ABSTRACT
The evaluation of the bioavailability of pollutants in soil is crucial to accurately assess the pollution risk, and whole-cell biosensor is one of the important tools for such evaluation. This study aimed to develop a novel whole-cell biosensor for the detection of methyl parathion in soil using. First, a whole-cell biosensor was constructed by the screened methyl parathion hydrolase mpd gene, the existing specific induction element pobR, and the pUC19 plasmid skeleton. Then, the detection method of methyl parathion in soil extracts was established using 96-well microtiter plate as carrier and five whole-cell biosensors as indicator. The method was applied in the detection of methyl parathion in tested and field soil extracts. Taking E. coli DH5α/pMP-AmilCP with the best detection performance as an example, this biosensor had a detection limit of 6.21-6.66 µg/L and a linear range of 10-10 000 µg/L for methyl parathion in four soil extracts. E. coli DH5α/pMP-RFP and E. coli DH5α/pMP-AmilCP methods have good detection performance for the analysis of methyl parathion in soil extract samples. This biosensor method can help to quickly assess the bioavailability of methyl parathion in soil, and thus help to understand the risk of soil pollution caused by organophosphorus pesticide methyl parathion.
Subject(s)
Methyl Parathion/analysis , Pesticides/analysis , Organophosphorus Compounds , Escherichia coli/genetics , Soil , Farms , Biosensing TechniquesABSTRACT
Background Parathion and methyl parathion are typical organophosphorus insecticides and para−nitrophenol (PNP) is their main specific metabolite. Previous studies have shown that parathion and methyl parathion may play a role as endocrine disrupting chemicals, but the evidence is limited. Objective Our aim is to evaluate association between urinary PNP concentration and thyroid function among healthy adults and whether this association has gender differences. Methods The study was based on the 2007—2008 US National Health and Nutrition ExaminationSurvey (NHANES). A total of 1071 subjects aging from 20 to 64 years with data on both urinary PNP and serum thyroid function indicators were finally enrolled. Thyroid function was evaluated by measuring serum thyroid stimulating hormone (TSH), free triiodothyronine (FT3), free thyroxine (FT4), total triiodothyronine (TT3), total thyroxine (TT4), thyroglobulin (TG), and thyroglobulin antibody (TG-Ab). A generalized linear model was used to analyze the relationship between urinary PNP and serum thyroid function indicators and the dose-response relationship. Gender differences were also explored. Results In the total population, the positive rate of PNP was 92.5%, and the median urinary PNP concentration adjusted for urinary creatinine was 0.62 μg·g−1. The median creatinine-adjusted urinary PNP concentrations in the male and female populations were 0.60 and 0.66 µg·g−1 respectively. The median activities or concentrations of serum thyroid function indicators TSH, FT3, FT4, TT3, and TT4 in the total population were 1500.00 μIU·L−1, 3200.00 pg·L−1, 8.00 ng·L−1, 1140.00 ng·L−1, and 76.00 μg·L−1 respectively. In the total population, a logarithmic unit increase of urinary PNP was associated with 1050.00 pg·L−1 decrease in serum FT3 levels (b=−0.02, 95%CI: −0.02-−0.01), 10.50 ng·L−1 decrease in FT4 levels (b=−0.02, 95%CI: −0.03-−0.01), and 10.50 ng·L−1 decrease in TT3 levels (b=−0.02, 95%CI: −0.03-−0.01), all in a dose-response manner (all Ptrend<0.05). After sex stratification, for every logarithmic unit increase of urinary PNP, the serum TG-Ab level was increased by 1100.00 IU·L−1 (b=0.04, 95%CI: 0.00-0.08) and the serum FT3 level was reduced by 1020.00 pg·L−1 (b=−0.01, 95%CI: −0.02-0.00) among males, and both showed dose-response relationships (both Ptrend<0.05); every logarithmic unit increase of urinary PNP was associated with 1050.00 pg·L−1 decrease in FT3 levels (b=−0.02, 95%CI: −0.03-−0.01), 10.50 ng·L−1decrease in FT4 levels (b=−0.02, 95%CI: −0.03-0.00), 10.70 ng·L−1 decrease in TT3 levels (b=−0.03, 95%CI: −0.05-−0.01), and 10.50 μg·L−1 decrease in TT4 levels (b=−0.02, 95%CI: −0.04-0.00) among females, and there were dose-response relationships of urinary PNP concentration with serum FT3 and TT3 levels (both Ptrend<0.001). Conclusion Changes in the concentration of PNP in urine are associated with changes in serum FT4, FT3, and TT3 levels and the results also show gender differences.
ABSTRACT
RESUMO Esta pesquisa propõe utilizar o fungo Aspergillus niger AN 400 no tratamento de matriz aquosa contendo metil paration por meio de reatores em batelada, sendo dividida em duas etapas. Na etapa I, foram montados reatores controle (RCs) contendo apenas metil paration em matriz aquosa; reatores contendo metil paration e suspensão de esporos de fungo (RFs); e reatores contendo metil paration, suspensão de esporos de fungo e etanol (RFEs). A cada tempo de reação (TR), um RC, um RF e um RFE eram colocados fora de operação. Os TRs estudados foram distribuídos em 30 dias. Na etapa II, operou-se um reator com biomassa imobilizada (RBI) alimentado por metil paration e etanol, efetuando-se cinco ciclos cada um com duração de uma semana. Como resultados, na Etapa I, verificou-se que o pH variou de 5 a 8, atingindo remoções finais de 61% (RF) e 89% (RFE) de demanda química de oxigênio (DQO) bruta; 67% (RF) e 52% (RFE) de nitrogênio amoniacal; 34% (RF) e 45% (RFE) de nitrato; 2% (RF) e 15% (RFE) de fósforo total. Na Etapa II, o pH variou de 3 a 8 e as médias de remoção final foram: 94% de DQO filtrada, 88% de DQO bruta, 19% de nitrogênio amoniacal, 96% de nitrato, 12% de fósforo total e metil paration de 95%, com biomassa imobilizada e 73% (95%) com biomassa dispersa. Os resultados mostraram que a utilização do fungo Aspergillus niger AN 400 pode ser uma alternativa no tratamento de água residuária contendo metil paration.
ABSTRACT This research proposes the use of the fungus Aspergillus niger AN 400 in treating aqueous matrix containing methyl parathion in batch reactors. The research was divided into two steps. In Step I, were mounted control reactors (RC) containing only methyl parathion in aqueous matrix; reactors with fungus (RF) containing methyl parathion and suspension of fungus spores; and reactors with fungus and ethanol (RFE) containing methyl parathion, the suspension of fungus spores and ethanol. Each reaction time (TR), one RC, one RF and one RFE were put out of operation. The reaction times were studied in 30 days. In Step II, operated a reactor with immobilized biomass (RBI) with methyl parathion and ethanol, making up 5 cycles each lasting one week. As a result, in Step I, it was found that the pH varied from 5 to 8. The final removal of 61% (RF) and 89% (RFE) of COD; 67% (RF) and 52% (RFE) of ammonia nitrogen; 34% (RF) and 45% (RFE) nitrate; 2% (RF) and 15% (RFE) of total phosphorus. In Step II, the pH ranged from 3 to 8 and the average final removal were 94% of filtered COD, 88% gross COD, 19% of ammonia nitrogen, 96% nitrate, 12% of total phosphorus and 95% of methyl parathion with immobilized biomass and 73% with disperse biomass. The results showed that the use of the fungus Aspergillus niger AN 400 can be an alternative for treating wastewater containing methyl parathion.
ABSTRACT
Abstract The aim of this work was to evaluate whether the heart function of bullfrog tadpoles (25 Gosner stage) is affected by their acute exposure (48 h) to a sub-lethal concentration (10 µg.L1) of the active principle of the organophosphorus pesticide Folisuper 600R (methyl parathion - MP). Our results demonstrated that MP causes not only a reduction in tadpoles cardiac ventricular mass, resulting in a marked reduction in their cardiac twitch force, but also impairs their swimming performance, irrespective of increasing their heart rate. Together, these findings indicate that low and realistic concentration of MP have a negative impact on tadpoles performance, jeopardizing their survival.
Resumo O objetivo do presente estudo foi avaliar se a função cardíaca de girinos de rãs-touro (estágio 25 de Gosner) é afetada pela exposição aguda (48h) a uma concentração sub-letal (10 µg.L1) do princípio ativo do pesticida organofosforado Folisuper 600R (metil paration MP). Nossos resultados demonstraram que o MP ocasionou não apenas uma redução na massa ventricular cardíaca dos girinos, como também provocou uma redução na sua força de contração cardíaca e de seu desempenho natatório, a despeito de ter sido observado um aumento de sua freqüência cardíaca. Conjuntamente, os achados aqui obtidos indicam que uma baixa e realística concentração de MP exerce um impacto negativo sobre o desempenho dos girinos, ameaçando sua sobrevivência.
ABSTRACT
Abstract The aim of this work was to evaluate whether the heart function of bullfrog tadpoles (25 Gosner stage) is affected by their acute exposure (48 h) to a sub-lethal concentration (10 µg.L–1) of the active principle of the organophosphorus pesticide Folisuper 600R (methyl parathion - MP). Our results demonstrated that MP causes not only a reduction in tadpoles’ cardiac ventricular mass, resulting in a marked reduction in their cardiac twitch force, but also impairs their swimming performance, irrespective of increasing their heart rate. Together, these findings indicate that low and realistic concentration of MP have a negative impact on tadpoles’ performance, jeopardizing their survival.
Resumo O objetivo do presente estudo foi avaliar se a função cardíaca de girinos de rãs-touro (estágio 25 de Gosner) é afetada pela exposição aguda (48h) a uma concentração sub-letal (10 µg.L–1) do princípio ativo do pesticida organofosforado Folisuper 600R (metil paration – MP). Nossos resultados demonstraram que o MP ocasionou não apenas uma redução na massa ventricular cardíaca dos girinos, como também provocou uma redução na sua força de contração cardíaca e de seu desempenho natatório, a despeito de ter sido observado um aumento de sua freqüência cardíaca. Conjuntamente, os achados aqui obtidos indicam que uma baixa e realística concentração de MP exerce um impacto negativo sobre o desempenho dos girinos, ameaçando sua sobrevivência.
Subject(s)
Animals , Heart/drug effects , Insecticides/toxicity , Methyl Parathion/toxicity , Rana catesbeiana/physiology , Heart/physiopathology , Larva/drug effects , Larva/growth & development , Larva/physiology , Rana catesbeiana/growth & development , SwimmingABSTRACT
The present study was conducted to evaluate the possible protective effect of selenium in reversing methyl parathion -induced testicular damage in male rats, using light and electron microscopy with reference to plasma testosterone (T) and lutenizing hormone (LH) levels. The animals were randomly divided into four groups, Group 1: control animals. Group 2: animals were treated with sodium selenite in a dose (10μg/kg b.w). Group 3: rats were given methyl parathion in a dose (0.28 mg/kg b.w). Group 4: rats were received sodium selenite prior to treatment with methyl parathion. Results showed that animals exposed to methyl parathion displayed a reduction in body and testicular weight and a reduction in seminiferous tubules diameter. At the end of the treatments plasma testosterone and LH concentrations were reduced significantly in methyl parathion-treated rats. Light and electron microscopy of testes from treated animals with methyl parathion showed disorganization of tubular elements with increased intercellular space. Also, revealed necrosis and cellular damage. In addition, a significant increase in sperm DNA fragmentation was detected. Selenium supplementation to rats given methyl parathion improved the testicular damage. In conclusion, Selenium may be useful for the prevention and treatment of methyl parathion -induced testicular damage.
ABSTRACT
Pesticides are major contaminating chemicals in agriculture environment and a hazard to exposed population. The pesticides form a strong class of environment pollutants, as they are sometimes nonbiodegradable, damaged not only the environment and agriculture but also have entered into the food chain thereby affecting health and development. Methyl parathion is a broad-spectrum organophosphorus insecticide generally used to control a variety of insects. The present study was planned to develop a new method for analysis of Methyl parathion in human blood samples using thin layer chromatography technique, which is simple and quick. Methyl Parathion was extracted from blood using solvent extraction methods and then identified on the TLC plates. For chromatographic separation, various binary and tertiary solvent systems were used and for detection on developed plates, palladium chloride reagent was used which successfully increased the sensitivity without dispensing with the simplicity of the method. Statistical analysis was performed on four solvent systems namely benzene: chloroform (80:20), hexane: carbontetrachloride (50:50), hexane: carbontetrachloride (20:80), hexane: propanol (20:80) which included the calculation of mean Rf value, value of standard deviation and coefficient of variance. It is evident from the statistical data that hexane: carbontetrachloride (50:50), hexane: carbon tetrachloride (20:80) is preferably good solvent systems for parathion identification by thin layer chromatography.
ABSTRACT
This study evaluated the glucose effect on the removal of methyl parathion by Aspergillus niger AN400. The study was conducted in two stages: toxicity tests on plates and assays in flasks, under an agitation of 200 rpm. The methyl parathion concentrations in the toxicity test ranged from 0.075 to 60 mg/L. The second stage consisted on evaluating reactors: six control reactors with methyl parathion solution; six reactors with fungi and methyl parathion, and six reactors containing fungi, methyl parathion, and glucose. The reaction times studied ranged from 1 to 27 days. Methyl parathion concentrations of up to 60 mg/L were not toxic for Aspergillus niger AN400. The first-order kinetic model served as a good representation of the methyl parathion conversion rate. The first-order kinetic constant was 0.063 ± 0.005 h-1 for flasks without addition of glucose, while a value of 0.162 ± 0.014 h-1 was obtained when glucose was added.
Este estudo avaliou o efeito da glicose na remoção de metil paration por Aspergillus niger AN400. O estudo foi realizado em duas etapas: testes de toxicidade em placas e ensaios em batelada, sob agitação de 200 rpm. As concentrações de metil paration no ensaio de toxicidade variaram de 0,075 a 60 mg/L. A segunda etapa consistiu na avaliação dos reatores divididos em lotes: seis reatores controle, com solução de metil paration; seis reatores com fungos e paration metílico e seis reatores com fungos, paration metílico e glicose. Os tempos de reação estudados variaram de 1 a 27 dias. Concentrações de paration metílico de até 60 mg/L não foram tóxicas para Aspergillus niger AN400. O modelo de primeira ordem representou bem a cinética de degradação do metil paration. A constante cinética foi de 0,063 ± 0,005 h¹ para reatores sem adição de glicose, enquanto o valor de 0,162 ± 0,014 h¹ foi obtido quando a glicose foi adicionada.
ABSTRACT
Bacterial organophosphate hydrolases (OPH) have been shown to hydrolyze structurally diverse group of organophosphate (OP) compounds and nerve agents. Due to broad substrate range and unusual catalytic properties, the OPH has successfully been used to develop eco-friendly strategies for detection and decontamination of OP compounds. However, their usage has failed to gain necessary acceptance, due to short half-life of the enzyme and loss of activity during process development. In the present study, we report a simple procedure for immobilization of OPH on biocompatible gelatin pads. The covalent coupling of OPH using glutaraldehyde spacer has been found to dramatically improve the enzyme stability. There is no apparent loss of OPH activity in OPH-gelatin pads stored at room temperature for more than six months. As revealed by a number of kinetic parameters, the catalytic properties of immobilized enzyme are found to be comparable to the free enzyme. Further, the OPH‑gelatin pads effectively eliminate OP insecticide methyl parathion and nerve agent sarin.
Subject(s)
Enzyme Stability , Enzymes, Immobilized/chemistry , Escherichia coli/enzymology , Escherichia coli/genetics , Gelatin/chemistry , Hydrolysis , Insecticides/poisoning , Methyl Parathion/chemistry , Organophosphorus Compounds/chemistry , Phosphoric Monoester Hydrolases/genetics , Phosphoric Monoester Hydrolases/isolation & purification , Phosphoric Monoester Hydrolases/metabolism , Sarin/chemistry , Substrate SpecificityABSTRACT
A study was conducted to find out the effect of different concentrations of Methyl parathion, an organophosphorus pesticide on soil bacterial population, soil respiratory activity and dehydrogenase activity, under laboratory conditions for a definite time period. The higher concentration (100 ppm) of Methyl parathion application, considerably reduced bacterial count, CO2 evolution and enzyme activity in soil but the microbial activities seemed to recover several weeks following pesticide application.
ABSTRACT
The main objective of this study was to collect data with regard to the pattern of acute methyl parathion poisoning in this part of the world. One hundred and fifty three patients with organophosphate poisoning presented to Kasturba Hospital, Manipal between January 2001 and December 2002, out of which 58 cases (37.9%) were due to methyl parathion exposure. The commonest reason for poisoning was suicide (98.2%). A significant proportion of victims were male (72.4%), many in the 21–30 years age group (43.1%). In 77.5% of the cases, the poisoning incident occurred during daytime. Manifestations were predominantly muscarinic in nature, and the median value of serum pseudocholinesterase at admission was 2407.5 IU/L. Respiratory failure was the commonest complication (41.2%). 25.8% of the cases ended in death, and 40% of these succumbed within 24 hours of exposure.
ABSTRACT
Pesticides plays an important role in the history of agricultural development,but the health hazards and environmental pollution problems are attracting increasing attention. Methyl parathion is one of the most widely used pesticides,its threat to human health caused increased emphasis. This paper introduced the chronic toxicity of methyl parathion to various systems such as the nervous system,endocrine system,immune system and reproductive system.
ABSTRACT
When methyl parathion (Ο,Ο dimethyl O p nitrophenyl phosphorothioate), an organophosphorous insecticide, was added to an exponentially growing culture of Chlorella protothecoides and the effects were followed for 12 days, the following observations were made: a) In autotrophic culture the cell number and the chlorophyll content decreased as compared to the control. These changes paralleled the inhibition of the rate of net photosynthesis, suggesting that the photosynthetic apparatus was the primary target of the insecticide action. b) The inhibition of cell growth (on cell number basis) also occurred in the case of heterotrophic culture at 100 μΜ insecticide concentration but the inhibition was less as compared to that of an autotrophic culture. c) The cell diameter in treated culture increased by 10 20% in both autotrophic and heterotrophic cultures. The observations, (b) and (c) suggest that apart from the photosynthetic apparatus, the insecticide has other sites of action, but the sensitivity of these sites to the insecticide is less than that of the photosynthetic apparatus.
ABSTRACT
The effect of methyl parathion (metacid-50), an organophosphorous insecticide, on the Hill reactions of isolated mesophyll chloroplasts of Sorghum vulgare was studied. The pesticide was found to inhibit the Hill reaction with all the Hill oxidants tested, namely potassium ferricyanide,2,6-dichlorophenol indophenol and para-benzoquinone. The concentration of the pesticide required to inhibit 50% of the control Hill activity (I50value) was found to vary with the different Hill oxidants.