Chlorpyrifos should be banned in agriculture and livestock production in Colombia

Chlorpyrifos (CPF) is a pesticide widely used in Colombia´s agriculture, including crops, farm animals and pets, despite it has been banned for use in the European Union and the United States. Studies demonstrate that even low blood levels of CPF -which do not inhibit blood acetylcholinesterase- can lead to child developmental and neurological disorders such as smaller head circumference and brain alterations, and psychomotor and cognitive deficits related to learning ability, attention and memory. In adults, CPF is an endocrine disruptor and breast carcinogen. High direct and indirect economic costs have been associated with CPF exposure. Not only farmers and their families -who have the highest exposures- but the general population consuming crops sprayed with CPF are also at risk. For these reasons CPF was recently banned by the European Union (2020) and the USA (2021). Pesticide regulation policies vary greatly depending on which and how scientific studies are used to assess health risks. Pesticide evaluations funded by the chemical industry should be rectified to avoid conflicts of interest. Furthermore, political alignment with the interests of the industry should not take precedence over independent scientific evidence. It is discouraging, to say the least, that until stricter health laws are passed in Colombia, CPFs and related pesticides will continue to be imported from those countries that have already banned them. Colombian scientists should raise their voice to challenge blind acceptance of profits over unintended consequences, and efforts to prevent pesticide´s abuse should be encouraged.

El clorpirifos (CPF) es un pesticida ampliamente utilizado en la agricultura de Colombia, incluidos cultivos, animales de granja y mascotas, a pesar de haber sido prohibido en la Unión Europea y Estados Unidos. Los estudios han demostrado que incluso niveles bajos de CPF en sangre -que no inhiben la acetilcolinesterasa sanguínea- pueden provocar trastornos neurológicos y del desarrollo infantil, como menor circunferencia de la cabeza y alteraciones cerebrales, y déficits psicomotores y cognitivos relacionados con la capacidad de aprendizaje, la atención y la memoria. En adultos, el CPF es un disruptor endocrino y causante de cáncer de mama. Altos costos económicos directos e indirectos se han asociado con la exposición al CPF. No solo los trabajadores agrícolas y sus familias, que están más expuestos, sino también la población en general que consume cultivos rociados con CPF también están en riesgo. Por estas razones el CPF fue prohibido recientemente por la Unión Europea (2020) y los EE. UU. (2021). Las políticas de regulación de plaguicidas varían mucho según los estudios científicos escogidos para evaluar los riesgos para la salud. Las evaluaciones de plaguicidas financiadas por la industria química deben rectificarse para evitar conflictos de interés. Además, ante la evidencia científica independiente no debería prevalecer la alineación política con los intereses de dicha industria. Es desalentador, por decir lo menos, que hasta que se aprueben leyes de salud más estrictas en Colombia se seguirán importando CPF y pesticidas relacionados desde aquellos países que ya los han prohibido. Los científicos colombianos deben alzar la voz para desafiar la aceptación ciega de ganancias por encima de las consecuencias no deseadas en salud pública, y se deben alentar los esfuerzos para prevenir el abuso de pesticidas.

Clorpirifós (CPF) é um pesticida registrado amplamente utilizado na agricultura colombiana, incluindo lavouras, animais de fazenda e animais de estimação, apesar de ter sido proibido na União Europeia e nos Estados Unidos. Estudos têm demonstrado que mesmo níveis baixos de CPF no sangue -que não inibem a acetilcolinesterase sanguínea-podem levar a distúrbios neurológicos e de desenvolvimento em crianças, como menor perímetro cefálico e alterações cerebrais, além de déficits psicomotores e cognitivos relacionados à capacidade de aprendizagem, atenção e memoria. Em adultos, o CPF é um desregulador endócrino e cancerígeno da mama. Altos custos econômicos diretos (devido ao tratamento) e indiretos (devido à perda de produtividade) têm sido associados à exposição ao CPF. Não apenas os trabalhadores agrícolas e suas famílias, que têm as maiores exposições, mas a população em geral que consome culturas pulverizadas com CPF também estão em risco. Por essas razões, o CPF foi recentemente proibido pela União Europeia (2020) e pelos EUA (2021). As políticas de regulamentação de pesticidas variam muito, dependendo de quais (e como) os estudos científicos são usados para avaliar os riscos à saúde. As avaliações de pesticidas financiadas pela indústria química devem ser retificadas para evitar conflitos de interesse. Além disso, o alinhamento político com os interesses da indústria não deve ter precedência sobre as evidências científicas independentes. É desanimador - para dizer o mínimo - que até que leis de saúde mais rígidas sejam aprovadas na Colômbia, o CPF e tóxicos relacionados continuarão a ser importados dos países que já os proibiram.

Using Citronella to Protect Bees (honeybee Apis mellifera L. ) from certain Insecticides and Their Nano Formulations / Uso da citronela para proteger as abelhas (Apis mellifera L. ) de certos inseticidas e suas nanoformulações

Abstract Experiments were performed investigating citronella (Cymbopogon winterianus Jowitt) as a repellent to honeybee Apis mellifera (L.) (Hymenoptera: Apidae) in Egypt, it was conducted in laboratory in the Department of Entomology and Pesticides Science, Faculty of Agriculture, Cairo University, to check long-term survival of honeybee when exposed to different nano insecticides alone or combined with citronella at the same examination box for each. In this study, we used a modeling approach regarding survival data of caged worker bees under chronic exposure to four insecticides (Chloropyrophos, Nano-chloropyrophos Imidacloprid, Nano-Imidacloprid) each of them was supplemented in a box alone and in combination with citronella. Having three replicates and five concentrations (100, 200, 300, 400 and 500 ppm). Laboratory bioassay of these insecticides showed that chloropyrophos and nano chloropyrophos were the most toxic at their high dose (500 ppm) with LT50 of 120.98 and 122.02 followed by 132.14 and 136.5 minutes for Imidacloprid and Nano-Imidacloprid, respectively. No consumption occurred by bees to mixed sugar syrup with insecticides in all treatments when citronella was added. These data highly recommended that adding citronella is very effective when nicotinoid pesticides are used to longevity honeybee life and keep bee safe.

Resumo Foram realizados experimentos para investigar a citronela (Cymbopogon winterianus Jowitt) como repelente de abelhas Apis mellifera (L.) (Hymenoptera: Apidae) no Egito, conduzidos no laboratório do Departamento de Entomologia e Ciência de Pesticidas, da Faculdade de Agricultura, da Universidade do Cairo, e verificar a sobrevivência a longo prazo das abelhas quando expostas a diferentes nanoinseticidas isoladamente ou combinados com citronela na mesma caixa de exame para cada um. Neste estudo, usamos uma abordagem de modelagem em relação aos dados de sobrevivência de abelhas operárias enjauladas sob exposição crônica a quatro inseticidas (clorpirifós, nanoclorpirifós, imidacloprida e nanoimidacloprida), e cada um deles foi suplementado em uma caixa e em combinação com citronela, tendo três repetições e cinco concentrações (100, 200, 300, 400 e 500 ppm). O bioensaio em laboratório desses inseticidas mostrou que clorpirifós e nanoclorpirifós foram os mais tóxicos em altas doses (500 ppm) com LT50 de 120,98 e 122,02, seguidos por 132,14 e 136,5 minutos para imidacloprida e nanoimidacloprida, respectivamente. Não houve consumo pelas abelhas do xarope de açúcar misto com inseticidas em todos os tratamentos quando a citronela foi adicionada. Esses dados recomendam a adição de citronela, sendo muito eficaz quando pesticidas nicotinoides são utilizados para longevidade das abelhas e para mantê-las seguras.

Outbreak of organophosphorus compound-induced delayed neurotoxicity in water buffaloes / Surto de neuropatia tardia induzida por organofosforados em búfalos

ABSTRACT: Forty 1-2-y-old water buffaloes were simultaneously treated with trichlorfon and chlorpyrifos products in the recommended dose for cattle. After a week, 19 animals started presenting clinical signs characterized by apathy, diarrhea, aggressiveness, dehydration, and motor incoordination, followed by flaccid paralysis and permanent lateral recumbency. All affected buffaloes died after a clinical course of 1-4 days. Reduction of serum cholinesterase activity in three cases was indicative of significant exposure to organophosphorus compounds (OPs). Pathological examination of three buffaloes revealed no gross and histological lesions. By thin layer chromatography, chlorpyrifos residues and trace of trichlorfon residues were detected in fresh tissue samples. The epidemiological, clinical, pathological, and toxicological findings were highly compatible with OPs-induced delayed neurotoxicity, a neurological manifestation rarely described in domestic animals.

RESUMO: Quarenta búfalos foram simultaneamente tratados com clorpirifós e triclorfom na dose recomendada para bovinos. Após uma semana, 19 animais apresentaram sinais clínicos caracterizados por apatia, diarreia, agressividade, desidratação e incoordenação motora, seguidos por paralisia flácida e decúbito lateral permanente. Todos os búfalos afetados morreram após um curso clínico de 1-4 dias. Redução da atividade da colinesterase sérica em três casos foi indicativa de exposição significativa a organofosforados (OPs). O exame patológico de três búfalos não revelou lesões macroscópicas e histológicas. Por cromatografia em camada delgada, resíduos de clorpirifós e traços de resíduos de triclorfon foram detectados em amostras de tecidos frescos. Os achados epidemiológicos, clínicos, patológicos e toxicológicos foram compatíveis com neuropatia tardia induzida por OPs, uma manifestação neurológica raramente descrita em animais domésticos.

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)

Cadmium (Cd) and Chlorpyrifos (CPF) Induced Pulmonary Toxicity in Wistar Rats

The present study was aimed to know the pulmonary toxicity by individual toxicities of cadmium, chlorpyrifos and their combination in albino wistar rats. The experiment was carried out for 28 days. Group 1 - Control. Group 2 - Cadmium chloride (Cd) @ 22.5 mg/ kg b.wt /per oral / day. Group 3 - Chlorpyrifos (CPF) @ 25 mg/ kg b.wt /per oral / day. Group 4 - Cadmium chloride (Cd) @22.5 mg + Chlorpyrifos (CPF) @ 25 mg/ kg b.wt /per oral / day. Lungs showed mild to moderate congestion in groups 2 and 3 and moderate to severe in group 4 on 15th and 29th day of the experiment. Lung sections of control rats showed normal architecture. Lung sections of group 2 rats on 15th day showed hemorrhages in the interstitium spaces with infiltration of lymphocytes, On 29th day, mild hyperplasia and desquamated bronchial epithelial cells, peri bronchial and peri vascular lymphoid aggregates were noticed. The sections of lung on 15th day of group 3 rats showed exudate and desquamated epithelial cells in the lumen of secondary bronchiole , on 29th day, emphysematous alveoli with loss of architecture of alveolar epithelium, interstitial edema with infiltration of lymphocytes, mild hyperplasia of bronchial epithelial cells were also noticed. In group 4 rats, similar lesions as described in groups 2 and 3 were observed with severe intensity on 15th and on 29th day of the experiment. In combined toxicity group, the severity of lesions were more thus suggesting synergistic effects of these components.

Laboratory study on chain-killing efficacy of four gel baits / 上海预防医学

Objective To study the first-time killing efficacy and the chain-killing efficacy of four gel baits against Blattella germanica: 1% chlorpyrifos, 0.05% fipronil, 2.15% imidacloprid, and 0.5% dinotefuran and provide a basis for drug selection in controlling Blattella germanica. Methods Laboratory killing efficacy test was conducted according to the national standard GB/T 13917.7-2009 and the chain-killing efficacy test was conducted for three rounds.The first round of chain efficacy test was conducted by feeding the cockroaches killed in the laboratory efficacy test, and each next round by feeding the cockroaches killed in the last round.Median lethal time (LT50), 95% confidence limit, and toxicological regression equation of each test were calculated by software DPS V9.01. Results The LT50 of the efficacy test with 1% chlorpyrifos gel bait was 0.745 5 (0.603 4-0.890 3) d.The LT50 of the first, second and third chain experiments increased by 3.30, 2.18 and 2.76 times, respectively.The LT50 of the efficacy test with 0.05% fipronil gel bait was 0.846 5(0.464 7-1.228 0)d, and increased by 5.42, 2.09 and 1.48 times, respectively, in the first, second and third chain experiments.The LT50 of the efficacy test with 2.15% imidacloprid gel bait was 3.192 1(2.865 0-3.506 0)d, and increased by 1.13, 1.65 and 1.15 times, respectively in the first, second and third chain experiments.The LT50 of the efficacy test with 0.5% dinotefuran gel bait was 0.997 1(0.805 8-1.191 6) d, and increased by 3.85, 1.37 and 1.78 times, respectively in the first, second and third chain experiments. Conclusion In the laboratory killing efficacy test, 1% chlorpyrifos, 0.05% fipronil, and 0.5% dinotefuran gel baits are better than 2.15% imidacloprid gel bait.In the chain-killing efficacy test, 2.15% imidacloprid and 0.5% dinotefuran gel baits are better than 1% chlorpyrifos and 0.05% fipronil gel baits.Based on our results, we recommend the use of 0.5% dinotefuran gel bait for comprehensive and sustained killing effect.

Inflammatory mechanism of chlorpyrifos-induced lung injury in rats / 中国职业医学

OBJECTIVE: To investigate the inflammatory mechanism of chlorpyrifos-induced lung injury in rats. METHODS: Specific pathogen free SD rats were randomly divided into control and low-, medium-and high-dose groups, 8 rats in each group. Rats were exposed to 48% chlorpyrifos by continuous oral administration for 28 consecutive days, once a day, with the doses of 0.0, 4.1, 8.2 and 16.3 mg/kg body mass. After the exposure, the enzyme-linked immunosorbent assay was used to detect the level of tumor necrosis factor-α(TNF-α) and interleukin-1(IL-1) in rat lung tissue. The expression of high mobility group protein-1(HMGB1) and nuclear transcription factor-κB(NF-κB) was detected by immunohistochemistry and Western blotting, respectively. RESULTS: The activity of the rats decreased after exposure in the low-, medium-and high-dose groups compared with the control group. The rats in the medium and high dose groups increased salivation, nasal secretions, and difficulty breathing. The rats in the high dose group also developed diarrhea, muscle tremor, unstable gait, as well as muscarinic and nicotinic symptoms. After the exposure, the lung tissues of rats in the low-, medium-and high-dose groups showed different degrees of inflammation, which increased in a dose-dependent manner; the body mass of rats in the 3 dose groups was lower than that in the control group(all P values were <0.05), and the body mass of rats decreased with the increase of chlorpyrifos dose(all P values were <0.05). The levels of TNF-α, IL-1 and the relative expression of HMGB1, NF-κB were higher in the 3 dose groups than those in the control group(all P values were <0.05), and the levels of TNF-α, IL-1 and the relative expression of HMGB1 increased with the increasing exposure dose(all P values were <0.05). CONCLUSION: Chlorpyrifos can activate the NF-κB signaling pathway and eventually induce the macrophages to secrete large amount of TNF-α and IL-1, resulting in lung inflammation and injury in rats. The effect of chlorpyrifos has a dose-effect relationship.

EFECTO BIOPLAGUICIDA DE EXTRACTOS VEGETALES PARA EL CONTROL DE Spodoptera frugiperda EN EL CULTIVO DE MAÍZ (Zea mays) / Bioplaguicide Effect of Vegetal Extracts to Control of Spodoptera frugiperda in Corn Crop (Zea mays)

RESUMEN El maíz es el segundo cereal de mayor producción en Colombia con un 21,9 % de la superficie total. La plaga Spodoptera frugiperda ataca la planta desde las primeras semanas de crecimiento, devorando sus hojas, tallo y granos; disminuyendo el rendimiento de los cultivos. Esta plaga se controla con el uso indiscriminado de plaguicidas sintéticos como: carbofurano, clorpirifos y atrazina. En esta investigación, los extractos de Azadirachta indica, Piper nigrum, Petiveria alliacea y sus mezclas; y los extractos de Nicotiana tabacum, Lippia alba, Allium sativum y sus mezclas se aplicaron como bioplaguicidas en plantas de maíz amarillo tradicional. Después de la tercera semana de crecimiento, los tratamientos se aplicaron dos veces al día cada tres días durante siete semanas. Las variables estudiadas fueron número de larvas muertas, altura de las plantas y daño en hojas y tallos. Las plantas tratadas crecieron dos veces más y su grado de afectación, según la escala de Mihm, fue menor que las plantas del grupo testigo. Los porcentajes de eficacia de las seis especies vegetales y sus mezclas fueron representativos (>80 %), de acuerdo con Henderson y Tilton, demostrando que estos extractos vegetales son una alternativa viable para el control de S. frugiperda.

ABSTRACT The corn crop is the second largest cereal in Colombia with 21.9 % of the total area produced. The plague Spodoptera frugiperda, attacks the plant from the first weeks of growth, devouring its leaves, stalk and grains; decreasing crop yield. This pest is controlled by the non-controlled use of synthetic pesticides such as, carbofuran, chlorpyrifos and atrazine. In this research, the extracts of Azadirachta indica, Piper nigrum, Petiveria alliacea and their mixtures; and extracts of Nicotiana tabacum, Lippia alba, Allium sativum and their mixtures, were applied as bioplaguicides in corn plants. The application was performed twice a day each two days for seven weeks, after of third week of growth (when the larvae were first observed). The number of dead larvae, plant height and damage in leaves and stems were the study variables. The treated plants grew twice and their degree of affection, according to the Mihm scale, was lesser than plants in the control group. The efficiency percentages of the six plant species and its mixture were representative (>80 %), in according to Henderson and Tilton, resulting in these plant extracts are a viable alternative for pest control of S. frugiperda.

Desarrollo y capacidad de remoción de los pesticidas atrazina, clorpirifós y endosulfán por parte de cepas de Aspergillus sección Flavi no toxigénicas / Development and removal ability of non-toxigenic Aspergillus section Flavi in presence of atrazine, chlorpyrifos and endosulfan

This study evaluated the in vitro effect of three concentrations of atrazine, chlorpyrifos and endosulfan on the growth parameters of four non-toxigenic Aspergillus section Flavi strains. The ability of the strains to remove these pesticides in a synthetic medium was also determined. Growth parameters were measured on soil extract solid medium supplied with 5,10 and 20mg/l of each pesticide, and conditioned to -0.70, -2.78, -7.06 and -10.0 water potential (MPa). Removal assays were performed in Czapek Doc medium (CZD) supplied with 20mg/l of each pesticide under optimal environmental conditions (-2.78 of MPa and 25 °C). The residual levels of each pesticide were detected by the reversed-phase HPLC/fluorescence detection system. The lag phases of the strains significantly decreased in the presence of the pesticides with respect to the control media. This result indicates a fast adaptation to the conditions assayed. Similarly, the mycelial growth rates in the different treatments increased depending on pesticide concentrations. Aspergillus oryzae AM 1 and AM 2 strains showed high percentages of atrazine degradation (above 90%), followed by endosulfan (56 and 76%) and chlorpyrifos (50 and 73%) after 30 days of incubation. A significant (p <0.001) correlation (r = 0.974) between removal percentages and growth rate was found. This study shows that non-toxigenic Aspergillus section Flavi strains from agricultural soils are able to effectively grow in the presence of high concentrations of atrazine, chlorpyrifos and endosulfan under a wide range of MPa conditions. Moreover, these strains have the ability to remove high levels of these pesticides in vitro in a short time.

En este estudio se evaluó los efectos in vitro de 3 concentraciones de atrazina, clorpirifós y endosulfán sobre los parámetros de crecimiento de 4 cepas no toxigénicas de Aspergillus sección Flavi. También se evaluó la capacidad de las cepas de remover los pesticidas. Los parámetros de crecimiento se ensayaron en medio agar extracto de suelo suplementado con 5, 10 y 20mg/l de cada pesticida y acondicionado a -0.70, -2.78, -7.06 y -10.0 de potencial de agua (MPa). Los ensayos de remoción se realizaron en medio Czapek Dox con 20mg/l de cada pesticida bajo condiciones óptimas de crecimiento (-2.78 de MPa y 25 °C). Los niveles residuales de atrazina, clorpirifós y endosulfán se detectaron en un sistema HPLC con detección por fluorescencia. La fase de latencia de las cepas disminuyó significantemente en presencia de los pesticidas, indicando una rápida adaptación a dichas condiciones. La velocidad de crecimiento se incrementó considerablemente dependiendo de la concentración de pesticida. Las cepas Aspergillus oryzae AM1 y AM2 mostraron porcentajes elevados de degradación de atrazina (aproximadamente el 90%), seguidos por endosulfán (56 y 76%) y clorpirifós (50 y 73%). Se observó una correlación (r = 0.974) significante (p <0.001) entre el porcentaje de pesticida removido y la velocidad de crecimiento. Este estudio muestra que cepas no-toxigénicas de Aspergillus sección Flavi aisladas de suelos agrícolas desarrollan eficientemente en presencia de altas concentraciones de atrazina, clorpirifós y endosulfán en un amplio rango de MPa. Además, presentan capacidad de remover in vitro altos niveles de pesticidas en corto tiempo.

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.

In vitro study of histocompatibility and clearance of hemoperfusion adsorbents / 中华劳动卫生职业病杂志

Objective@#To evaluate the histocompatibility and clearance of chlorpyrifos and its metabolite of activated charcoal and adsorption resin by in vitro study.@*Methods@#Venous blood from volunteers were incubation with activated charcoal or adsorbent resins, cytometry parameters and plasma components were detected for evaluation the histocompatibility of adsorbents. Venous blood from volunteers mixed with chlorpyrifos and its metabolite were incubation with activated charcoal or adsorbent resins, plasma concentration of chlorpyrifos and its metabolite were detected for evaluation the efficacy of adsorbents.@*Results@#Incubation tests show that the absorbents reduce the blood platelet (F=3.671, P<0.05) , serum glucose (F=10.564, P<0.05) , albumin (F=5.239, P<0.05) , uric acid (F=7.175, P<0.05) , creatinine (F=23.673, P<0.05) , T3 (F=11.161, P<0.05) and free T3 (F=10.256, P<0.05) . However, other cytometry parameters and plasma components were not influenced. Both activated charcoal and adsorbent resins could reduce the plasma concentration of chlorpyrifos (F=798.110, P<0.01) and its metabolite (F=1495.212, P<0.05) .@*Conclusion@#In vitro test show that both activated charcoal and adsorbent resins could clear chlorpyrifos and its metabolite, however, could not influence main cytometry parameters and plasma components, the histocompatibility of adsorbents are satisfactory.

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.

Identification and Quantification of Chlorpyrifos Metabolites in Urine Samples by Ultra Performance Liquid Chromatography-Triple Quadrupole-Linear Ion Trap Mass Spectrometry / 分析化学

A method was established for the determination of chlorpyrifos metabolites employing QuEChERS method and ultra performance liquid chromatography-triple quadrupole-linear ion trap mass spectrometry (UPLC-QTRAP). The urine samples were extracted by acetonitrile and then cleaned up with PSA and GCB. The samples were separated with the gradient elution of acetonitrile-0.2% ammonia water on ZORBAX Eclipse Plus C18column. The analytes were detected by tandem mass spectrometry under negative ion mode with electrospray ionization (ESI) source and MRM-IDA-EPI mode. Under the optimized conditions, the calibration curve was linear in range of 1.0-100.0 μg/L,and the limits of detection were 0.10-0.73 μg/L. The average recoveries were 80.3%-90.1%, and RSDs were all within 10%. The developed method was simple,sensitive,accurate,and repeatable,and could avoid false positive result of samples effectively. The established method was successfully applied to determine the exposure level of chlorpyrifos metabolites in real samples of human health risk analysis. The results showed that the maximum concentration of chlorpyrifos metabolites was 54.6 μg/L. This method provided technic support for simultaneous identification and quantification of chemicals in complex matrix.

Assessment of pesticide contaminated sediment using biological response of tropical chironomid, Chironomus javanus Kiffer as biomarker

Objective To investigate the use of a biomarker for assessment of the effects on the tropical chironomid, Chironomus javanus (C. javanus), Kiffer of sediment contaminated with an insecticide (chlorpyrifos). Methods A wide range of biological responses to the tropical chironomid exposed were measured, including survival, growth rate and Acetylcholinesterase (AChE) activity. Results The measured median lethal concentration (96 h LC

Using Citronella to Protect Bees (honeybee Apis mellifera L.) from certain Insecticides and Their Nano Formulations

Abstract Experiments were performed investigating citronella (Cymbopogon winterianus Jowitt) as a repellent to honeybee Apis mellifera (L.) (Hymenoptera: Apidae) in Egypt, it was conducted in laboratory in the Department of Entomology and Pesticides Science, Faculty of Agriculture, Cairo University, to check long-term survival of honeybee when exposed to different nano insecticides alone or combined with citronella at the same examination box for each. In this study, we used a modeling approach regarding survival data of caged worker bees under chronic exposure to four insecticides (Chloropyrophos, Nano-chloropyrophos Imidacloprid, Nano-Imidacloprid) each of them was supplemented in a box alone and in combination with citronella. Having three replicates and five concentrations (100, 200, 300, 400 and 500 ppm). Laboratory bioassay of these insecticides showed that chloropyrophos and nano chloropyrophos were the most toxic at their high dose (500 ppm) with LT50 of 120.98 and 122.02 followed by 132.14 and 136.5 minutes for Imidacloprid and Nano-Imidacloprid, respectively. No consumption occurred by bees to mixed sugar syrup with insecticides in all treatments when citronella was added. These data highly recommended that adding citronella is very effective when nicotinoid pesticides are used to longevity honeybee life and keep bee safe.

Resumo Foram realizados experimentos para investigar a citronela (Cymbopogon winterianus Jowitt) como repelente de abelhas Apis mellifera (L.) (Hymenoptera: Apidae) no Egito, conduzidos no laboratório do Departamento de Entomologia e Ciência de Pesticidas, da Faculdade de Agricultura, da Universidade do Cairo, e verificar a sobrevivência a longo prazo das abelhas quando expostas a diferentes nanoinseticidas isoladamente ou combinados com citronela na mesma caixa de exame para cada um. Neste estudo, usamos uma abordagem de modelagem em relação aos dados de sobrevivência de abelhas operárias enjauladas sob exposição crônica a quatro inseticidas (clorpirifós, nanoclorpirifós, imidacloprida e nanoimidacloprida), e cada um deles foi suplementado em uma caixa e em combinação com citronela, tendo três repetições e cinco concentrações (100, 200, 300, 400 e 500 ppm). O bioensaio em laboratório desses inseticidas mostrou que clorpirifós e nanoclorpirifós foram os mais tóxicos em altas doses (500 ppm) com LT50 de 120,98 e 122,02, seguidos por 132,14 e 136,5 minutos para imidacloprida e nanoimidacloprida, respectivamente. Não houve consumo pelas abelhas do xarope de açúcar misto com inseticidas em todos os tratamentos quando a citronela foi adicionada. Esses dados recomendam a adição de citronela, sendo muito eficaz quando pesticidas nicotinoides são utilizados para longevidade das abelhas e para mantê-las seguras.

Assessment of pesticide contaminated sediment using biological response of tropical chironomid, Chironomus javanus Kiffer as biomarker

Objective: To investigate the use of a biomarker for assessment of the effects on the tropical chironomid, Chironomus javanus (C. javanus), Kiffer of sediment contaminated with an insecticide (chlorpyrifos). Methods: A wide range of biological responses to the tropical chironomid exposed were measured, including survival, growth rate and Acetylcholinesterase (AChE) activity. Results: The measured median lethal concentration (96 h LC50) of chlorpyrifos to C. javanus was 0.056 (95％ CI 0.024–0.124) μg/kg. For sub-chronic levels of chlor-pyrifos between 0.001 and 0.25μg/kg administered for 10 days, the effects on the growth of C. javanus were reduced (larva size, head structure width and dry weight) at the significance level (P < 0.01) and the effects were concentration dependent. Following exposure to chlorpyrifos at the level of 0.001μg/kg for 48 and 96 h, the AChE activity in C. javanus was inhibited compared with control samples (P<0.05). Conclusions: This study demonstrated that C. javanus was sensitive when exposed to chlorpyrifos. This species could serve as a potential biomarker for assessing pesticide contamination at low environmental persistence and provides limited effects data on the sensitivity of tropical biota to contaminants for ecological risk assessment of organo-phosphate pesticides in the tropical aquatic ecosystem.

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.

Detecting chlorpyrifos and its metabolitein plasma by UPLC / 中国职业医学

OBJECTIVE: To establish a simple and sensitive method for simultaneous detection of chlorpyrifos( CPF),and its metabolite 3,5,6-trichloro-2-pyridinol( TCP) in plasma samples by ultra performance liquid chromatography( UPLC).METHODS: The 0. 5 m L of blood sample was extracted by ethyl acetate,then separated by C18 column using acetonitrile /water as a mobile phase and detected by diode-array detector under the ultraviolet spectrum of 298 nm( 0. 0-2. 0 min) and289 nm( 2. 0-5. 0 min) through UPLC. RESULTS: The method showed that a good linear range was 1. 00-50. 00 mg / L of both CPF and TCP,and the correlation coefficients was 0. 999 9. The limit of detection was 0. 30 mg / L and the lower limits of quantitation was 1. 00 mg / L of both CPF and TCP. The recovery rates of CPF and TCP were 87. 20 %-103. 08 %and 86. 20 %-99. 28 %,respectively. The within-run relative standard deviation( RSD) of CPF and TCP was 5. 28 %-6. 17 % and 2. 32 %-4. 43 %,and the between-run RSD was 6. 62 %-7. 53 % and 3. 55 %-5. 24 %. Samples can be kept in4 degrees Celsius refrigerator for 7 days. CONCLUSION:s The proposed method is simple,reliable and sensitive. It can be applied for simultaneous detection of CPF and its metabolite TCP in plasma samples.

Model establishment and injury assessment of chlorpyrifos dynamic-inhalation of rats / 中国药理学与毒理学杂志

OBJECTIVE To establish a model for chlorpyrifos(CPF)whole-body dynamic inhalation exposure in SD rats and investigate the injury effects after acute exposure by CPF. METHODS By optimizing the aerosol parameters ,the animal acute dynamic inhalation exposure of CPF was established. Absorption sampling-gas phase detecting technology was used to monitor the concentration of CPF in the whole-body dynamic-inhalation exposure cabin by exploring the relationship between the concentration , particle size of CPF aerosol and the CPF inhalation time in the exposure cabin via a particle size detector. Using Bliss method,specific pathogen free SD male rats were allocated to the environment of CPF exposure at different lethal concentrations and time points. The symptoms and deaths of these SD male rats in different groups were recorded within the following 10 d. Based on the median lethal concentra?tion time(LCt50),the values of plasma cholinesterase(ChE)were checked at different time points after being exposed at different doses. RESULTS The mean concentrations of CPF aerosol at nine time points was 160.6 mg · m-3,the relative standard deviation value was 6.9%;the geometrical mean of aerosol particle size was 1.1 μm,and the geometric standard deviation was 1.8. The results met the technical requirements of Organization for Economic Cooperation and Development regarding acute inhalation exposure. Under these equipment conditions,the LCt50 of CPF acute inhalation of SD male rats was 1654.2 mg · m-3 · h,suggesting that plasma ChE inhibitory rate was higher with the increase in the exposing dose,and that there was a significant difference as compared with the controls(P<0.05). CONCLU?SION The model for whole-body dynamic-inhalation exposure of CPF is applicable to rats,which can serve as an experimental platform and technical support to inhalation vulnerability and the research on prevention and cure of organophosphate industrial products and nerve agents.

A physiologically based toxicokinetics and toxicodynamics model in rats following both oral and subcutaneous exposure to chlorpyrifos / 中国药理学与毒理学杂志

OBJECTIVE To develop and validate a physiologically based toxicokinetics and toxico?dynamics(PBTK/TD)model for chlorpyrifos(CPF)in rats following both oral and subcutaneous expo?sures to CPF. METHODS ①A PBTK/TD model was established with toxicokinetics and toxicodynam?ics data in literature,which was used for predicting contents of CPF and 3,5,6-trichloro-2-pyridinol (TCP)in blood and activities of acetylcholine esterase(AChE)in the plasma and brain of rats exposed to CPF.②Rats were given 50 mg · kg-1 CPF oral and 50 mg · kg-1 CPF sc simultaneously. Blood and brain samples were collected at 0,1,2,4,6,8,12,24 and 48 h,respectively,after CPF administration (n=5). CPF And TCP contents in plasma,activities of AChE in the plasma and brain were deter?mined,and compared with the simulation values by PBTK/TD model in order to validate the accuracy of the model. RESULTS It was predicted by the PBTK/TD model that after the administration (oral+sc) of CPF 20+20,10+30 and (30+10)mg · kg-1,the concentrations of CPF and TCP in plasma increased and then decreased with time in each group. The inhibitory level of AChE activity in the plasma was orally dose-dependent,while AChE activity of the brain was more sensitive to CPF subcutaneous exposure. The simulation values obtained by the PBTK/TD model were not significantly different from the experimental values obtained by co-administered CPF at(50+50)mg · kg-1. CONCLUSION This CPF PBTK/TD model can quantitatively estimate target tissue dosimetry and AChE inhibition.