RESUMO

Carbofuran (CF) is a carbamate class pesticide, widely used in agriculture for pest control in crops. This pesticide has high toxicity in non-target organisms, and its presence in the environment poses a threat to the ecosystem. Research has revealed that this pesticide acts as an inhibitor of acetylcholinesterase (AChE), inducing an accumulation of acetylcholine in the brain. Nonetheless, our understanding of CF impact on the central nervous system remains elusive. Therefore, this study explored how CF influences behavioral and neurochemical outcomes in adult zebrafish. The animals underwent a 96-hour exposure protocol to different concentrations of CF (5, 50, and 500 µg/L) and were subjected to the novel tank (NTT) and social preference tests (SPT). Subsequently, they were euthanized, and their brains were extracted to evaluate neurochemical markers associated with oxidative stress and AChE levels. In the NTT and SPT, CF did not alter the evaluated behavioral parameters. Furthermore, CF did not affect the levels of AChE, non-protein sulfhydryl groups, and thiobarbituric acid reactive species in the zebrafish brain. Nevertheless, further investigation is required to explore the effects of environmental exposure to this compound on non-target organisms.

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RESUMO

Abstract This study was aimed to investigate Carbofuran (CF)-induced pathological changes in cattle egret. Two hundred cattle egrets were reared and equally divided into four groups and given different CF concentrations (0.03 mg/L, 0.02 mg/L, 0.01 mg/L and 0 mg/L (control group)). Hematology, serum biochemistry, histopathology, and immunological markers were studied. Our results confirm that CF induces anemic conditions, leukocytosis, elevated liver enzymatic activity, and alterations in renal biomarkers. Moreover, specific microscopic lesions such as multifocal necrosis, pyknotic nuclei, hemorrhages, congestion, and inflammatory cell proliferation were observed in the liver, kidney, spleen, and thymus. These findings suggest that CF can induce harmful effects, so the application of this pesticide in the field must be strictly monitored to mitigate the possibility of exposure to non-target species.

Resumo Este estudo teve como objetivo investigar as alterações patológicas induzidas por carbofurano (CF) em garças-vaqueiras. Duzentas dessas garças foram criadas e divididas igualmente em quatro grupos e receberam diferentes concentrações de CF: 0,03 mg/L; 0,02 mg/L; 0,01 mg/L; e 0 mg/L (grupo controle). Foram realizadas análises de hematologia, bioquímica sérica, histopatologia e marcadores imunológicos. Nossos resultados confirmaram que CF induz condições anêmicas, leucocitose, atividade enzimática hepática elevada e alterações nos biomarcadores renais. Além disso, lesões microscópicas específicas, como necrose multifocal, núcleos picnóticos, hemorragias, congestão e proliferação de células inflamatórias, foram observadas no fígado, rim, baço e timo. Esses achados sugerem que o CF pode causar efeitos nocivos, portanto a aplicação desse agrotóxico no campo deve ser rigorosamente monitorada para mitigar a possibilidade de exposição a espécies não alvo.

Assuntos

RESUMO

Abstract This study was aimed to investigate Carbofuran (CF)-induced pathological changes in cattle egret. Two hundred cattle egrets were reared and equally divided into four groups and given different CF concentrations (0.03 mg/L, 0.02 mg/L, 0.01 mg/L and 0 mg/L (control group)). Hematology, serum biochemistry, histopathology, and immunological markers were studied. Our results confirm that CF induces anemic conditions, leukocytosis, elevated liver enzymatic activity, and alterations in renal biomarkers. Moreover, specific microscopic lesions such as multifocal necrosis, pyknotic nuclei, hemorrhages, congestion, and inflammatory cell proliferation were observed in the liver, kidney, spleen, and thymus. These findings suggest that CF can induce harmful effects, so the application of this pesticide in the field must be strictly monitored to mitigate the possibility of exposure to non-target species.

Resumo Este estudo teve como objetivo investigar as alterações patológicas induzidas por carbofurano (CF) em garças-vaqueiras. Duzentas dessas garças foram criadas e divididas igualmente em quatro grupos e receberam diferentes concentrações de CF: 0,03 mg/L; 0,02 mg/L; 0,01 mg/L; e 0 mg/L (grupo controle). Foram realizadas análises de hematologia, bioquímica sérica, histopatologia e marcadores imunológicos. Nossos resultados confirmaram que CF induz condições anêmicas, leucocitose, atividade enzimática hepática elevada e alterações nos biomarcadores renais. Além disso, lesões microscópicas específicas, como necrose multifocal, núcleos picnóticos, hemorragias, congestão e proliferação de células inflamatórias, foram observadas no fígado, rim, baço e timo. Esses achados sugerem que o CF pode causar efeitos nocivos, portanto a aplicação desse agrotóxico no campo deve ser rigorosamente monitorada para mitigar a possibilidade de exposição a espécies não alvo.

RESUMO

In the present study, two agro-industrial wastes, sugarcane bagasse, and peanut shell were employed as support of magnetite nanoparticles for the synthesis of magnetic bio-composites: magnetic sugarcane bagasse (MBO) and magnetic peanut shell (MPSo). The presence of magnetite was verified by Raman spectroscopy. Magnetic nanoparticles shape and size distribution were studied by TEM, while composites morphologies were observed by SEM. Structural characteristics of the pesticides and their possible chemical adsorption on composites were analyzed by FTIR. The removal was carried out by a batch adsorption process, and UV-VIS technique was used for pesticide concentration estimation. Elovich model described better all systems pointing out to a chemical adsorption process occurring. Experimental data isotherms of carbofuran and iprodione can be best explained by more than one mathematical model, but Sip was the ordinary equation in all systems. Maximum adsorption capacities of 175 and 89.3 mg/g for carbofuran, and 119 and 2.76 mg/g for iprodione, were obtained for MBo and MPSo, respectively.

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RESUMO

Granular activated carbon (GAC) fixed bed adsorption technology was applied to remove carbamates carbaryl, methomyl and carbofuran from public water supply. In order to minimize the effect of clogging and to evaluate adsorbent saturation for carbamates, the microfiltration (MF) was previously used to adsorb and the backwash procedure of the GAC bed was carried out. The determination and quantification of the carbamates were performed by analytical technique in high performance liquid chromatography with post-column derivatization and fluorescence detector. The MF of the water previously adsorbed in the GAC fixed bed allowed the greater removal of 100% of the carbamates pesticides with an initial concentration of 25 µg L-1 during the first 48 h of operation. The saturation of the GAC fixed bed occurred in 240 h, due to the partial removal of the natural organic matter by the MF, consequently the competition for adsorptive sites of the GAC was smaller. The backwashing procedure contributed to the partial recovery of the performance of the hydraulic filtration and allowed to identify the saturation of the adsorption column, since the sealing phenomenon preceded the saturation. Finally, the use of public water supply was considered a relevant and positive aspect, since it allowed the identification of the performance of this technology in the removal of carbamates pesticides considering the presence of substances inherent to the public water supply.

Assuntos

RESUMO

Carbofuran is an anticholinesterase carbamate commonly used as an insecticide, nematicide and acaricide in agricultural practice throughout the world. However, data on its sorption in temperate soils from Europe is limited. Laboratory studies were conducted to determine the adsorption of carbofuran on three distinct Austrian soils using batch experiments and radiometric techniques. Carbofuran adsorption capacity of the soils was found to be low in the three soils tested and showed to be related to the soils clay and organic carbon contents. The pesticide presented linear adsorption isotherms in all of the three soils. Due to the low sorption of carbofuran in the soils tested and to its high water solubility, there is a risk of migration to water bodies through run off and consequent negative effects on aquatic organisms and soil biota.

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RESUMO

The application of a fixed bed adsorption column of granular activated carbon (FBAC-GAC), in the removal of carbaryl, methomyl and carbofuran at a concentration of 25 µg L-1 for each carbamate, from the public water supply was investigated. For the determination of the presence of pesticides in the water supply, the analytical technique of high-performance liquid chromatography with post-column derivatization was used. Under conditions of constant diffusivity, the FBAC-GAC was saturated after 196 h of operation on a pilot scale. The exhaust rate of the granular activated carbon (GAC) in the FBAC-GAC until the point of saturation was 0.02 kg GAC m-3 of treated water. By comparing a rapid small-scale column test and FBAC-GAC, it was confirmed that the predominant intraparticle diffusivity in the adsorption column was constant diffusivity. Based on the results obtained on a pilot scale, it was possible to estimate the values to be applied in the FBAC-GAC (full scale) to remove the pesticides, which are particle size with an average diameter of 1.5 mm GAC; relationship between the internal diameter of the column and the average diameter of GAC ≥50 in order to avoid preferential flow near the adsorption column wall; surface application rate 240 m3 m-2 d-1 and an empty bed contact time of 3 min. ABBREVIATIONS: BV: bed volume; CD: constant diffusivity; EBCT: empty bed contact time; FBAC-GAC: fixed bed adsorption column of granular activated carbon; GAC: granular activated carbon; MPV: maximum permitted values; NOM: natural organic matter; PD: proportional diffusivity; pHPCZ: pH of the zero charge point; SAR: surface application rate; RSSCT: rapid small-scale column test; WTCS: water treated conventional system.

Assuntos

RESUMO

Population growth requires more food production and as a consequence, there is the indiscriminate use of agrochemicals, among them major group are carbamates. At times, runoff of pesticides leads to surface water pollution that serves as a source of public supply. Thus, the presence of these microcontaminants in surface water has become increasingly frequent. The treatment developed in this work uses the principle of adsorption as a technology for the removal of carbamates, more specifically carbofuran. Two methods of coating the polystyrene beads with iron oxide were used to adsorb these microcontaminants from the water. The coating was evaluated through the chemical extraction of iron, analysis by scanning electron microscopy and BET analysis. The metallurgy that presented the best coating was the one that used the ferric chloride. The beads coated by this methodology were used for adsorption tests of carbofuran and showed positive results after verification of the influence of pH on the adsorption process.

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RESUMO

O objetivo do trabalho foi avaliar a interação do herbicida tebuthiuron (Combine® 500 SC), com nematicidas carbofuram (Furadan® 350 SC) e benfuracarbe (Pottente®), aplicados no plantio da cultura da cana-de-açúcar (RB 867515). O experimento foi conduzido em casa de vegetação da Universidade Paranaense, em Umuarama ­ PR, no período de abril a agosto de 2014. Foi instalado em vasos com capacidade para 4,5 L, contendo uma planta por vaso, em delineamento inteiramente casualizado, com seis tratamentos e quatro repetições, sendo os tratamentos testemunha (T1), sem aplicação de produtos; aplicação isolada de carbofuran (T2); aplicação isolada de benfuracarbe (T3); aplicação isolada de tebuthiuron (T4); aplicação combinada de carbofuran e tebuthiuron (T5) e aplicação combinada de benfuracarbe e tebuthiuron (T6). O experimento foi submetido a duas avaliações, 45 e 90 dias após o plantio (DAP) sendo que na primeira, as variáveis avaliadas foram altura da parte aérea, número de folhas e número de plantas daninhas por vaso, e, na segunda, altura da parte aérea; número de folhas; número de plantas daninhas; massa fresca e seca da parte aérea; massa fresca do sistema radicular; população final total de nematoides por vaso, calculada pelo somatório de nematoides nas raízes e solo. Quanto ao número de folhas, o tratamento T4 demonstrou fitotoxicidade aos 45 DAP. Os tratamentos T3, T5 e T6 apresentaram as maiores massa fresca e seca da parte área da cana, demonstraram ausência de interação antagônica entre as combinações do herbicida com os nematicidas aos 90 DAP. Os tratamentos T3 e T5 foram eficientes no controle populacional de P. zeae.(AU)

The aim of the study was to evaluate the interaction of the herbicide tebuthiuron (Combine® SC 500), with the following nematicides: carbofuran (350 Furadan® SC) and benfuracarb (Pottente®) applied during the planting of cane sugar (RB 867515). The experiment was conducted in a greenhouse at Universidade Paranaense in Umuarama - PR, from April to August 2014. The crop was started in 4.5-L vases containing one plant per vase, in a completely randomized design with six treatments and four replications, namely control treatments (T1), with no application of products; isolated application of carbofuran (T2); isolated application of benfuracarb (T3); isolated application of tebuthiuron (T4); combined application of carbofuran and tebuthiuron (T5) and combined application of benfuracarb and tebuthiuron (T6). The experiment was submitted to two assessments, at 45 and 90 days after planting (DAP). On the first assessment, the variables analyzed were shoot height, number of leaves and number of weeds per vase. The second assessment analyzed shoot height; number of leaves; number of weeds; fresh and dry weight of shoot; fresh weight of the root system; total final population of nematodes per vase, calculated by the sum of nematodes in the roots and soil. Regarding the number of leaves, the T4 treatment showed phytotoxicity at 45 DAP. The T3, T5 and T6 treatments had the highest fresh and dry weight of the aerial part of the sugar cane; with absence of antagonistic interaction between the combinations of herbicide and nematicides at 90 DAP. The T3 and T5 treatments were effective in controlling the population of P. zeae.(AU)

El objetivo del estudio ha sido evaluar la interacción del herbicida tebuthiuron (Combine® 500 SC), con nematicidas carbofuram (Furadan® 350 SC) y benfuracarbe (Pottente®), aplicados en plantío de caña de azúcar (RB 867515). El experimento ha sido dirigido en el área de vegetación de la Universidad Paranaense, en Umuarama - PR, en el período de abril a agosto de 2014. Se ha instalado en floreros con capacidad para 4,5 L, conteniendo una planta por florero, en delineamiento enteramente casualizado, con seis tratamientos y cuatro repeticiones, siendo los tratamientos testigo (T1), sin aplicación de productos; aplicación aislada de carbofuran (T2); aplicación aislada de benfuracarbe (T3); aplicación aislada de tebuthiuron (T4); aplicación combinada de carbofuran y tebuthiuron (T5) y aplicación combinada de benfuracarbe y tebuthiuron (T6). El experimento ha sido sometido a dos evaluaciones, 45 y 90 días después del plantío (DAP) siendo que en la primera, las variables evaluadas fue la altura de la parte aérea, número de hojas y el número de plantas dañinas por florero, y, en la segunda, altura de la parte aérea, número de hojas, número de plantas dañinas; masa fresca y seca de la parte aérea; masa fresca del sistema radicular; población final total de nematodos por florero, calculado por la suma de nematodos en las raíces y suelo. Cuanto al número de hojas, el tratamiento T4 demostró citotoxicidad a los 45 DAP. Los tratamientos T3, T5 y T6 presentaron mayor masa fresca y seca en la parte aérea de la caña, demostraron ausencia de interacción antagónica entre las combinaciones de los herbicidas con los nematicidas a los 90 DAP. Los tratamientos T3 y T5 fueron eficientes en el control poblacional de P. zeae.(AU)

Assuntos

RESUMO

El propósito del presente estudio fue estimar la toxicidad del pesticidas carbofurán sobre los parámetros hematológicos (hematocrito, hemoglobina, glucosa en la sangre y conteo de eritrocitos y leucocitos totales), sobre la excreción de amoníaco y el consumo de oxígeno en individuos juveniles de Oreochromis niloticus (longitud total: 12±0,5 mm). Los espécimenes fueron expuestos a diferentes concentraciones del plaguicida carbofurán (0, 0,1, 0,5, 1,0, 2,0, y 4,0 mg L-1), a diferentes temperaturas (15, 20 y 25 °C) y pH 7. Los valores de LC50 en períodos de 24, 48, 72, 96 h para los juveniles de O. niloticus expuestos al carbofurán fueron 3,00; 2,84; 2,71 e 2,45 mg L−1 para 15 °C; 3,00; 2,69; 2,33 e 2,20 mg L−1 para 20 °C; y 2,84; 2,44; 1,71; 1,62 mg L−1 para 25 °C, respectivamente. Los resultados evidenciaron que con el aumento de la temperatura de 15 a 25 °C hubo un aumento de la sensibilidad de los peces al carbofurán de 21,80%, 9,55%, 31,92% y 30,87%, después de 24, 48, 72 y 96 h de exposición, respectivamente. Por otra parte, se observó que en peces expuestos al carbofurán en concentración de 2 mg L-1 ocurrió una disminución en la tasa de hemoglobina total y una elevación en la tasa de glucosa sanguínea, consumo de oxígeno y excreción de amonio. Estos resultados indican que la exposición al carbofurán, especialmente a altas temperaturas es un factor significativo a ser considerado en el manejo de la acuacultura.

Oreochromis niloticus juveniles (total length 12±0.5 mm) were exposed to different concentrations of carbofuran, using the static renewal method at different temperatures (15, 20 and 25°C) at pH 7. The 24, 48, 72, 96 h LC50 values of carbofuran in Oreochromis niloticus juveniles were 3.00, 2.84, 2.71 and 2.45 mg L−1 at 15°C; 3.00, 2.69, 2.33 and 2.20 mg L−1 at 20°C; and 2.84, 2.44, 1.7 1 and 1.62 mg L−1 at 25°C, respectively. Results show that a temperature increment from 15 to 25°C increased the carbofuran susceptibility in fish by 21.80%, 9.55%, 31.92% and 30.87%, after 24, 48, 72 and 96 hours of exposure, respectively. Furthermore, we found that exposure of fish to carbofuran caused an elevation in total hemoglobin and blood glucose concentration of 2 mg L-1. These results indicate that exposure to carbofuran, especially at lower temperatures is a significant factor to be considered in aquaculture management.

Assuntos

RESUMO

O objetivo do trabalho foi avaliar a interação do herbicida tebuthiuron (Combine® 500 SC), com nematicidas carbofuram (Furadan® 350 SC) e benfuracarbe (Pottente®), aplicados no plantio da cultura da cana-de-açúcar (RB 867515). O experimento foi conduzido em casa de vegetação da Universidade Paranaense, em Umuarama ­ PR, no período de abril a agosto de 2014. Foi instalado em vasos com capacidade para 4,5 L, contendo uma planta por vaso, em delineamento inteiramente casualizado, com seis tratamentos e quatro repetições, sendo os tratamentos testemunha (T1), sem aplicação de produtos; aplicação isolada de carbofuran (T2); aplicação isolada de benfuracarbe (T3); aplicação isolada de tebuthiuron (T4); aplicação combinada de carbofuran e tebuthiuron (T5) e aplicação combinada de benfuracarbe e tebuthiuron (T6). O experimento foi submetido a duas avaliações, 45 e 90 dias após o plantio (DAP) sendo que na primeira, as variáveis avaliadas foram altura da parte aérea, número de folhas e número de plantas daninhas por vaso, e, na segunda, altura da parte aérea; número de folhas; número de plantas daninhas; massa fresca e seca da parte aérea; massa fresca do sistema radicular; população final total de nematoides por vaso, calculada pelo somatório de nematoides nas raízes e solo. Quanto ao número de folhas, o tratamento T4 demonstrou fitotoxicidade aos 45 DAP. Os tratamentos T3, T5 e T6 apresentaram as maiores massa fresca e seca da parte área da cana, demonstraram ausência de interação antagônica entre as combinações do herbicida com os nematicidas aos 90 DAP. Os tratamentos T3 e T5 foram eficientes no controle populacional de P. zeae.(AU)

The aim of the study was to evaluate the interaction of the herbicide tebuthiuron (Combine® SC 500), with the following nematicides: carbofuran (350 Furadan® SC) and benfuracarb (Pottente®) applied during the planting of cane sugar (RB 867515). The experiment was conducted in a greenhouse at Universidade Paranaense in Umuarama - PR, from April to August 2014. The crop was started in 4.5-L vases containing one plant per vase, in a completely randomized design with six treatments and four replications, namely control treatments (T1), with no application of products; isolated application of carbofuran (T2); isolated application of benfuracarb (T3); isolated application of tebuthiuron (T4); combined application of carbofuran and tebuthiuron (T5) and combined application of benfuracarb and tebuthiuron (T6). The experiment was submitted to two assessments, at 45 and 90 days after planting (DAP). On the first assessment, the variables analyzed were shoot height, number of leaves and number of weeds per vase. The second assessment analyzed shoot height; number of leaves; number of weeds; fresh and dry weight of shoot; fresh weight of the root system; total final population of nematodes per vase, calculated by the sum of nematodes in the roots and soil. Regarding the number of leaves, the T4 treatment showed phytotoxicity at 45 DAP. The T3, T5 and T6 treatments had the highest fresh and dry weight of the aerial part of the sugar cane; with absence of antagonistic interaction between the combinations of herbicide and nematicides at 90 DAP. The T3 and T5 treatments were effective in controlling the population of P. zeae.(AU)

El objetivo del estudio ha sido evaluar la interacción del herbicida tebuthiuron (Combine® 500 SC), con nematicidas carbofuram (Furadan® 350 SC) y benfuracarbe (Pottente®), aplicados en plantío de caña de azúcar (RB 867515). El experimento ha sido dirigido en el área de vegetación de la Universidad Paranaense, en Umuarama - PR, en el período de abril a agosto de 2014. Se ha instalado en floreros con capacidad para 4,5 L, conteniendo una planta por florero, en delineamiento enteramente casualizado, con seis tratamientos y cuatro repeticiones, siendo los tratamientos testigo (T1), sin aplicación de productos; aplicación aislada de carbofuran (T2); aplicación aislada de benfuracarbe (T3); aplicación aislada de tebuthiuron (T4); aplicación combinada de carbofuran y tebuthiuron (T5) y aplicación combinada de benfuracarbe y tebuthiuron (T6). El experimento ha sido sometido a dos evaluaciones, 45 y 90 días después del plantío (DAP) siendo que en la primera, las variables evaluadas fue la altura de la parte aérea, número de hojas y el número de plantas dañinas por florero, y, en la segunda, altura de la parte aérea, número de hojas, número de plantas dañinas; masa fresca y seca de la parte aérea; masa fresca del sistema radicular; población final total de nematodos por florero, calculado por la suma de nematodos en las raíces y suelo. Cuanto al número de hojas, el tratamiento T4 demostró citotoxicidad a los 45 DAP. Los tratamientos T3, T5 y T6 presentaron mayor masa fresca y seca en la parte aérea de la caña, demostraron ausencia de interacción antagónica entre las combinaciones de los herbicidas con los nematicidas a los 90 DAP. Los tratamientos T3 y T5 fueron eficientes en el control poblacional de P. zeae.(AU)

Assuntos

RESUMO

El propósito del presente estudio fue estimar la toxicidad del pesticidas carbofurán sobre los parámetros hematológicos (hematocrito, hemoglobina, glucosa en la sangre y conteo de eritrocitos y leucocitos totales), sobre la excreción de amoníaco y el consumo de oxígeno en individuos juveniles de Oreochromis niloticus (longitud total: 12±0,5 mm). Los espécimenes fueron expuestos a diferentes concentraciones del plaguicida carbofurán (0, 0,1, 0,5, 1,0, 2,0, y 4,0 mg L-1), a diferentes temperaturas (15, 20 y 25 °C) y pH 7. Los valores de LC50 en períodos de 24, 48, 72, 96 h para los juveniles de O. niloticus expuestos al carbofurán fueron 3,00; 2,84; 2,71 e 2,45 mg L−1 para 15 °C; 3,00; 2,69; 2,33 e 2,20 mg L−1 para 20 °C; y 2,84; 2,44; 1,71; 1,62 mg L−1 para 25 °C, respectivamente. Los resultados evidenciaron que con el aumento de la temperatura de 15 a 25 °C hubo un aumento de la sensibilidad de los peces al carbofurán de 21,80%, 9,55%, 31,92% y 30,87%, después de 24, 48, 72 y 96 h de exposición, respectivamente. Por otra parte, se observó que en peces expuestos al carbofurán en concentración de 2 mg L-1 ocurrió una disminución en la tasa de hemoglobina total y una elevación en la tasa de glucosa sanguínea, consumo de oxígeno y excreción de amonio. Estos resultados indican que la exposición al carbofurán, especialmente a altas temperaturas es un factor significativo a ser considerado en el manejo de la acuacultura.(AU)

Oreochromis niloticus juveniles (total length 12±0.5 mm) were exposed to different concentrations of carbofuran, using the static renewal method at different temperatures (15, 20 and 25°C) at pH 7. The 24, 48, 72, 96 h LC50 values of carbofuran in Oreochromis niloticus juveniles were 3.00, 2.84, 2.71 and 2.45 mg L−1 at 15°C; 3.00, 2.69, 2.33 and 2.20 mg L−1 at 20°C; and 2.84, 2.44, 1.7 1 and 1.62 mg L−1 at 25°C, respectively. Results show that a temperature increment from 15 to 25°C increased the carbofuran susceptibility in fish by 21.80%, 9.55%, 31.92% and 30.87%, after 24, 48, 72 and 96 hours of exposure, respectively. Furthermore, we found that exposure of fish to carbofuran caused an elevation in total hemoglobin and blood glucose concentration of 2 mg L-1. These results indicate that exposure to carbofuran, especially at lower temperatures is a significant factor to be considered in aquaculture management.(AU)

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RESUMO

Due the negative effects of pesticides on environment and human health, more efficient and environmentally friendly methods are needed. In this sense, a simple, fast, free from memory effects and economical direct-immersion single drop micro-extraction (SDME) method and GC-MS for multi-class pesticides determination in mango samples was developed. Sample pre-treatment using ultrasound-assisted solvent extraction and factors affecting the SDME procedure (extractant solvent, drop volume, stirring rate, ionic strength, time, pH and temperature) were optimized using factorial experimental design. This method presented high sensitive (LOD: 0.14-169.20µgkg-1), acceptable precision (RSD: 0.7-19.1%), satisfactory recovery (69-119%) and high enrichment factors (20-722). Several obtained LOQs are below the MRLs established by the European Commission; therefore, the method could be applied for pesticides determination in routing analysis and custom laboratories. Moreover, this method has shown to be suitable for determination of some of the studied pesticides in lime, melon, papaya, banana, tomato, and lettuce.

Assuntos

RESUMO

Carbofuran is a toxic carbamate pesticide, and its use has increased in recent years. While marketing information indicates stability in different chemical media, carbofuran exhibits relative photolability. The aim of this research was to decompose carbofuran and to identify the photoproducts achieved when two different doped titania photocatalysts were employed under UV irradiation. The iron-doped TiO2 materials were obtained (a) via a hydrothermal method and (b) by an ultrasound-assisted sol-gel method. The precursors were TiOSO4⋅xH2O and Fe3(NO3)·9H2O. X-ray studies confirmed that the anatase phase of the iron-doped TiO2 resulted from the two preparation methods. The photocatalytic performance of the prepared materials was monitored by LC/ESI-QTOF-MS, enabling the identification of photoproducts: oxo-carbamates, hydroxylated benzofuranes, a carboxamide, and one amine. By using the iron-doped TiO2 materials, 2,2-dimethyl-2,3-dihydrobenzofuran-3,7-diol was the most abundant photoproduct, and N,2,2-trimethyl-2,3-dihydrobenzofuran-7-amine was the only compound that had not been previously reported in the photolysis and photocatalysis of carbofuran. The product 3-hydroxy carbofuran, a cholinesterase inhibitor, was quantified and was found to be transformed into compounds that lack this inhibitive property.

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RESUMO: A complexidade físico-química de micropoluentes, como os defensivos agrícolas, exige o uso de tecnologias avançadas de tratamento de água para abastecimento. O objetivo deste estudo foi avaliar a remoção de carbofurano em nível de bancada (batelada) utilizando membranas comerciais de nanofiltração (NF90 - DowFilmtec (r)) e osmose inversa (HR - Koch Membrane Systems(r) ). Nos experimentos foi avaliada a influência da qualidade da matriz de alimentação (água ultrapura, bruta e pré-tratada) contendo carbofurano (50 µgL-1), e da pressão de operação (8 e 15 bar para a NF90 e 15 e 30 bar para a HR). Para a NF90, com a matriz de água ultrapura, as eficiências de remoção foram inferiores (89,8%), porém o fluxo permeado foi superior (132,1 Lm-2h-1) àquelas obtidas com a matriz de água bruta (98,4% - 94,7 Lm-2h-1) e água pré-tratada (95,2% - 95,3 Lm-2h-1) para a pressão de 15 bar. Para a membrana HR, remoções relativamente superiores foram observadas para a pressão de 30 bar para as três matrizes, com a água bruta apresentando os melhores resultados (99,7% - 49,7 Lm-2h-1). Concluiu-se, portanto, que o pré-tratamento da água bruta não acarretou diferença significativa na remoção do carbofurano e não influenciou no fluxo de permeado de acordo com a metodologia adotada (baixo tempo de separação em batelada com recirculação).

ABSTRACT: The physicochemical complexity of micropollutants such as pesticides requires the use of advanced technologies of drinking water treatment. The main objective of this study was to evaluate the removal of carbofuran using commercial nanofiltration (NF90 - DowFilmtec(r)) and reverse osmosis (HR - Koch Membrane Systems(r)) membranes in a bench-scale system (batch operation). The effect of feed matrix quality (ultrapure water, raw water and pretreated water) with carbofuran (50 µgL-1) and the applied pressure (8 and 15 bar for NF90 and 15 and 30 bar for HR) were studied. For NF90, with ultrapure water matrix, the removal efficiencies were lower (89.4%), but the permeate flow was higher (132.1 Lm-2h-1) than those obtained with the raw water (98.4% - 94.7 Lm-2h-1) and pretreated water (95.2% - 95.3 Lm-2h-1) to 15 bar of pressure. For HR membrane relatively higher removals were observed for 30 bar of pressure for the three matrices, with a better behavior for raw water (99.7% - 49.7 Lm-2h-1). In accordance to the methodology adopted (low separation time in batch with recirculation), it can be concluded, therefore, that the pretreatment of raw water did not caused significant difference in carbofuran removal and did not influenced the permeate flux.

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Biomixtures are used for the removal of pesticides from agricultural wastewater. As biomixtures employ high content of lignocellulosic substrates, their bioaugmentation with ligninolytic fungi represents a novel approach for their enhancement. Nonetheless, the decrease in the concentration of the pesticide may result in sublethal concentrations that still affect ecosystems. Two matrices, a microcosm of rice husk (lignocellulosic substrate) bioaugmented with the fungus Trametes versicolor and a biomixture that contained fungally colonized rice husk were used in the degradation of the insecticide/nematicide carbofuran (CFN). Elutriates simulating lixiviates from these matrices were used to assay the ecotoxicological effects at sublethal level over Daphnia magna (Straus) and the fish Oreochromis aureus (Steindachner) and Oncorhynchus mykiss (Walbaum). Elutriates obtained after 30 d of treatment in the rice husk microcosms at dilutions over 2.5% increased the offspring of D. magna as a trade-off stress response, and produced mortality of neonates at dilutions over 5%. Elutriates (dilution 1:200) obtained during a 30 d period did not produce alterations on the oxygen consumption and ammonium excretion of O. mykiss, however these physiological parameters were affected in O. aureus at every time point of treatment, irrespective of the decrease in CFN concentration. When the fungally colonized rice husk was used to prepare a biomixture, where more accelerated degradation is expected, similar alterations on the responses by O. aureus were achieved. Results suggest that despite the good removal of the pesticide, it is necessary to optimize biomixtures to minimize their residual toxicity and potential chronic effects on aquatic life.

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Carbofuran (2,3-dihydro-2,2-dimethyl-7-benzofuranyl methylcarbamate; C12H15NO3) is one of the most toxic carbamate pesticides. For acute toxicity of carbofuran, juveniles of Macrobrachium olfersii were exposed to different concentrations of carbofuran using the static renewal method at different temperature levels (15, 20 and 25°C) at pH 7.0. The main purpose of the present study was to detect the acute toxicity of carbofuran to M. olfersii and investigate its effects on oxygen consumption and ammonium excretion; these tests have not been carried out in this species before. First, the acute toxicity - median lethal concentration - of carbofuran to M. olfersii for 24, 48, 72 and 96 h was examined, which resulted in the following values: 1.64, 1.22, 0.86 and 0.42 mg L(-1), respectively. Furthermore, we also found that carbofuran caused an inhibition in oxygen consumption of 60.6, 65.3 and 66.2% with respect to the control. In addition, after separate exposures to carbofuran, elevations in ammonium excretion were more than 500% with respect to the control.

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The objective of this study was to determine the acute toxicity of some pesticides used in irrigated rice farming to Lithobates catesbeianus tadpoles. The LC 50-96h for commercial formulations containing bentazon, penoxsulam, vegetable oil, permethrin and carbofuran, separately and their mixtures, were determined at the proportions commonly used in the field. The limits of risk concentrations of these products for the studied species were also established. The LC 50-96h for tadpoles was 4,530 mg L(-1) for bentazon; 7.52 mg L(-1) for penoxsulam + 145.66 mg L(-1) of vegetable oil; 81.57 mg L(-1) for vegetable oil; 0.10 mg L(-1) for permethrin; 29.90 mg L(-1) for carbofuran (active ingredients), and 38.79 times the dose used in the field for the mixture of these products. The environmental risk was determined only for permethrin, and care should be taken when using the vegetable oil.

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In this work, a biosensor was constructed by physical adsorption of the isolated endophytic fungus Eupenicillium shearii FREI-39 esterase on halloysite, using graphite powder, multi-walled carbon nanotubes and mineral oil for the determination of carbofuran pesticide by inhibition of the esterase using square-wave voltammetry (SWV). Specific esterase activities were determined each 2 days over a period of 15 days of growth in four different inoculation media. The highest specific activity was found on 6th day, with 33.08 U on PDA broth. The best performance of the proposed biosensor was obtained using 0.5 U esterase activity. The carbofuran concentration response was linear in the range from 5.0 to 100.0 µg L(-1) (r=0.9986) with detection and quantification limits of 1.69 µg L(-1) and 5.13 µg L(-1), respectively. A recovery study of carbofuran in spiked water samples showed values ranging from 103.8±6.7% to 106.7±9.7%. The biosensor showed good repeatability and reproducibility and remained stable for a period of 20 weeks. The determination of carbofuran in spiked water samples using the proposed biosensor was satisfactory when compared to the chromatographic reference method. The results showed no significant difference at the 95% confidence level with t-test statistics. The application of enzymes from endophytic fungi in constructing biosensors broadens the biotechnological importance of these microorganisms.

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Se validó una metodología analítica que permite cuantificar residuos de carbofuran en muestras de suelo. La extracción del plaguicida desde la matriz se realizó mediante agitación mecánica empleando acetato de etilo como solvente, los extractos obtenidos se sometieron a extracción en fase sólida (EFS) utilizando cartuchos C18, finalmente, la determinación y cuantificación del carbofuran se llevó a cabo mediante cromatografía líquida de alta eficiencia con detección ultravioleta (CLAR-UV) a una longitud de onda de 205 nm. La metodología validada es específica y selectiva para el carbofuran, lineal en el rango desde 0,47 hasta 2,36 mgKg-1, precisa con un coeficiente de variación típico (CVtip) de 10,78%; exacta brindando un porcentaje de recuperación para la metodología global (porcentaje de R) equivalente a 98,25±3,97% y sensible con límites de detección y cuantifica-ción de 0,045 y 0,149 mgKg-1, respectivamente. También se verificó la robustez del método. Se analizaron dos muestras de suelo dedicados al cultivo de café, y se encontraron residuos de carbofuran durante los primeros 30 días después de su aplicación.

An analytic method was validated to quantify Carbofuran residues in soil samples. The pesticides were extracted from the matrix by mechanic stirring, using ethyl acetate as a solvent. These extracts were cleaned by using cartridges C18. The determination and quantification of Carbofuran was made by high performance liquid chromatography with ultraviolet detection (HPLC-UV). The wavelength was 205 nm. The validated method is specific and selective for Carbofuran, is linear in the range from 0.47 to 2.36 mg kg-1, is accurate with a typical variation coefficient of 10.78%, is exact with recovering percentage (% R) equivalent to 98.25±3.97% and sensitive with detection and quantification limits since 0.045 and 0.149 mg kg-1 respectively. The robustness of the method was recognized. Two samples from soil of coffee cultivation were analyzed. Residues ofCarbofuranwerefoundduringthe first thirty days after application. Two samples of soil coffee were analyzed finding residues of carbofuran during the first thirty days after application.

Neste artigo validou-se uma metodologia analítica que quantifica resíduos de carbo-furano em amostras de solo. Por agitação mecânica se extraíram pesticidas da matriz, utilizando acetato de etilo como solvente. Os extratos obtidos foram submetidos à extração em fase sólida (EFS) com cartuchos de C18. Em seguida, a identificação e quantificação de Carbofuran foi realizada por cromatografia líquida de alta eficiência com detecção ultravioleta (CLAE-UV). A longitude de onda foi 205 nm. A metodologia validada é específica e seletiva para car-bofuran; linear no intervalo de 0,47-2,36 mgkg-1, cocomumcoeficientedevariação (C. Vtip) típico de 10,78%, fornecendo uma taxa de recuperação precisa da meto-dologiaglobal(R%)equivalentea98,25± 3,97%. Os limites de sensibilidade de detecção e quantificação são 0,045 e 0,149 mg kg-1, respectivamente. Verificou-se também a robustez do método. Analisadas duas amostras de terra dedicada ao cultivo do café, se encontraram resíduos de carbofuran nos trinta primeiros dias após aplicá-lo.