Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 1.253
Filtrar
1.
Ecotoxicology ; 29(3): 327-339, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32107697

RESUMO

Chrysoperla externa and Coleomegilla quadrifasciata are important biological control agents in peach orchards. However, orchard management with these predatory insects is viable only by using selective agrochemicals. The objective of this study is to evaluate the toxicity of nine agrochemicals used in peach orchards in larval and adult stages of the C. externa and C. quadrifasciata in laboratory conditions. The bioassays followed the methodologies proposed by the International Organization for Biological and Integrated Control (IOBC). Larvae and adults of C. externa and C. quadrifasciata were exposed to the dry residues of these products. Lethal and sublethal effects were evaluated in bioassays with the larval and adult stages of both predators. The agrochemicals were classified according to the IOBC guidelines. The insecticide chlorantraniliprole was harmless (class 1) to the larval stage of C. externa and C. quadrifasciata. Azadirachtin, copper 25% + calcium 10%, and deltamethrin were harmless to the adult stage of both insect species. The organophosphates fenitrothion and malathion were harmful (class 4) to both species in the larval and adult stages and should not be used in peach orchards. Therefore, this study demonstrates the importance of toxicity and the lethal and sublethal effects of these agrochemicals to better determine their compatibility with IPM in peach production.


Assuntos
Agroquímicos/toxicidade , Agentes de Controle Biológico , Insetos/fisiologia , Prunus persica , Agricultura , Animais , Besouros , Inseticidas/toxicidade , Larva , Limoninas , Malation , Nitrilos , Piretrinas , ortoaminobenzoatos
3.
J Environ Manage ; 255: 109845, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31778866

RESUMO

The magnetic adsorbent prepared with hydrocalumite-iron oxide (HC/Fe) modified with dodecyl sulfate (DS) was examined for the removal of the agrichemicals atrazine (ATZ) and chlorpyrifos (CPF) from aqueous solution. The adsorbent HC-DS/Fe was characterized by infrared spectroscopy (IR), Raman spectroscopy, X-ray diffractometry (XRD) and atomic absorption spectrometry. The effects of adsorbent dosage, contact time, pH and initial concentration of ATZ and CPF were evaluated. HC-DS/Fe presented a maximum adsorption capacity for ATZ of 4.5 mg g-1 (30 min) and for CPF of 72.9 mg g-1 (210 min) at 25 °C. HC-DS/Fe can be readily removed from the aqueous solution by magnetization because of its magnetic properties. The free energy variation for HC-DS/Fe during the adsorption of the ATZ was -48.78 to -53.91 kJ mol-1 and for the CPF of -55.79 to -59.28 kJ mol-1, suggesting the spontaneity of the adsorption process. The positive value of △H suggests an endothermic process for the interaction of ATZ and CPF by HC-DS/Fe. This adsorbent showed satisfactory results when used in the treatment of a sample of river water, fortified with the agrichemicals chlorpyrifos, atrazine, thiamethoxam and acetamiprid.


Assuntos
Poluentes Químicos da Água , Purificação da Água , Adsorção , Agroquímicos , Óxido de Alumínio , Cloreto de Cálcio , Compostos Férricos , Concentração de Íons de Hidrogênio , Cinética , Fenômenos Magnéticos , Dodecilsulfato de Sódio
4.
São Paulo; s.n; 2020. 195 p.
Tese em Português | LILACS | ID: biblio-1050627

RESUMO

Introdução: O uso excessivo e descuidado de pesticidas tem se tornado um problema global de saúde pública, especialmente nos países de baixa e média renda. O Brasil é o maior consumidor mundial de pesticidas desde 2018, mas poucos estudos epidemiológicos exploram os seus efeitos à saúde. Objetivos: Avaliar os efeitos da exposição aos pesticidas à saúde de agricultores familiares em São José de Ubá (SJU), Estado do Rio de Janeiro, e analisar os efeitos respiratórios em crianças por exposição aos pesticidas, a partir de revisão da literatura. Métodos: Na safra de 2014, 82 agricultores familiares convenientemente selecionados foram entrevistados sobre a exposição aos pesticidas e submetidos à avaliação clínica com anamnese, avaliação respiratória (questionário e espirometria) e rastreamento de saúde mental (SRQ-20). Analisou-se as enzimas colinesterase (AChE e BChE) como biomarcadores de efeito. A avaliação respiratória foi repetida na entressafra de 2015 para comparação entre os períodos de maior e menor uso de pesticidas. Os participantes foram comparados com valores de referência e entre os grupos ocupacionais (aplicadores ou ajudantes) e os efeitos respiratórios foram analisados por regressão múltipla. Para ampliar o olhar aos riscos da exposição ambiental, realizou-se uma revisão sistemática sobre os efeitos dos pesticidas à saúde respiratória de crianças. Resultados: Os agricultores familiares avaliados em SJU estavam ocupacionalmente e ambientalmente expostos aos pesticidas desde tenra idade, trabalhavam sem apoio técnico e uso de equipamentos de proteção individual (EPI) completo, estavam expostos a complexas misturas de pesticidas frequentemente e apresentaram diversos sintomas de intoxicação aguda, mentais, respiratórios e alterações na espirometria. No geral, observou-se uma maior prevalência de efeitos respiratórios na safra do que na entressafra e associações significativas entre alterações espirométricas e os indicadores de exposição tanto na safra quanto na entressafra. Enquanto os aplicadores eram principalmente homens e apresentaram mais alterações de BChE, os ajudantes eram majoritariamente mulheres, tiveram ainda menos treinamento, usavam menos EPI e relataram maior prevalência de sintomas de intoxicação, saúde mental e o dobro apresentou um possível transtorno mental comum (depressão e ansiedade). A revisão da literatura sobre efeitos da exposição aos pesticidas agrícolas à saúde infantil apresentou vasta evidência sobre efeitos respiratórios e alérgicos. Conclusões: É fundamental melhorar o apoio técnico e treinamento ocupacional dos agricultores familiares brasileiros e promover práticas laborais e alternativas de cultivo mais sustentáveis. São necessários mais estudos sobre os efeitos dos pesticidas à saúde dos agricultores familiares e à saúde respiratória de crianças no Brasil e em outros países de menor renda, que usam métodos mais convencionais de cultivo e possuem maior população infantil no campo. Recomenda-se o fortalecimento de políticas públicas e a implementação de ações integrais e transversais a todos os níveis de atenção à saúde e áreas de governo, além da promoção de estratégias mais abrangentes de mitigação de riscos e intervenções comportamentais para reduzir o uso de pesticidas, a exposição e os riscos à saúde.


Introduction: Excessive and careless use of pesticides has become a global public health problem, especially in low- and middle-income countries. Brazil is the world's largest consumer of pesticides since 2018, but few epidemiological studies explore its health effects. Objectives: To evaluate the health effects of pesticide exposure on family farmers in São José de Ubá (SJU), State of Rio de Janeiro, and to analyze the respiratory effects of pesticide exposure among children, based on a literature review. Methods: In the crop season of 2014, 82 family farmers conveniently selected were interviewed about pesticide exposure and subjected to clinical evaluation with anamnesis, respiratory assessment (questionnaire and spirometry), and mental health screening (SRQ-20). Cholinesterase enzymes (AChE and BChE) were analyzed as effect biomarkers. The respiratory assessment was repeated in the off-season period (2015) to compare periods of higher and lower pesticide use. Participants were compared with reference values and between occupational groups (applicators or helpers), and respiratory effects were analyzed by multiple regression. A systematic review of the pesticide effects of children's respiratory health was conducted to broaden the understanding of the pesticide risks of environmental exposure. Results: Family farmers evaluated in SJU were occupationally and environmentally exposed to pesticides from an early age, worked without technical support and use of full personal protection equipment (PPE), were frequently exposed to complex mixtures of pesticides and presented several symptoms of acute intoxication, mental, respiratory, and changes in spirometry. Overall, there was a higher prevalence of respiratory effects in the crop season than in the off-season and significant associations between spirometric changes and exposure indicators in both the crop season and off-season. While the applicators were mostly men and had more BChE depletion, the helpers were mostly women, had even less occupational training, used less PPE, and reported a higher prevalence of pesticide poisoning symptoms, mental health, and twice as much as a probable common mental disorder (depression and anxiety). The literature review on the effects of agricultural pesticide exposure on children's health has provided ample evidence on respiratory and allergic effects. Conclusions: It is essential to improve the technical support and occupational training of Brazilian family farmers and to promote more sustainable labor practices and farming alternatives. Further studies are needed on the effects of pesticides on family farmer's health and children's respiratory health in Brazil and other lower-income countries that use more conventional cultivation methods and have a larger child population in the countryside. Strengthening public policies and implementing comprehensive and crosscutting actions at all levels of health care and areas of government is recommended, along with the promotion of broader risk mitigation strategies and behavioral interventions to reduce pesticide use, exposure, and health risks.


Assuntos
Praguicidas , Sinais e Sintomas Respiratórios , Espirometria , Saúde Mental , Colinesterases , Saúde do Trabalhador , Agroquímicos
5.
Int. arch. otorhinolaryngol. (Impr.) ; 23(4): 389-395, Out.-Dez. 2019. ilus, tab
Artigo em Inglês | LILACS | ID: biblio-1024150

RESUMO

Introduction: Agrochemicals, also known as pesticides, are widely used in agriculture and in public health. They are organic and inorganic chemical substances with a high level of toxicity not only for the environment, but also for human health. Objective: To verify findings on labyrinthine assessment in endemic disease control agents, and to recommend the inclusion of the vestibular exam in the set of tests for pesticide-exposed populations. Methods: Descriptive, prospective, cross-sectional study with a sample comprising 15 endemic disease control agents, males, mean age of 51.6 years old (standard deviation [SD] = 5.9). All of the participants were submitted to anamnesis, otorhinolaryngological screening, and vestibular assessment. Results: Regarding the most reported complaints, dizziness (73.4%), headache (60%), and tingling in the extremities (53.4%) were observed. The findings of the vestibular exams were normal in 53.3%, while 46.7% showed peripheral vestibular disorder, of which 26.7% were of deficitary type, and 20% of the irritative type. Conclusions: Alteration in the vestibular system was verified in 50% of the workers, with a greater prevalence in the caloric testing. Several disorders related to pesticides intoxication are scientifically known. Actions promoting knowledge and qualification of this population for the proper handling of chemicals are suggested, in addition to the elaboration and inclusion of protocols of vestibular assessment in hearing health programs for the prevention, diagnosis and treatment of vestibular disorders (AU)


Assuntos
Humanos , Masculino , Pessoa de Meia-Idade , Idoso , Doenças Vestibulares/diagnóstico , Exposição Ocupacional , Exposição a Praguicidas , Doenças dos Trabalhadores Agrícolas/diagnóstico , Doenças Vestibulares/induzido quimicamente , Estudos Transversais , Estudos Prospectivos , Agroquímicos/efeitos adversos , Doenças do Sistema Nervoso/diagnóstico , Doenças do Sistema Nervoso/induzido quimicamente
6.
Sci Total Environ ; 694: 133661, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31756788

RESUMO

Soil pollution by anthropogenic chemicals is a major concern for sustainability of crop production and of ecosystem functions mediated by natural plant biodiversity. The complex effects on plants are however difficult to apprehend. Plant communities of field margins, vegetative filter strips or rotational fallows are confronted with agricultural pollutants through residual soil contamination and/or through drift, run-off and leaching events that result from chemical applications. Exposure to xenobiotics and heavy metals causes biochemical, physiological and developmental effects. However, the range of doses, modalities of exposure, metabolization of contaminants into derived xenobiotics, and combinations of contaminants result in variable and multi-level effects. Understanding these complex plant-pollutant interactions cannot directly rely on toxicological or agronomical approaches that focus on the effects of field-rate pesticide applications. It must take into account exposure at root level, sublethal concentrations of bioactive compounds and functional biodiversity of the plant species that are affected. The present study deals with agri-environmental plant species of field margins, vegetative filter strips or rotational fallows in European agricultural landscapes. Root and shoot physiological and growth responses were compared under controlled conditions that were optimally adjusted for each plant species. Contrasted responses of growth inhibition, no adverse effect or growth enhancement depended on species, organ and nature of contaminant. However, all of the agricultural contaminants under study (pesticides, pesticide metabolites, heavy metals, polycyclic aromatic hydrocarbons) had significant effects under conditions of sublethal exposure on at least some of the plant species. The fungicide tebuconazole and polycyclic aromatic hydrocarbon fluoranthene, which gave highest levels of responses, induced both activation or inhibition effects, in different plant species or in different organs of the same plant species. These complex effects are discussed in terms of dynamics of agri-environmental plants and of ecological consequences of differential root-shoot growth under conditions of soil contamination.


Assuntos
Agroquímicos/análise , Monitoramento Ambiental , Poluentes Ambientais/análise , Agricultura , Ecossistema
7.
J Agric Food Chem ; 67(50): 13904-13913, 2019 Dec 18.
Artigo em Inglês | MEDLINE | ID: mdl-31765135

RESUMO

A series of N-aryl-pyridine-4-one derivatives were designed and synthesized using maltol and antidesmone as lead compounds, and then their fungicidal/bactericidal activities and possible mechanism of action against Colletotrichum musae were explored. Most of these compounds exhibited significant fungicidal activity in vitro. Especially, compound 23 has more than 90% inhibitory activity against nine plant pathogenic fungi at 50 µg mL-1, which is superior to azoxystrobin. Moreover, an in vivo bioassay also demonstrated that compound 23 exhibited high-efficiency broad-spectrum antifungal activity and can effectively control postharvest diseases of mango. In addition, it was found that compounds 22 and 23 can also effectively control rice bacterial leaf blight in pot experiments, which was even more effective than zhongshengmycin. Preliminary mechanism studies revealed that compound 23 may cause cell membrane and mitochondria destruction. These findings indicate that compound 23 can be used to develop potential agrochemical fungicides and bactericides.


Assuntos
Agroquímicos/química , Agroquímicos/farmacologia , Antibacterianos/química , Antibacterianos/farmacologia , Fungicidas Industriais/química , Fungicidas Industriais/farmacologia , Agroquímicos/síntese química , Colletotrichum/efeitos dos fármacos , Fungicidas Industriais/síntese química , Mangifera/microbiologia , Estrutura Molecular , Oryza/microbiologia , Doenças das Plantas/microbiologia , Piridinas/química , Piridinas/farmacologia , Rhizoctonia , Relação Estrutura-Atividade , Xanthomonas/efeitos dos fármacos , Xanthomonas/crescimento & desenvolvimento
8.
Science ; 366(6464): 416-417, 2019 10 25.
Artigo em Inglês | MEDLINE | ID: mdl-31649179
9.
Rev. Pesqui. (Univ. Fed. Estado Rio J., Online) ; 11(5): 1319-1325, out.-dez. 2019. tab, ilus, graf
Artigo em Inglês, Português | LILACS, BDENF - Enfermagem | ID: biblio-1022203

RESUMO

Objective: The study's goal has been to analyze if environmental or occupational exposure to pesticides can produce changes in pregnant women living in a countryside municipality. Methods: The participants of this study were twenty-three pregnant women, who both answered a questionnaire and donated biological material in order to perform Micronucleus (MN) Tests in lymphocytes, oral epithelial cells, and also for measuring the enzyme activity of erythrocyte acetylcholinesterase. Results: Considering the total analyzed samples, the following was found: an average of 8 ± 2.92 MN/1000 oral epithelial cells from urban participants; an average of 6.82 ± 3.43 MN/1000 oral epithelial cells from rural participants; and 100% of the microscope slides contained cells with two MN, which shows high intensity lesions to the DNA. There was found a high frequency of spontaneous abortions (34.8%), greater than in Brazil. Conclusion: The exposure of pregnant women living in a countryside municipality to pesticides may increase the rate of spontaneous abortions, as well as the chances of mutagenic effects


Objetivo: Analisar se a exposição ambiental ou ocupacional aos agrotóxicos causa alterações em gestantes residentes em um município rural. Métodos: Compuseram a amostra 23 gestantes, que responderam a um questionário e doaram amostras biológicas para a realização dos testes de micronúcleos (MN) em linfócitos, em células do epitélio oral, e para a dosagem da atividade da enzima acetilcolinesterase eritrocitária. Resultados: Obteve-se uma média de 8 ± 2,92 MN/1000 células do epitélio oral analisadas em amostras de participantes da zona urbana, 6,82 ± 3,43 MN/1000 de participantes da zona rural, e 100% das lâminas continham células com dois MN, o que demonstra lesões ao DNA de maior intensidade. Encontrou-se uma frequência elevada de casos de abortos espontâneos (34,8%), superior à encontrada no Brasil. Conclusão: A exposição de gestantes residentes em um município rural aos agrotóxicos eleva a taxa de abortos espontâneos, bem como as chances de ocorrência de efeitos mutagênicos


Objetivo: Analizar si la exposición ambiental o ocupacional a los agrotóxicos causa cambios en gestantes residentes en un municipio rural. Métodos: Compusieron la muestra 23 gestantes, que respondieron a un cuestionario y donaron muestras biológicas para la realización de las pruebas de micronúcleos (MN) en linfocitos, en células del epitelio oral, y para la dosificación de la actividad de la enzima acetilcolinesterasa eritrocitaria. Resultados: Se obtuvieron una media de 8 ± 2,92 MN / 1000 células del epitelio oral analizadas en muestras de participantes de la zona urbana, 6,82 ± 3,43 MN / 1000 de participantes de la zona rural, y el 100% de las láminas contenían células con dos MN, lo que demuestra lesiones al ADN de mayor intensidad. Se encontró una frecuencia elevada de casos de abortos espontáneos (34,8%), superior a la encontrada en Brasil. Conclusión: La exposición de gestantes residentes en un municipio rural a los agrotóxicos eleva la tasa de abortos espontáneos, así como las posibilidades de ocurrencia de efectos mutagênicos


Assuntos
Humanos , Feminino , Gravidez , Adolescente , Adulto , Agroquímicos/toxicidade , Aborto , Testes de Mutagenicidade/métodos , Acetilcolinesterase/farmacologia , Saúde da População Rural/estatística & dados numéricos , Exposição Ocupacional/efeitos adversos
10.
J Agric Food Chem ; 67(42): 11598-11606, 2019 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-31560195

RESUMO

A total of 22 quinazoline thioether derivatives incorporating a 1,2,4-triazolo[4,3-a]pyridine moiety were designed, synthesized, and evaluated as antimicrobial agents in agriculture. Among these compounds, the chemical structure of compound 6l was further confirmed via single-crystal X-ray diffraction analysis. The bioassay results revealed that some of the compounds possessed noticeable in vitro antibacterial activities against the tested phytopathogenic bacteria. For example, compounds 6b and 6g had EC50 values as low as 10.0 and 24.7 µg/mL against Xanthomonas axonopodis pv. citri (Xac), respectively, which were significantly better than that of the commercial agrobactericide bismerthiazol (56.9 µg/mL). Particularly, compound 6b was also found to be capable of suppressing the pathogenic bacterium Xanthomonas oryzae pv. oryzae (Xoo) approximately 12-fold more potent than control bismerthiazol, in terms of their EC50 values (7.2 versus 89.8 µg/mL). Importantly, the most active compound 6b turned out to be one with the highest hydrophilicity and the lowest molecular weight within the series. In vivo bioassays further showed the application prospect of 6b as a promising plant bactericide for controlling Xoo. Additionally, in vitro antifungal activities of these compounds were also evaluated at the concentration of 50 µg/mL. Overall, the present study demonstrated the potential of 1,2,4-triazolo[4,3-a]pyridine-bearing quinazoline thioether derivatives as efficient agricultural antibacterial agents for crop protection.


Assuntos
Antibacterianos/química , Antibacterianos/farmacologia , Quinazolinas/química , Quinazolinas/farmacologia , Sulfetos/química , Sulfetos/farmacologia , Agroquímicos/química , Agroquímicos/farmacologia , Antibacterianos/síntese química , Desenho de Fármacos , Piridinas/química , Relação Estrutura-Atividade , Xanthomonas/efeitos dos fármacos
11.
Chemosphere ; 226: 945-955, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31509924

RESUMO

Threats to wetland water quality and aquatic insect secondary production in agricultural landscapes are multifaceted and are known to vary spatially and temporally. We designed this study with the aim to disentangle the effects of multiple stressors on emerging aquatic insects from wetlands impacted by intensive agricultural practices and receiving runoff from neonicotinoid-treated canola. A total of 22 semi-permanent wetlands were monitored over two growing seasons (11 different wetlands per year) in central Saskatchewan, Canada. Over the two sampling years, dipterans from the families Chironomidae (60-67%), Muscidae (13-15%) and Ceratopogonidae (7-13%) made up the majority of emergent taxa, representing 80-95% of the total emergence. Multivariate ordination analyses of eight water quality and nine wetland habitat variables revealed that neonicotinoid concentration, turbidity, vegetation disturbance, and continuity of a vegetative grass buffer zone were significant factors influencing the aquatic insect taxa composition. Generalized linear mixed effects models indicated that total insect emergence over time was significantly predicted by neonicotinoid concentrations (imidacloprid toxic equivalency, TEQ) and vegetation disturbance. Higher neonicotinoid concentrations negatively affected insect emergence over time, whereas vegetation disturbance increased total emergence, likely due to the abundance of disturbance-tolerant taxa. Overall, we observed community-level responses driven by multiple indicators of wetland degradation (insecticides, turbidity, and vegetation disturbance). Collectively, these multivariate field data provide an in-depth understanding of how agricultural management practices, including neonicotinoid use, interact to shape wetland aquatic insect communities.


Assuntos
Agricultura , Agroquímicos/toxicidade , Insetos/efeitos dos fármacos , Inseticidas/toxicidade , Neonicotinoides/toxicidade , Poluentes Químicos da Água/toxicidade , Agroquímicos/análise , Animais , Ecossistema , Inseticidas/análise , Neonicotinoides/análise , Poluentes Químicos da Água/análise , Qualidade da Água
12.
Mikrochim Acta ; 186(10): 678, 2019 09 12.
Artigo em Inglês | MEDLINE | ID: mdl-31515633

RESUMO

Nanosheets of a porous layered double hydroxide were directionally arranged on boehmite nanowires and porous carbon and used as a coating for solid-phase microextraction (SPME) method. Porous carbon tubes were prepared from goat grass and then coated with layered double hydroxide nanosheets and boehmite nanowires. The nanomaterial was placed on a stainless-steel wire which then was used for the extraction of fifteen agrochemicals from aqueous sample solutions. The extraction temperature, extraction time, ionic strength, stirring rate, and desorption temperature and time were optimized. Following thermal desorption of the agrochemicals in the injector of the gas chromatograph, they were quantified by GC/MS. Under optimum conditions, the repeatability for one fiber, expressed as relative standard deviation, was between 2.9 and 11.1%. The detection limits for the agrochemicals are between 2-29 ng L-1. The method is simple, fast, and inexpensive (in terms of equipment). The fiber is thermally stable, and the relative recoveries from spiked samples are better compared to conventional methods of extraction. Graphical abstract Schematic illustration of the preparation of three-dimensional hierarchical boehmite/ layered double hydroxides/ porous carbon (Boeh/LDH/pC) SPME fibers and application for the extraction of fifteen agrochemicals from aqueous sample solutions following quantification by GC/MS.


Assuntos
Agroquímicos/química , Nanocompostos/química , Praguicidas/análise , Extratos Vegetais/análise , Microextração em Fase Sólida/instrumentação , Poluentes Químicos da Água/química , Hidróxido de Alumínio/química , Óxido de Alumínio/química , Carbono/química , Hidróxidos/química , Poaceae/química , Aço Inoxidável/química
13.
Bioresour Technol ; 291: 121861, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31376666

RESUMO

The aim of this work was to investigate whether the agronomic traits of vermicompost prepared from partially stabilised sewage sludge digestate after thermophilic composting were more favourable than those of conventional compost. The effects of various additives (green waste, spent mushroom compost, wheat straw, biochar) were also tested after 1.5 months precomposting followed by 3 months vermicomposting with Eisenia fetida or by compost maturing. Vermicomposting did not result in significantly more intensive mineralisation than composting; the average organic carbon contents were 21.2 and 22.2% in vermicomposts and composts, respectively. Hence, the average total (N: 2.4%; P: 1.9%; K: 0.9%) and available (N: 160 mg/kg; P: 161 mg/kg; K: 0.8%) macronutrient concentrations were the same in both treatments. The processing method did not influence the organic matter quality (E4/E6) either. However, on average the concentration of the plant growth regulator kinetin was more than twice as high in vermicomposts.


Assuntos
Agroquímicos/metabolismo , Compostagem , Esgotos , Agroquímicos/análise , Animais , Oligoquetos/metabolismo , Esgotos/química
14.
Sci Total Environ ; 690: 181-188, 2019 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-31288109

RESUMO

Agricultural chemicals are normally used as mixtures of several isomers, e.g., enantiomers. In theory, in order to minimize the pesticides dose, it is desirable to use the most target-active isomer. Metolachlor is a typical multichiral herbicide belonging to amide herbicides. An asymmetric carbon atom and a chiral axis yield four stereoisomers. In this study, a novel laboratory method was developed to prepare the S-metolachlor and the four stereoisomers using high performance liquid chromatography. The separated isomers had a purity of >99%, with their absolute configurations assigned by electronic circular dichroism. The enantioseparation by ultra performance convergence chromatography tandem mass spectrometry was also performed for the rapid and sensitive detection of metolachlor stereoisomers. The enantioselective herbicidal activity toward the target weed (Echinochloa crusgalli) was systematically assessed for the first time by measuring the morphology of the weed after treatment with rac-, S-metolachlor and the four stereoisomers, respectively. Among the commercial pesticides, S-metolachlor was more effective in weed inhibition than rac-metolachlor, and to the four stereoisomers, the herbicidal activities were ranked as: SS > SR ≫ RS > RR, and the RR-isomer even had some stimulative effect to the weed growth at lower concentration (1 ppm). Thus, we concluded that in these cases, the chiral carbon feature played a major role in herbicidal activity rather than the chiral axis feature, and the higher bioactivity of the S-isomers was confirmed by more effective uptake and stronger interaction with target enzymes that were involved in the gibberellic acid biosynthesis. Although the SS-isomer shows the highest herbicidal activity, controlling the major chiral feature is still much easier and more economical than controlling two chiral features.


Assuntos
Acetamidas/toxicidade , Agroquímicos/toxicidade , Echinochloa/efeitos dos fármacos , Herbicidas/toxicidade , Acetamidas/química , Agroquímicos/química , Relação Dose-Resposta a Droga , Herbicidas/química , Estereoisomerismo
15.
Chemosphere ; 235: 70-75, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31255767

RESUMO

Some agrochemicals are genotoxic to several organisms. Nevertheless, few protocols are currently available for measuring the toxicogenetic effects of these compounds in target and non-target field-collected species of insects important to agriculture. Herein, we used the species Ceraeochrysa claveri (Neuroptera: Chrysopidae), a non-target predator insect, to investigate the ability of an azadirachtin-based biopesticide (Azamax™) to induce DNA damage. The alkaline version of the comet assay was standardized to evaluate genetic instability caused by the toxicant in somatic (gut) and germ (nurse cells and oocytes) cells of C. claveri. For this, C. claveri larvae were distributed into three groups (10/each) and treated with Azamax™ at 0, 0.3% or 0.5% throughout the larval stage. DNA damage (tail intensity) was measured in adult insects, four days after emerged. The data showed that both doses of Azamax™ (0.3% and 0.5%) were able to significantly (p < 0.05) increase DNA damage in somatic and germ cells of C. claveri. In conclusion, C. claveri (intestinal and ovarian cells) was a sensitive bioindicator for identifying Azamax™ genotoxic potential, whereas the comet assay was a useful tool for detecting the genotoxic hazard of the pesticide in the field-collected insect species. Given that estimation of adverse effects of pollutants on ecosystems is an essential component of environmental risk assessment, the approach used can be recommended to estimate the ecotoxicity of agricultural chemicals.


Assuntos
Agroquímicos/farmacologia , Insetos/efeitos dos fármacos , Testes de Mutagenicidade/métodos , Praguicidas/toxicidade , Agroquímicos/toxicidade , Animais , Ensaio Cometa/métodos , Dano ao DNA/efeitos dos fármacos , Ecossistema , Células Germinativas/efeitos dos fármacos , Larva/efeitos dos fármacos , Limoninas , Praguicidas/química
16.
Int. j. cardiovasc. sci. (Impr.) ; 32(3): 247-252, May-June 2019. graf
Artigo em Inglês | LILACS | ID: biblio-1002222

RESUMO

Brazil is the worldwide leader in the long-term use of pesticides and herbicides. This compromises the health of handlers by causing harmful neurological, respiratory, and cardiovascular changes. The herbicide 2.4D has been shown to cause cardiac overload with subsequent pathological remodeling. Objective: To analyze the cardiac morphological repercussions on the left ventricle (LV) of mice submitted to nebulization by the herbicide 2.4D. Methods: Fifteen mice were divided into three groups: control group (CG; n = 5) exposed to nebulization with sodium chloride solution; low concentration group (LCG; n = 5) exposed to nebulization of the herbicide 2.4D with 3.71 x 10-3 grams; and high concentration group (HCG; n = 5) exposed to nebulization of the herbicide 2.4D with 9.28 x 10-3 grams for 15 minutes. The fractal dimension analysis was performed through the box-counting method. Later, the ImageJ program was used to calculate the fractal dimension of each group. To evaluate cardiac remodeling, histological slides were prepared and stained with Hematoxylin-Eosin (HE). Fifty areas of cardiomyocytes were analyzed per animal. The comparisons between groups were performed by ANOVA One-Way with Tukey's posttest (p < 0.05). Results: There was no change in fractal dimension values between the CG = 1.37 ± 0.02, LCG = 1.33 ± 0.04 and the HCG = 1.33 ± 0.07 groups. However, cardiac hypertrophy occurred in the HCG = 303.9 ± 38.80 µm(2) when compared to the CG group = 236.9 ± 61.71 µm(2) (p = 0.034). Conclusion: The herbicide 2.4D used for 72 hours did not promote cardiotoxicity when evaluated by fractal dimension. However, cardiomyocyte hypertrophy was observed in the LV


Assuntos
Animais , Ratos , Praguicidas/efeitos adversos , Inalação , Função Ventricular Esquerda , Remodelação Ventricular , Herbicidas/efeitos adversos , Doenças Respiratórias , Brasil , Estudos Transversais/métodos , Análise Estatística , Análise de Variância , Agroquímicos/efeitos adversos , Hipertrofia Ventricular Esquerda , Modelos Animais , Camundongos , Manifestações Neurológicas
18.
Rev. salud pública Parag ; 9(1): [P9-P18], jun. 2019.
Artigo em Espanhol | LILACS, BDNPAR | ID: biblio-1047012

RESUMO

Dentro del Proyecto CONACYT "Construyendo estándares socioambientales y de salud pública con el sector primario para incremento de la competitividad en los mercados PIN15-1103. CONACYT/ALTER VIDA" se aplicó un Cuestionario de Monitoreo Comunitario para la exposición y posibles impactos a la salud por el uso de plaguicidas; el objetivo de este artículo es validar el cuestionario de monitoreo comunitario y presentar los datos del trabajo de campo. El diseño del estudio fue observacional y descriptivo, se tomaron dos comunidades dedicadas a la producción agrícola, una en Caaguazú y otra en San Pedro. El muestro fue no probabilístico por bola de nieve comprendiendo a aquellos expuestos a plaguicidas en ambos distritos seleccionados, con una distancia máxima 1 kilómetro a los cultivos o plantaciones. Las variables analizadas incluyeron datos de filiación, uso y exposición de los agroquímicos, uso de equipos de protección individual, gestión de los residuos de plaguicidas, capacitación, salud. También se aplicó el alfa de Cronbach para estudiar la confiabilidad del instrumento. Todos los análisis fueron hechos con SPSS 25. Como conclusión, se ha detectado que la gestión en el uso de los agroquímicos en la población analizada debe ser reforzada en varios ejes, desde la capacitación, gestión en el uso, la disposición final, entre otras. El instrumento tiene buena consistencia y fiabilidad interna. Palabras clave: exposición ocupacional a agroquímicos, impactos a la salud, Paraguay.


Within the CONACYT Project "Building socio-environmental and public health standards with the primary sector to increase competitiveness in the markets PIN15-1103.CONACYT/ALTER VIDA" a Community Monitoring Questionnaire was applied for the exhibition and possible impacts on health for the use of pesticides, the objective of this article is to validate the community monitoring questionnaire and present the data of the field work. The design of the study was observational and descriptive, taking two communities dedicated to agricultural production, one in Caaguazú and the other in San Pedro. The sampling was not probabilistic by snowball comprising those exposed to pesticides in both selected districts, with a maximum distance of 1 kilometre to crops or plantations. The variables analyzed include filiation's data, use and exposure of agrochemicals, use of personal protection equipment, and management of pesticide residues, training, and health. Cronbach's alpha was also applied to study the reliability of the instrument. All analyzes were done with SPSS 25. In conclusion, it has been detected that the management in the use of agrochemicals in the analyzed population must be reinforced in several areas, from training, management in use, final disposal, among others. The instrument has good internal consistency. Key words: occupational exposure to agrochemicals; health impacts; Paraguay


Assuntos
Humanos , Masculino , Feminino , Monitoramento Ambiental , Agroquímicos , Grupos de Risco , Participação da Comunidade
19.
J Agric Food Chem ; 67(24): 6700-6707, 2019 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-31135150

RESUMO

A novel pH and redox dual-responsive cellulose-based nanogel was prepared for the controlled release of agrochemicals. To synthesize the responsive nanogel, palmitoyl chloride and glyoxal were modified on carboxymethyl cellulose sequentially and 3,3'-dithiobis(propionohydrazide) was used as a cross-linker to assemble the nanogel. The morphology, structure, and physical properties of nanogels were characterized with transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), particle size analysis, and zeta-potential measurement. Facing pH and redox stimulation, the nanogel showed reversible sol-gel transitions, indicating good pH- and redox-responsiveness. The nanogel loaded with agrochemicals exhibited high loading capacity and various release behaviors. In addition, the experiment of nanogel on heavy metal ions complexation displayed the potential of improving soil condition while delivering agrochemicals.


Assuntos
Agroquímicos/química , Celulose/química , Preparações de Ação Retardada/química , Portadores de Fármacos/química , Nanopartículas/química , Composição de Medicamentos , Géis/química , Concentração de Íons de Hidrogênio , Microscopia Eletrônica de Transmissão , Oxirredução , Tamanho da Partícula
20.
Environ Sci Pollut Res Int ; 26(18): 18230-18239, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31041701

RESUMO

Biochar as a carbon-rich highly porous substance has been proposed for use in agriculture and horticulture as a soil amendment. One of the main concerns of this application of biochar is its potential contamination with heavy metals (HMs) and polycyclic aromatic hydrocarbons. The aim of this research was to access the environmental risk of biochar used as a soil amendment on soil mesofauna (mites and springtails). We conducted both field and laboratory experiments with the use of wood-chip biochar from low-temperature (300 °C) flash pyrolysis. Biochar was free from polycyclic aromatic hydrocarbons (PAH), and the concentration of all tested toxic compounds was very low or even under the level of detection. Both the results of field and laboratory studies show no toxic effects on soil mesofauna. In the field studies, the biochar application of 50 t/ha in maize and oilseed rape crops significantly increased the mean number of mesofauna. This change probably resulted from improved soil chemical properties (in particular organic carbon content and cation exchange capacity) upon biochar addition. The results of the avoidance test with the use of springtail species Folsomia candida showed the possible short-term toxicity risk from a dose of 5%. The results of the reproduction test indicate the negative response of F. candida from the rate of 25% (higher than the field dose, which corresponds to 10% in laboratory tests). The reason for the short-term toxicity might be the considerable increase in soil pH after biochar addition. To our knowledge, this is the first study that has looked so widely into the effect of biochar on soil mesofauna. We encourage further studies into the risk assessment of biochar on soil organisms in both a controlled laboratory environment and in the open field.


Assuntos
Carvão Vegetal , Solo , Agricultura , Agroquímicos , Animais , Artrópodes/efeitos dos fármacos , Temperatura Baixa , Hidrocarbonetos Policíclicos Aromáticos/análise , Medição de Risco , Solo/química , Solo/parasitologia , Poluentes do Solo/análise , Temperatura , Madeira/química
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA