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Bulletin of Environmental Contamination... May 2022Organism tolerance thresholds for emerging contaminants are vital to the development of water quality criteria. Acute (96-h) and chronic (10-day) effects thresholds for...
Organism tolerance thresholds for emerging contaminants are vital to the development of water quality criteria. Acute (96-h) and chronic (10-day) effects thresholds for neonicotinoid pesticides clothianidin and thiamethoxam, and the carbamate pesticide methomyl were developed for the midge Chironomus dilutus to support criteria development using the UC Davis Method. Median lethal concentrations (LC50s) were calculated for acute and chronic exposures, and the 25% inhibition concentrations (IC25) were calculated for the chronic exposures based on confirmed chemical concentrations. Clothianidin effect concentrations were 4.89 µg/L, 2.11 µg/L and 1.15 µg/L for 96-h LC50, 10-day LC50 and 10-day IC25, respectively. Similarly, thiamethoxam concentrations were 56.4 µg/L, 32.3 µg/L and 19.6 µg/L, and methomyl concentrations were 244 µg/L, 266 µg/L and 92.1 µg/L. Neonicotinoid effect concentrations compared favorably to previously published 96-h and 14-day LC50 concentrations, and methomyl effect concentrations were within the acute survival range reported for Chironomus species and other organisms.
Topics: Animals; Chironomidae; Guanidines; Insecticides; Methomyl; Neonicotinoids; Nitro Compounds; Thiamethoxam; Thiazoles; Water Pollutants, Chemical
PubMed: 34874464
DOI: 10.1007/s00128-021-03416-z -
Saudi Journal of Biological Sciences Sep 2022Cytomixis is a common phenomenon observed in meiotic cells such as anther which is influenced by various factors. Use of pesticides is a common practice in agriculture....
Cytomixis is a common phenomenon observed in meiotic cells such as anther which is influenced by various factors. Use of pesticides is a common practice in agriculture. However, it is not known whether pesticides can induce cytomixis in plant cells and induce genetic variation. To understand this, the present study was planned to assess the cytomixis and syncytes behaviors in PMCs of L. Seeds of (Family: Fabaceae) were treated with different concentrations of commonly used pesticides methomyl (ME), imbraclaobrid (IM) and clethodim (CL). Seeds were treated with various concentrations (0.1, 0.2, 0.3, 0.4 and 0.5% of ME, IM and CL prepared in water) for 1 and 3 h. Effect of pesticides on pollen fertility, frequency of cytomixis, and kind of cytomixis cells was assessed. In the cytomixis cells, the cytomictic channel (CC) and direct fusion (DF), and various stages of meiosis (PI, MI, AI and TI) with cytomixis cells were observed. In addition, frequency of syncytes cell and their various stages of meiosis I (PI, MI, AI and TI) in pollen mother cells (PMCs) was assessed. During the microsporogenesis in the occurrence of cytomixis and syncytes at various stages of meiosis I were seen. The formation of cytoplasmic channels and direct fusing of pollen mother cells (PMCs) were both seen to cause cytomixis, with the former being more common than the latter. The percentage of PMCs with cytomixis and syncytes cells increased with increase in the concentration of pesticides. The result of the present investigation indicates that commonly used pesticides ME, IM, and CL have a significant effect on pollen fertility, frequency of cytomixis, and kind of cytomixis cells, the cytomictic channel (CC) and direct fusion (DF), in addition, frequency of syncytes cell and their various stages of meiosis I (PI, MI, AI and TI) in pollen mother cells (PMCs) on .
PubMed: 35935105
DOI: 10.1016/j.sjbs.2022.103390 -
Molecules (Basel, Switzerland) Feb 2020Methomyl is a broad-spectrum oxime carbamate commonly used to control arthropods, nematodes, flies, and crop pests. However, extensive use of this pesticide in... (Review)
Review
Methomyl is a broad-spectrum oxime carbamate commonly used to control arthropods, nematodes, flies, and crop pests. However, extensive use of this pesticide in agricultural practices has led to environmental toxicity and human health issues. Oxidation, incineration, adsorption, and microbial degradation methods have been developed to remove insecticidal residues from soil/water environments. Compared with physicochemical methods, biodegradation is considered to be a cost-effective and ecofriendly approach to the removal of pesticide residues. Therefore, micro-organisms have become a key component of the degradation and detoxification of methomyl through catabolic pathways and genetic determinants. Several species of methomyl-degrading bacteria have been isolated and characterized, including , , , , , , , , and . The degradation pathways of methomyl and the fate of several metabolites have been investigated. Further in-depth studies based on molecular biology and genetics are needed to elaborate their role in the evolution of novel catabolic pathways and the microbial degradation of methomyl. In this review, we highlight the mechanism of microbial degradation of methomyl along with metabolic pathways and genes/enzymes of different genera.
Topics: Adsorption; Alcaligenes; Bacillus; Biodegradation, Environmental; Cholinesterase Inhibitors; Flavobacterium; Humans; Incineration; Insecticides; Metabolic Networks and Pathways; Methomyl; Oxidation-Reduction; Paracoccus; Pseudomonas; Serratia; Soil Pollutants; Trametes; Water Pollutants, Chemical
PubMed: 32046287
DOI: 10.3390/molecules25030738 -
Toxicology Research Oct 2021We investigated the ameliorative effect of the curcumin against methomyl-induced potential nephrotoxicity in Wistar albino male rats. In the present study, curcumin...
We investigated the ameliorative effect of the curcumin against methomyl-induced potential nephrotoxicity in Wistar albino male rats. In the present study, curcumin (100 mg kg bw), methomyl (0,8 mg kg bw) and methomyl plus curcumin were given to rats by oral for 28 days (for subacute examination). Concentrations of blood urea nitrogen, uric acid and creatinine in serum and malondialdehyde level and activities of antioxidant enzyme (superoxide dismutase, catalase, glutathione peroxidase and glutathione S transferase) and histopathological alterations in kidney tissues were studied. Methomyl caused an increment in the concentrations of blood urea nitrogen, creatinine, uric acid and MDA levels. In addition, methomyl caused a diminution in the activities of superoxide dismutase, catalase, glutathione peroxidase and glutathione S transferase. Tubular and glomerular degenerations occurred in the kidney tissues of methomyl-received rats. However, coadministration of curcumin with methomyl significantly minimized the adverse effects of methomyl on kidney function parameters, lipid peroxidation and antioxidant enzyme activities and histological structure of kidney tissue. The results showed that curcumin significantly mitigated methomyl-induced nephrotoxicity in rats.
PubMed: 34733485
DOI: 10.1093/toxres/tfab080 -
Toxics Apr 2023There is limited literature analyzing the outcome of human poisoning with methomyl and cypermethrin pesticide mixture. Between 2002 and 2018, a total of 63 patients...
There is limited literature analyzing the outcome of human poisoning with methomyl and cypermethrin pesticide mixture. Between 2002 and 2018, a total of 63 patients intoxicated with methomyl, cypermethrin, or their pesticide mixture were treated at Chang Gung Memorial Hospital. The patients were categorized into three groups based on the type of pesticide, as methomyl (n = 10), cypermethrin (n = 31), or methomyl and cypermethrin (n = 22). Demographic, clinical, laboratory, and mortality data were obtained for analysis. The patients were aged 54.9 ± 18.9 years. Following ingestion, the patients experienced a wide range of clinical symptoms, including aspiration pneumonia (50.8%), acute respiratory failure (41.3%), acute kidney injury (33.3%), multiple organ failure (19.0%), emesis (19.0%), acute hepatitis (12.7%), diarrhea (7.9%), seizures (4.8%), lacrimation (4.8%), etc. After analysis, it was found that patients with methomyl and cypermethrin poisoning suffered higher incidences of acute respiratory failure ( < 0.001), aspiration pneumonia ( = 0.004), acute kidney injury ( = 0.011), and multiple organ failure ( < 0.001) than the other groups. Laboratory analyses revealed that patients with methomyl and cypermethrin poisoning had a higher creatinine level ( = 0.011), white blood cell count ( < 0.001), and neutrophil count ( = 0.019) than the other groups. A total of seven (11.1%) patients died. The average duration of hospitalization was 9.8 ± 10.0 days. In a multivariate logistic regression model, it was revealed that methomyl pesticide ( = 0.045) or methomyl and cypermethrin pesticide mixture ( = 0.013) were significant risk factors for acute respiratory failure. Nevertheless, no mortality risk factor could be identified. Therefore, the analytical results suggest that methomyl pesticide is the major contributor to the toxicity of methomyl and cypermethrin pesticide mixture poisoning. More research is needed.
PubMed: 37112599
DOI: 10.3390/toxics11040372 -
Scientific Reports May 2023Insecticides are an integral part of most of the cropping systems worldwide; however, these usually exert negative impact on the environment and non-target insects as...
Insecticides are an integral part of most of the cropping systems worldwide; however, these usually exert negative impact on the environment and non-target insects as well. Non-target insects are prone to develop resistance to insecticides due to prolonged and repeated lethal and sublethal exposures. Musca domestica is a common non-target, pollinator and nectar feeder species in cotton ecosystem, besides its status as a public health pest in human habitations. In the present work, resistance to methomyl, one of the major insecticides used for cotton pest management, was assessed in 20 M. domestica strains from the major cotton producing areas of the Punjab and Sindh provinces of Pakistan. The results revealed that toxicity values of methomyl for Punjabi and Sindhi strains ranged from 28.07 to 136.16 µg fly and 29.32 to 136.87 µg fly, respectively. Among Punjabi strains, D.G. Khan, Lodhran, Bahawalpur, Toba Tek Singh, Bahawalnagar, Rajanpur and Jhang strains exhibited very high levels of resistance (RR > 100) to methomyl; Bhakkar, Kasur, Vehari, Layyah, Muzaffargarh and R.Y. Khan showed high resistance (RR = 51-100 fold), while the Mianwali strain showed a moderate level of resistance to methomyl (RR = 36.45 fold). In case of Sindhi strains, very high levels of resistance (> 100 fold) were reported for Sukkar and Sanghar strains, high levels of resistance (RR 51-100 fold) for Khairpur, Jamshoro and Ghotki, and moderate resistance to methomyl (38.08 fold) in the Dadu strain. There was a significant synergism of methomyl toxicity in all field strains when methomyl bioassayed along with piperonyl butoxide (PBO) and S,S,S-tributylphosphorotrithioate (DEF) providing clues of metabolic-based mechanisms of resistance to methomyl. In conclusion, insecticides used in crop farming can cause resistance development in non-target M. domestica. It is necessary to adopt the pest management activities that are safe for the environment and non-target insect species.
Topics: Animals; Humans; Insecticides; Methomyl; Houseflies; Pakistan; Ecosystem; Insecticide Resistance
PubMed: 37127684
DOI: 10.1038/s41598-023-34331-4 -
Mutation Research. Genetic Toxicology... Dec 2019Exposure of pregnant women to pesticides in an occupational or incidental manner has been pointed out as a possible cause of health problems in newborns. Cypermethrin...
Genotoxic and mutagenic evaluation of the protective effect of exogenous melatonin in adult rats and their offspring exposed to the insecticides methomyl and cypermethrin during pregnancy.
Exposure of pregnant women to pesticides in an occupational or incidental manner has been pointed out as a possible cause of health problems in newborns. Cypermethrin and methomyl are insecticides whose active compounds and metabolites can cause harm to the health of pregnant women and their offspring. Both contribute to increases in the concentrations of oxidizing agents that damage DNA, causing mutations. Thus, the use of antioxidant substances, such as melatonin, could serve as protection against genetic damage, reducing the problems caused by insecticides. Here, we evaluated the protective effect of exogenous melatonin in adult rats and their offspring exposed to methomyl and cypermethrin during the gestational period. Thirty adult rats were divided into five groups from the first day of pregnancy: NC - negative control, Mth received 0.02 mg/kg/day of methomyl, Cyp received 0.05 mg/kg/day cypermethrin, MthMl received 0.02 mg/kg/day methomyl combined with 10 mg/kg/day melatonin, and CypMl received 0.05 mg/kg/day cypermethrin combined with 10 mg/kg/day melatonin. Blood and liver samples were collected from the dams; blood, liver, and brain samples were collected from the offspring. All tissues were used for comet assay; blood was used for micronucleus test. Our results demonstrate that cypermethrin and methomyl induce significant genetic damage in the tissues of dams and offspring. Treatment with melatonin significantly reduced cypermethrin-induced genetic damage in dams and pups; however, melatonin was not effective against the genetic damage caused by methomyl. Thus, melatonin may be considered a promising agent for the reduction of genotoxic effects induced by cypermethrin but appears to be inefficient against the genotoxic effects caused by methomyl, probably due to differences in the metabolism of each pesticide.
Topics: Animals; Female; Insecticides; Male; Maternal Exposure; Melatonin; Methomyl; Micronucleus Tests; Pregnancy; Pyrethrins; Rats
PubMed: 31708074
DOI: 10.1016/j.mrgentox.2019.503107 -
Journal of Toxicologic Pathology Jan 2017The aim of this study was to investigate the lethal and sublethal toxicity of a methomyl-based insecticide in , as methomyl-based insecticides are applied in massive...
The aim of this study was to investigate the lethal and sublethal toxicity of a methomyl-based insecticide in , as methomyl-based insecticides are applied in massive amounts and agrochemicals have effects on the decline in amphibian populations. To evaluate the toxic effects of methomyl from agricultural application, a methomyl-based insecticide containing 40% methomyl was selected. The median lethal concentration of 96 hours of methomyl exposure was 8.69 ppm for tadpoles. The lethal concentration also produced severe histological damage in the livers and kidneys of the exposed tadpoles. The sublethal concentration used for methomyl was 144 ppb during the metamorphosis period. It was found that the sublethal concentration of the methomyl compound could decrease growth, metamorphosis time, and size, disturb biochemical parameters, and produce histological damage. In livers, methomyl effects increased oxidative stress and dramatically decreased the glycogen level of the treated froglets. Mononuclear infiltration, blood congestion, amorphous substances, and hepatocytes vacuolization were observed throughout liver tissue. The methomyl-based insecticide also increased oxidative stress and decreased nitric oxide levels in the kidneys of the exposed froglets. Renal tissue damage including blood congestion, amorphous substances, and Bowman's capsule spaces reduction were found in the methomyl exposure group. The methomyl compound also produced vacuoles in various stages of oocytes, but no histological damage was found in testicular tissue. Our results indicated strong toxic effects of the methomyl-based insecticide on s, a broadly tolerant anuran.
PubMed: 28190921
DOI: 10.1293/tox.2016-0039 -
Journal of Occupational Health Jan 2021To assess pesticide exposure and understand the resultant health effects of agricultural workers in Northern Thailand.
OBJECTIVES
To assess pesticide exposure and understand the resultant health effects of agricultural workers in Northern Thailand.
METHODS
This was a cross-sectional study. We quantified exposure to pesticides, including chlorpyrifos, methomyl, and metalaxyl, by air sampling and liquid chromatography/mass spectrometry. We estimated differences in self-reported health outcomes, complete blood counts, cholinesterase activity, and serum/urine calcium and creatinine concentrations at baseline between farmworkers and comparison workers, and after pesticide spraying in farmworkers only.
RESULTS
This study included 97 men between the ages of 22 and 76 years; 70 were conventional farmworkers; and 27 did not report any prior farmwork or pesticide spraying. None of the farmworkers wore standardized personal protective equipment (PPE) for the concentrated chemicals they were working with. Methomyl (8.4-13 481.9 ng/m ), ethyl chlorpyrifos (11.6-67 759 ng/m ), and metalaxyl (13.9-41 191.3 ng/m ) were detected via personal air sampling. When it came to reporting confidence in the ability to handle personal problems, only 43% of farmworkers reported feeling confident, which reflects higher stress levels in comparison to 78% of comparison workers (P = .028). Farmworkers also had significantly lower monocyte counts (P = .01), serum calcium (P = .01), red blood count (P = .01), white blood cell count (P = .04), and butyrylcholinesterase activity (P < .0001), relative to comparison workers. After adjusting for body mass index (BMI), age, and smoking, methomyl air concentrations were associated with a decrease in farmworker acetylcholinesterase activity (beta = -0.327, P = .016).
CONCLUSIONS
This population of farmworkers had significant alterations in stress measures and clinical biomarkers, including decreased blood cell counts and cholinesterase activity, relative to matched controls. These changes are potentially linked to occupational pesticide exposures. Improving PPE use presents a likely route for preventive intervention in this population.
Topics: Adult; Aged; Agriculture; Biological Monitoring; Biomarkers; Blood Cell Count; Calcium; Cholinesterases; Creatinine; Cross-Sectional Studies; Environmental Monitoring; Farmers; Humans; Male; Middle Aged; Occupational Exposure; Personal Protective Equipment; Pesticides; Thailand; Young Adult
PubMed: 33973692
DOI: 10.1002/1348-9585.12222