Application of the QuEChERS method combined with UHPLC-QqQ-MS/MS for the determination of isoprocarb and carbaryl pesticides in Indonesian coffee.

The performance of the QuEChERS method in this study, as indicated by a high percentage (>90%) of recovery observations falling within the range of 60-140% and a sample replicate deviation (% RSD) of <20%, for the routine analysis of isoprocarb and carbaryl pesticides, has been evaluated over a 14-month period for the export of Indonesian coffee. Following a seven-day observation of the stability of these pesticides in coffee extract, it was found that the added standard calibration solution remained stable and useable for seven days when stored at 4 °C and -20 °C. This validated method, with high sensitivity (a LOQ of 0.001 mg kg-1 for isoprocarb and carbaryl), has been employed to monitor residues in Indonesian coffee exports to comply with maximum residue limits (MRLs). The samples with higher contamination levels were predominantly from robusta coffee (57.76%), followed by arabica coffee (6.17%). The detection rates for residues decreased by more than 90% in the last two months of the method's application. In the observation of coffee processing, it was found that isoprocarb residues in contaminated samples could be transferred to the processed coffee (roasted and its infusion) to a limited extent, while residues from the carcinogenic carbaryl were not detected due to evaporation. Additionally, chronic dietary risk assessment showed that contaminated samples of robusta and arabica coffees should not be considered a significant public health concern (hazard index HI < 1). However, continuous monitoring of pesticide residues in Indonesian coffee is still recommended, not only to conform to the MRLs of importing countries but also to ensure food trade.

Cobalt ferrite/semiconducting single-walled carbon nanotubes based field-effect transistor for determination of carbamate pesticides.

Carbaryl and carbofuran are the carbamate pesticides which have been widely used worldwide to control insects in crops and house. If the pesticides entered in to the food products and drinking water, they could cause serious health effects in humans. Therefore, the development of a rapid, simple, sensitive and selective analytical device for on-site detection of carbamates is crucial to evaluate food and environmental samples. Recently, semiconducting single-walled carbon nanotube-based field effect transistors (s-SWCNT/FETs) have shown several advantages such as high carrier mobility, good on/off ratio, quasi ballistic electron transport, label-free detection and real-time response. Herein, cobalt ferrite (CFO) nanoparticles decorated s-SWCNTs have been prepared and used to bridge the source and drain electrodes. As-prepared CFO/s-SWCNT/FET had been used for the non-enzymatic detection of carbaryl and carbofuran. When used as a sensing platform, the CFO/s-SWCNT hybrid film exhibited high sensitivity, and selectivity with a wide linear range of detection from 10 to 100 fMand the lowest limit of detections for carbaryl (0.11 fM) and carbofuran (0.07 fM) were estimated. This sensor was also used to detect carbaryl in tomato and cabbage samples, which confirmed its practical acceptance. Such performance may be attributed to the oxidation of carbamates by potent catalytic activity of CFO, which led to the changes in the charge transfer reaction on the s-SWCNTs/FET conduction channel. This work presents a novel CFO/s-SWCNT based sensing system which could be used to quantify pesticide residues in food samples.

Carbon nanomaterial functionalization with pesticide-detoxifying carboxylesterase.

Four carbon materials, spent coffee-ground biochar, carbon black, short CNTs, and nitrogen-doped few-layer graphene (N-graphene) were tested for their functionalization with a commercial carboxylesterase. Their robustness to variations in time and key physicochemical parameters (temperature and pH) was analysed. In general, carbon nanomaterials showed better performance than biochar, both in terms of binding capacity and resilience in harsh conditions, at statistically significant levels. Among the tested materials, functionalized N-graphene also showed the highest level of inhibition of carboxylesterase by pesticide exposure. Therefore, N-graphene was selected for biotechnological application of pesticide scavenging toxicity in T. thermophila, a ciliate bioindicator of water quality. While immobilization of the enzyme was not effective in the case of carbaryl, a methyl carbamate, in the case of the organophosphorus dichlorvos, a 1- or 30-min contact time with a water solution containing 5 times the LC100 - 0.5 mM - allowed 50% and 100% rescue of ciliate survival, respectively. These results suggest that functionalization with carboxylesterase may be of additional benefit compared to bare carbon in water clean-up procedures, especially for highly hydrophilic pesticides such as dichlorvos.

Microfluidic Paper Based Analytical Devices for the Detection of Carbamate Pesticides.

Microfluidic paper-based analytical devices (µ-PADs) are a new technology platform for the development of extremely low-cost sensing applications. In this study, µ-PADs has been developed for quantitative determination of carbamate pesticides. Key experimental parameters including concentration and volume of acetylcholinesterase, acetylthiocholine iodide and 5,5'-dithiobis-(2-nitrobenzoic acid), incubation time and image capturing time were systematically optimized. Under optimal conditions, the method showed wide range of linearity (0.25-16 mg/L), repeatability (4%-5% RSD) and intermediate precision (7%-10% RSD). Limit of detection was observed to be 0.4, 0.24 and 0.46 mg/L for carbaryl, carbosulfan and furathiocarb, respectively. An acceptable mean recovery (87% to 94%) was observed for the three pesticides at 1 mg/L fortification level. The results reveal that the developed method requires minimal reagents, simple and is easy to handle. It can be used for the quantification of carbamate pesticides in resource limited laboratories without the need for the conventional analytical instruments.

Pesticides applied to crops and amyotrophic lateral sclerosis risk in the U.S.

BACKGROUND: Environmental exposures are implicated in the etiology of amyotrophic lateral sclerosis (ALS). Application of insecticides, herbicides, and fungicides with neurotoxic properties to crops is permitted in the U.S., however reporting of the quantities is government mandated. OBJECTIVE: To identify pesticides that may be associated with ALS etiology for future study. METHODS: We geospatially estimated exposure to crop-applied pesticides as risk factors for ALS in a large de-identified medical claims database, the SYMPHONY Integrated Dataverse®. We extracted residence at diagnosis of ∼26,000 nationally distributed ALS patients, and matched non-ALS controls. We mapped county-level U.S. Geological Survey data on applications of 423 pesticides to estimate local residential exposure. We randomly broke the SYMPHONY dataset into two groups to form independent discovery and validation cohorts, then confirmed top hits using residential history information from a study of NH, VT, and OH. RESULTS: Pesticides with the largest positive statistically significant associations in both the discovery and the validation studies and evidence of neurotoxicity in the literature were the herbicides 2,4-D (OR 1.25 95 % CI 1.17-1.34) and glyphosate (OR 1.29 95 %CI 1.19-1.39), and the insecticides carbaryl (OR 1.32 95 %CI 1.23-1.42) and chlorpyrifos (OR 1.25 95 %CI 1.17-1.33). SIGNIFICANCE: Our geospatial analysis results support potential neurotoxic pesticide exposures as risk factors for sporadic ALS. Focused studies to assess these identified potential relationships are warranted.

Investigating the Effects of Pesticides on Ramshorn Snails (Planorbella [Helisoma] trivolvis) Infected with Echinostoma spp.

Globally, parasite-induced diseases in humans and wildlife are on the rise, and pesticide pollution may be a contributing factor. Echinostoma spp. trematode parasites are prominent in North America, and they use ramshorn snails (Planorbella [Helisoma] trivolvis) as intermediate hosts. We investigated the impact of chronic exposure to 1 of 5 pesticide treatments (control, or 50 µg/L of atrazine, glyphosate, carbaryl, or malathion) on uninfected and Echinostoma-infected snails for 41 d in the laboratory. We recorded snail mortality, the number of egg masses laid, change in mass, and behavior. Chronic exposure to atrazine, carbaryl, and malathion significantly decreased snail survival, whereas parasite infection status or exposure to glyphosate did not. Pesticide and parasite treatments did not influence growth or behavior, but parasite infection caused complete reproductive failure in snail hosts. Our results indicated that the direct effects of pesticides could threaten snail populations in natural environments and disrupt host-parasite dynamics.  Environ Toxicol Chem 2021;40:2755-2763. © 2021 SETAC.

Epigenetic effects of insecticides on early differentiation of mouse embryonic stem cells.

Increasing evidence indicates that many insecticides produce significant epigenetic changes during embryogenesis, leading to developmental toxicities. However, the effects of insecticides on DNA methylation status during early development have not been well studied. We developed a novel nuclear phenotypic approach using mouse embryonic stem cells harboring enhanced green fluorescent protein fused with methyl CpG-binding protein to evaluate global DNA methylation changes via high-content imaging analysis. Exposure to imidacloprid, carbaryl, and o,p'-DDT increased the fluorescent intensity of granules in the nuclei, indicating global DNA methylating effects. However, DNA methylation profiling in cell-cycle-related genes, such as Cdkn2a, Dapk1, Cdh1, Mlh1, Timp3, and Rarb, decreased in imidacloprid treatments, suggesting the potential influence of DNA methylation patterns on cell differentiation. We developed a rapid method for evaluating global DNA methylation and used this approach to show that insecticides pose risks of developmental toxicity through DNA methylation.

Production of a specific monoclonal antibody for 1-naphthol based on novel hapten strategy and development of an easy-to-use ELISA in urine samples.

1-naphthol (1-NAP) is the main metabolite of pesticide carbaryl and naphthalene, and is also a genotoxic and carcinogenic intermediate in the synthesis of organic compound, dyes, pigment and pharmaceutical industry. In this work, two novel haptens were designed and synthesized for developing a competitive indirect enzyme-linked immunosorbent assay (ciELISA) method for 1-NAP in urine samples. The assay showed a limit of detection of 2.21 ng/mL and working range from 4.02 ng/mL to 31.25 ng/mL for 1-NAP in optimized working buffer. The matrix effect of samples was eliminated via 15-fold dilution of optimized working buffer. Good average recoveries (102.4%-123.4%) with a coefficient of variation from 11.7% to 14.7% was obtained for spiked urine samples. Subsequent instrument verification test showed good correlation between the results of ciELISA and high-performance liquid chromatography. The developed ciELISA is a high-throughput tool to monitor 1-NAP in urine, which can provide technical support for the establishment of biological exposure level for the exposure to carbaryl, naphthalene and other related pollutants.

Identification and characterization of a novel bacterial carbohydrate esterase from the bacterium Pantoea ananatis Sd-1 with potential for degradation of lignocellulose and pesticides.

OBJECTIVE: Identification and characterization of a novel bacterial carbohydrate esterase (PaCes7) with application potential for lignocellulose and pesticide degradation. RESULTS: PaCes7 was identified from the lignocellulolytic bacterium, Pantoea ananatis Sd-1 as a new carbohydrate esterase. Recombinant PaCes7 heterologously expressed in Escherichia coli showed a clear preference for esters with short-chain fatty acids and exhibited maximum activity towards α-naphthol acetate at 37 °C and pH 7.5. Purified PaCes7 exhibited its catalytic activity under mesophilic conditions and retained more than 40% activity below 30 °C. It displayed a relatively wide pH stability from pH 6-11. Furthermore, the enzyme was strongly resistant to Mg2+, Pb2+, and Co2+ and activated by K+ and Ca2+. Both P. ananatis Sd-1 and PaCes7 could degrade the pesticide carbaryl. Additionally, PaCes7 was shown to work in combination with cellulase and/or xylanase in rice straw degradation. CONCLUSIONS: The data suggest that PaCes7 possesses promising biotechnological potential.

Detection of DDT and carbaryl pesticides in honey by means of immunosensors based on high fundamental frequency quartz crystal microbalance (HFF-QCM).

BACKGROUND: In recent years there has been a concern about the presence of pesticides in honey because residues of DDT and carbaryl were found in honey samples. Traditional techniques, such as chromatography, reach the required limits of detection (LOD) but are not suitable for in situ implementation in the honey-packaging industry due to their high cost and the need for highly qualified staff for routine operation. Biosensors offer simplicity, low cost, and easy handling for analytical purposes in food applications. RESULTS: Piezoelectric immunosensors based on high fundamental frequency quartz crystal microbalance (HFF-QCM) have been developed for the detection of carbaryl and DDT in honey. Biorecognition was based on competitive immunoassays in the conjugate-coated format, using monoclonal antibodies as specific immunoreagents. The assay LODs attained by the HFF-QCM immunosensors were 0.05 µg L-1 for carbaryl and 0.24 µg L-1 for DDT, reaching a similar level of detectability to that of the usual reference techniques. The practical LODs in honey samples were 8 µg kg-1 for carbaryl and 24 µg kg-1 for DDT. The immunosensors' analytical performance allow the detection of these pesticides in honey at EU regulatory levels with good accuracy (recovery percentages ranging from 94% to 130% within the working range of each pesticide standard curve) and precision (coefficients of variation in the 9-36% range). CONCLUSION: The proposed immunosensor is a promising analytical tool that could be implemented for quality control in the honey packaging industry, to simplify and to reduce the cost of the routine pesticide analysis in this appreciated natural food. © 2020 Society of Chemical Industry.

A Rare Case of Chromoblastomycosis in a 12-year-old boy.

Chromoblastomycosis is a chronic fungal infection of the subcutaneous tissue. The infection usually results from a traumatic injury and inoculation of the microorganism by a specific group of dematiaceous fungi, resulting in the formation of verrucous plaques. The fungi produce sclerotic or medlar bodies (also called muriform bodies or sclerotic cells) seen on direct microscopic examination of skin smears. The disease is often found in adults due to trauma. We report a case of chromoblastomycosis in a 12-year-old child in whom the infection started when he was only 4 years old with secondary involvement of bones, cartilage, tongue and palatine tonsils. The child was not immunosuppressed.

Glutathione reductase and catalase as potential biomarkers for synergistic intoxication of pesticides in fish.

Synergy occurs when chemicals give pronounced effect on combination in contrast to their individual effect. The objective of this study was to investigate the synergistic effect of pesticides carbaryl (C) and methyl parathion (MP) on oxidative stress biomarkers viz catalase (CAT), glutathione reductase (GSSG-R) including different enzymes like lactate dehydrogenase (LDH), succinate dehydrogenase (SDH) and acetyl cholinesterase (AChE) in different tissues of carps Catla catla. Fishes were exposed to 6.25 mg/L of MP and 2.3 mg/L of C in mixture (one-third of LC50 value). CAT and GSSG-R were studied in gills, brain, liver and muscle of carp were found to be elevated significantly (p < 0.005). LDH activity increased significantly (p < 0.005) in synergistic group, there was a seven-fold (748%) increase in LDH activity in muscle compared to individual studies with same pesticides. Contrary to LDH, sudden decrease in SDH activity was accounted. Significant (p < 0.005) decrease in AChE activity after initial 24 h was remarkable addressing to the shift in neurotransmission pathway in organism. Significant increase was observed in activity of CAT and GSSG-R in all tissues compared to control fishes in individual as well as synergistic (MP + C) group suggesting that CAT and GSSG-R can be a potential biomarker of oxidative stress when studied in combination.

Variability in Assembly of Degradation Operons for Naphthalene and its derivative, Carbaryl, Suggests Mobilization through Horizontal Gene Transfer.

In the biosphere, the largest biological laboratory, increased anthropogenic activities have led microbes to evolve and adapt to the changes occurring in the environment. Compounds, specifically xenobiotics, released due to such activities persist in nature and undergo bio-magnification in the food web. Some of these compounds act as potent endocrine disrupters, mutagens or carcinogens, and therefore their removal from the environment is essential. Due to their persistence, microbial communities have evolved to metabolize them partially or completely. Diverse biochemical pathways have evolved or been assembled by exchange of genetic material (horizontal gene transfer) through various mobile genetic elements like conjugative and non-conjugative plasmids, transposons, phages and prophages, genomic islands and integrative conjugative elements. These elements provide an unlimited opportunity for genetic material to be exchanged across various genera, thus accelerating the evolution of a new xenobiotic degrading phenotype. In this article, we illustrate examples of the assembly of metabolic pathways involved in the degradation of naphthalene and its derivative, Carbaryl, which are speculated to have evolved or adapted through the above-mentioned processes.

The histopathological, cytopathological and ultrastructural effects of carbaryl on gills of Oreochromis niloticus (Linnaeus, 1758).

Ultrastructural and histopathological reponses in the organs of living organisms are important and useful tools to determine the health condition and the effects of pollutants, such as pesticides, on the organisms. The aim of this study is to determine possible histopathological, cytopathological and ultrastructural alterations in gills of Oreochromis niloticus individuals exposed to 850 µg/L carbaryl standart at 7th, 14th and 21st days with light and electron microscopes. The fish were exposed to carbaryl for 21 days and the histopatological, ultrastructural and cytopathological alterations occuring in the gill tissues of organisms were determined by light, Scanning and Transmission Electron Microscopes (SEM and TEM). At the end of the study, it was observed that carbaryl caused both histopathological and cytopathological changes in the gills of O. niloticus. It has been determined that the most of the pathological changes in the exposed organisms are the metabolic defence reactions.

Reduced graphene oxide decorated on Cu/CuO-Ag nanocomposite as a high-performance material for the construction of a non-enzymatic sensor: Application to the determination of carbaryl and fenamiphos pesticides.

A novel electrochemical sensor based on the reduced graphene oxide-Cu/CuO-Ag nanocomposite modified glassy carbon electrode (rGO/Cu/CuO-Ag/GCE) has been applied for the simultaneous analysis of carbaryl and fenamiphos as two important pesticides. The electrochemical behavior of carbaryl and fenamiphos at rGO/Cu/CuO-Ag/GCE was studied by cyclic voltammetry and differential pulse voltammetry. The modified electrode exhibited two separated oxidation signals for the simultaneous determination of both carbaryl and fenamiphos with excellent sensitivity. The characteristics of the modified electrode were studied with transmission electron microscopy, X-ray diffraction and Fourier transform-infrared spectroscopy techniques. Under optimized conditions, the rGO/Cu/CuO-Ag/GCE detected carbaryl and fenamiphos with the wide linear ranges of 0.05-20 and 0.01-30 µM, and the detection limits were 0.005 and 0.003 µM, respectively. This developed electrochemical platform applied as a simple and cost-effective sensor for the detection of low levels of carbaryl and fenamiphos in fruit and vegetable samples successfully.

N-methylcarbamate pesticides and their phenolic degradation products: hydrolytic decay, sequestration and metal complexation studies.

We report on the rates of decomposition of a group of N-methylcarbamate (NMC) pesticides (carbaryl, carbofuran and propoxur) under pre-determined tropical field conditions. Rates of decomposition for three NMCs were determined at pH 7.08 and T = 20 °C and pH 7.70 and T = 33 °C respectively, as follows: carbaryl (78 days and 69 days); carbofuran (143 days and 83 days) and propoxur (116 days and 79 days). Investigation on methods for removal of NMCs and their phenolic decomposition products shows that activated charcoal outperforms zeolite, alumina, diatomaceous earth, cellulose and montmorillonite clay in the removal of both NMCs and phenols from aqueous solution. Furthermore, metal complexation studies on the NMCs and phenols showed that Fe (III) forms a complex with isopropoxyphenol (IPP) within which the Fe:IPP ratio is 1:3, indicative of the formation of a metal chelate complex with the formula Fe(IPP)3.

An amphibian with a contracting range is not more vulnerable to pesticides in outdoor experimental communities than common species.

In areas with heavy pesticide use, it is easy to attribute population declines to environmental contamination. The Blanchard's cricket frogs (Acris blanchardi) is an amphibian experiencing declines and range contractions across its distribution in the Midwest Corn Belt (USA). Experimental studies suggest that cricket frogs are sensitive to pesticides, but there are few studies examining this species' susceptibility to contaminants in realistic environments or comparing relative impacts with other anuran species. I reared 3 summer breeding anurans in outdoor mesocosms posthatching through metamorphosis to examine the effects of 2 insecticides (imidacloprid and carbaryl) and 1 herbicide (glyphosate with polyoxyethylene tallow amine) on larval development and metamorphosis. Cricket frogs were positively affected by insecticide exposure, likely a result of changes in the food web that increased food abundance. However, metamorphosis of green frogs (Lithobates clamitans) and gray tree frogs (Hyla chrysoscelis) appeared unaffected by pesticide exposure. The results of the present study suggest that the impacts of pesticides alone are unlikely to have population-level impacts for the anurans examined. Environ Toxicol Chem 2018;37:2699-2704. © 2018 SETAC.

Histopathological analysis of carbaryl-induced toxicity in the spleen of Levantine frog, Pelophylax bedriagae (Anura: Ranidae).

This study describes the histopathological effects of carbaryl in the spleen of Levantine frog, Pelophylax bedriage. Due to its primary role in immune system, it is important to research the toxic effects of pesticides, which play an important role in environmental pollution, on spleen. To that end, adult frogs were exposed to carbaryl for 96 h. Experimental groups contained low dose, (0.05 mg/g), medium dose (0.1 mg/g) and high dose (0.2 mg/g). After following exposure to carbaryl, the frogs were euthanised and dissected. In low-dose group, there were no important changes in spleen tissue. In medium-dose group, prominence in haemorrhage just below the capsule and an increase in the melanomacrophage number were determined. In high-dose group, in addition to increases in the melanomacrophages, separations in capsule, haemorrhage below capsule and within splenic tissue, sinusoidal enlargement, congestion in dilated sinusoid, hypertrophic plasma cells and fibrosis were determined as important histological lesions in exposed frogs. This study clearly showed that carbaryl caused important histopathological damages in splenic tissue of Pelophylax bedriagae. In view of these findings, it can be said that this insecticide has the capacity to disrupt spleen' functions.

Nano carbon black-based screen printed sensor for carbofuran, isoprocarb, carbaryl and fenobucarb detection: application to grain samples.

An electrochemical screening assay for the detection of phenyl carbamates (i.e. carbaryl, carbofuran, isoprocarb and fenobucarb) was developed and applied to grains samples (i.e. durum wheat, soft wheat and maize). Nano carbon black (CB) was strategically employed to realize an effective, reproducible, fouling resistant, low cost, delocalisable screen printed sensor (CB-SPE). CB-SPEs morphology (SEM and FEM) and electrochemical property (CV and EIS) were studied. The final pesticides analysis protocol consist of: (i) extraction of the analyte (just by mixing), (ii) alkaline hydrolysis (10 min R.T.), (iii) DPV detection directly of 100 µL of extract on the CB-SPE surface. Linear range between 1.0 × 10-7 and 1.0 × 10-4 mol L-1, good determination coefficients (R2 ≥ 0.9971) and satisfactory sensitivity (≥ 3.90 × 10-1 A M-1 cm-2) and LODs (≤ 8.0 × 10-8 mol L-1) were obtained for all the analytes. Excellent recoveries (78-102%) and accuracy (relative error vs. HPLC-MS/MS between 9.0% and -7.8%) resulted from the analysis of grains samples. The proposed CB-SPE based approach has demonstrated to be able to detect carbaryl at Maximum residue limits levels (MRLs), allowing class selective detection of commonly employed phenyl carbamates in food samples.

Long term exposure to low dose neurotoxic pesticides affects hatching, viability and cholinesterase activity of Artemia sp.

The brine shrimp Artemia was used as a model organism to test toxicity of several neuroactive pesticides (chlorpyrifos (CLP), chlorpyrifos oxon (CLP ox), diazinon (DZN), carbaryl (CBR)) following exposure to far below than lethal doses. Cysts were exposed to the pesticides in order to test a scenario similar to actual coastal environment contamination, by analyzing different responses. Cysts were rehydrated in water containing the pesticides at concentrations ranging from 10-11 to 10-5 M, for 72, 96 and 192 h, respectively. For these exposure times, morpho-functional and biochemical parameters, such as hatching speed and viability were investigated in the larvae together with cholinesterase (ChE) activity quantification and histochemical localization. Finally, ChE inhibition was also compared with conventional selective ChE inhibitors. Results showed that CLP ox and CBR caused a significant dose-dependent decrease in hatching speed, followed by high percentages of larval death, while CLP and DZN were responsible for irregular hatching patterns. In addition, the pesticides mostly caused larval death some days post-hatching, whereas this effect was negligible for the specific ChE inhibitors, suggesting that part of pesticide toxicity may be due to molecules other than the primary target. ChE activity was observed in the protocerebrum lobes, linked to the development of pair eyes. Such activity was inhibited in larvae exposed to all pesticides. When compared to conventional selective inhibitors of ChE activities, this inhibition demonstrated that the selected pesticides mainly affect acetylcholinesterase and, to a lesser extent, pseudocholinesterases. In conclusion, the brine shrimp is a good model to test the environmental toxicity of long term exposure to cholinergic pesticides, since changes in hatching speed, viability and ChE activity were observed.