Effects of the pesticides chlorpyriphos, metsulfuron-methyl, and thiamethoxam on ant communities in wheat crop

Ants are important components of food webs in several ecosystems. In anthropic areas, they can be used as bioindicators of the environmental impacts caused by many factors or in the evaluation of the dynamics of the recovery of an area after a certain disturbance. In this context, ants can be used as bioindicators in studies on the evaluation of environmental disturbances caused by pesticide use. Thus, the present work investigated the environmental impacts caused by the application of the insecticides chlorpyriphos and thiamethoxam and the herbicide metsulfuron-methyl in the community of ants in wheat crop (Triticum aestivum L.). The data were collected by pitfall traps and Berlese funnels. A Principal Response Curve was used for a relative abundance analysis. In addition, diversity index and richness were calculated for ant communities. The presence of six families, 11 tribes, 15 genera, and 19 morphospecies of ants belonging to the guilds of fungivorous, omnivorous, and predaceous ants were observed in the soil of the wheat crop. The insecticides chlorpyriphos and thiamethoxam reduced the richness, diversity, and relative abundance of ants of all the guilds on the surface and inside the soil. The effect of the herbicide metsulfuron-methyl on the community of ants was lower than the impact of the insecticides on these insects.

Development of a novel high throughput brain-on-chip with 3D structure and its application in evaluation of pesticide-induced-neurotoxicity / 生物工程学报

We designed and fabricated a novel high throughput brain-on-chip with three dimensional structure with the aim to simulate the in vivo three-dimensional growth environment for brain tissues. The chip consists of a porous filter and 3D brain cell particles, and is loaded into a conventional 96-well plate for use. The filter and the particle molds were fabricated by using computer modeling, 3D printing of positive mold and agarose-PDMS double reversal mold. The 3D cell particles were made by pouring and solidifying a suspension of mouse embryonic brain cells with sodium alginate into a cell particle mold, and then cutting the resulting hydrogel into pieces. The loaded brain-on-chip was used to determine the neurotoxicity of pesticides. The cell particles were exposed to 0, 10, 30, 50, 100 and 200 µmol/L of chlorpyrifos or imidacloprid, separated conveniently from the medium by removing the porous filter after cultivation. Subsequently, cell proliferation, acetylcholinesterase activity and lactate dehydrogenase release were determined for toxicity evaluation. The embryonic brain cells were able to grow and proliferate normally in the hydrogel particles loaded into the filter in a 96-well plate. Pesticide neurotoxicity test showed that both chlorpyrifos and imidacloprid presented dose-dependent inhibition on cell growth and proliferation. Moreover, the pesticides showed inhibition on acetylcholinesterase activity and increase release of lactate dehydrogenase. However, the effect of imidacloprid was significantly weaker than that of chlorpyrifos. In conclusion, a novel brain-on-chip was developed in this study, which can be used to efficiently assess the drug neurotoxicity, pharmacodynamics, and disease mechanism by combining with a microtiterplate reader.

Use of bone marrow for detection of toxic chemicals for the elucidation of poisoning in forensic veterinary medicine / Uso de medula óssea para detecção de produtos químicos tóxicos para a elucidação de intoxicação em patologia veterinária forense

In forensic toxicology, the detection of toxic chemicals from human bone marrow is often used in cases with an extended post mortem interval; however, in veterinary medicine, this practice is not used. Therefore, this study was performed to investigate the suitability of bone marrow for toxicological analysis in dogs and cats. Six animals with suspected poisoning were selected; the carcasses were sent for necropsy, and the organs were collected and preserved in buffered formalin and processed routinely for histological examination. In addition, bone marrow samples from the femur, humerus, and tibia were collected for toxicological analysis by liquid chromatography coupled to mass spectrometry detection (LC-MS). This analysis confirmed the presence of aldicarb, aldicarb sulfone, asulam, carbendazim, chlorpyrifos, dichlorvos, thifensulfuron methyl and trifloxysulfuron-sodium and associated with clinical symptoms and anatomo-histopathological alterations it was recognized the poisonings. It is expected that this study will promote the toxicological investigation of bone marrow and open avenues for the use of this tissue as an option for the detection of toxic chemicals in cases of forensic pathology.(AU)

Na toxicologia forense, a detecção de substâncias químicas tóxicas provenientes da medula óssea humana é frequentemente usada em casos com intervalo post mortem prolongado; no entanto, na medicina veterinária, essa prática não é utilizada. Portanto, este estudo foi realizado para investigar a utilização da medula óssea nas análises toxicológicas em cães e gatos. Seis animais com suspeita de intoxicação foram selecionados; as carcaças foram enviadas para necropsia e os órgãos foram coletados e preservados em formalina tamponada e processados rotineiramente para exame histológico. Amostras de medula óssea de fêmur, úmero e tíbia foram coletadas para análise toxicológica por cromatografia líquida acoplada à espectrometria de massa-massa (LC-MS). A análise por LC-MS confirmou a presença dos agrotóxicos aldicarbe, aldicarbe sulfona, asulam, carbendazim, clorpirifós, diclorvós, tifensulfuron metil e trifloxisulfuron-sódico, e em associação com sinais clínicos e achados anatomo-histopatológicos comprovou-se as intoxicações. Espera-se que este estudo promova a utilização da medula óssea como uma opção na investigação toxicológica para a detecção de produtos químicos tóxicos em casos de patologia forense.(AU)

Impact of phosphate solubilizing bacteria on wheat (Triticum aestivum ) in the presence of pesticides / Impacto das bactérias solubilizantes de fosfato no trigo (Triticum aestivum ) na presença de pesticidas

Abstract Three phosphate solubilizing bacteria were isolated and identified by 16S rRNA sequencing as Pseudomonas putida, Pseudomonas sp and Pseudomonas fulva . The strains were subjected to plant biochemical testing and all the PGPR attributes were checked in the presence of pesticides (chlorpyrifos and pyriproxyfen). The phosphate solubilizing index of strain Ros2 was highest in NBRIP medium i.e 2.23 mm. All the strains showed acidic pH (ranges from 2.5-5) on both medium i.e PVK and NBRIP. Strain Ros2 was highly positive for ammonia production as well as siderophore production while strain Rad2 was positive for HCN production. The results obtained by the strains Rad1, Rad2 and Ros2 for auxin production were 33.1, 30.67 and 15.38 µg ml-1, respectively. Strain Rad1 showed 16% increase in percentage germination in comparison to control in the presence of pesticide stress. Most promising results for chlorophyll content estimation were obtained in the presence of carotenoids upto 6 mgg-1 without stress by both strains Rad1 and Rad2. Study suggests that especially strain Ros2 can enhance plant growth parameters in the pesticide stress.

Resumo Três bactérias solubilizantes de fosfato foram isoladas e identificadas por seqüenciamento de rRNA 16S como Pseudomonas putida, Pseudomonas sp e Pseudomonas fulva. As estirpes foram submetidas a testes bioquímicos de plantas e todos os atributos PGPR foram verificados na presença de pesticidas (clorpirifos e piriproxifeno). O índice de solubilização de fosfato da estirpe Ros2 foi mais elevado no meio NBRIP, isto é, 2,23 mm. Todas as estirpes apresentaram um pH ácido (varia de 2,5-5) em ambos os meios, isto é PVK e NBRIP. A estirpe Ros2 foi altamente positiva para a produção de amoníaco, bem como a produção de sideróforos enquanto a estirpe Rad2 foi positiva para a produção de HCN. Os resultados obtidos pelas estirpes Rad1, Rad2 e Ros2 para a produção de auxina foram 33,1, 30,67 e 15,38 μg ml-1 , respectivamente. A deformação Rad1 mostrou aumento de 16% na germinação percentual em comparação com o controlo na presença de stress de pesticida. Os resultados mais promissores para a estimativa do teor de clorofila foram obtidos na presença de carotenóides até 6 mgg-1 sem estresse por ambas as cepas Rad1 e Rad2. Estudo sugere que especialmente a estirpe Ros2 pode melhorar parâmetros de crescimento de plantas no estresse de pesticidas.

A novel chlorpyrifos hydrolase CPD from Paracoccus sp. TRP: molecular cloning, characterization and catalytic mechanism

Background: Biodegradation is a reliable approach for efficiently eliminating persistent pollutants such as chlorpyrifos. Despite many bacteria or fungi isolated from contaminated environment and capable of degrading chlorpyrifos, limited enzymes responsible for its degradation have been identified, let alone the catalytic mechanism of the enzymes. Results: In present study, the gene cpd encoding a chlorpyrifos hydrolase was cloned by analysis of genomic sequence of Paracoccus sp. TRP. Phylogenetic analysis and BLAST indicated that CPD was a novel member of organophosphate hydrolases. The purified CPD enzyme, with conserved catalytic triad (Ser155-Asp251-His281) and motif Gly-Asp-Ser-Ala-Gly, was significantly inhibited by PMSF, a serine modifier. Molecular docking between CPD and chlorpyrifos showed that Ser155 was adjacent to chlorpyrifos, which indicated that Ser155 may be the active amino acid involved in chlorpyrifos degradation. This speculation was confirmed by site-directed mutagenesis of Ser155Ala accounting for the decreased activity of CPD towards chlorpyrifos. According to the key role of Ser155 in chlorpyrifos degradation and molecular docking conformation, the nucleophilic catalytic mechanism for chlorpyrifos degradation by CPD was proposed. Conclusion: The novel enzyme CPD was capable of hydrolyze chlorpyrifos and Ser155 played key role during degradation of chlorpyrifos.

Soil bacteria showing a potential of chlorpyrifos degradation and plant growth enhancement

ABSTRACT Background: Since 1960s, the organophosphate pesticide chlorpyrifos has been widely used for the purpose of pest control. However, given its persistence and toxicity towards life forms, the elimination of chlorpyrifos from contaminated sites has become an urgent issue. For this process bioremediation is the method of choice. Results: Two bacterial strains, JCp4 and FCp1, exhibiting chlorpyrifos-degradation potential were isolated from pesticide contaminated agricultural fields. These isolates were able to degrade 84.4% and 78.6% of the initial concentration of chlorpyrifos (100 mg L-1) within a period of only 10 days. Based on 16S rRNA sequence analysis, these strains were identified as Achromobacter xylosoxidans (JCp4) and Ochrobactrum sp. (FCp1). These strains exhibited the ability to degrade chlorpyrifos in sterilized as well as non-sterilized soils, and were able to degrade 93-100% of the input concentration (200 mg kg-1) within 42 days. The rate of degradation in inoculated soils ranged from 4.40 to 4.76 mg-1 kg-1 d-1 with rate constants varying between 0.047 and 0.069 d-1. These strains also displayed substantial plant growth promoting traits such as phosphate solubilization, indole acetic acid production and ammonia production both in absence as well as in the presence of chlorpyrifos. However, presence of chlorpyrifos (100 and 200 mg L-1) was found to have a negative effect on indole acetic acid production and phosphate solubilization with percentage reduction values ranging between 2.65-10.6% and 4.5-17.6%, respectively. Plant growth experiment demonstrated that chlorpyrifos has a negative effect on plant growth and causes a decrease in parameters such as percentage germination, plant height and biomass. Inoculation of soil with chlorpyrifos-degrading strains was found to enhance plant growth significantly in terms of plant length and weight. Moreover, it was noted that these strains degraded chlorpyrifos at an increased rate (5.69 mg-1 kg-1 d-1) in planted soil. Conclusion The results of this study clearly demonstrate that the chlorpyrifos-degrading strains have the potential to develop into promising candidates for raising the productivity of crops in pesticide contaminated soils.

Efficacy of three insecticides on rat flea [Xenopsylla cheopis] infesting rodents in Giza Governorate, Egypt

The extensive use of insecticides in public health and agriculture sectors is the main reason for development of resistance in fleas associated in domestic rodents. The present work was planned to investigate the insecticidal efficacy of Lambda-cyhalothrin, Chlorpyrifos and Fenitrothion against rat flea [Xenopsylla cheopis] infesting rodent species in Giza Governorate, Egypt. The lethal concentration LC[50] and Lc[90] of population percent were obtained from the established regression log concentrate-response lines. Data indicated that the values of lethal concentration [LC[50]] were 0.293, 1.725 and 2.328% for Lambda-cyhalothrin, chlorpyrifos and Fenitrothion, respectively. The values of lethal concentration [Lc[90]] were 0.467, 2.839 and 5.197% for Lambda-cyhalothrin, chlorpyrifos and Fenitrothion, respectively

Toxicity induced by dieldrin and chlorpyrifos in the freshwater crayfish Cambarellus montezumae (Cambaridae) / Toxicidad inducida por dieldrín y clorpirifós en Cambarellus montezumae (Cambaridae)

The toxicity induced by insecticides in aquatic organisms is of utmost relevance because it may give a clue about the degree of health or damage of the involved ecosystem. In the present report, we determined the effect of dieldrin (DD) and chlorpyrifos (CP) on the freshwater crayfish, Cambarellus montezumae. The organisms (4-6cm in diameter) were collected in the Ignacio Ramírez Reservoir, situated at 50km Northeast of Mexico City, in the Rio Lerma Basin. Initially, we determined the LC50 value with the Probit method, then the DNA damage with single cell gel electrophoresis (comet assay applied at 24, 48, and 72h of exposure) to the brain and hepatopancreas of animals exposed (in reconstituted water) to 0.05 and 0.5µg/L of each insecticide. In the hepatopancreas of the same organisms, we determined the lipid peroxidation by applying the TBARS test. DNA damage and lipid peroxidation were also evaluated with the same methods to organisms exposed in water from the reservoir. In regard to the LC50 at 72h of exposure, we found a value of 5.1µg/L and a value of 5.62µg/L for DD and CP, respectively. The comet assay applied at different exposure times showed significant DNA damage to both organs, with respect to the control level. In the case of DD, statistical significance was observed for the two doses in the whole evaluated schedule. CP was genotoxic in the brain with the high dose at 72h, and in the hepatopancreas with the two tested doses at all evaluated exposure times. Also, a significant lipid peroxidation increase was detected with the two doses of insecticides. In the study with water from the reservoir, a more pronounced DNA damage was detected. Our results showed strong DNA damage induced by both insecticides in the crayfish, as well as a correlation with the lipid peroxidation effect, suggesting that oxidative stress is involved in the genotoxic alteration. Our results also showed the usefulness of the studied organism as well as the applied tests for the evaluation of toxicological effects, and suggested the pertinence of applying the comet assay to other freshwater organisms to evaluate the bioaccumulation of insecticides. Rev. Biol. Trop. 63 (1): 83-96. Epub 2015 March 01.

La toxicidad inducida por insecticidas en organismos acuáticos es de gran relevancia porque puede orientar sobre el grado de salud o daño del ecosistema involucrado. En el presente estudio determinamos el efecto del dieldrín (DD) y del clorpirifós (CP) en el acocil de agua dulce Cambarellus montezumae. Los organismos (4-6cm de diámetro) se recolectaron en la Represa Ignacio Ramírez, situada a 50km al Noreste de la Ciudad de México, en la cuenca del Río Lerma. Inicialmente determinamos la LC50 con el método de Probit y después el daño al ADN mediante la electroforesis unicelular en gel (ensayo cometa, aplicado a las 24, 48 y 72 h de exposición) en el cerebro y el hepatopáncreas de animales expuestos (en agua reconstituida) a 0.05 y 0.5µg/L de cada insecticida. En el hepatopáncreas de los mismos organismos determinamos la peroxidación lipídica aplicando la prueba de TBARS. El daño al ADN y la peroxidación lipídica también se evaluaron con los mismos métodos en organismos expuestos a los insecticidas en agua de la represa. En relación a la LC50, a las 72h de exposición encontramos un valor de 5.1µg/L y un valor de 5.62µg/L para DD y CP, respectivamente. El ensayo cometa aplicado a diferentes tiempos de exposición mostró un significativo daño al ADN en ambos órganos con respecto al valor del testigo. En el caso del DD se observó significancia estadística para las dos dosis en todo el horario evaluado. CP fue genotóxico en el cerebro con la dosis más alta a las 72 h y en hepatopáncreas con las dos dosis, en todos los tiempos de exposición evaluados. También se detectó un significativo aumento de la peroxidación lipídica con las dos dosis de los insecticidas. En el estudio con el agua de la represa se detectó un daño más pronunciado en el ADN. Nuestros resultados mostraron un fuerte daño al ADN en Cambarellus montezumae por ambos insecticidas, así como una correlación con el efecto de la peroxidación lipídica, lo que sugiere que el estrés oxidativo está involucrado en la alteración genotóxica. Nuestros resultados también mostraron la utilidad del organismo estudiado y de las pruebas aplicadas para evaluar efectos tóxicos, y sugieren la pertinencia de aplicar el ensayo cometa en otros organismos de agua dulce para evaluar la bioacumulación de insecticidas.

Chlorpyrifos Determined in Human Blood by UPLC-MS/MS and Its Application in Poisoning Cases / 法医学杂志

OBJECTIVE@#To determine the chlorpyrifos in human blood by liquid chromatography-tandem mass spectrometry and to validate its application in poisoning cases.@*METHODS@#The samples were extracted by a simple one-step protein precipitation procedure. Chromatography was performed on a Capcell Pack C18 MGII column (250 mm x 2.0 mm, 5 μm) using an isocratic elution of solvent A (0.1% formic acid-water with 2 mmol/L ammonium acetate) and solvent B (methanol with 2 mmol/L ammonium acetate) at 5:95 V:V).@*RESULTS@#The linear ranged from 5 to 500 ng/mL (r = 0.998 7). The limit of detection (LOD) and the lower limit of quantification (LLOQ) were 2 ng/mL and 4 ng/mL, respectively. For this method, the precision and accuracy of intra-day and inter-day were < 10% and 97.44%-101.10%, respectively. The results in stability test of long-term frozen were satisfied. The matrix effect, recovery and process efficiency were 64.97%-86.81%, 76.70%-85.52%, and 55.57%-66.58%, respectively.@*CONCLUSION@#This method can provide a rapid approach to chlorpyrifos extraction and determination in toxicological analysis of forensic and clinical treatment.

The rabbit experimental study for toxicokinetics of chlorpyrifos impacted by hemoperfusion / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To investigate toxicokinetic parameters impacted by hemoperfusion after oral chlorpyrifos exposure, to investigate the adsorption effect of hemoperhusion for chlorpyrifos poisoning.</p><p><b>METHODS</b>12 rabbits were divided into two groups after oral exposure with chlorpyrifos 300 mg/kg body weight. Control group: without hemoperfusion; hemoperfusion group: hemoperfusion starts 0.5 h after chlorpyrifos exposure and lasts for 2h. Blood samples were collected at different times, concentrations of chlorpyrifos were tested by GC, then, toxicokinetic parameterswere calculated and analysis by DAS3.0.</p><p><b>RESULTS</b>In hemoperfusion group, peak time was (7.19±3.74) h, peak concentrations was (1.37±0.56) mg/L, clearance rate was (13.93±10.27) L/h/kg, apparent volume of distribution was (418.18±147.15) L/kg The difference of these parameter were statistically significant compared with control group (P<0.05).</p><p><b>CONCLUSION</b>Hmoperfusion will decrease the inner exposure and load dose of rabbits with chlorpyrifos poisoning.</p>

CONTAMINACIÓN DE OPERARIOS CON CLORPIRIFOS, POR PRÁCTICA DE "EMBOLSADO" DE BANANO (Musa sp. ) EN URABÁ, ANTIOQUIA / CONTAMINATION OF WORKERS WITH CHLORPYRIFOS, DUE TO "BANANA (Musa sp. ) BAGGING TECHNIQUE" IN URABÁ (ANTIOQUIA, COLOMBIA)

Introducción: Teniendo en cuenta el daño potencial que se genera en la salud humana en la región de Urabá (Antioquia, Colombia) a través de la utilización de agrotóxicos, con énfasis en clorpirifos, se realizó esta investigación donde se evalúan los niveles de contaminación de los operarios expuestos al insecticida contenido en la bolsa de campo empleada en el cultivo de banano. Metodología: Este trabajo descriptivo se llevó a cabo mediante la obtención de muestras de sangre a los trabajadores de las fincas seleccionadas. Se registraron los niveles de colinesterasa eritrocítica y la prevalencia de sintomatología asociada con la exposición a plaguicidas con énfasis en organofosforados. Mediante encuestas se obtuvo información demográfica, socioeconómica y laboral y se caracterizó la exposición individual y ambiental. Resultados: Se determinó que es una población joven (entre 20 y 40 años) con falencias en sus sistemas de protección a través de un vestido de labor que deja áreas expuestas. 80% de los embolsadores de una de las fincas han presentado alteraciones en su nivel de colinesterasa comparada con las otras analizadas, lo que demandaría una especial mirada ambiental y de procesos. La sobreexposición laboral a agrotóxicos (11 años de exposición promedia) debida a la especialización de trabajadores que manipulan además otros productos con otras categorías toxicológicas, demanda vigilancia epidemiológica integral de estos obreros y su actividad. Son numerosas las personas intervinientes en la ruta tóxica que sigue la bolsa impregnada con clorpirifos sin que se les hagan los chequeos mínimos de seguimiento sanitario.

Introduction: Considering the potential harm to human health that is generated in the Urabá region (Antioquia, Colombia) through the use of agro-toxic chemicals with emphasis in chlorpyrifos, this research was conducted in order to assess levels of contamination of workers exposed to insecticide contents in field bags used in banana crops. Methodology: This descriptive study was conducted obtaining blood samples from workers in selected farms. Erythrocyte cholinesterase levels and the prevalence of symptoms associated with exposure to organophosphate pesticides with emphasis on organophosphorous were recorded. Demographic, socioeconomic and employment information was obtained and individual and environmental exposure was characterized. Results: It was determined that it is a young population (between twenty and forty) with gaps in their protection systems through a work dress that leaves areas exposed; 80% of the baggers of one of the farms have presented alterations in their cholinesterase level compared to the other analyzed, which would require special environmental and process supervision. Occupational overexposures to agro-toxic chemicals (average 11 years of exposure) due to the specialization of workers who handle other products with other toxicological categories demand comprehensive epidemiological surveillance of these workers and their activity. There are numerous people involved in the toxic route followed by bags impregnated with chlorpyrifos without having had the minimal health monitoring checkups.

A single high dose of chlorpyrifos reduces long-term basal c-fos expression in the rat arcuate hypothalamic nucleus / La administración de una dosis aguda de clorpirifós reduce a largo plazo la expresión basal de c-fos en el núcleo arqueado del hipotálamo

Chlorpyrifos (CPF) is an organophosphate compound used worldwide as a pesticide in agriculture that, after subcutaneous injection, keeps acetylcholinesterase (AChE) activity inhibited within an organism for months. Ample clinical and experimental evidence shows that CPF exposure induces relevant and persistent neurobehavioral deficits in humans and animals, even after one single episode/injection. Additionally, clinical and epidemiological studies evidence that a significant percentage (60%) of Gulf War veterans as well as agricultural workers suffering from acute OP intoxication may have developed intolerance to nicotine and ethanol-containing beverages. Consistent with it, administration of a single high dose of CPF to adult Wistar rats elicited long-lasting reduced voluntary ethanol drinking and increased sedation to ethanol without evidence of altered ethanol metabolism, which indicates that CPF-ethanol neurobiological interactions may exist. In this study, we explore whether CPF exposure induces significant disturbances in basal and/or ethanol-evoked neural activity in a set of cholinoceptive brain regions critically involved with neurobiological responses to ethanol. For this aim, brain regional c-fos expression in response to acute ethanol (1.5 or 3.0 g/kg, i.p.) or saline was assessed in adult male Wistar rats previously injected with either a single high dose of CPF (250 mg/kg, sc) or vehicle. We found that CPF administration reduces long-term basal, but not ethanol-evoked, c-fos expression in the arcuate hypothalamic nucleus. Because independent brain pathways may modulate acute responses to ethanol and voluntary ethanol consumption, we do not rule out the contribution of basal neural disturbances observed in the Arc to CPF-elicited ethanol avoidance.

El clorpirifós (CPF) es un compuesto organofosforado utilizado como plaguicida en todo el mundo. Después de ser inyectado de manera subcutánea, mantiene la actividad de la enzima acetilcolinesterasa (AChE) inhibida durante meses. Estudios clínicos y experimentales muestran que la exposición al CPF induce déficits neuroconductuales persistentes en seres humanos y animales, incluso después de un solo episodio/inyección. Además, estudios epidemiológicos evidencian que un porcentaje significativo (60%) de los veteranos de la Guerra del Golfo, así como los agricultores que sufren una intoxicación aguda por organofosforados, desarrollan intolerancia a la nicotina y las bebidas que contienen etanol. Datos experimentales mostraron que la administración de una sola dosis alta de CPF en ratas Wistar adultas provoca una reducción a largo plazo del consumo voluntario de etanol y un incremento en la sedación provocada por etanol sin evidencias de alteración del metabolismo de esta sustancia, lo que indica que pueden existir interacciones neurobiológicas entre CPF-etanol. En este estudio, se explora si la exposición a CPF induce alteraciones significativas en la actividad neuronal basal o evocada por el etanol en un conjunto de regiones colinoceptivas del cerebro involucradas en las respuestas neurobiológicas al etanol. Para ello, se evaluó la expresión de c-fos en respuesta a una dosis de etanol aguda (1.5 o 3.0 g/kg, ip) o solución salina en ratas Wistar macho adultas previamente inyectados con dosis aguda de CPF (250 mg/kg, sc) o un vehículo. Encontramos que la administración de CPF redujo la expresión basal de c-fos a largo plazo, pero no la evocada por el etanol en el núcleo arqueado del hipotalámo. Debido a que vías cerebrales independientes podrían modular las respuestas agudas al etanol y el consumo voluntario del mismo, no se descarta la contribución de las alteraciones neuronales basales observadas en el Arc en la evitación del consumo de etanol provocado por CPF.

Resistance and control of cypermethrin and chlorpyrifos as acaricide for control of hard tick Haemaphysalis longicornis (acari: ixodidae) / 대한수의학회지

Chemotherapeutic treatment is still the foundation of tick control programs. This study investigated the acaricidal efficacy of cypermethrin alone and in combination with chlorpyrifos against Haemaphysalis (H.) longicornis. Unfed larval ticks were exposed to 0.1, 1.0, and 10 mg/mL cypermethrin for 60 min, after which the acaricidal efficacy was examined based on tick mortality. All compounds showed similar suppression curves, with the best control being achieved by cypermethrin and chlorpyrifos (1 : 1 ratio) at 10 mg/mL. Effective cypermethrin concentrations for tick control were two to seven times higher than the recommended doses, indicating resistance by H. longicornis.

EVALUACIÓN AMBIENTAL DE LA PRÁCTICA "EMBOLSADO" EN PLÁTANO (Musa AAB SIMMONDS). QUINDÍO, COLOMBIA. / ENVIRONMENTAL ASSESSMENT OF THE "BAGGING" PRACTICE IN PLANTAIN (Musa AAB SIMMONDS). QUINDÍO, COLOMBIA.

En el cultivo de plátano de explotación comercial se utilizan bolsas de polietileno de baja densidad (PEBD) impregnadas con clorpirifos (insecticida) a 1%, como principal práctica de protección de frutos del ataque de plagas que demeritan su apariencia. No existen estudios que aporten datos sobre la magnitud de los efectos ambientales que causa la técnica de embolsado de plátano en el Quindío, razón por la cual se realizó este trabajo descriptivo analítico mediante un sondeo a partir de encuestas en cinco municipios plataneros de este departamento y seguimiento de la ruta tóxica de las bolsas, donde se cualifica el impacto ambiental generado por este procedimiento, se describe la disposición final de las bolsas tratadas y sin tratar, y se valora la cantidad de plástico que es utilizado en la labor de embolse de racimo en el departamento del Quindío. El embolsado no presenta mayor utilidad económica para el productor en comparación con la no ejecución de la práctica. Los agricultores en el Quindío que realizan la comercialización a través de intermediarios, no tienen clara la función de la bolsa de polietileno tratada con clorpirifos y sin tratar. El embolse no es una actividad indispensable en el manejo agronómico del cultivo para control de plagas no propagadas por todo el territorio, es una actividad de "moda" generalizada en la zona platanera del Quindío, con impacto ambiental de 840 toneladas/anuales de plástico que entran al sistema más 7,14 toneladas/año de clorpirifos.

Low density polyethylene (LDPE) bags impregnated with chlorpyrifos (insecticide) at 1% are used in the cultivation of commercial exploitation plantain as the main crops protection practice against pests that detract their appearance. There are no studies that provide data on the magnitude of the environmental effects that the plantain bagging technique causes in the Department of Quindío, reason why this descriptive analytical work was conducted with surveys from interviews in five plantain producer municipalities in this region and with environmental monitoring of the toxic route of bags, in which the environmental impact generated with this procedure, is qualified, the final disposal of the treated and untreated bags is described, and the amount of plastic used in the bagging practice in Quindío.is valued. Bagging does not represent greater economic benefit to the producer compared to the non-implementation of the practice. Quindío producers who carry out commercialization through intermediaries, do not have clarity about the function of the polyethylene bag treated with chlorpyrifos and no treated bags. Bagging is a non-essential activity in the agronomic management to control crop pests which are not spread throughout the region; it is a "fashion" activity widespread in plantain cultivations in the Quindío area, with environmental impact of 840 tons/year of polyethylene that enter in the system more than 7.14 tons/year of chlorpyrifos.

Neurotoxicidade de pesticidas organofosforados durante o desenvolvimento: alterações bioquímicas e comportamentais / Neurotoxicity of organophosphorus pesticides during development: behavioral and biochemical changes

Pesticidas organofosforados são amplamente usados e seu uso constitui um grave problema de saúde pública. A ação clássica destes compostos é a inibição irreversível da acetilcolinesterase, promovendo acúmulo de acetilcolina nas sinapses e hiperestimulação colinérgica. No entanto, as consequências da exposição a baixas doses podem se estender a outros mecanismos de ação e sistemas neurotransmissores. Considerando que crianças constituem um grupo particularmente vulnerável aos efeitos de pesticidas, neste trabalho investigamos os efeitos da exposição aos organofosforados metamidofós (MET) e clorpirifós (CPF) durante o desenvolvimento sobre os sistemas colinérgico e serotoninérgico e sobre o comportamento de camundongos. Para isso, camundongos suíços foram expostos a injeções subcutâneas de MET, clorpirifós ou veículo do terceiro (PN3) ao nono (PN9) dias de vida pós-natal. As doses de exposição foram previamente escolhidas através da construção de uma curva dose-resposta que identificou como mais adequadas para este estudo as doses de 1mg/kg de MET e 3mg/kg de CPF, as quais promoveram em torno de 20% de inibição da acetilcolinesterase. Em PN10, parte dos animais foi sacrificada e foram avaliados os sistemas colinérgico e serotoninérgico no tronco encefálico e córtex cerebral. De PN60 a PN63, os animais foram submetidos a uma bateria de testes comportamentais. Em seguida, estes animais também foram sacrificados tendo sido avaliados os sistemas colinérgico e serotoninérgico. Em PN10, MET e CPF causaram alterações que sugerem aumento da atividade colinérgica respectivamente no tronco e córtex em fêmeas. No sistema serotoninérgico, apenas CPF promoveu alterações, aumentando a ligação ao receptor 5HT1A e transportador 5HT em fêmeas e diminuindo na ligação ao 5HT2. Em PN63, a atividade da acetilcolinesterase foi reestabelecida em todos os grupos. Ainda assim, MET diminuiu a atividade da colina acetiltransferase no córtex e a ligação ao transportador colinérgico.

Organophosphate pesticides are widely used and its use consist on a severe public health problem. The classic effect of these compounds involve irreversible inhibition of the enzyme acetylcholinesterase, causing an accumulation of acetylcholine at cholinergic synapses and, consequently, cholinergic hyperstimulation. However, when the doses of exposure are low, other the mechanisms of action may play a role and other neurotransmitter systems may be affected. Considering that children are particularly vulnerable to effects of these compounds, in this study we investigated the effects of methamidophos and chlorpyrifos organophosphate exposure during development on cholinergic and serotonergic systems and behavior. For this purpose, Swiss mice received subcutaneous injections of methamidophos or chlorpyrifos, or vehicle from the third to the nineth postnatal day (PN3 - PN9). Initially, a dose-response study was performed and the doses of 1mg/kg methamidophos and 3mg/kg chlorphrifos, which promoted 20% inhibition of acetylcholinesterase activity in brain were chosen to be used in the next set of experiments. At PN10, one day after exposure, a group of animals was sacrificed and the brainstem and cortex collected and stored to further analysis of cholinergic and serotonergic systems. From PN60 to PN63 the animals were submitted to behavioral tests in order to evaluate: anxiety, locomotor activity, decision making, depressive-like behavior and learning/memory. After the last test, the animals were sacrificed and the brainstem and cortex collected and stored to further analysis of cholinergic and serotonergic systems. At PN10, methamidophos and chlorpyrifos promoted alterations that suggest an increase of cholinergic activity respectively on the brainstem and cortex of females. As for the serotonergic system: only chlorpyrifos elicited alterations: There were increases in 5HT1A receptor and 5HT transporter binding in females and a decrease in 5HT2 receptor binding.

Morpho-toxicology of chlorpyrifos to prolactin cells of a freshwater catfish, Heteropneustes fossilis / Morfotoxicologia de clorpirifos para as células de prolactina de bagre de água doce Heteropneustes fossilis

In the present study, an organophosphorus compound Coroban (active ingredient chlorpyrifos ­ E.C. 20%) was used. In short-term exposure the fish were subjected to 0.8 of 96h LC50 value of chlorpyrifos (1.76 mg L-1) for 96h. In long-term exposure the experiment was performed for 28 days by using 0.2 of 96h LC50 value of chlorpyrifos (0.44 mg L-1). Fish were killed on each time intervals from control and experimental (chlorpyrifos) groups after 24, 48, 72, and 96h in short-term exposure and after 7, 14, 21, and 28 days in long-term experiment. Blood samples were collected and sera were analyzed for calcium. Pituitary glands were fixed for histological studies and stained with Herlant tetrachrome and Heidenhain's azan techniques. Short-term exposure of chlorpyrifos caused decrease in the serum calcium levels. No change was noticed in the prolactin cells of chlorpyrifos treated fish. Long-term treatment with chlorpyrifos provoked hypocalcemia. The prolactin cells of treated fish exhibited slight degranulation after 21 days whereas the nuclear volume remained unchanged. After 28 days, the prolactin cells exhibited further degranulation and the nuclear volume recorded an increase. Cytolysis and vacuolization were also visible.

No estudo presente, o composto organofosforo Coroban (ingrediente ativo clorpirifo ­ E.C. 20%) foi usado. Na exposição a curto prazo os peixes foram submetido a 0,8 de valor LC50 de 96h de clorpirifo (1,76 mg L-1) durante 96h. Na exposição a longo prazo o experimento foi executado durante 28 dias usando 0,2 de valor LC50 de 96h de clorpirifos (0,44 mg L-1). Os peixes foram mortos a cada intervalo dos grupos controle e experimental (clorpirifos) após 24, 48, 72, e 96h em exposição a curto prazo e após 7, 14, 21, e 28 dias no experimento a longo prazo. As amostras de sangue foram colhidas e o soro foi analisado para cálcio. As glândulas pituitárias foram fixadas para estudos histológicos e colorido por tetracromo de Herlant e por técnicas de azan do Heidenhain. A exposição a curto prazo do clorpirifo diminuiu os níveis de cálcio no soro. Nenhuma mudança foi observada nas células de prolactina nos peixes tratados com clorpirifo. O tratamento a longo prazo com clorpirifo causou hipocalcemia. As células de prolactina dos peixes tratados mostraram uma leve degranulação após 21 dias ao passo que o volume nuclear permaneceu inalterado. Depois de 28 dias, as células de prolactina mostraram mais degranulação e o volume nuclear registrou um aumento. Citólise e vacuolização também eram visíveis.

Detection of chlorpyrifos in air of workplace with HPLC / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To establish the method of detecting the concentrations of chlorpyrifos in air of workplace with high performance liquid chromatographic (HPLC).</p><p><b>METHODS</b>According to standards of methods for determining the chemical substances in workplace air, chlorpyrifos in the air was collected by silicone tube, then dissolved by acetonitrile and determined by high performance liquid chromatography with UV-detector.</p><p><b>RESULTS</b>There was a linear relationship within the range of 0 ∼ 10.0 µg/ml, and regression equation was y = 5206.1x - 104.7, correlation coefficient was 0.9999, the detection limit was 0.006 µg/ml. The lowest detected concentration was 0.001 mg/m(3) (sampling volume 4.5 L). The average recoveries was 98.3% ∼ 102.5%. The within-run precision was 1.96% ∼ 4.39%, the between-run precision was 2.76% ∼ 5.87%. The desorption efficiencies were 99.0% ∼ 103.3% and the sampling efficiencies were 94%. The samples in silicone tube could be stored for 15 days at room temperature.</p><p><b>CONCLUSION</b>The present method could meet with the requirements of Guide for establishing occupational health standards-Part 4 Determination methods of air chemicals in workplace and be feasible for determination of chlorpyrifos in workplace air.</p>

Clinical study of the relationship between organophosphate insecticides exposure and allergic asthma in preschool children

Bronchial asthma is a major public health problem affecting millions of people worldwide. There is an increasing concern that the prevalence of the disease could be attributed to new or modified patterns of exposures to chemicals, including insecticides. Organophosphates insecticides [OPs] account for 50% of all insecticides used. Chlorpyrifos is the third most commonly used among all pesticides applied by homeowners and commercial applicators. Interlukin-4 [IL-4] is one of the most important cytokines underlying the development of the allergic asthma. The aim of this work was to evaluate the relationship between the immunomodulatory effects of the environmental exposure to organophosphate insecticides and allergic asthma in preschool children living in rural areas. The current study was conducted in the period from October, 2008 to October 2010. 200 children were classified into 2 groups: Group I: 100 diseased preschool children, living in rural areas and diagnosed as allergic asthma, selected from the pediatrics outpatient clinic, Zagazig University Hospitals. Group II: Control group, 100 healthy children matching the diseased group in the age, sex and residency, selected from the outpatient clinic of minor surgeries, Zagazig University Hospitals. There was a non-significant difference between males and females or between different age categories of the asthmatic group as regard severity of asthma. Serum interleukin-4 and concentration were significantly higher in the asthmatic group as compared to the control group. A significant positive correlation was found between either IL-4 level and clorpyriphos concentration and the severity of asthma. Moreover, there was a significant positive correlation between chlorpyrifos concentration and IL-4 level in the asthmatic children. It was concluded that exposure to organophosphate insecticides [OPs] is associated with elevated serum IL-4 which plays important role in the pathogenesis of allergic asthma. This immunomodulating effect of OPs can explain the increased prevalence of allergic asthma among rural preschool children exposed to these insecticides

Determination of LC[50] of chlorpyrifos and neem extract on third instar larvae of house flies and their effect on fecundity

Two pesticides one from OP compound [Chlorpyrifos] and other from Biopesticides [Neem extract] were applied against 3[rd] instar larvae of house flies by contact method. LC[50 of Chlorpyrifos and Neem extract was calculated as 0.25% for chlorpyrifos and 0.42% for Neem Extract. Treated larvae when succeeded to reach the adult stage, the effects of the mentioned insecticides were noted on fecundity of adults of Musca domestica. Chlorpyrifos delayed egg-laying while Neem extract completely inhibited the egg-laying. Moreover, the treated larvae when succeeded to pupate, they failed to emerge from the pupal case completely and the larvae got heavy melanization after 48 hours of treatment

Chlorpyrifos Blood Level and Exposure Symptoms among Paddy Farmers in Sabak Bernam, Malaysia

The extensive and intensive use of pesticides in agricultural practices has exposed farmers to various hazards resulting in varying degrees of health outcomes. We conducted a cross-sectional study among paddy farmers in Sabak Bernam district, Malaysia. The objective of this study was to gather baseline information on chlorpyrifos blood level and its relationship with pesticides exposure symptoms. We detected chlorpyrifos in farmers’ blood in 7 percent of the respondents, with mean 7.29 nanogram per millilitre blood (sd 5.84 nanogram per millilitre). The percentage of farmers who experienced at least one pesticide exposure symptoms was 75 percent. However, we found no significant association between chlorpyrifos blood level and its exposure symptoms. The farmers had low scores on safe practice of pesticide use even though they have high marks on knowledge and attitude. We found no significant association between the scores on knowledge, attitude and practice on pesticide use and the chlorpyrifos blood level. The presence of pesticide exposure symptoms proved that most of the farmers were exposed to hazardous effects of pesticides. Specific trainings on safe use and handling of pesticides should be given on regular basis to these farmers to ensure they are protected from hazardous effects of pesticides exposure.