Transcriptome analyses in juvenile yellow perch (Perca flavescens) exposed in vivo to clothianidin and chlorantraniliprole: Possible sampling bias.

The St. Lawrence River is an important North American waterway that is subject to anthropogenic pressures including intensive urbanization, and agricultural development. Pesticides are widely used for agricultural activities in fields surrounding the yellow perch (Perca flavescens) habitat in Lake St. Pierre (Quebec, Canada), a fluvial lake of the river where the perch population has collapsed. Clothianidin and chlorantraniliprole were two of the most detected insecticides in surface waters near perch spawning areas. The objectives of the present study were to evaluate the transcriptional and biochemical effects of these two pesticides on juvenile yellow perch exposed for 28d to environmental doses of each compound alone and in a mixture under laboratory/aquaria conditions. Hepatic mRNA-sequencing revealed an effect of chlorantraniliprole alone (37 genes) and combined with clothianidin (251 genes), but no effects of clothianidin alone were observed in perch. Dysregulated genes were mostly related to circadian rhythms and to Ca2+ signaling, the latter effect has been previously associated with chlorantraniliprole mode of action in insects. Moreover, chronic exposure to clothianidin increased the activity of acetylcholinesterase in the brain of exposed fish, suggesting a potential non-target effect of this insecticide. Further analyses of three clock genes by qRT-PCR suggested that part of the observed effects of chlorantraniliprole on the circadian gene regulation of juvenile perch could be the result of time-of-day of sacrifice. These results provide insight into biological effects of insecticides in juvenile perch and highlight the importance of considering the circadian rhythm in experimental design and results analyses.

A dye elution method for the quantification of insecticidal crystal proteins from Bacillus thuringiensis and its compatibility with the presence of agro-industrial raw materials and waste products.

The insecticidal crystal proteins produced by Bacillus thuringiensis during sporulation are active ingredients against lepidopteran, dipteran, and coleopteran insects. Several methods have been reported for their quantification, such as crystal counting, ELISA, and SDS-PAGE/densitometry. One of the major tasks in industrial processes is the analysis of raw material dependency and costs. Thus, the crystal protein quantification method is expected to be compatible with the presence of complex and inexpensive culture medium components. This work presents a revalidated elution-based method for the quantification of insecticidal crystal proteins produced by the native strain B. thuringiensis RT. To quantify proteins, a calibration curve was generated by varying the amount of BSA loaded into SDS-PAGE gels. First, SDS-PAGE was performed for quality control of the bioinsecticide. Then, the stained protein band was excised from 10% polyacrylamide gel and the protein-associated dye was eluted with an alcoholic solution of SDS (3% SDS in 50% isopropanol) during 45 min at 95°C. This protocol was a sensitive procedure to quantify proteins in the range of 2.0-10.0 µg. As proof of concept, proteins of samples obtained from a complex fermented broth were separated by SDS-PAGE. Then, Cry1 and Cry2 proteins were properly quantified.

Exposure of Male Farmers and Nonfarmers to Neonicotinoid Pesticides in the South-West and Littoral Regions of Cameroon: A Comparative Study.

Pesticides, especially the newly developed neonicotinoids, are increasingly used in many countries around the world, including Cameroon, to control pests involved in crop destruction or disease transmission. Unfortunately, the pesticides also pose tremendous environmental problems because a predominant amount of their residues enter environmental matrices to affect other nontargeted species including humans. This therefore calls for continuous biomonitoring of these insecticides in human populations. The present study sought to assess the neonicotinoid insecticide exposures in two agrarian regions of Cameroon, the South-West region and Littoral region. The study involved 188 men, including 125 farmers and 63 nonfarmers. Spot urine samples were obtained from these subjects and subjected to liquid chromatographic-tandem mass spectrometric analysis for concentrations of neonicotinoid compounds, including acetamiprid, clothianidin, dinotefuran, imidacloprid, thiacloprid, nitenpyram, thiamethoxam, and N-dm-acetamiprid. Neonicotinoid compounds were detected in all study participants, and residues of all the screened pesticides were detected among participants. N-dm-Acetamiprid and imidacloprid were the most prevalent among the subjects (100.0% and 93.1%, respectively), whereas nitenpyram was less common (3.2%). The median values of imidacloprid and total urinary neonicotinoid concentrations were elevated among farmers (0.258 vs. 0.126 µg/L and 0.829 vs. 0.312 µg/L, respectively). Altogether the findings showed that both the farmer and nonfarmer study populations of Cameroon were exposed to multiple residues of neonicotinoids, with relatively higher levels of pesticides generally recorded among farmers. Although exposure levels of the neonicotinoids were generally lower than their respective reference doses, these results warrant further research on the health risk evaluation of multiple residues of the pesticides and reinforcement of control measures to minimize the exposure risks, especially among farmers. Environ Toxicol Chem 2024;43:952-964. © 2024 SETAC.

Residual estimation of spirotetramat and its metabolites in chilli and soil by LC-MS/MS.

Two applications of spirotetramat were done to study the dissipation and persistence of spirotetramat and its four different metabolites in chilli and soil at 10 days interval. Total spirotetramat residues were estimated by LC-MS/MS instrument. The mean initial deposits of total spirotetramat after application of spirotetramat 15.31 OD @ 60 (X dose), 75 (1.25 × dose) and 120 (2 × dose) g a.i. ha-1 on green chilli were found to vary from 0.38 to 0.83 mg kg-1 during the initial year. Spirotetramat and its metabolite residues in green chilli were found to be below limit of quantification (0.01 mg kg-1) after 15 days of application. The spirotetramat cis enol (the major metabolite) was formed in both the soil and the plant. The residues of spirotetramat-monohydroxy were below LOQ irrespective of any substrate during the estimation. In soil, the total initial spirotetramat deposits for the 1st year were found 0.09 for X dose, 0.12 for 1.25 × dose and 0.20 mg kg-1 for 2 × dose. After 3 days for both X and 1.25 × doses and 5 days for 2 × dose, the total spirotetramat residues were below LOQ. The spirotetramat's half-life values have been determined to be between 3.19 and 3.93 days and 1.00 and 1.59 days, respectively, in soil and green chilli fruits. One day waiting period is proposed for the safe consumption of green chilli when the spirotetramat was applied irrespective of the dose.

Optimization of an HPLC-MS/MS method to analyze chlordecone in bovine serum and correlations with levels in liver, muscle and fat.

Chlordecone is an organochlorine pesticide used from 1972 to 1993 in the French West Indies. Its extensive use and high persistence in soils induced massive contamination of the environment and of the food chain, especially in cattle through contaminated soil ingestion. To ensure suitability for consumption of bovine meat, monitoring plans are set up based on perirenal fat concentrations after slaughtering. In the present study, we have investigated an in-vivo monitoring approach by measuring chlordecone levels in serum samples. For this purpose, a sensitive high-performance liquid-chromatography-tandem mass spectrometry (HPLC-MS/MS) method following a QuEChERS extraction method was successfully optimized and validated, reaching a limit of quantification of 0.05 ng g-1 fresh weight. This method was applied to 121 serum samples collected from bovines originating from contaminated areas of Martinique and Guadeloupe. Chlordecone was detected in 88% of the samples, and quantified in 77% of the samples, with concentrations ranging from 0.05 to 22 ng g-1. Perirenal fat, liver, and muscle were also sampled on the same animals and the measured concentrations of chlordecone were statistically correlated to the levels determined in serum. Mean concentration ratios of 6.5 for fat/serum, 27.5 for liver/serum, and 3.3 for muscle/serum were calculated, meaning that chlordecone was not only distribute in fat (as expected), muscle and liver, but also in serum. Good correlations were found to allow prediction of chlordecone concentrations in muscle based on concentrations measured in serum. This study opens the door to possible pre-control of bovines before slaughter. In cases of probable non-compliance with maximum residue levels (MRLs), farm management could proceed to allow for depuration under controlled conditions. This would have a strong impact on both economic and food safety management measures.

Neonicotinoid insecticides and metabolites levels in neonatal first urine from southern China: Exploring links to preterm birth.

Neonicotinoids (NEOs) have indeed become the most widely used insecticides worldwide. Concerns have been raised about their potential impact on newborns due to maternal exposure and their unique neurotoxic mode of action. However, it is still poorly understood whether in utero exposure of pregnant women to environmental NEOs and their metabolites can cause carryover effects on vulnerable newborns and subsequent health consequences. In this study, we determined the concentrations of 13 NEOs and their metabolites in the first urine collected from 92 newborns, both preterm and full-term, in southern China during 2020 and 2021. NEOs and their metabolites were identified in 91 urine samples, with over 93% of samples containing a cocktail of these compounds, confirming their maternal-fetal transfer. N-desmethyl-acetamiprid, imidaclothiz, clothianidin and flonicamid were the most commonly detected analytes, with detection frequencies of 59-87% and medians of 0.024-0.291 ng/mL in the urine. The relative abundance of imidaclothiz was significantly higher in preterm newborns, those with head circumferences below 33 cm, birth lengths less than 47 cm, and weights below 2500 g (p < 0.05). When comparing newborns in the 2nd quartile of imidaclothiz concentrations with those in the 1st quartile, we observed a significant increase in the odds of preterm outcomes in the unadjusted model (odds ratio = 3.24, 95% confidence interval = 1.02-10.3). These results suggest that exposure to elevated concentrations of imidaclothiz may be associated with preterm birth.

An integrated approach to assess human health risk of neonicotinoid insecticides in surface water of the Yangtze River Basin, China.

Neonicotinoids are widely used insecticides that have raised considerable concerns for both environmental and human health. However, there lack of comprehensive evaluation of their accumulation in surface water ecosystems and exposure to various human groups. Additionally, there's a distinct lack of scientific evidence describing the carcinogenic and non-carcinogenic impacts of neonicotinoids from surface water. Using an integrated approach employing the Relative Potency Factor (RPF), Hazard Index (HI), and Monte Carlo Simulation (MCS), the study assessed neonicotinoid exposure and risk to four demographic groups via dermal contact and mistaken oral intake pathways in the Yangtze River Basin (YRB), China. Neonicotinoid concentrations range from 0.1 to 408.12 ng/L, indicating potential risk (10-3 to 10-1) across the studied demographic groups. The Incremental Lifetime Cancer Risk (ILCR) for dermal contact was within a moderate range of 2.00 × 10-3 to 1.67 × 10-2, while the mistaken oral intake was also within a moderate range of 3.07 × 10-3 to 7.05 × 10-3. The Hazard Index (HI) for dermal exposure ranged from 1.49 × 10-2 to 0.125, while for mistaken oral intake, it varied between 2.69 × 10-2 and 0.14. The findings highlight the importance of implementing specific interventions to address neonicotinoid exposure, especially among demographic groups that are more susceptible. This research underscores the urgent need for targeted strategies to address neonicotinoid risks to vulnerable populations within the YRB while contributing to insights for effective policies to mitigate neonicotinoid exposure in surface water ecosystems globally.

Actinomycetota, a central constituent microbe during long-term exposure to diazinon, an organophosphorus insecticide.

Microbial biodegradation is a primary pesticide remediation pathway. Despite diazinon is one of the most frequently used organophosphate insecticides worldwide, its effect on soil microbial community remains obscure. We hypothesize that diazinon exposure reshapes microbial community, among them increased microbes may play a crucial role in diazinon degradation. To investigate this, we collected soil from an organic farming environment, introduced diazinon, cultivated it in a greenhouse, and then assessed its effects on soil microbiomes at three distinct time points: 20, 40, and 270 days after treatment (DAT). Results from HPLC showed that the level of diazinon was gradually degraded by 98.8% at 270 DAT when compared with day zero, whereas 16S rRNA gene analysis exhibited a significant reduction in the bacterial diversity, especially at the early two time points, indicating that diazinon may exert selection pressure to the bacteria community. Here, the relative abundance of phylum Actinomycetota increased at 20 and 40 DATs. In addition, the bacterial functional gene profile employing PICRUSt2 prediction also revealed that diazinon exposure induced the genomic function related to xenobiotics biodegradation and metabolism in soil, such as CYB5B, hpaC, acrR, and ppkA. To validate if bacterial function is caused by increased relative abundance in diazinon enriched soil, further bacteria isolation resulted in obtaining 25 diazinon degradation strains out of 103 isolates. Notably, more than 70% (18 out of 25) isolates are identified as phylum Actinomycetota, which empirically confirms and correlates microbiome and PICRUSt2 results. In conclusion, this study provides comprehensive information from microbiome analysis to obtaining several bacteria isolates responsible for diazinon degradation, revealing that the phylum Actinomycetota is as a key taxon that facilitates microbial biodegradation in diazinon spoiled soil. This finding may assist in developing a strategy for microbial detoxification of diazinon, such as using an Actinomycetota rich synthetic community (SynCom).

Spatial distribution of two acaricides and five neonicotinoids in beehives and surrounding environments in China.

Managed bees commonly suffer from cross-contamination with acaricides and neonicotinoids, posing robust threats to bee population health. However, their residual characteristics and spatial distribution in beehives and surrounding environments are poorly understood. This study detected two common acaricides and five neonicotinoids in 240 beehive samples and 44 surrounding environmental samples collected from 25 Chinese provinces. The results showed that 40.0% of the honey samples contained acaricides and 83.1% contained neonicotinoids. Neonicotinoid concentrations in honey were geographically distinguished by the "Hu Huanyong line", and concentrations of neonicotinoids in honey from eastern areas were 2.65-fold higher than those in honey from western areas. Compared to the approved acaricide amitraz, the banned acaricide coumaphos was detected more frequently in honey and was positively correlated with that quantified in the paired pollen samples. Although coumaphos was identified in only three soil samples, lower coumaphos residues in honey might be associated with persistent pollution in the surrounding environment. Conversely, neonicotinoids were detected at higher levels in honey than in the pollen and soil, demonstrating that the neonicotinoid residues in honey have a cumulative effect. This study contributes to a better understanding of the pesticide contamination scenarios that underlie the exposure risks of bees.

Associations of pyrethroid exposure with bone mineral density and osteopenia in adults.

INTRODUCTION: This study was to investigate the correlations between pyrethroid exposure and bone mineral density (BMD) and osteopenia. MATERIALS AND METHODS: This cross-sectional study included 1389 participants over 50 years of age drawn from the 2007-2010 and 2013-2014 National Health and Nutrition Examination Survey (NHANES). Three pyrethroid metabolites, 3-phenoxybenzoic acid (3-PBA), trans-3-(2,2-dichlorovinyl)-2,2-dimethyl-cyclopropane-1-carboxylic acid (trans-DCCA), and 4-fluoro-3-phenoxybenzoic acid (4-F-3PBA) were used as indicators of pyrethroid exposure. Low BMD was defined as T-score < - 1.0, including osteopenia. Weighted multivariable linear regression analysis or logistic regression analysis was utilized to evaluate the correlation between pyrethroid exposure and BMD and low BMD. Bayesian kernel machine regression (BKMR) model was utilized to analyze the correlation between pyrethroids mixed exposure and low BMD. RESULTS: There were 648 (48.41%) patients with low BMD. In individual pyrethroid metabolite analysis, both tertile 2 and tertile 3 of trans-DCCA were negatively related to total femur, femur neck, and total spine BMD [coefficient (ß) = - 0.041 to - 0.028; all P < 0.05]. Both tertile 2 and tertile 3 of 4-F-3PBA were negatively related to total femur BMD (P < 0.05). Only tertile 2 [odds ratio (OR) = 1.63; 95% CI = 1.07, 2.48] and tertile 3 (OR = 1.65; 95% CI = 1.10, 2.50) of trans-DCCA was correlated with an increased risk of low BMD. The BKMR analysis indicated that there was a positive tendency between mixed pyrethroids exposure and low BMD. CONCLUSION: In conclusion, pyrethroids exposure was negatively correlated with BMD levels, and the associations of pyrethroids with BMD and low BMD varied by specific pyrethroids, pyrethroid concentrations, and bone sites.

Microbial-based metabolites associated with degradation of imidacloprid and its impact on stress-responsive proteins.

Imidacloprid (IMD), a neonicotinoid insecticide, is intensively used in agricultural fields for effective protection against aphids, cane beetles, thrips, stink bugs, locusts, etc., is causing serious environmental concerns. In recent years, seed treatment with Imidacloprid is being practiced mainly to prevent sucking insect pests. In India, due to the increase in application of this insecticide residue has been proven to have an impact on the quality of soil and water. In view of this, the current investigation is focussed on sustainable approach to minimize the residual effect of IMD in agricultural fields. The present study reveals a most promising imidacloprid resistant bacterium Lysinibacillus fusiformis IMD-Bio5 strain isolated from insecticide-contaminated soil. The isolated bacterial strain upon tested for its biodegradation potential on mineral salt medium (MSM) showed a significant survival growth at 150 g/L of IMD achieved after 3 days, whereas immobilized cells on MSM amended with 200 g/L of IMD as the sole carbon source provided degradation of 188 and 180 g/L of IMD in silica beads and sponge matrices, respectively. The liquid chromatography mass spectrometry was performed to test the metabolite responsive for IMD biodegradation potential of L. fusiformis IMD-Bio5 which showed the induced activity of the metabolite 6-Chloronicotinic acid. Furthermore, as compared to the untreated control, the Lysinibacillus fusiformis IMD-Bio5 protein profile revealed a range of patterns showing the expression of stress enzymes. Thus, results provided a most effective bacterium enabling the removal of IMD-like hazardous contaminants from the environment, which contributes to better agricultural production and soil quality, while long-term environmental advantages are restored.

Heterologous antigen selection of chicken single-chain variable fragments against thiamethoxam.

Single-chain variable fragments (scFvs) are valuable in the development of immunoassays for pesticide detection. In this study, scFvs specific to thiamethoxam (Thi) were successfully isolated from a library generated by chicken immunization through heterologous coating selection. These scFvs were subsequently expressed with fusion with an Avi tag and alkaline phosphatase. After combination and optimization, a scFv-biotin based enzyme linked immunosorbent assay (ELISA) was developed for the detection of Thi, demonstrating an impressive half-maximum signal inhibition concentration (IC50) of 30 ng mL-1 and a limit of detection (LOD) of 1.8 ng mL-1. The immunoassay exhibited minimal cross-reactivity with other neonicotinoid insecticides, except for 7.5% for imidacloprid and 6.7% for imidaclothiz. The accuracy of the assay was confirmed by testing spiked samples of apple, pear, cabbage, and cucumber, which resulted in average recoveries ranging between 82% and 119%, closely aligning with the results obtained through high-performance liquid chromatography. Therefore, the chicken scFv-biotin based assay showed promise as a high-throughput screening tool for Thi in agricultural samples.

Inverse association between plasma chlordecone concentrations and progression of alcoholic liver fibrosis: the role of liver metabolism.

BACKGROUND AND AIMS: Chlordecone is a persistent organochlorinated insecticide, extensively used in the French West Indies and has been contaminating the population for more than thirty years. Its potentiation effect on hepatotoxic agents has been demonstrated in animal models. We investigated the relationship between environmental exposure to chlordecone and the progression of liver fibrosis. METHODS: This study included 182 consecutive patients with chronic alcoholic hepatitis whose liver fibrosis was assessed using non-invasive methods. Measured plasma chlordecone concentrations at inclusion were used as surrogate of long-term exposure under steady-state conditions. As the pharmacokinetic processing of chlordecone is largely determined by the liver, we used a human physiologically based pharmacokinetic model to predict plausible changes in the steady-state blood chlordecone concentrations induced by liver fibrosis. RESULTS: With a median follow-up of 27.1 years after the onset of alcohol consumption, we found a significant decrease in the risk of advanced liver fibrosis with increasing plasma chlordecone concentration (adjusted hazard ratio = 0.56; 95% confidence interval: 0.34-0.95 for the highest vs. lowest tertile, p = 0.04). Changes induced by liver fibrosis influenced the pharmacokinetic processing of chlordecone, resulting in substantial modifications in its steady-state blood concentrations. CONCLUSION: According to this human model of coexposure to alcohol, reverse causality is the most plausible explanation of this inverse association between plasma chlordecone concentrations and progression of liver fibrosis. This study underlines the importance of considering the pharmacokinetic of environmental contaminants in epidemiological studies when biomarkers of exposure are used to investigate their own impact on the liver. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT03373396.

Neonicotinoid insecticides in waters of the northern Jiangsu segment of the Beijing-Hangzhou Grand Canal: Environmental and health implications.

Neonicotinoid (NEO) insecticides have been frequently detected in natural aquatic environments. Nevertheless, the distribution of NEOs in artificial environments is not clear. The Beijing-Hangzhou Grand Canal is the longest canal in the world. The northern Jiangsu segment of the Grand Canal was selected to study the spatiotemporal variation and source of eight NEOs in the canal water and assess their ecological and health risks. The total NEO concentration in the canal water was 12-289 ng L-1 in the dry season and 18-373 ng L-1 in the wet season, which were within the concentration range in other 11 natural rivers worldwide. The average total NEO concentrations were not statistically different between the seasons; only the concentrations of imidaclothiz, thiacloprid (THI), acetamiprid, and dinotefuran were different. At city scale, the total NEO concentration in the dry season showed a decreasing trend along the water flow from Xuzhou City to Yangzhou City. The total NEO concentrations were found to be positively correlated with the sown area of farm crops and the rural labour force, indicating the agricultural influence on the spatial distribution of NEO concentrations. In the wet season, relatively high NEO concentrations were distributed in downstream sites under the influence of artificial regulation. The primary contributor to the NEO inputs into the canal was the nonpoint source in the dry and wet seasons, with a relative contribution of 68 %. THI, imidacloprid, clothianidin and thiamethoxan would produce chronic ecological risks in both seasons. Further consideration needs to be given to the above four NEOs and NEO mixtures. The human health risks that NEOs posed by drinking water were assessed based on the chronic daily intake (CDI). The maximum CDI for adults and children was lower than the reference doses. This suggested public health would not be at risk from canal water consumption.

Highly Sensitive and Rapid Screening Technique for the Detection of Organophosphate Pesticides and Copper Compounds Using Bifunctional Recombinant TrxA-PvCarE1.

Enabling the detection of organophosphate pesticide (OP) residues through enzyme inhibition-based technology is crucial for ensuring food safety and human health. However, the use of acetylcholinesterase, the primary target enzyme for OPs, isolated from animals in practical production poses challenges in terms of sensitivity and batch stability. To address this issue, we identified a highly sensitive and reproducible biorecognition element, TrxA-PvCarE1, derived from red kidney beans and successfully overexpressed it in Escherichia coli. The resulting recombinant TrxA-PvCarE1 exhibited remarkable sensitivity toward 10 OPs, surpassing that of commercial acetylcholinesterase. Additionally, this approach demonstrated the capability to simultaneously detect copper compounds with high sensitivity, expanding the range of pesticides detectable using the traditional enzyme inhibition method. Spiking recovery tests conducted on cowpea and carrot samples verified the suitability of the TrxA-PvCarE1-based technique for real-life sample analysis. In summary, this study highlights a promising comprehensive candidate for the rapid detection of pesticide residues.

Chemical composition and mosquitocidal properties of essential oil from Indian indigenous plants Ocimum tenuiflorum L. and Ocimum americanum L. against three vector mosquitoes.

Mosquitoes stand out as the most perilous and impactful vectors on a global scale, transmitting a multitude of infectious diseases to both humans and other animals. The primary objective of the current research was to assess the effectiveness of EOs from Ocimum tenuiflorum L. and Ocimum americanum L. in controlling Anopheles stephensi Liston. Culex quinquefasciatus Say and Aedes aegypti L. mosquitoes. The larvae, pupae and eggs of the mosquitoes were exposed to four different concentrations (6.25-50 ppm). The tested EOs resulted in >99-100 % mortality at 120 h for the eggs of all examined mosquito species. It also showed robust larvicidal and pupicidal activity with LC50 and LC90 values of 17-39, 23-60 ppm and 46-220, and 73-412 ppm against Aedes, Culex and Anopheles mosquito species, respectively, at 24 h of treatment. The Suitability Index or Predator Safety Factor demonstrated that the EOs extracted from O. tenuiflorum L. and O. americanum L. did not cause harm to P. reticulata, D. indicus (water bug), G. affinis and nymph (dragonfly). GC-MS analysis identified the major probable constituents of the oil, including Phenol, 2-Methoxy-4-(1-Propenyl)- (28.29 %); 1-Methyl-3-(1'-Methylcyclopropyl) Cyclopentene (46.46 %); (E,E,E)-3,7,11,15-Tetramethylhexadeca-1,3,6,10,14-Pentaene (18.91 %) and 1,3-Isobenzofurandione, 3a,4,7,7a-Tetrahydro-4,7-Dimethyl (33.02 %). These constituents may play a significant role in the mosquitocidal activity of the oil. The same results were identified in the formulation prepared from the EOs. This marks the first report confirming the successful utilization of EOs derived from O. tenuiflorum L. and O. americanum L. in mosquito population control initiatives.

Gold nanoparticle-based selective and efficient spectrophotometric assay for the insecticide methamidophos.

A reliable, rapid, and inexpensive nano-sized chemosensor is presented for methamidophos (MET) - an insecticide. Poly(lactic acid) (PLA)-stabilized gold nanoparticles (AuNPs) were synthesized by a simple one-pot, two-phase chemical reduction method. The synthesized PLA-AuNPs were subsequently employed for selective, efficient, and quantitative detection of MET. MET is one of the highly toxic pesticides used for eradication of agricultural and urban insects. Upon the addition of MET, the wine-red color of PLA-AuNPs swiftly transformed into greyish-blue, further corroborated by a significant bathochromic and hyperchromic shift in the SPR band. The presence of other interfering insecticides, metal salts, and drugs did not have any pronounced effect on quantitative MET detection. The detection limit, the quantification limit, and linear dynamic range of MET utilizing PLA-AuNPs were  0.0027 µM, 0.005 µM, and 0.005-1000 µM, respectively. The PLA-AuNP-based assay renders an efficient, rapid, accurate, and selective quantification of MET in food, biological, and environmental samples. The proposed sensor provides an appropriate platform for fast and on-the-spot determination of MET without requiring a well-equipped lab setup.

Identification of key factors affecting neonicotinoid residues in crops and risk of dietary exposure.

Neonicotinoids, widely used on farmland, are ubiquitous in food; however, their distribution among various crops and associated exposure risks at the provincial level in China remain unclear. We collected 19 types of crop samples (fruits, vegetables, and tea) from farmland in nine prefectural cities in Zhejiang Province, China. We analyzed nine commonly used neonicotinoids in the edible portions of these crops. A notable detection rate (42.1 %-82.9 %) and high residual neonicotinoid concentrations (278 ± 357 ng/g) were observed. Tea exhibited the highest residue, followed by fruits, and vegetables showed the lowest (P < 0.05). Neonicotinoid ratios in crops to soil (R_C/S) and soil to water (R_S/W) were defined to discern insecticide distribution across different environments. Increased water solubility leads to increased migration of neonicotinoids (R_S/W) from agricultural soils to water through runoff, thereby increasing the relative contribution of nitenpyram and dinotefuran in water. In comparison with other studied compounds, all crops demonstrated the strongest soil uptake of thiamethoxam, denoted by the highest R_C/S value. Elevated R_C/S values in tea, pickled cabbage, and celery suggest increased susceptibility of these crops to neonicotinoid absorption from the soil (P < 0.05). Estimated dietary intake for teenagers, adults and elders was 8.9 ± 0.5, 8.9 ± 0.6, and 8.8 ± 0.3 µg/kg/d, respectively, below the reference dose (57 µg/kg/d). Teenagers, compared to adults and elders, exhibited significantly higher neonicotinoid exposure through fruit consumption, emphasizing the need for increased attention to neonicotinoid exposure among vulnerable populations.

Neonicotinoid insecticides in plant-derived Foodstuffs: A review of separation and determination methods based on liquid chromatography.

Neonicotinoids (NEOs) are the most widely used insecticides globally. They can contaminate or migrate into foodstuffs and exert severe neonic toxicity on humans. Therefore, lots of feasible analytical methods were developed to assure food safety. Nevertheless, there is a lack of evaluation that the impacts of food attributes on the accurate determination of NEOs. This review aims to provide a comprehensive overview of sample preparation methods regarding 6 categories of plant-derived foodstuffs. Currently, QuEChERS as the common strategy can effectively extract NEOs from plant-derived foodstuffs. Various enrichment technologies were developed for trace levels of NEOs in processed foodstuffs, and multifarious novel sorbents provided more possibility for removing complex matrices to lower matrix effects. Additionally, detection methods based on liquid chromatography were summarized and discussed in this review. Finally, some limitations were summarized and new directions were proposed for better advancement.

Dissipation and evaluation of different treatments on the residues of different insecticides in/on cauliflower curd.

A field study to understand dissipation rates and effect of various washing treatments on the residues of seven different insecticides, i.e. tetraniliprole 200 SC, emamectin benzoate 5 SG, lufenuron 5.4 EC, indoxacarb 14.5 SC, thiodicarb 75 WP, profenofos 50 EC and cypermethrin 25 EC in/on cauliflower curd has been conducted. The results showed that initial deposits (just after the last insecticide application, i.e. 0 d) of tetraniliprole, emamectin benzoate, lufenuron, indoxacarb, thiodicarb, profenofos and cypermethrin were 0.43, 0.03, 0.25, 0.28, 0.38, 6.70 and 0.68 mg kg-1, respectively. The dissipation pattern of all the tested insecticides followed monophasic, first order kinetics with the half-lives of 6.25, 8.85, 3.27, 7.71, 4.36, 2.98 and 3.76 d, respectively. Proposed pre-harvest intervals for these insecticides are 6, 9, 3, 8, 4, 3 and 4 d, respectively. All the decontamination techniques showed reductions in residue levels. However, treatment by soaking in 5% sodium bicarbonate aqueous solution showed 54%, 42%, 53%, 48%, 22%, 54% and 77% maximum reductions in residues of tetraniliprole, emamectin benzoate, lufenuron, indoxacarb, profenofos and cypermethrin, respectively, in cauliflower curds. The next best treatment was soaking cauliflower curds in water at 45-50 °C for 10 min, which reduced the residues of cypermethrin, profenofos, tetraniliprole, thiodicarb, emamectin benzoate and lufenuron.