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Document formatted into pages; contains 78 pages. / Title from PDF of title page. / Thesis (M.S.P.H.)--University of South Florida, 2003. / Includes bibliographical references. / Text (Electronic thesis) in PDF format. / ABSTRACT: Malathion is a commonly used organophosphate pesticide on field crops, fruits, nut trees, vegetables, livestock, agricultural premises, and land. The approved uses also include mosquito and medfly control. These uses can result in human skin contact. The purpose of this study is to evaluate the human skin absorption of malathion for the purpose of assessing the risks associated with aqueous solution exposures following applications. Aerial applications can result in solubilized malathion in swimming pools and other waters that may be contacted. Human volunteers were selected and exposed to aqueous solutions of malathion at various concentrations. Participants submerged their arms and hands in twenty liters of dilute malathion solution in either a stagnant or stirred environment. The "disappearance method" was applied by measuring malathion concentrations in the water before and after human subject exposure to the water for various periods of time. Malathion was measured using Gas Chromatography. No measurable skin absorption was detected in 42% of the participants. Measurable skin absorption among the remaining 58% of participants resulted in doses that were more than an order of magnitude less than the minimal dose necessary to cause a measurable change in red blood cell acetylcholinesterase (RBC-AChE). Extrapolation of these results to a mathematical model for recreational swimmers and bathers exposed to contaminated swimming pools and surface waters typically detected after bait application again are an order of magnitude below the doses needed to cause a detectable change in RBC-AChE. These data indicate that exposure to aqueous malathion following usual aerial bait applications is not appreciably absorbed, and therefore, it is not a public health hazard. / System requirements: World Wide Web browser and PDF reader. / Mode of access: World Wide Web.

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Tests were conducted for 71 pesticides in weekly bulk (wet + dry) deposition samples collected from May 25 to September 21 over two years at two sites in the City of Winnipeg, Canada. Twenty-one pesticides and their metabolites were detected in this study and 99% of samples collected contained mixtures of two or more pesticides. Malathion and glyphosate were the largest contributors to bulk deposition in 2010 and 2011, respectively. A second study examined the mineralization of 2,4-D and 17β-estradiol using a novel in-field soil microcosm study and a series of laboratory experiments under different temperature incubations. Results indicated that temperature fluctuations do not greatly affect the amount or rate of mineralization relative to the traditionally constant laboratory incubations of 20°C; however long-term freezing of soil reduced potential mineralization over time. This research advances scientific knowledge of agri-chemical fate and provides data for strengthening current environmental policy analysis in Canada.

Tests were conducted for 71 pesticides in weekly bulk (wet + dry) deposition samples collected from May 25 to September 21 over two years at two sites in the City of Winnipeg, Canada. Twenty-one pesticides and their metabolites were detected in this study and 99% of samples collected contained mixtures of two or more pesticides. Malathion and glyphosate were the largest contributors to bulk deposition in 2010 and 2011, respectively. A second study examined the mineralization of 2,4-D and 17β-estradiol using a novel in-field soil microcosm study and a series of laboratory experiments under different temperature incubations. Results indicated that temperature fluctuations do not greatly affect the amount or rate of mineralization relative to the traditionally constant laboratory incubations of 20°C; however long-term freezing of soil reduced potential mineralization over time. This research advances scientific knowledge of agri-chemical fate and provides data for strengthening current environmental policy analysis in Canada.

Universiẗat, Diss., 2003--Stuttgart.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Organophosphorus (OP), among them malathion, are responsible for most of the poisonings reported annually in Brazil. In addition to symptoms of cholinergic poisoning, the exposure to OP causes affective and cognitive disorders, which are not necessarily related to acetylcholinesterase (AChE) enzyme activity inhibition. One of these disorders is depression. Diphenyl diselenide [(PhSe)2] is an organoselenium compound that presents pharmacological effects, among them the antioxidant effect. Therefore, this study was designed to investigate a potential antidepressant-like effect of (PhSe)2 on a depression model induced by malathion in rats. The role of Na+K+ ATPase, AChE and monoamine oxidase (MAO) activities and oxidative stress was investigated in cerebral cortices of rats. Rats were exposed once a day for three consecutive days to malathion (50 mg/kg, intraperitoneal) and (PhSe)2 (50 mg/kg, oral). To investigate the antidepressant-like behavior rats were submitted to the forced swimming test (FST) and the open-field test (OFT). Thiobarbituric acid reactive species (TBARS) levels, enzymatic and non-enzymatic antioxidant defenses were carried out in cerebral cortices of rats. The results confirmed that malathion increased immobility time in the FST without altering the locomotor performance in the OFT. Treatment with (PhSe)2 ameliorated performance in the FST without altering the crossing numbers in the OFT. The inhibition of Na+K+ATPase activity caused by malathion was prevented by treatment with (PhSe)2. Exposure to malathion did not alter parameters of oxidative stress as well as AChE and MAO activities in cerebral cortex of rats. In conclusion, (PhSe)2 exerted antidepressant-like effect in rats exposed to malathion. Na+K+ ATPase activity is, at least in part, involved in (PhSe)2 antidepressant-like behavior. / Os inseticidas organofosforados (OF), entre eles o malation, são responsáveis por grande parte das intoxicações relatadas anualmente no Brasil. Além dos sintomas da intoxicação colinérgica, a exposição a OF causa distúrbios cognitivos e afetivos, que não necessariamente estão relacionados à inibição da atividade da enzima acetilcolinesterase (AChE). Dentre esses prejuízos destaca-se a depressão. O disseleneto de difenila [(PhSe)2] é um composto orgânico de selênio que possui diversas propriedades farmacológicas, entre elas, a atividade antioxidante. Dessa forma, o presente trabalho teve por objetivo investigar um possível efeito do tipo antidepressivo do (PhSe)2 em um modelo de depressão induzida por malation em ratos. O papel das atividades da Na+ K+ ATPase, AChE e monoamina oxidase (MAO) bem como do estresse oxidativo no comportamento antidepressivo foram investigados no córtex cerebral de ratos. Os ratos foram expostos ao malation na dose de 50 mg/kg por via intraperitonial (i.p.) e ao (PhSe)2 na dose de 50 mg/kg por via oral (p.o.) uma vez ao dia durante três dias. 24 h após a última administração de malation e/ou (PhSe)2, foram realizados os testes comportamentais e em seguida os animais foram submetidos à eutanásia. Para investigar o comportamento do tipo antidepressivo, os ratos foram submetidos ao teste do nado forçado (TNF) e ao teste do campo aberto (TCA). Os níveis de espécies reativas ao ácido tiobarbitúrico (TBARS), bem como as defesas antioxidantes enzimáticas e não-enzimáticas foram determinadas no córtex cerebral dos ratos. Os resultados confirmaram que o malation aumenta o tempo de imobilidade no TNF sem alterar a atividade locomotora no TCA. O tratamento com (PhSe)2 melhorou a performance dos animais no TNF sem que houvesse alteração no número de cruzamentos no TCA. Houve uma inibição da atividade da Na+ K+ ATPase nos animais tratados somente com malation e essa inibição foi prevenida pelo (PhSe)2. A exposição ao malation não alterou os parâmetros de estresse oxidativo bem como as atividades das enzimas AChE e MAO. Com esse trabalho, conclui-se que o (PhSe)2 exerce efeito do tipo antidepressivo em ratos expostos ao malation. A atividade da Na+ K+ ATPase está, pelo menos em parte, envolvida no comportamento do tipo antidepressivo do (PhSe)2.

Made available in DSpace on 2014-06-11T19:32:05Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-01-20Bitstream added on 2014-06-13T19:42:24Z : No. of bitstreams: 1 botti_mv_dr_jabo.pdf: 509674 bytes, checksum: fa0ca90368b7cf8b75fc5f41544521b3 (MD5) / Universidade Estadual Paulista (UNESP) / O controle de larvas e adultos de Aedes aegypti é a forma disponível para controlar a Dengue. O uso de temefós é importante para o controle de larvas. O controle de adultos é realizado por nebulização de malathion nos imóveis, apresentando riscos ocupacionais aos aplicadores. Objetivou-se avaliar o período residual do temefós em recipientes de diferentes materiais pela validação de método analítico; propor um nível de aceitabilidade de controle de larvas; determinar o período residual de controle (PRC) em recipientes de borracha (pneus); propor um procedimento para monitorar o PRC em Pontos Estratégicos (PEs); avaliar as exposições dérmicas (EDs) e respiratórias (ERs); calcular a necessidade de controle das exposições potenciais (EPs); comparar a eficiência de duas vestimentas de proteção; classificar a segurança das condições de trabalho sem e com o uso das vestimentas; calcular a necessidade de controle das exposições e o tempo de trabalho seguro (TTS) proporcionado pelas vestimentas. O método validado é adequado para determinar a concentração do temefós na água. O material do recipiente afeta a dissipação do temefós. O controle de larvas nos pneus é aceitável (90%) por 22 dias após a aplicação. O procedimento com pneus amostradores é adequado para determinar o PRC de larvas em PEs. As EDs foram muito superiores às ERs. É necessário controlar 91,34 % das EPs. A vestimenta Agro Light é mais eficiente que a da SUCEN e a única em que a atividade foi classificada como segura. A atividade executada com a vestimenta da SUCEN se torna segura se for aumentado o controle da exposição em 11,4 %, ou a redução do tempo de trabalho ao TTS de 1,4 horas / Controlling Aedes aegypti larvae and adults is the only possible way to control Dengue. The use of temephos is essential for larvae control. The control of adults is carried out by spraying malathion on buildings, which poses occupational risks to those who apply it. We aimed to evaluate the temephos’ residual period in containers made out of different materials through validation of the analytical method; to propose a level of acceptability of larvae control; to determine the residual period of control (PRC) in rubber containers (tires); to propose a procedure to monitor PRC in Strategic Points (PEs); to evaluate dermal (EDs) and respiratory exposure (ERs); to compute the need to control potential exposure (EPs); to compare the efficiency of two protective equipments; to classify the safety of working conditions with and without protective equipments; to calculate the need to control exposure and time of safe work (TTS) provided by the protective equipment. The validated method is suitable to determine the concentration of temephos in water. The material of the container affects temephos degradation. Larvae control in tires is acceptable (90%) for 22 days after application. The procedure with tire samplers is suitable to determine PRC of larvae in PEs. EDs was much higher than ERs. 91.34% of EPs need to be controlled. The Agro Light protective equipment is more efficient than that of SUCEN and activities are considered safe only with its use. Activities performed with the protective equipment provided by SUCEN are considered safe if exposure control is increased by 11.4% or working time is reduced to the TTS of 1.4 hours

Orientador: Maria Aparecida Marin Morales / Banca: Silvia Tamie Matsumoto / Banca: Mário sérgio Mantovani / Resumo: Os agrotóxicos, substâncias químicas muito utilizadas para combater pragas na agricultura e nas residências, além de contribuírem para o aumento da produtividade e, conseqüentemente, o crescimento economia, também são responsáveis pela contaminação ambiental, quando utilizados indiscriminadamente, e por muitos casos de intoxicações e doenças genéticas nos seres humanos. Dependendo de sua composição química, degradabilidade e persistência no ambiente, os agrotóxicos podem comprometer a cadeia alimentar e afetar o ecossistema como um todo. Dentre os agrotóxicos bastante utilizados em todo o mundo, está o organofosforado malation. Pelo seu amplo uso, torna-se preocupante os possíveis danos que este inseticida possa promover no meio ambiente e nos organismos a ele expostos, pois alguns trabalhos já mostram esta sua ação detrimental. Desta forma, este trabalho investigou o potencial de indução de danos no DNA, para diferentes concentrações de malation, por meio das técnicas de aberrações cromossômicas e teste do micronúcleo em A. cepa e micronúcleo e ensaio do cometa em células HTC (hepatoma tissue culture). Nos testes com células meristemáticas e F1 de A. cepa, expostas por 24 e 48 horas ao malation, foram verificadas freqüências significativamente elevadas de AC e MN. Após 24 horas de exposição, não houve aumento na quantidade de AC, mas sim de MN. A análise das células F1 de A. cepa, juntamente com o teste de AC, forneceu dados importantes sobre a fixação dos danos genéticos induzidos pelo malation. Nenhum resultado relevante de citotoxicidade foi verificado em A. cepa. Após passarem pelo teste de recuperação, somente as células expostas às menores concentrações testadas apresentaram diminuição nos índices de AC e MN. / Abstract: Pesticides, chemicals widely used to combat pest in agriculture and in homes, besides contribute to the increase productivity and the economy, are also responsible for environmental pollution and for many intoxications cases and genetic diseases in human beings. Depending on their chemical composition, degradability and degree of persistence in the environment, the pesticides can endanger the food chain and affect the entire ecosystem. Among the pesticides most used in the world is the organophosphate malathion. Due to its widespread use it has been worrying the possible damages that can promote this insecticide in the environment and in organisms exposed to it. This study investigated the induction potential of DNA damage with several malathion concentrations using chromosomic aberration (CA) techniques, micronucleus test (MN) in A. cepa and micronucleus and comet assay in hepatoma tissue culture (HTC). In A. cepa tests, meristematic and F1 cells exposed for 24 and 48 hours to malathion showed significative frequencies of CA and MN. After 24 hours of exposure, there was no increase in the CA amounts, but was observed an increase to frequency of MN. The F1 cells analysis, together with the CA tests, provided important data on the genetic damages fixation induced by malathion. No relevant results of citotoxicity were verified in A. cepa. After the recovery test, the cells exposed to the smaller tested concentrations of malathion showed reduction of AC and MN indices. In the HTC cells test, was verified by the comet assay, genotoxic effects for all the tested concentrations, after exposure for 24 hours to the insecticide, but by the micronucleus tests, no significative results were found. These data suggest that the DNA lesions were repaired and not elapsed in mutation. With the concomitant realization of different tests, the clastogenic action of malathion could be verified. / Mestre

Publicación a texto completo no autorizada por el autor / Determina los efectos del Malathion sobre el desarrollo embrionario post-implantacional usando como modelo biológico al ratón. Los efectos del Malathion sobre el desarrollo embrionario post-implantacional son evaluados usando ratonas albinas preñadas separadas en 4 grupos de tratamiento a las que se les administra intraperitonealmente diferentes dosis de Malathion de grado comercial (150, 100, 50 y 0 mg de Malathion/ Kg de peso del animal) desde el día 9 al día 17 de preñez. En el día 18 de preñez las ratonas son sacrificadas realizándose la evaluación sobre el desarrollo embrionario post-implantacional en los fetos. Los resultados encontrados muestran que Malathion produce toxicidad materna cuando son expuestas a la dosis más alta (150 mg de Malathion/ Kg de peso del animal). También se halla un aumento en la embriotoxicidad evidenciado por la mortalidad fetal y en la morfogénesis del sistema esquelético por retraso en la osificación. Se encuentran algunas malformaciones pero ninguna es significativamente diferente al grupo control (p≥0.05). / Tesis