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Journal of Separation Science Jun 2016An analytical method to detect phorate and its metabolites, including phorate sulfone, phorate sulfoxide, phoratoxon, phoratoxon sulfone, and phoratoxon sulfoxide, in...
QuEChERS method for the simultaneous quantification of phorate and its metabolites in porcine and chicken muscle and table eggs using ultra-high performance liquid chromatography with tandem mass spectrometry.
An analytical method to detect phorate and its metabolites, including phorate sulfone, phorate sulfoxide, phoratoxon, phoratoxon sulfone, and phoratoxon sulfoxide, in porcine and chicken muscles and table eggs was developed and validated. Extraction was performed using a quick, easy, cheap, effective, rugged, and safe method and analysis was conducted using ultra-high performance liquid chromatography-tandem mass spectrometry. Matrix-matched calibrations were linear over the tested concentrations, with determination coefficient ≥ 0.995 for all tested analytes in the different matrices. The limits of detection and quantification were 0.001 and 0.004 mg/kg, respectively. The calculated recovery rates at three fortification levels were satisfactory, with values between 74.22 and 119.89% and relative standard deviations < 10%. The method was applied successfully to commercial samples collected from locations throughout the Korean Peninsula, and none of them showed any traces of the tested analytes. Overall, the developed method is simple and versatile, and can be used for monitoring phorate and its metabolites in animal products rich in protein and fat.
Topics: Animals; Chickens; Chromatography, High Pressure Liquid; Eggs; Molecular Structure; Muscle, Skeletal; Phorate; Swine; Tandem Mass Spectrometry
PubMed: 27061785
DOI: 10.1002/jssc.201600151 -
Neurotoxicology Sep 2018Organophosphorus (OP) compounds, including pesticides and chemical warfare nerve agents (CWNA), are threats to the general population as possible weapons of terrorism or...
Evaluating the broad-spectrum efficacy of the acetylcholinesterase oximes reactivators MMB4 DMS, HLö-7 DMS, and 2-PAM Cl against phorate oxon, sarin, and VX in the Hartley guinea pig.
Organophosphorus (OP) compounds, including pesticides and chemical warfare nerve agents (CWNA), are threats to the general population as possible weapons of terrorism or by accidental exposure whether through inadvertent release from manufacturing facilities or during transport. To mitigate the toxicities posed by these threats, a therapeutic regimen that is quick-acting and efficacious against a broad spectrum of OPs is highly desired. The work described herein sought to assess the protective ratio (PR), median effective doses (ED), and therapeutic index (TI = oxime 24-h LD/oxime ED) of MMB4 DMS, HLö-7 DMS, and 2-PAM Cl against the OPs sarin (GB), VX, and phorate-oxon (PHO). All OPs are representative of the broader classes of G and V chemical warfare nerve agents and persistent pesticides. MMB4 DMS and HLö-7 DMS were previously identified as comparative efficacy leads warranting further evaluations. 2-PAM Cl is the U.S. FDA-approved standard-of-care oxime therapy for OP intoxication. Briefly, PRs were determined in male guinea pigs by varying the subcutaneously (SC) delivered OP dose followed then by therapy with fixed levels of the oxime and atropine (0.4 mg/kg; administered intramuscularly [IM]). EDs were determined using a similar approach except the OP dose was held constant at twice the median lethal dose (2 × LD) while the oxime treatment levels were varied. The ED information was then used to calculate the TI for each OP/oxime combination. Both MMB4 DMS and HLö-7 DMS provided significant protection, i.e., higher PR against GB, VX, and PHO when compared to atropine controls, but significance was not readily demonstrated across the board when compared against 2-PAM Cl. The ED values of MMB4 DMS was consistently lower than that of the other oximes against all three OPs. Furthermore, based on those EDs, the TI trend of the various oximes against both GB and VX was MMB4 DMS > HLö-7 DMS > 2-PAM Cl, while against PHO, MMB4 DMS > 2-PAM Cl > HLö-7 DMS.
Topics: Animals; Chemical Warfare Agents; Cholinesterase Inhibitors; Cholinesterase Reactivators; Guinea Pigs; Insecticides; Male; Organophosphates; Organothiophosphorus Compounds; Oximes; Phorate; Pralidoxime Compounds; Pyridinium Compounds; Sarin
PubMed: 30056178
DOI: 10.1016/j.neuro.2018.07.014 -
International Journal of Hygiene and... Apr 2018Occupational studies suggest that exposure to organophosphate insecticides (OPs) can lead to vision or hearing loss. Yet the effects of early-life exposure on visual and...
BACKGROUND
Occupational studies suggest that exposure to organophosphate insecticides (OPs) can lead to vision or hearing loss. Yet the effects of early-life exposure on visual and auditory function are unknown. Here we examined associations between prenatal OP exposure and grating visual acuity (VA) and auditory brainstem response (ABR) during infancy.
METHODS
30 OPs were measured in umbilical cord blood using gas chromatography tandem mass spectrometry in a cohort of Chinese infants. Grating visual acuity (VA) (n = 179-200) and auditory brainstem response (ABR) (n = 139-183) were assessed at 6 weeks, 9 months, and 18 months. Outcomes included VA score, ABR wave V latency and central conduction time, and head circumference (HC). Associations between sensory outcomes during infancy and cord OPs were examined using linear mixed models.
RESULTS
Prenatal chlorpyrifos exposure was associated with lower 9-month grating VA scores; scores were 0.64 (95% CI: -1.22, -0.06) points lower for exposed versus unexposed infants (p = 0.03). The OPs examined were not associated with infant ABR latencies, but chlorpyrifos and phorate were both significantly inversely associated with HC at 9 months; HCs were 0.41 (95% CI: 0.75, 0.6) cm and 0.44 (95% CI: 0.88, 0.1) cm smaller for chlorpyrifos (p = 0.02) and phorate (p = 0.04), respectively.
CONCLUSIONS
We found deficits in grating VA and HC in 9-month-old infants with prenatal exposure to chlorpyrifos. The clinical significance of these small but statistically significant deficits is unclear. However, the disruption of visual or auditory pathway maturation in infancy could potentially negatively affect downstream cognitive development.
Topics: Adult; Chlorpyrifos; Cohort Studies; Developmental Disabilities; Environmental Pollutants; Evoked Potentials, Auditory, Brain Stem; Female; Fetal Blood; Hearing; Hearing Disorders; Humans; Infant; Insecticides; Male; Maternal Exposure; Mothers; Organophosphorus Compounds; Phorate; Pregnancy; Prenatal Exposure Delayed Effects; Sensation; Vision Disorders; Vision, Ocular; Visual Acuity
PubMed: 29402694
DOI: 10.1016/j.ijheh.2018.01.010 -
Sensors (Basel, Switzerland) Jul 2022In this work, we reported a rapid and sensitive fluorescence assay in homogenous solution for detecting organophosphorus pesticides by using tetramethylrhodamine...
In this work, we reported a rapid and sensitive fluorescence assay in homogenous solution for detecting organophosphorus pesticides by using tetramethylrhodamine (TAMRA)-labeled aptamer and its complementary DNA (cDNA) with extended guanine (G) bases. The hybridization of cDNA and aptamer drew TAMRA close to repeated G bases, then the fluorescence of TAMRA was quenched by G bases due to the photoinduced electron transfer (PET). Upon introducing the pesticide target, the aptamer bound to pesticide instead of cDNA because of the competition between pesticide and cDNA. Thus, the TAMRA departed from G bases, resulting in fluorescence recovery of TAMRA. Under optimal conditions, the limits of detection for phorate, profenofos, isocarbophos, and omethoate were 0.333, 0.167, 0.267, and 0.333 µg/L, respectively. The method was also used in the analysis of profenofos in vegetables. Our fluorescence design was simple, rapid, and highly sensitive, which provided a means for monitoring the safety of agricultural products.
Topics: Aptamers, Nucleotide; DNA, Complementary; Fluorescence; Organophosphorus Compounds; Pesticides
PubMed: 35957269
DOI: 10.3390/s22155712 -
Environment International Sep 2018Little is known about modifiable risk factors for thyroid disease. Several pesticides have been implicated in thyroid disruption, but clinical implications are not clear.
BACKGROUND
Little is known about modifiable risk factors for thyroid disease. Several pesticides have been implicated in thyroid disruption, but clinical implications are not clear.
OBJECTIVE
We assessed associations between pesticide use and other farm exposures and incident hypothyroidism and hyperthyroidism in female spouses of farmers in the Agricultural Health Study (AHS).
METHODS
We used Cox proportional hazards models to estimate hazard ratios (HR) and 95% confidence intervals for risk of thyroid disease in 24,092 spouses who completed at least one follow-up questionnaire.
RESULTS
We identified 1627 hypothyroid and 531 hyperthyroid cases over 20 years of follow-up. The fungicides benomyl, maneb/mancozeb, and metalaxyl, the herbicide pendimethalin, and among those over 60 years of age the insecticides parathion and permethrin (applied to crops) were associated with elevated hypothyroidism risk, with HR ranging from 1.56-2.44. Conversely, the insecticide phorate, and the herbicides imazethapyr and metolachlor were associated with decreased risk (HR ranging 0.63-0.73), as were long-term farm residence and other farm-related activities (HR ranging 0.69-0.84). For hyperthyroidism, the insecticide diazinon, the fungicides maneb/mancozeb, and the herbicide metolachlor were associated with increased risk (HR ranging 1.35-2.01) and the herbicide trifluralin with decreased risk (HR: 0.57).
CONCLUSIONS
Several individual pesticides were associated with increased risk of hypothyroidism and hyperthyroidism, although some pesticides were associated with decreased risk. Some of the findings, specifically associations with fungicides, are consistent with results from an earlier analysis of prevalent diseases in AHS spouses.
Topics: Female; Follow-Up Studies; Humans; Male; Occupational Exposure; Pesticides; Spouses; Surveys and Questionnaires; Thyroid Diseases
PubMed: 29908479
DOI: 10.1016/j.envint.2018.05.041 -
Journal of Hazardous Materials Apr 2022In this study, three-dimensional reduced graphene oxide aerogel (rGOA)-supported nanozero-valent iron (rGOA-nZVI) was successfully synthesized via tailored design and...
In this study, three-dimensional reduced graphene oxide aerogel (rGOA)-supported nanozero-valent iron (rGOA-nZVI) was successfully synthesized via tailored design and applied to activate persulfate (PS) to degrade three organophosphorus pesticides (OPPs; phorate, terbufos and parathion) in water and a historically contaminated soil. The results showed that loading nZVI nanoparticles on rGOA could prevent the aggregation of nZVI. rGOA-nZVI presented a better catalytic performance for PS activation to degrade the three OPPs than bare nZVI and rGOA, with degradation efficiencies of greater than 99.5% within 5 min. pH had negligible effects on the PS activated by rGOA-nZVI (rGOA-nZVI/PS). EPR measurements and radical quenching experiments showed that ·SO and ·OH were the main radicals responsible for OPP removal in the rGOA-nZVI/PS system. Furthermore, nine intermediates were identified, and the oxidation and scission of C-S-C, P-S/O and PS were the dominant degradation pathways of the three OPPs in aqueous solutions treated with rGOA-nZVI/PS. Additionally, rGOA-nZVI/PS achieved degradation efficiencies of 95.1% for phorate, 79.9% for terbufos and 89.1% for parathion in the contaminated soil, and the detected intermediates could be further degraded except triethylphosphate. Overall, this study provides practical knowledge for OPP removal by rGOA-nZVI/PS in wastewater and actual contaminated soil.
Topics: Graphite; Organophosphorus Compounds; Pesticides; Water Pollutants, Chemical
PubMed: 35051772
DOI: 10.1016/j.jhazmat.2022.128254 -
Movement Disorders : Official Journal... May 2022Dream-enacting behavior is a characteristic feature of rapid eye movement sleep behavior disorder, the most specific prodromal marker of synucleinopathies. Pesticide...
BACKGROUND
Dream-enacting behavior is a characteristic feature of rapid eye movement sleep behavior disorder, the most specific prodromal marker of synucleinopathies. Pesticide exposure may be associated with dream-enacting behaviors, but epidemiological evidence is limited.
OBJECTIVES
To examine high pesticide exposure events in relation to dream-enacting behaviors among farmers in the Agricultural Health Study.
METHODS
We conducted multivariable logistic regression analyses to examine high pesticide exposure events reported from 1993 to 1997 in relation to dream-enacting behaviors assessed from 2013 to 2015 among 11,248 farmers (age 47 ± 11 years).
RESULTS
A history of dream-enacting behaviors was reported by 939 (8.3%) farmers. Compared with farmers who did not report any high pesticide exposure event, those who reported were more likely to endorse dream-enacting behaviors 2 decades later (odds ratio = 1.75; 95% confidence interval [CI], 1.49-2.05). The association appeared stronger when there was a long delay in washing with soap and water after the event (2.63 [95% CI, 1.62-4.27] for waiting >6 hours vs. 1.71 [95% CI, 1.36-2.15] for washing within 30 minutes) and when the exposure involved the respiratory or digestive tract (2.04 [95% CI, 1.62-2.57] vs. 1.58 [95% CI, 1.29-1.93] for dermal contact only). In the analyses of specific pesticides involved, we found positive associations with two organochlorine insecticides (dichlorodiphenyltrichloroethane and lindane), four organophosphate insecticides (phorate, ethoprop, terbufos, and parathion), two herbicides (alachlor and paraquat), and fungicides as a group.
CONCLUSIONS
This study provides the first epidemiological evidence that high pesticide exposures may be associated with a higher risk of dream-enacting behaviors. © 2022 International Parkinson and Movement Disorder Society.
Topics: Adult; Agriculture; Farmers; Humans; Insecticides; Middle Aged; Occupational Exposure; Pesticides
PubMed: 35152487
DOI: 10.1002/mds.28960 -
International Journal of Legal Medicine Jul 2021Organophosphorus pesticides (OP) are widely used in the world, and many poisoning cases were caused by them. Phorate intoxication is especially common in China. However,...
Organophosphorus pesticides (OP) are widely used in the world, and many poisoning cases were caused by them. Phorate intoxication is especially common in China. However, there are currently few methods for discriminating phorate poisoning death from phorate exposure after death and interpretation of false-positive results due to the lack of effective biomarkers. In this study, we investigated the metabonomics of rat plasma at different dose levels of acute phorate intoxication using ultra-performance liquid chromatography quadrupole-time of flight mass spectrometry (UPLC-Q-TOF-MS) analysis. A total of 11 endogenous metabolites were significantly changed in the groups exposed to phorate at LD level and three times of LD50 (3LD) level compared with the control group, which could be potential biomarkers of acute phorate intoxication. Plasma metabonomics analysis showed that diethylthiophosphate (DETP) could be a useful biomarker of acute phorate intoxication. The levels of uric acid, acylcarnitine, succinate, gluconic acid, and phosphatidylcholine (PC) (36:2) were increased, while pyruvate level was decreased in all groups exposed to phorate. The levels of ceramides (Cer) (d 18:0/16:0), palmitic acid, and lysophosphatidylcholine (lysoPC) (18:1) were only changed after 3LD dosage. The results of this study indicate that the dose-dependent relationship exists between metabolomic profile change and toxicities associated with apoptosis, fatty acid metabolism disorder, energy metabolism disorder especially tricarboxylic acid (TCA) cycle, as well as liver, kidney, and nervous system functions after acute exposure of phorate. This study shows that metabonomics is a useful tool in identifying biomarkers for the forensic toxicology study of phorate poisoning.
Topics: Animals; Biomarkers; Chromatography, High Pressure Liquid; Disease Models, Animal; Lethal Dose 50; Mass Spectrometry; Metabolome; Metabolomics; Organophosphate Poisoning; Phorate; Rats
PubMed: 33987742
DOI: 10.1007/s00414-021-02532-z -
Toxics Apr 2022Transmission Electron Microscopic (TEM) assessments were performed on the renal cells of common carp to observe the deleterious effects of two organophosphate...
Transmission Electron Microscopic (TEM) assessments were performed on the renal cells of common carp to observe the deleterious effects of two organophosphate insecticides, Phorate and Dimethoate. Pesticides such as Phorate and Dimethoate often pollute aquatic systems where they may negatively impact fish, but so far, the ultrastructural toxicity of these pesticides remains poorly understood. Here, we use Transmission Electron Microscopy (TEM) to determine how acute exposure to sublethal concentrations of these two pesticides may affect the renal cells of common carp . For each insecticide, the fish were divided in four experimental conditions: a control and three different exposure concentrations of the pesticide. The Phorate treated fish were exposed to three sublethal concentrations of 0.2 mg/L, 0.4 mg/L, 0.6 mg/L for a duration of 24, 48 & 72 h. The dimethoate treated fish were exposed to three sublethal concentrations of 0.005 mL/L, 0.01 mL/L, 0.015 mL/L for a duration of 24, 48 and 72 h. The two-dimensional transmission electron microscopy revealed ultrastructural abnormalities in the treated fish renal cells when exposed to two toxicants including deformation in the glomerulus, vacuolization of cytoplasm, degenerative nucleus and damaged mitochondria. Furthermore, the ultrastructural abnormalities were more prominent with the increase in the concentrations of both the insecticides and also with their exposure period. Overall, these results provide important baseline data on the ultrastructural toxicity of Phorate and Dimethoate and will allow important follow-up studies to further elucidate the underlying cellular mechanisms of pesticide toxicity in wildlife.
PubMed: 35448438
DOI: 10.3390/toxics10040177 -
Journal of Food Protection Mar 2021We evaluated fresh vegetables for residues of 18 pesticides with different chemical structures, including organochlorine pesticides, organophosphorus pesticides,...
ABSTRACT
We evaluated fresh vegetables for residues of 18 pesticides with different chemical structures, including organochlorine pesticides, organophosphorus pesticides, carbamate pesticides, and pyrethroid pesticides and estimated that the potential health risks for consumers. A total of 313 samples were collected from 12 kinds of vegetables in Changchun, the capital of Jilin Province, People's Republic of China. Pesticide residues were analyzed by gas chromatography and mass spectrometry, and the curves were highly linear at 0.01 to 1.00 μg/mL (R2 ≥ 0.99). The mean recovery rate of the pesticides was 62 to 110% (relative standard deviation of <5%). The limit of detection was 0.0001 to 0.0167 mg/kg, the limit of quantification was 0.0002 to 0.0556 mg/kg, and the overall detection rate was 28.43%. The prevalence of pesticides and of samples above the standard limit were highest in celery, the prevalence of pesticides was lowest in potatoes, and the prevalence of samples above the standard limit was lowest in cucumber. Three of the 18 pesticides were not detected: omethoate, chlorpyrifos, and fenvalerate. Among the 15 pesticides detected, the maximum risk factor of six (carbofuran, omethoate, phorate, dicofol, dimethoate, and dichlorvos) is >1, indicating possible harm to human health. Residues of a single pesticide may not adversely affect a person's health, but multiple pesticide residues could present a health risk.
Topics: China; Food Contamination; Humans; Pesticide Residues; Pesticides; Vegetables
PubMed: 33108463
DOI: 10.4315/JFP-20-236