A third generation was completed for the thiamethoxam test, and a significant decrease in reproduction was observed in all treatments and controls compared with previous generations. No significant difference between thiamethoxam treatments and the control treatment was reported for the third generation. Collectively, these data indicate that exposure of oligochaetes to these two insecticides at concentrations representative of field conditions may result in long-term stresses. Environ Toxicol Chem 2024;43:2058-2070. © 2024 The Author(s). Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.