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Toxicological Sciences : An Official... Sep 2019This in vitro study evaluated the "triple protocol" of dry decontamination, the ladder pipe system (a method for gross decontamination), and technical decontamination...
This in vitro study evaluated the "triple protocol" of dry decontamination, the ladder pipe system (a method for gross decontamination), and technical decontamination for the decontamination of hair following chemical contamination. First, we assessed the efficacy of the 3 protocols, alone or in combination, on excised porcine skin and human hair contaminated with either methyl salicylate (MS), phorate (PHR), sodium fluoroacetate (SFA), or potassium cyanide (KCN). A second experiment investigated the residual hair contamination following decontamination with the triple protocol at different intervals postexposure. In a third experiment, hair decontaminated after exposure to MS or PHR was evaluated for off-gassing. Though skin decontamination was highly effective, a substantial proportion (20%-40%) of the lipophilic compounds (MS and PHR) remained within the hair. The more water-soluble contaminants (SFA and KCN) tended to form much smaller reservoirs within the hair. Interestingly, substantial off-gassing of MS, a medium volatility chemical, was detectable from triple-decontaminated hair up to 5 days postexposure. Overall, the decontamination strategies investigated were effective for the decontamination of skin, but less so for hair. These findings highlight the importance of contaminated hair serving as a source of potential secondary contamination by contact or inhalation. Therefore, consideration should be given to the removal of contaminated hair following exposure to toxic chemicals.
PubMed: 31241158
DOI: 10.1093/toxsci/kfz145 -
Zhongguo Zhong Yao Za Zhi = Zhongguo... Apr 2019The study aims at taking risk assessment of pesticide residues in ginseng and high risk pesticides were picked up in order to provide a scientific basis for the...
The study aims at taking risk assessment of pesticide residues in ginseng and high risk pesticides were picked up in order to provide a scientific basis for the establishment of maximum residue limits(MRLs) for pesticides in ginseng. Residues of 246 pesticides in 80 ginseng samples collected from different place were detected by GC-MS/MS and LC-MS/MS method. Acute and chronic intake risks were evaluated by using deterministic approach, and the matrix ranking developed by the Veterinary Residues Committee of the United Kingdom was referred to assess risk score of pesticides. The 25 kinds of pesticide residues were detected in ginseng samples, the detection rate of quintozene(PCNB) was 78%, which was the most frequently detectable pesticide. The chronic dietary intake risks of 25 pesticide residues expressed as %ADI were 0.00%-2.6%, and their acute dietary intake risks expressed as %ARfD were 0.00%-104.2%. Among them the acute dietary intake risks of PCNB was 104%,which was the highest. The 25 pesticides were divided into 3 groups by risk score, high risk group(4 pesticides), medium risk group(6 pesticides), and low risk group(15 pesticides). Hexachlorobenzene, phorate, PCNB and BHC were classified as high risk group. It is necessary and effective to establish the limit of residual organic chlorine in ginseng from Chinese Pharmacopoeia(2015 edition). MRLs for PCNB and hexachlorobenzene in ginseng were proposed to be revised based on the results of risk assessment.
Topics: Chromatography, Liquid; Drugs, Chinese Herbal; Panax; Pesticide Residues; Risk Assessment; Tandem Mass Spectrometry
PubMed: 31090288
DOI: 10.19540/j.cnki.cjcmm.20190319.102 -
Fa Yi Xue Za Zhi Jun 2018To investigate the maximum allowable deviation of retention time (RT) or relative retention time (RRT) between the common poisons (drugs) and standard...
OBJECTIVES
To investigate the maximum allowable deviation of retention time (RT) or relative retention time (RRT) between the common poisons (drugs) and standard solvent by gas chromatography-mass spectrometry (GC-MS).
METHODS
After pretreatment with liquid-liquid extraction, four common poisons (drugs)-dichlorvos, phorate, diazepam and estazolam-were detected by full scan mode GC-MS. RT and RRT were analyzed according to combined uncertainty and expanded uncertainty.
RESULTS
The expanded uncertainty of RT and RRT were 6.0×10-14.1×10 and 2.5×10-5.9×10 (=3), respectively. The RT of poisons (drugs) was relatively stable in blood samples with different mass concentrations. Among dichlorvos, phorate, diazepam and estazolam, the absolute deviation and relative deviation of RT were ≤0.03 min and ≤0.4%, respectively, and those of RRT were ≤0.003 min and ≤0.3%, respectively.
CONCLUSIONS
The maximum allowable deviations of RT and RRT for common poisons (drugs) in blood samples are recommended to be ±0.05 min and ±0.5%.
Topics: Gas Chromatography-Mass Spectrometry; Poisons
PubMed: 30896095
DOI: 10.12116/j.issn.1004-5619.2018.06.004 -
Journal of Chromatography. A Jan 2019In this work, magnetic nanoporous carbons (MNPCs) based on Zn/Co-MOFs was synthesized via a facial one-step carbonization method. The prepared MNPCs exhibited high...
Metal organic frameworks-derived magnetic nanoporous carbon for preconcentration of organophosphorus pesticides from fruit samples followed by gas chromatography-flame photometric detection.
In this work, magnetic nanoporous carbons (MNPCs) based on Zn/Co-MOFs was synthesized via a facial one-step carbonization method. The prepared MNPCs exhibited high specific surface areas, good chemical stability and high extraction efficiency for interest organophosphorus pesticides (OPPs). The good extraction performance of the MNPCs for interest OPPs can be primarily attributed to π-π interaction and hydrophobic interaction between MNPCs and OPPs. Based on it, MNPCs-based MSPE-GC-FPD method was established for the quantification of five OPPs in fruit samples. The main experimental conditions for MSPE of five target OPPs were investigated systematically and optimized, such as the desorption solvent and volume, extracted volume, ionic strength, extraction time and desorption time. Under the optimal conditions, the limits of detection (LODs, S/N = 3) were found to be in the range of 0.018 (ethion) -0.045 (malathion) μg/L. The linearity was 0.05-100 μg/L for phorate, diazinon, ethion and 0.1-100 μg/L for malathion, fenthion respectively. The reproducibility of the method was in the range of 3.5-9.7%. The recovery experiments were carried out by spiking target OPPs at three concentration levels to validate the accuracy of the proposed method, and the recoveries for target OPPs were 84-116%. The results show that the proposed method in this work can be successfully used to analyze OPPs residue in fruit sample.
Topics: Carbon; Chromatography, Gas; Fruit; Limit of Detection; Magnetic Phenomena; Metal-Organic Frameworks; Methanol; Nanopores; Organophosphorus Compounds; Organothiophosphorus Compounds; Osmolar Concentration; Pesticide Residues; Pesticides; Photometry; Reproducibility of Results; Solid Phase Extraction; Solvents; Time Factors
PubMed: 30442472
DOI: 10.1016/j.chroma.2018.11.012 -
Food and Chemical Toxicology : An... Jan 2019Human exposure to pesticides can be estimated through different approaches. The approach adopted in this study is based on internal dose measures. Studies published... (Review)
Review
Human exposure to pesticides can be estimated through different approaches. The approach adopted in this study is based on internal dose measures. Studies published during 2001 and 2017 were collected from PubMed and Scopus databases, filtered and organized. The intake of parent compounds is estimated based on the urinary excretion of different OP metabolites applying a mathematical model previously used for similar purposes. Once defined an Estimated Daily Intake (EDI), risk assessment is performed through comparison with specific guideline values and hazard index (HI) is calculated to assess cumulative health risk. The EDI was expressed as malathion, diazinon, parathion, phorate and dimethoate equivalents. Differences in exposure between pregnant women, general population, children and farmers are highlighted and exposures are presented by country and sampling year. Higher exposure to OPs was calculated for farmers, followed by children whereas pregnant women were less exposed. Median HQ values for children ranged between 0.016 and 0.618, for pregnant women 0.005-0.151, for general population 0.008-0.206 and for farmers 0.009-0.979. Combined exposure to dimethoate and phorate was the worst-case scenario. The annual distribution of the urinary DAPs showed that exposure to OPs since 1998 tends to be stable for both children and adults.
Topics: Animals; Environmental Exposure; Environmental Monitoring; Food Contamination; Humans; Organophosphorus Compounds; Pesticides
PubMed: 30352298
DOI: 10.1016/j.fct.2018.10.047 -
Frontiers in Microbiology 2018This work performed a large scale assessment for organophosphorus pesticides (OPPs) degradation activity of 121 (.) strains. Six strains (P9, IMAU80110, IMAU40100,...
This work performed a large scale assessment for organophosphorus pesticides (OPPs) degradation activity of 121 (.) strains. Six strains (P9, IMAU80110, IMAU40100, IMAU10585, IMAU10209, and IMAU80070) were found to possess high capacity of degrading three commonly used OPPs, namely dimethoate, phorate, and omethoate; and they were selected for more detailed characterization. Moreover, the three OPPs were mainly detected in the culture supernatants but not in the cell extracts, further confirming that the OPPs were degraded rather than absorbed by the cells. Among the six selected strains, P9 was most tolerant to gastrointestinal juices and bile. We thus used ultra-high performance liquid chromatography electron spray ionization coupled with time-of-flight mass spectrometry (UPLC/ESI-Q-TOF/MS) to generate the metabolomic profiles of the strain P9 growing in MRS medium with and without containing phorate. By using orthogonal partial least squares discriminant analysis, we identified some potential phorate-derived degradative products. This work has identified novel lactic acid bacteria resources for application in pesticide degradation. Our results also shed light on the phorate degradation mechanism by P9.
PubMed: 30233531
DOI: 10.3389/fmicb.2018.02048 -
Royal Society Open Science Jul 2018This study was performed to determine the storage stability of organophosphorus pesticide residues in high oil content commodity matrices, peanut and soya bean. The...
This study was performed to determine the storage stability of organophosphorus pesticide residues in high oil content commodity matrices, peanut and soya bean. The storage conditions included different types of solvents (ethyl acetate, acetone and hexane) and corresponding extracted matrix solutions, light and temperature. It was found that three pesticides degraded quickly especially in ethyl acetate solvent. They decreased greater than 30% when stored for 3 days at -20°C in ethyl acetate; the results showed that the stability could be improved in the extracted matrix solutions. Light had a slight effect for stability of phorate and fenthion, while it played an important effect for disulfoton with the exception of ethyl acetate as solvent. Even at -20°C, exposure to solvents or extracted matrix solution resulted in 40.67, 96.33 and 35.07% loss of phorate, disulfoton and fenthion. Hence, it could be assumed that these three residues could be more stable at lower temperature, in the dark and in acetone or hexane extracted peanut and soya bean solutions.
PubMed: 30109115
DOI: 10.1098/rsos.180757 -
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 -
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 -
Ecotoxicology and Environmental Safety Sep 2018Microbial consortia isolated from aged phorate contaminated soil were used to degrade phorate. The consortia of three microorganisms (Brevibacterium frigoritolerans,...
Microbial consortia isolated from aged phorate contaminated soil were used to degrade phorate. The consortia of three microorganisms (Brevibacterium frigoritolerans, Bacillus aerophilus and Pseudomonas fulva) could degrade phorate, and the highest phorate removal (between 97.65 and 98.31%) was found in soils inoculated with mixed cultures of all the three bacterial species. However, the mixed activity of any of two of these bacteria was lower than mixed consortia of all the three bacterial species. The highest degradation by individual mixed consortia of (B. frigoritolerans+B.aerophilus, B. aerophilus+P. fulva and B. frigoritolerans+P. fulva) appeared in soil between (92.28-94.09%, 95.45-97.15% and 94.08-97.42%, respectively). Therefore, inoculation of highly potential microbial consortia isolated from in situ contaminated soil could result in most effective bioremediation consortia for significantly relieving soils from phorate residues. This much high phorate remediation from phorate contaminated soils have never been reported earlier by mixed culture of native soil bacterial isolates.
Topics: Bacillus; Biodegradation, Environmental; Insecticides; Microbial Consortia; Phorate; Pseudomonas; Soil Microbiology; Soil Pollutants
PubMed: 29772463
DOI: 10.1016/j.ecoenv.2018.04.063