Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 90
Filtrar
1.
Int Arch Occup Environ Health ; 95(4): 811-823, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-34761282

RESUMO

OBJECTIVE: Although apple trees are heavily sprayed, few studies have assessed the pesticide exposure of operators and workers in apple orchards. However, these data are crucial for assessing the health impact of such exposures. The aim of this study was to measure pesticide exposure in apple growing according to tasks and body parts. METHODS: A non-controlled field study was conducted in apple orchards in 4 regions of France during the 2016 and 2017 treatment seasons. Workers' external contamination and their determinants were assessed over 156 working days corresponding to 30 treatment days, 68 re-entry days and 58 harvesting days. We measured pesticide dermal contamination during each task and made detailed observations of work characteristics throughout the day. Captan and dithianon were used as markers of exposure. RESULTS: The median dermal contamination per day was 5.50 mg of captan and 3.33 mg of dithianon for operators, 24.39 mg of captan and 1.84 mg of dithianon for re-entry workers, and 5.82 mg of captan and 0.74 mg of dithianon for harvesters. Thus, workers performing re-entry tasks, especially thinning and anti-hail net opening, presented higher contamination, either equal to or higher than in operators. For these last ones, mixing/loading and equipment cleaning were the most contaminating tasks. Most of the contamination was observed on workers' hands in all tasks, except for net-opening in which their heads accounted for the most daily contamination. CONCLUSIONS: This study highlights the importance of taking indirect exposures into account during re-entry work in apple growing.


Assuntos
Malus , Exposição Ocupacional , Praguicidas , Captana/análise , Humanos , Exposição Ocupacional/análise , Estações do Ano
2.
Environ Monit Assess ; 193(3): 129, 2021 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-33587214

RESUMO

Samples of leaves, flowers, soil, pollen, bee workers, bee brood, honey, and beeswax were collected to assess the possibility of a transfer of captan, thiacloprid, penthiopyrad, and λ-cyhalothrin from apple trees of Idared variety to honey bee (Apis mellifera) hives. Chemical analyses were performed using the Agilent 7890 Gas Chromatograph equipped with the Micro-cell Electron Capture Detector. It was found that significant amounts of penthiopyrad, the active ingredient of Fontelis 200 SC, were present in leaves, flowers, pollen, bee workers, and beeswax. Simultaneously, captan was present in the brood, worker bees, and honey samples. Significant levels of the captan residues were also detected on the soil surface. In honey samples, captan residue levels exceeded the acceptable standard, reaching 160% of its maximum residue level. However, in no case the amounts of captan, thiacloprid, penthiopyrad, and λ-cyhalothrin ingested with honey by an adult consumer exceeded the level of 0.02% of the acceptable daily intake. Despite the trace amounts of pesticide residues in honey samples collected during the field trial, bee honey consumption can be considered safe. An adult consumer can safely consume about 16 kg of honey.


Assuntos
Inseticidas , Malus , Animais , Abelhas , Captana/análise , Monitoramento Ambiental , Insetos , Inseticidas/análise , Inseticidas/toxicidade , Neonicotinoides , Nitrilas , Pirazóis , Piretrinas , Tiazinas , Tiofenos
3.
J Environ Sci Health B ; 53(1): 18-24, 2018 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-29083963

RESUMO

This investigation was undertaken to determine whether active ingredients (AIs) of currently recommended plant protection products (PPPs) could be transferred to beehives from apple and pear trees. A field trial was carried out with apple trees of Ligol and Idared variety, and pear trees of Conference variety. For pest and diseases control of fungal origin, recommended PPPs were applied. Samples of flowers from the above-mentioned varieties of fruit trees, of bees, brood and honey from beehives located in their direct neighborhood were collected regularly and analyzed for the presence of lambda-cyhalothrin (an insecticide) and cyprodinil, captan, fluopyram, kresoxim-methyl, penthiopyrad and trifloxystrobin (fungicides). In samples of flowers of Ligol variety, fluopyram residues (on average 0.621 µg single flower-1) were at the highest levels, whereas in samples of pear flowers of Conference variety, and in flowers of Idared variety, captan residues (on average, respectively, 0.705 and 165.7 µg single flower-1). In samples of bees and honey, residues of five AIs were detected, and in brood six AIs, whereby in each case captan residues prevailed, respectively, up to 585.2, 51.52 and 126.5 µg kg-1 bees and honey. In the honey, significantly larger residues of captan were found out than maximum residue level (MRL) for this AI - 103.04% MRL. In the case of any AI, the daily intake did not exceed 0.002% acceptable daily intake (ADI).


Assuntos
Abelhas , Poluentes Ambientais/análise , Fungicidas Industriais/análise , Mel/análise , Inseticidas/análise , Acetatos/análise , Animais , Benzamidas/análise , Captana/análise , Flores/química , Frutas/química , Iminas/análise , Malus , Nitrilas/análise , Polônia , Piretrinas/análise , Piridinas/análise , Pyrus , Estrobilurinas/análise
4.
Bull Environ Contam Toxicol ; 96(2): 217-23, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26611369

RESUMO

A novel bio-analytical method has been devised based on the change in catalytic activity of acetylcholinesterase (AChE) enzyme induced by captan, carbosulfan, 2,3,7,8-tetrachlorodibenzodioxin (TCDD) and pentachlorophenol (PCP) for the investigation of inhibition efficiency and sensitivity using Pt/ZnO/AChE/Chitosan bioelectrode. The inhibition curves of captan, carbosulfan, TCDD and PCP were similar to Michaelis-Menten curve. TCDD held the minimum inhibitor Michaelis-Menten constant ([Formula: see text]) value (10.2 nM) in comparison with PCP (10.9 nM), carbosulfan (14.5 nM) and captan (7.9 × 10(3) nM). The maximum inhibition of AChE enzyme by captan was about 100 %, which was much higher than that of TCDD (72.7 %), PCP (68.1 %) and carbosulfan (47.7 %). The calculated theoretical sensitivity was in the order of TCDD > PCP > carbosulfan > captan. Comparing with TCDD (35.3 %), PCP (47.8 %) and carbosulfan (20.9 %), only the inhibition efficiency of captan (55.0 %) was the maximum. The developed bioelectrode exhibited high recovery and low relative standard deviation in local tap water samples.


Assuntos
Técnicas Biossensoriais , Captana/análise , Carbamatos/análise , Pentaclorofenol/análise , Resíduos de Praguicidas/análise , Dibenzodioxinas Policloradas/análise , Água/química , Acetilcolinesterase/química , Captana/química , Carbamatos/química , Pentaclorofenol/química , Dibenzodioxinas Policloradas/química
5.
Anal Bioanal Chem ; 407(16): 4863-8, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25895947

RESUMO

The presence of captan residues in apples shows high toxicity, which often causes eye and skin irritation, dermatitis, conjunctivitis, and vomiting in humans. In this context, an electrochemical biosensor based on acetylcholinesterase (AChE) immobilized on a ZnO nanorod interface has been proposed. In this work, Hill, dose-response, and first-, second-, and third-order polynomial regression models were successfully applied and the prediction ability of these models was tested with the use of current density obtained from the cyclic voltammograms of appropriate captan solutions. The Pt/ZnO/AChE bioelectrode showed a high sensitivity of 0.538 µA cm(-2) µM(-1) in the linear range from 0.05 to 25.0 µM with a limit of detection of 107 nM. The recovery results were observed between 98.4 and 102.4 % from the apple sample. This work provides a new promising tool for the detection of captan in apple samples.


Assuntos
Acetilcolinesterase/química , Técnicas Biossensoriais , Captana/análise , Técnicas Eletroquímicas , Limite de Detecção
6.
Talanta ; 274: 126011, 2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38574537

RESUMO

In this article, we have studied the potential of flexible microtube plasma (FµTP) as ionization source for the liquid chromatography high-resolution mass spectrometry detection of non-easily ionizable pesticides (viz. nonpolar and non-ionizable by acid/basic moieties). Phthalimide-related compounds such as dicofol, dinocap, o-phenylphenol, captan, captafol, folpet and their metabolites were studied. Dielectric barrier discharge ionization (DBDI) was examined using two electrode configurations, including the miniaturized one based on a single high-voltage (HV) electrode and a virtual ground electrode configuration (FµTP), and also the two-ring electrode DBDI configuration. Different ionization pathways were observed to ionize these challenging, non-easily ionizable nonpolar compounds, involving nucleophilic substitutions and proton abstraction, with subtle differences in the spectra obtained compared with APCI. An average sensitivity increase of 5-fold was attained compared with the standard APCI source. In addition, more tolerance with matrix effects was observed in both DBDI sources. The importance of the data reported is not just limited to the sensitivity enhancement compared to APCI, but, more notably, to the ability to effectively ionize nonpolar, late-eluting (in reverse-phase chromatography) non-ionizable compounds. Besides o-phenylphenol ([M - H]-), all the parent species were efficiently ionized through different mechanisms involving bond cleavages through the effect of plasma reagent species or its combination with thermal degradation and subsequent ionization. This tool can be used to figure out overlooked nonpolar compounds in different environmental samples of societal interest through non-target screening (NTS) strategies.


Assuntos
Espectrometria de Massas , Praguicidas , Praguicidas/análise , Praguicidas/química , Praguicidas/sangue , Cromatografia Líquida/métodos , Espectrometria de Massas/métodos , Ftalimidas/química , Ftalimidas/análise , Contaminação de Alimentos/análise , Miniaturização , Captana/análise , Captana/sangue , Captana/química , Análise de Alimentos/métodos
7.
Chemosphere ; 313: 137498, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36495984

RESUMO

Apples play an important role in everyone's diet and may contain pesticide residues that can pose a significant health problem for consumers. Various technological processes are promising methods for minimizing pesticide concentrations in fruit. Therefore, the subject of this comprehensive study was to investigate the effects of high-temperature (baking) and low-temperature (freeze-drying) processes on the change in the levels of nine fungicides in apples with skin and peeled. The investigated compounds belong to the chemical groups of benzimidazole (thiophanate methyl and carbendazim), phtalimide (captan and their metabolite tetrahydrophtalimid (THPI)), strobilurin (pyraclostrobin, trifloxystrobin) and triazole (difenoconazole, tebuconazole, tetraconazole). Processing factors (PF) were calculated for each pesticide-process-product combination. The results show that baking and freeze-drying generally reduced pesticide concentrations, with PFs ranging from 0.31 to 0.81 and 0.26 to 0.68, respectively. Apart from freeze-drying for carbendazim and baking for captan, PFs were above 1. Only for thiophanate-methyl, a complete reduction was observed, which resulted from complete degradation to carbendazim. The study also aimed to assess human risk according to the new strategy for different sub-populations with conversion using the 36 PFs obtained. The highest acute exposure (expressed as %ARfD) was obtained for tebuconazole in raw apples (initial concentration of 1.42 mg/kg; 400% ARfD) for Dutch toddlers. After food processing, this decreased to 284% (0.74 mg/kg, baking) and to 137% (0.37 mg/kg, freeze-drying), but was still above the safety limit. Similarly, for adults and the general French population for tebuconazole, the %ARfD was high as it reached the values of 104% (initial concentration of 0.89 mg/kg) in unprocessed apples, 73.9% after baking (0.73 mg/kg) and 35.6% after freeze-drying (0.35 mg/kg). The results indicate that food processing techniques can potentially be used to minimize the hazardous effects of pesticide residues on human health.


Assuntos
Malus , Resíduos de Praguicidas , Praguicidas , Adulto , Humanos , Praguicidas/análise , Malus/química , Resíduos de Praguicidas/análise , Captana/análise , Temperatura , Frutas/química , Ingestão de Alimentos , Medição de Risco , Contaminação de Alimentos/prevenção & controle , Contaminação de Alimentos/análise
8.
Mycologia ; 114(5): 813-824, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35862659

RESUMO

The aim of this work was to isolate fungal strains from phytotoxic agricultural soils, screen them, categorize the most tolerant fungi to three fungicides, and identify them by a molecular approach. In this study, 28 fungal strains were isolated from phytotoxic agricultural soil with intensive use of pesticides. The capacity of fungi to resist and degrade different concentrations of carbendazim, captan, and zineb was determined by an exploratory multivariate analysis. Actinomucor elegans LBM 239 was identified as the most tolerant fungus to these fungicides, degrading a 86.62% of carbendazim after 7 days of treatment. In conclusion, A. elegans LBM 239 demonstrated the highest tolerance and capacity to biodegrade carbendazim, becoming a potential candidate for bioremediation of contaminated soils with carbendazim, captan, or zineb.


Assuntos
Fungicidas Industriais , Poluentes do Solo , Zineb , Captana/análise , Fungicidas Industriais/farmacologia , Solo , Microbiologia do Solo , Poluentes do Solo/metabolismo
9.
Ann Occup Hyg ; 55(6): 620-33, 2011 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-21427168

RESUMO

OBJECTIVES: To identify and quantify determinants of captan exposure among 74 private orchard pesticide applicators in the Agricultural Health Study (AHS). To adjust an algorithm used for estimating pesticide exposure intensity in the AHS based on these determinants and to compare the correlation of the adjusted and unadjusted algorithms with urinary captan metabolite levels. METHODS: External exposure metrics included personal air, hand rinse, and dermal patch samples collected from each applicator on 2 days in 2002-2003. A 24-h urine sample was also collected. Exposure determinants were identified for each external metric using multiple linear regression models via the NLMIXED procedure in SAS. The AHS algorithm was adjusted, consistent with the identified determinants. Mixed-effect models were used to evaluate the correlation between the adjusted and unadjusted algorithm and urinary captan metabolite levels. RESULTS: Consistent determinants of captan exposure were a measure of application size (kilogram of captan sprayed or application method), wearing chemical-resistant (CR) gloves and/or a coverall/suit, repairing spray equipment, and product formulation. Application by airblast was associated with a 4- to 5-fold increase in exposure as compared to hand spray. Exposure reduction to the hands, right thigh, and left forearm from wearing CR gloves averaged ∼80%, to the right and left thighs and right forearm from wearing a coverall/suit by ∼70%. Applicators using wettable powder formulations had significantly higher air, thigh, and forearm exposures than those using liquid formulations. Application method weights in the AHS algorithm were adjusted to nine for airblast and two for hand spray; protective equipment reduction factors were adjusted to 0.2 (CR gloves), 0.3 (coverall/suit), and 0.1 (both). CONCLUSIONS: Adjustment of application method, CR glove, and coverall weights in the AHS algorithm based on our exposure determinant findings substantially improved the correlation between the AHS algorithm and urinary metabolite levels.


Assuntos
Agricultura/métodos , Poluentes Ocupacionais do Ar/análise , Captana/análise , Fungicidas Industriais/análise , Exposição Ocupacional/estatística & dados numéricos , Pele/química , Poluentes Ocupacionais do Ar/urina , Algoritmos , Captana/administração & dosagem , Captana/urina , Cromatografia Líquida de Alta Pressão , Monitoramento Ambiental/métodos , Antebraço , Frutas , Fungicidas Industriais/administração & dosagem , Fungicidas Industriais/urina , Cromatografia Gasosa-Espectrometria de Massas , Mãos , Inquéritos Epidemiológicos/estatística & dados numéricos , Humanos , Modelos Lineares , Modelos Químicos , Exposição Ocupacional/análise , Saúde Ocupacional , Roupa de Proteção/estatística & dados numéricos , Coxa da Perna
10.
Food Chem ; 354: 129360, 2021 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-33735697

RESUMO

In this study, effects of low-intensity electrical currents (200, 800 and 1400 mA), ultrasound frequencies (24 and 40 kHz) and their combinations were applied at the duration period of 2, 4, 6, 8, and 10 min for the degradation of captan, thiamethoxam and metalaxyl residues in lettuce samples. Residues of the pesticides were determined by gas chromatography with tandem mass spectrometry and electron capture detector. The results indicated that the combination of low-intensity electrical current and ultrasound was found to be effective for the reduction of the pesticides. The most effective combination was obtained to be current of 1400 mA and ultrasound frequency of 24 kHz at 10 min. Under this circumstance, 92.57, 81.99 and 93.09% of captan, thiamethoxam and metalaxyl residues were decreased, respectively. The findings suggest that the combination of low-intensity electrical current and ultrasound applications has an important potential for the degradation of pesticide residues.


Assuntos
Contaminação de Alimentos/análise , Lactuca/química , Resíduos de Praguicidas/análise , Alanina/análogos & derivados , Alanina/análise , Alanina/química , Captana/análise , Captana/química , Eletricidade , Cromatografia Gasosa-Espectrometria de Massas/métodos , Lactuca/metabolismo , Resíduos de Praguicidas/química , Sonicação , Tiametoxam/análise , Tiametoxam/química
11.
Food Chem ; 309: 125691, 2020 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-31679853

RESUMO

This study presented a HPTLC platformed luminescent biosensor system for screening captan residue. First, the potential bio-effects of layers materials on the detectability of a luminescent bacteria Photobacterium phosphoreum (ATCC 11040) as the sensor cell were assessed. From comparison, it was noteworthy that the combination of sensor cells with normal silica gel layer exclusively gave outstanding detectability (<10 ng/zone). On this basis, HPTLC mediated separation and biosensing was further optimized. Then, the obtained graphic results were digitally quantified via software processing, offering satisfactory selectivity, linearity (R2 = 0.9901 within 10-80 ng/zone) and sensitivity (0.5 mg/kg against MRLs ≥ 6 mg/kg). Additionally, the performance of the established method was validated with different fruits (recover rates 75-96%, RSD < 11.8%). Meanwhile, it was demonstrated that detectability of this hybrid system would be tuneable by altering the combination of bacteria strains and layer materials, which was meaningful to strengthen the usability of microbial biosensors.


Assuntos
Técnicas Biossensoriais/métodos , Captana/análise , Fungicidas Industriais/análise , Cromatografia em Camada Fina , Frutas/química , Frutas/metabolismo , Malus/química , Malus/metabolismo , Photobacterium/química , Photobacterium/isolamento & purificação , Sílica Gel/química
12.
J Econ Entomol ; 102(1): 20-9, 2009 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19253613

RESUMO

Three almond field trials were conducted during 2003 and 2004 at two locations in central (Fresno County) and northern (Yolo County) California to evaluate the potential effects of commercial applications of Captan on honey bees, Apis mellifera L. Captan was applied at 5.0 kg (AI)/ha during bloom. Hives were evaluated for hive health and brood development parameters for approximately 2 mo after application. This study showed that the application of Captan was not harmful to foraging honey bees or their brood. No treatment-related effects were noted on hive weights, dead bee deformity, number of dead bees, survival of individual larvae, weight of individual emerging adults, and other hive health parameters.


Assuntos
Abelhas/efeitos dos fármacos , Captana/farmacologia , Fungicidas Industriais/farmacologia , Resíduos de Praguicidas/análise , Agricultura , Animais , Abelhas/crescimento & desenvolvimento , Peso Corporal/efeitos dos fármacos , California , Captana/análise , Flores/química , Fungicidas Industriais/análise , Mel/análise , Prunus/química , Tempo (Meteorologia)
13.
Artigo em Inglês | MEDLINE | ID: mdl-31535952

RESUMO

In this study, we propose an improved analytical method for the multiresidue analysis of captan (plus its metabolite, tetrahydrophthalimide), folpet (plus its metabolite, phthalimide), captafol, and iprodione in cereals using liquid chromatography tandem mass spectrometry (LC-MS/MS). As captan, captafol, and folpet are easily degraded during homogenisation and extraction, samples were comminuted with liquid nitrogen, and both QuEChERS and ethyl acetate-based extraction workflows provided a satisfactory method performance. The optimised LC-MS/MS procedure with electrospray ionisation did not degrade these compounds, and offered sufficient method selectivity by resolving and minimising co-eluting matrix-derived interferences. The method also resolved the problem of non-specific mass spectra that these compounds usually produce on GC-MS analysis involving electron ionisation. The method performance was satisfactory for all 6 compounds at 0.01 mg kg-1 and higher levels of fortification, and validated as per the SANTE/11813/2017 guidelines of analytical quality control in a wide range of cereals including rice, wheat, sorghum, and corn. The method provides special advantage of simultaneous analysis of captan, and folpet along with their metabolites (tetrahydrophthalimide, and phthalimide, respectively) in combination with captafol, and iprodione in a single chromatographic run. Although iprodione is known to degrade to 3,5-dichloroaniline, since this metabolite is not a part of the residue definition, it was not included in the scope of this method. As the method demonstrates satisfactory selectivity, sensitivity, accuracy, precision, and robustness in a wide range of cereal matrices, it is recommended for regulatory testing of these compounds in cereals.


Assuntos
Aminoimidazol Carboxamida/análogos & derivados , Captana/análogos & derivados , Captana/análise , Cicloexenos/análise , Contaminação de Alimentos/análise , Hidantoínas/análise , Resíduos de Praguicidas/análise , Ftalimidas/análise , Aminoimidazol Carboxamida/análise , Cromatografia Líquida , Grão Comestível/química , Análise de Alimentos , Espectrometria de Massas em Tandem
14.
Food Chem ; 301: 125216, 2019 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-31404804

RESUMO

An improved liquid chromatography tandem mass spectrometry method is reported for the determination of residues of captan (+tetrahydrophthalimide), captafol, folpet (+phthalimide), and iprodione in fruits and vegetables. The optimized electrospray ionization parameters (high cone gas flow, and a low desolvation temperature) did not result in degradation of target compounds, rather they provided a significant advantage over the conventional GC-MS/MS methods, which lack sensitivity and repeatability. Strategies for minimizing losses in recovery of these compounds during sample preparation included cryogenic comminution, extraction with acidified ethyl acetate or acetonitrile, and dilution of the final extract with acidified water prior to LC-MS/MS analysis. The method performance complied with the SANTE/11813/2017 guidelines, with recoveries in the range of 70-120% at the LOQ of 0.01 mg/kg across the tested matrices at various pHs. The efficiency of the method was reflected in its precision (RSDs < 10%) for incurred residues.


Assuntos
Cromatografia Líquida/métodos , Contaminação de Alimentos/análise , Frutas/química , Resíduos de Praguicidas/análise , Espectrometria de Massas em Tandem/métodos , Verduras/química , Aminoimidazol Carboxamida/análogos & derivados , Aminoimidazol Carboxamida/análise , Captana/análogos & derivados , Captana/análise , Cicloexenos/análise , Hidantoínas/análise , Limite de Detecção , Ftalimidas/análise
15.
Anal Bioanal Chem ; 392(4): 749-54, 2008 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-18665351

RESUMO

A novel method was developed for the determination of captan, folpet, and captafol in apples by dispersive liquid-liquid microextraction (DLLME) coupled with gas chromatography-electron capture detection (GC-ECD). Some experimental parameters that influence the extraction efficiency, such as the type and volume of the disperser solvents and extraction solvents, extraction time, and addition of salt, were studied and optimized to obtain the best extraction results. Under the optimum conditions, high enrichment factors for the compounds were achieved ranging from 824 to 912. The recoveries of fungicides in apples at spiking levels of 20.0 microg kg(-1) and 70.0 microg kg(-1) were 93.0-109.5% and 95.4-107.7%, respectively. The relative standard deviations (RSDs) for the apple samples at 30.0 microg kg(-1) of each fungicide were in the range from 3.8 to 4.9%. The limits of detection were between 3.0 and 8.0 microg kg(-1). The linearity of the method ranged from 10 to 100 microg kg(-1) for the three fungicides, with correlation coefficients (r (2)) varying from 0.9982 to 0.9997. The obtained results show that the DLLME combined with GC-ECD can satisfy the requirements for the determination of fungicides in apple samples.


Assuntos
Captana/análogos & derivados , Captana/análise , Cromatografia Gasosa/métodos , Cicloexenos/análise , Malus/química , Ftalimidas/análise , Antifúngicos/química , Calibragem , Reprodutibilidade dos Testes , Sais , Soluções , Solventes , Fatores de Tempo
16.
Ann Occup Hyg ; 52(3): 153-66, 2008 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-18326518

RESUMO

Pesticide exposure assessment in the Agricultural Health Study (AHS) has relied upon two exposure metrics: lifetime exposure days and intensity-weighted lifetime exposure days, the latter incorporating an intensity score computed from a questionnaire-based algorithm. We evaluated this algorithm using actual fungicide exposure measurements from AHS private orchard applicators. Captan was selected as a marker of fungicide exposure. Seventy-four applicators from North Carolina and Iowa growing apples and/or peaches were sampled on 2 days they applied captan in 2002 and 2003. Personal air, hand rinse, 10 dermal patches, a pre-application first-morning urine and a subsequent 24-h urine sample were collected from each applicator per day. Environmental samples were analyzed for captan, and urine samples were analyzed for cis-1,2,3,6-tetrahydrophthalimide (THPI). Task and personal protective equipment information needed to compute an individual's algorithm score was also collected. Differences in analyte detection frequency were tested in a repeated logistic regression model. Mixed-effects models using maximum-likelihood estimation were employed to estimate geometric mean exposures and to evaluate the measured exposure data against the algorithm. In general, captan and THPI were detected significantly more frequently in environmental and urine samples collected from applicators who used air blast sprayers as compared to those who hand sprayed. The AHS pesticide exposure intensity algorithm, while significantly or marginally predictive of thigh and forearm captan exposure, respectively, did not predict air, hand rinse or urinary THPI exposures. The algorithm's lack of fit with some exposure measures among orchard fungicide applicators may be due in part to the assignment of equal exposure weights to air blast and hand spray application methods in the current algorithm. Some modification of the algorithm is suggested by these results.


Assuntos
Agricultura , Captana/administração & dosagem , Fungicidas Industriais/administração & dosagem , Exposição Ocupacional/análise , Algoritmos , Captana/análise , Monitoramento Ambiental/métodos , Feminino , Frutas , Fungicidas Industriais/análise , Humanos , Masculino , Modelos Biológicos
17.
Pest Manag Sci ; 64(5): 565-78, 2008 May.
Artigo em Inglês | MEDLINE | ID: mdl-18189242

RESUMO

BACKGROUND: Captan is an important fungicide for controlling diseases in horticultural crops. Understanding its dissipation is important for estimating dietary risks and optimising pesticide application. Field experiments were conducted on apple leaves and fruit to investigate (1) the temporal variability of captan residues, (2) the contribution of several factors to the variability in residues and (3) the relationship between residues and climatic conditions. RESULTS: Initial captan deposits and subsequent residues on fruit and leaves were closer to a lognormal than to a normal distribution. The unit-to-unit variation contributed most to the observed variability in the initial deposit and subsequent residues. Variability due to orchards or trees or tree-zone interactions was also frequently important, but there was no discernable trend in the effects. The variability in residues did not appear to decrease over time. Canopy structure affected greatly the initial deposition but had little direct effect on subsequent captan loss. Fruit and leaves on the outside of the tree canopy received more deposit than those on the inside, but these differences gradually decreased over time. Captan loss resulted mainly from the first rainfall after an application. CONCLUSIONS: Captan loss is mainly due to rain, and the loss is negligible under dry conditions.


Assuntos
Captana/análise , Frutas/química , Fungicidas Industriais/análise , Malus/química , Resíduos de Praguicidas/análise , Folhas de Planta/química , Fatores de Tempo , Tempo (Meteorologia)
18.
Pest Manag Sci ; 64(3): 296-307, 2008 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-18172881

RESUMO

BACKGROUND: Captan is an important fungicide for controlling diseases in horticultural crops. Predicting its dissipation is important for estimating dietary risks and optimising pesticide application. Experiments were conducted to determine the relationship of captan loss on apple leaves with temperature, humidity and rainfall, and to investigate captan loss on fruit in dry conditions. RESULTS: There was large unit-to-unit variability in captan residues in spite of the controlled application. Temperature and humidity had negligible effects on captan loss. Captan loss is predominately due to washoff by rain, although a certain proportion of captan may bind to the plant surface tightly and hence may not be readily removed by rain. About 50% of captan can be washed off by as little as 1 mm of rain after an application, and the loss appeared not to relate to the amount of rain. Under dry conditions, daily loss of captan is estimated to be around 1% on both fruit and leaves, giving a half-life of ca 70 days. CONCLUSIONS: Captan loss on leaf and fruit surfaces is primarily due to rain washoff.


Assuntos
Captana/análise , Fungicidas Industriais/análise , Malus/química , Resíduos de Praguicidas/análise , Tempo (Meteorologia) , Captana/metabolismo , Contaminação de Alimentos/análise , Frutas/química , Resíduos de Praguicidas/metabolismo , Folhas de Planta/química , Fatores de Tempo
19.
Food Chem ; 267: 60-66, 2018 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-29934190

RESUMO

In this study, effects of low intensity electrical current (EC) and ultrasound (US) treatments on the reduction of some important pesticides (captan, thiamethoxam and metalaxyl) residues in tomato samples were investigated. Three different currents (200, 800 and 1400mA) of EC were applied at various time intervals (2, 4, 6, 8 and 10min). Two kinds of US treatments including ultrasonic bath (UB) at 40kHz and ultrasonic probe (UP) at 24kHz were tested for the determination of US effectiveness. In addition, synergistic effects of US on EC treatments were evaluated. The most effective conditions for reduction of captan, thiamethoxam and metalaxyl residues were 1400mA+40kHz, 800mA+24kHz and 1400mA+24kHz, respectively. The residues of captan, thiamethoxam and metalaxyl were reduced in the order of 94.24%, 69.80% and 95.06% by using these combinations. EC and US strategies can be considered as effective treatments in industrial scale in order to remove the pesticide residues from vegetables.


Assuntos
Contaminação de Alimentos/análise , Resíduos de Praguicidas/análise , Solanum lycopersicum/química , Alanina/análogos & derivados , Alanina/análise , Alanina/química , Captana/análise , Captana/química , Cromatografia Gasosa , Eletricidade , Frutas/química , Frutas/metabolismo , Limite de Detecção , Solanum lycopersicum/metabolismo , Neonicotinoides/análise , Neonicotinoides/química , Nitrocompostos/análise , Nitrocompostos/química , Oxazinas/análise , Oxazinas/química , Resíduos de Praguicidas/química , Sonicação , Tiametoxam , Tiazóis/análise , Tiazóis/química
20.
Appl Spectrosc ; 61(2): 204-11, 2007 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-17331313

RESUMO

The aim of this study was to investigate the surface variability of 13 powder-free, unlined, and unsupported nitrile rubber gloves using attenuated total reflection Fourier transform infrared (ATR-FT-IR) spectrophotometry at key wavelengths for analysis of captan contamination. The within-glove, within-lot, and between-lot variability was measured at 740, 1124, 1252, and 1735 cm(-1), the characteristic captan reflectance minima wavelengths. Three glove brands were assessed after conditioning overnight at relative humidity (RH) values ranging from 2 +/- 1 to 87 +/- 4% and temperatures ranging from -8.6 +/- 0.7 to 59.2 +/- 0.9 degrees C. For all gloves, 1735 cm(-1) provided the lowest background absorbance and greatest potential sensitivity for captan analysis on the outer glove surface: absorbances ranged from 0.0074 +/- 0.0005 (Microflex) to 0.0195 +/- 0.0024 (SafeSkin); average within-glove coefficients of variation (CV) ranged from 2.7% (Best, range 0.9-5.3%) to 10% (SafeSkin, 1.2-17%); within-glove CVs greater than 10% were for one brand (SafeSkin); within-lot CVs ranged from 2.8% (Best N-Dex) to 28% (SafeSkin Blue); and between-lot variation was statistically significant (p < or = 0.05) for all but two SafeSkin lots. The RH had variable effects dependent on wavelength, being minimal at 1735, 1252, and 1124 cm(-1) and highest at 3430 cm(-1) (O-H stretch region). There was no significant effect of temperature conditioning. Substantial within-glove, within-lot, and between-lot variability was observed. Thus, surface analysis using ATR-FT-IR must treat glove brands and lots as different. ATR-FT-IR proved to be a useful real-time analytical tool for measuring glove variability, detecting surface humidity effects, and choosing selective and sensitive wavelengths for analysis of nonvolatile surface contaminants.


Assuntos
Captana/análise , Elastômeros/química , Fungicidas Industriais/análise , Luvas Protetoras , Nitrilas/química , Umidade , Indicadores e Reagentes , Espectrofotometria Infravermelho , Espectroscopia de Infravermelho com Transformada de Fourier , Temperatura
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA