Submitted by Marcos Anselmo (marcos.anselmo@unipampa.edu.br) on 2016-04-04T19:06:17Z No. of bitstreams: 1 Anderson da Silva Rosa.pdf: 3717734 bytes, checksum: 87724729c4a8c7bfe10174d0b64ea722 (MD5) / Made available in DSpace on 2016-04-04T19:06:17Z (GMT). No. of bitstreams: 1 Anderson da Silva Rosa.pdf: 3717734 bytes, checksum: 87724729c4a8c7bfe10174d0b64ea722 (MD5) Previous issue date: 2013-10-12 / Pesticidas são compostos sintéticos que possibilitam o aumento da produção e da qualidade dos produtos agrícolas através da diminuição das perdas geradas por organismos indesejados. No entanto, eles podem gerar um gradativo impacto ambiental devido a sua toxicidade. Resíduos de pesticidas e seus metabólitos têm sido frequentemente encontrados em águas subterrâneas e de superfície. Desta forma, a contaminação de corpos d'água pode afetar direta ou indiretamente a saúde humana e a integridade do ecossistema por induzir uma ameaça significativa em ambientes aquáticos e recursos de água potável. A descontaminação de águas contaminadas por pesticidas tem um custo elevado e envolve grande gasto de energia. A fitorremediação (o uso de plantas para descontaminação de compostos xenobióticos) ganhou popularidade como uma rentável, ambientalmente amigável e eficiente tecnologia insitu para uma variedade de poluentes e, entre eles, muitos pesticidas. O presente estudo avaliou o potencial de fitorremediação da alface (Lactuca sativa L.) em águas contendo uma mistura dos pesticidas quincloraque, 2,4-D, clomazone, propanil e tebuconazole na concentração de 50 μg/L através de cultivo hidropônico. Para tal fim, foi desenvolvido e validado um método multirresidual para a determinação destes pesticidas citados por cromatografia líquida de alta eficiência com detecção por arranjo de diodos (HPLCDAD) em água potável e de cultivo hidropônico. O método desenvolvido mostrou-se eficaz, confiável, com boa sensibilidade e repetibilidade para a determinação dos compostos de interesse. O método proporciona ainda, flexibilidade para incluir novos pesticidas e/ou seus produtos de degradação. Para a avaliação da fitorremediação, mudas de alface foram cultivadas e após dez dias os meios de cultivo foram fortificados com os pesticidas em estudo. Foram coletadas amostras da água de cultivo no dia da fortificação, no sétimo e décimo-quarto dia após o tratamento. Houve uma diminuição significativa das concentrações de quincloraque, tebuconazole, 2,4-D e clomazone, sendo os melhores resultados obtidos após sete dias para os dois primeiros compostos e quatorze dias para os últimos, respectivamente. Esse estudo mostra o potencial do cultivo hidropônico de alface para a fitorremediação de pesticidas em água. / Pesticides are synthetic compounds that enable an increased production and quality of agricultural products by reducing losses caused by unwanted organisms. However, they can generate a gradual environmental problem due to their toxicity. Pesticide residues and their metabolites have often been found in groundwater and surface. Thus, the contamination of water bodies may directly or indirectly affect human health and the ecosystem integrity by inducing a significant threat to aquatic environments and drinking water resources. The decontamination of water contaminated by pesticides is expensive and involves great expenditure of energy. The phytoremediation (the use of plants to decontaminate xenobiotics) has gained popularity as a low cost, environmentally friendly and efficient in situ technology for a variety of pollutants and, among them, many pesticides. The present study evaluated the potential for phytoremediation of lettuce to water containing a mixture of pesticides quinclorac, 2,4- D, clomazone, propanil and tebuconazole concentration of 50 μg/L through hydroponics. Therefore, a multirresidue method for determination of pesticides cited by high performance liquid chromatography, with diode array detection (HPLC-DAD), in drinking water and hydroponic medium was developed and validated. The method has proven effective, reliable with good sensitivity and reproducibility for determining the compounds of interest. The method provides further flexibility to add new pesticide and/or its degradation products. For the evaluation of phytoremediation lettuce seedlings were grown and after ten days, the culture media was fortified with the x pesticides under study. Water samples were collected from cultivation on fortification, on the 7th and 14th days after treatment. It was observed a significant decrease in concentrations of quinclorac, tebuconazole, clomazone and 2,4-D, and the best results were obtained after seven days for the first two compounds and for the past fourteen days, respectively. This study shows the potential of hydroponic cultivation of lettuce for phytoremediation of pesticides in water.

Bed bugs were once considered eliminated from the United States, so recent resurgence of this pest has been cause for concern. Presence of these troublesome insects has resulted in the proposal of controversial policies. For example, the state of Ohio petitioned the EPA for a FIFRA Section 18 emergency exemption to use the insecticide propoxur, a neurotoxin, to treat bed bug infestations in the state. In this thesis, I analyzed public comments for the exemption, task force reports, and media to examine how health and the urban indoor environment are framed in this decision-making process. Though bed bugs carry stigma, those who have them are not overtly blamed for the pest. However, an inability to eliminate them effectively is situated as a lack of personal responsibility. A political ecology of health analysis and healthism are used to understand how narratives of health and personal responsibility justify use of this pesticide.

A capacidade de degradação de compostos xenobióticos por organismos vivos, principalmente bactérias, tem sido objeto intenso de pesquisa, principalmente por aqueles microrganismos isolados do solo. Dessa forma, a busca por novos nichos que resultem no isolamento de microrganismos altamente eficientes se torna cada vez mais necessária. Assim, dada a diversidade de interações inseto - bactérias, este estudo buscou explorar insetos resistentes a inseticidas como nicho de bactérias com capacidade de degradação de pesticidas para o desenvolvimento de estudos voltados à i) utilização dessas bactérias na biorremediação e ii) determinação de sua contribuição na metabolização de inseticidas pelo hospedeiro. Assim, esse trabalho teve por objetivos i) isolar, identificar e caracterizar microrganismos associados ao trato digestivo de linhagens de Spodoptera frugiperda (J.E. Smith, 1797) (Lepidoptera: Noctuidae) resistentes a lambda-cyhalothrin e deltamethrin (piretróide), chlorpyrifos ethyl (organofosforado), spinosad (naturalyte) e lufenuron (inibidor de síntese de quitina), ii) verificar o seu potencial de biodegradação desses compostos, iii) estudar sua associação a populações naturais de S. frugiperda e iv) determinar seu papel na metabolização de xenobióticos. Bactérias com potencial de biodegradação foram selecionadas via cultivo seletivo da flora associada ao trato intestinal de lagartas de quinto ínstar de S. frugiperda em meio mínimo M9 acrescido de 10 ?g/mL de um dos inseticidas em estudo como única fonte de carbono. As bactérias isoladas foram sujeitas à análise de PCR-RFLP do gene do 16S rDNA, com três enzimas de restrição (EcoRI, Rsa, DdeI), resultando na identificação de 16 isolados. Após sequenciamento, dez filotipos foram identificados, distribuídos em Firmicutes (Enterococcaceae e Staphylococcaceae), ?-Proteobacteria (Enterobacteriaceae e Pseudomonadaceae), ?-Proteobacteria (Comamonadaceae) e Actinobacteria (Micrococcaceae e Microbacteriaceae). Enterococcus, Pseudomonas e Microbacterium foram os únicos representados por dois filotipos, sendo ainda encontrados um filotipo de Delftia, Leclercia, Staphylococcus e Arthrobacter. Enterococcus casseliflavus e Enterococcus mundtii foram isolados de praticamente todas as linhagens resistentes de S. frugiperda. Análises de antibiograma e do metabolismo de carboidratos indicaram a similaridade entre os clones de E. casseliflavus, enquanto que os clones de E. mundtii diferiram de maneira expressiva. Apesar disso, os alelos analisados para tipagem via multilocus não resultaram em diferenças. Análises de PCR-diagnóstico do intestino de lagartas de S. frugiperda de linhagem suscetível de laboratório resultaram na detecção de quatro dos dez filotipos isolados do intestino de linhagens resistentes de S. frugiperda. Já em populações naturais foram encontrados cinco dos dez filotipos. O isolado com maior capacidade de crescimento em cada inseticida foi selecionado e todos apresentaram resposta dependente da concentração dos inseticidas, sendo encontrado efeito antimicrobiano em alguns inseticidas. A análise de cromatografia acoplada a espectrometria de massas comprovou a degradação dos inseticidas utilizados pelos diferentes isolados. A colonização do trato digestivo de linhagem suscetível de S. frugiperda com um dos filotipos (Microbacterium arborescens) isolado de lagartas resistentes a lufenuron resultou em CL50 cerca de 10 vezes superior àquela da linhagem apossimbionte. Assim, linhagens resistentes de S. frugiperda se mostraram um excelente reservatório de bactérias com capacidade de degradação dos inseticidas testados e que podem auxiliar na metabolização desses produtos pelo hospedeiro, assim como ser exploradas na descontaminação de áreas que apresentam resíduos desses xenobióticos. / The capacity of living organisms to degrade xenobiotics has been intensively studied, mainly for soil-associated bacteria. Thus, there is a growing need to search for new niches to lead to the isolation of highly efficient microrganisms. As insect-bacteria interactions are very diverse, we focused on exploiting insecticide resistant insects as a niche of pesticidedegrading bacteria to develop studies devoted to a) bacterial utilization in bioremediation and ii) determination of bacterial contribution to insecticide metabolization by the host insect. Our main objetives were to i) isolate, identify and characterize the microrganisms associated to the gut of resistant strains of Spodoptera frugiperda (J.E. Smith, 1797) (Lepidoptera: Noctuidae) capable to degrade lambda-cyhalothrin,deltamethrin (pyrethroids), chlorpyrifos ethyl (organophosphate), spinosad (naturalyte) and lufenuron (chitin synthesis inhibitor), ii) verify their potential to degrade these insecticides, iii) to verify their association to natural populations of S. frugiperda, and iv) to determine their role in the metabolization of xenobiotics in the host. Bacteria with biodegrading capacity were selected from the gut flora of fifth instars of S. frugiperda on selective media based on the minimum media M9 added of 10 ?g/mL of one of the insecticides selected as the sole carbon source. The isolated bacteria were subjected to RFLP-PCR analysis of the 16S rDNA gene using three restriction enzymes (EcoRI, Rsa, DdeI), which led to the identification of 16 isolates. These isolates were grouped in ten phylotypes after sequencing, representing Firmicutes (Enterococcaceae and Staphylococcaceae), ?-Proteobacteria (Enterobacteriaceae and Pseudomonadaceae), ?- Proteobacteria (Comamonadaceae) and Actinobacteria (Micrococcaceae e Microbacteriaceae). Enterococcus, Pseudomonas and Microbacterium were the only represented by more than two phylotypes. Delftia, Leclercia, Staphylococcus and Arthrobacter were also represented. Enterococcus casseliflavus and Enterococcus mundtii were isolated from almost all resistant lines of S. frugiperda. Antibiogram and carbohydrate metabolism assays indicated the similarity among the isolates of E. casseliflavus, while those of E. mundtii displayed some differences. However, no molecular differences were observed by comparing different alleles in multilocus sequence analysis. Diagnostic-PCR analysis of a susceptible, lab-strain of S. frugiperda allowed the identification of four out of the ten phylotypes isolated from resistant strains. But no bacteria from the susceptible strain could be cultivated in the selective media. In natural populations of S. frugiperda, five out of the ten isolates were detected. The most active isolate to degrade each pesticide was selected for further tests and all displayed a dose-dependent response to the insecticides. Analyses by gas or liquid chromatography-coupled mass spectrometry demonstrated the capacity of each isolate to degrade the insecticides tested. Gut colonization of larvae from the susceptible strain with Microbacterium arborescens isolated from resistant larvae increased the LC50 to lufenuron in 10 fold when compared to the aposymbiont strain. Thus, resistant strains of S. frugiperda are an excellent reservoir of bacteria capable of degrading the tested insecticides, and have a potential to be exploited for the bioremediation of xenobiotic contaminated areas. Moreover, these bacteria can auxiliate the host insect to metabolize insecticides and may play a role in insect response to insecticides.

A presente tese constitui um estudo de saúde ambiental em avaliação de risco. Fatores de risco relacionados ao trabalho agrícola e ao contato com os agrotóxicos foram discutidos, traduzindo um alerta à necessidade de melhoria da qualidade da saúde do trabalhador rural na região central do estado de São Paulo, fortemente agrícola, a exemplo do município de Bariri, estudo de caso da pesquisa. Constou de uma abordagem sobre problemas ambientais advindos da agricultura moderna que podem refletir na saúde humana, inclusive aqueles de maior dificuldade de associação estatística e de maior escala temporal causa-efeito, como o câncer. Teve como cerne o levantamento de casos de câncer em base hospitalar de referência regional, o Hospital Amaral Carvalho, em Jaú, reconhecido como um dos melhores do país realizando tratamentos no sistema público de saúde a mais de 85 anos. Foram realizadas análises estatísticas referentes ao gênero e à idade, bem como calculado o risco relativo para um grupo de casos registrados num universo de 336 ocorrências para Bariri, entre os anos de 2000 a 2002, e um grupo controle selecionado do mesmo hospital, em outro banco de dados com 596 registros. Um mapa indicando a localização de casos (68) e não-casos (60) foi elaborado por técnicas de geoprocessamento. A pesquisa concluiu que para o período e grupo estudados as maiores prevalências foram as neoplasias de pele (45%) e do sistema digestório (36%). Bariri apresentou 24 casos para cada 10.000 habitantes, para todos os tipos de câncer, entre trabalhadores rurais, durante os anos de 2000 - 2002. O risco relativo calculado entre expostos (ser agricultor) e não expostos (outras ocupações) foi de 1.6, indicando uma probabilidade quase duas vezes maior de adoecer para os expostos. O uso de geoprocessamento permitiu perceber que não existem padrões na distribuição geográfica da doença, para o período, entre trabalhadores rurais de Bariri. Contudo, um maior número de ocorrências positivas na periferia sudoeste, aponta para uma área que deve ser priorizada em campanhas informativas e de educação preventiva em saúde ambiental / This thesis reports an environmental health study on risk assessment. It discusses risk factors linked to rural work and pesticide contact in a restricted geographic area and shows the necessity of improving rural workers’ health in the central part of São Paulo state. The municipality of Bariri, which is the case studied in this research, typifies this agriculturally-based region. The study focuses on environmental problems engendered by modern agriculture that may have human-health repercussions such as cancer, as indicated by hard statistical association on an extended cause-effect time scale. For specific cases, the research used a database containing records of Amaral Carvalho Hospital, located in the city of Jaú and a highly respected regional reference unit for over 85 years as one of the best in the brazilian public health system for treating cancer. Statistics for age and gender were analyzed and a relative risk was calculated for a group of cases registered from a 336 database for Bariri, from 2000 to 2002, as well as for a randomly selected control group from the same hospital in a 596 database. A map indicating the residences of cases (68) and non-cases (60) was made by geoprocessing techniques. For the period of time and the group studied, the authors concluded that the cancers of the skin (45%) and digestive system (36%) were the most prevalent. Bariri presented 24 cases representing all cancer types for each group of 10,000 citizens. The study indicated an almost two times higher probability of cancer development among rural workers, with a calculated relative risk between those exposed (agriculture workers) and the non-exposed (other occupations) of 1.6. No patterns of geographical distribution of cancer in that time period were recorded among rural workers of Bariri. However, the higher number of positive occurrences in the southwestern outskirts of the city indicated an area that must be prioritized in distributing environmental health information and conducting preventive education campaigns

Organophosphates (OPs) and Pyrethroids (PYRs) are widely used pesticides in both agricultural and non-agricultural environments. In agricultural work settings, typically more than one pesticide is used in combination, or sequentially, to kill pests. There is currently a gap in research that looks at how exposures to multiple pesticides can impact human health – particularly among adolescents who work in these environments. The goal of this dissertation research was to examine the use of OP (chlorpyrifos, and profenofos) and PYR (λ-Cyhalothrin, α-Cypermethrin) pesticides across an application season and how exposure is associated with symptoms and cholinesterase enzyme activity, and to examine the impact of a sequential exposure to multiple OPs, and exposure to both OPs and PYRs. Urine and blood samples, questionnaire data, and a medical exam were collected over a 10-month period from adolescent pesticide applicators in Egypt. Overall, applicators had higher exposure than non-applicators to all four pesticides. The non-applicators were also exposed and had levels 4 times higher in urine metabolite levels than the general population in the U.S. In addition, these exposures caused increased symptoms and severity of symptoms among both applicators and non-applicators. In conclusion, adolescent agriculture workers in the Egyptian cotton fields are exposed to multiple pesticides and are susceptible to the impact of those exposures on their health.

Invasive fire ants are aggressive predators of ground nesting birds and reptiles and are spreading rapidly throughout tropical and temperate climates. Fire ants have been known to prey on a variety of reptile species, including threatened loggerhead sea turtles. The granular fire ant bait AMDRO® is being used on sea turtle nesting beaches to protect nests and hatchlings from these predators, however no studies have been conducted to thoroughly assess its effect on any reptile species. In this field study, I examined the impact of AMDRO® on hatching and emergence success, body condition, and orientation behavior in loggerhead sea turtles (Caretta caretta) in Juno Beach, Florida, USA. Pesticide granules were placed in a one-foot diameter circle directly above nest chambers during the final 5-10 days of incubation, which is representative of typical field applications of this pesticide on nesting beaches. Two controls were used in this study: cornmeal granules in soybean oil served as the vehicle control, and a second group of untreated control nests were left to incubate naturally, undisturbed. After a natural emergence, hatchlings were collected to calculate a body condition index (BCI). For a subset of the nests, 20 hatchlings were collected to perform orientation assays to assess the hatchlings’ ability to orient correctly toward the ocean, a visually mediated process that could be altered by visual impairments resulting from ADMRO® exposure. Three days following a mass emergence event, nests were excavated to collect hatching and emergence success data. Sand samples were collected to determine if the toxicant persisted in the environment or penetrated the egg chamber. Analyses indicated that the toxicant had no effect on hatchling morphology, hatching success, or emergence success. It also had no effect on the ability of hatchlings to orient toward the ocean. However, the pesticide granules attracted more predators than were seen at control nests. Thus, while AMDRO® might not directly impact reproductive success or hatchling behavior, it had the unanticipated effect of possibly increasing nest vulnerability to predators. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2019. / FAU Electronic Theses and Dissertations Collection

Orientador: George Shogueki Yasui / Resumo: Nas últimas décadas o Brasil tornou-se um dos líderes mundiais no uso de agrotóxicos, devido à grande utilização destas substâncias na agricultura; o estado de São Paulo utiliza aproximadamente 25% do total de agrotóxicos comercializados no país sendo os herbicidas os agrotóxicos de maior consumo, devido as suas características de amplo espectro e eficiência em diferentes culturas terrestres, bem como a facilidade no controle de plantas daninhas, estes agentes químicos também são utilizados para o controle e manejo de macrófitas aquáticas. As macrófitas são plantas presentes nos ecossistemas aquáticos lóticos e lênticos, podendo ser flutuantes ou submersas, tendo basicamente como importância ecológica a criação de habitats para peixes. No entanto, o crescimento desordenado dessas plantas, devido à alta produção primária faz com que grandes extensões de área sejam tomadas pela colonização destas. Para solucionar este problema, torna-se necessário a aplicação de métodos de controle e manejo dessas plantas, através de métodos químicos, biológicos e mecânicos. Os testes de toxicidade aquática são de grande importância porque os ecossistemas aquáticos constituem os principais receptáculos de contaminantes, podendo estes serem oriundos de lançamentos direto aos corpos d’água, emitidos no ar ou solo. A concentração letal média (CL50) é aquela responsável pela morte de 50% da população, sendo utilizada em situações em que a substância é administrada em meio no qual o animal habita, n... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: In the recent decades, Brazil has become one of the world leaders in pesticides use, due its large use in agriculture; São Paulo State uses approximately 25% of the total pesticides traded in the country, being herbicides the most consumed pesticide, due to its broad spectrum and efficiency in different terrestrial crops, as well as the ease of weed control and in the management of aquatic macrophytes. Macrophytes are aquatic plants present in lotic and lentic aquatic ecosystems, where they can be floating or submerged, basically having ecological importance in the creation of habitats for many fish species. However, disordered plant growth, due to the high primary production, can lead to the colonization of large areas. To solve this problem, it’s necessary to make use of chemical, biological and mechanical methods to control these plants proliferation. Aquatic toxicity tests are of great importance since the aquatic ecosystems are major contaminant receptacles, which may come from direct releases to water bodies, carried by air or soil. The median lethal concentration (LC50) is a concentration of a given agent that kills 50% of the population, and it is used in situations where the substance is administered in the habitats that are directly in contact with the animal. In the present work, we used the yellow-tail tetra (Astyanax altiparanae) as model for the aquatic toxicity tests. Results on CL50 for adults were 3.11 mg/L for RoundUp Transorb and 4.21 mg/L for ArsenalNa. Fo... (Complete abstract click electronic access below) / Mestre

Pesticides are toxic by nature and they pose a serious threat to populations in agricultural communities, particularly to children, and farmers in low-income countries. Children living in agricultural communities may face a higher risk from pesticide exposure in the home environment than children in the general population. Farmers in low-income countries may also have higher risks from increased pesticide exposure due to the use of highly toxic pesticides that are banned in other countries and to unsafe practices and behaviors while handling pesticides. There is a growing body of literature that suggests pesticides, specifically organophosphorus pesticides (OPs), cause neurobehavioral impairment in children and adults. In a fruit orchard community in the U.S. Pacific Northwest, dust was collected from households and analyzed for four types of OPs. Various factors such as housing characteristics and resident behaviors were evaluated to examine their relationships with the OP concentrations in the home dust. School-aged children completed a battery of neurobehavioral tests at two time points, one year apart. The relationship between pesticide exposure, measured with parents’ occupations and a summary OP concentration, and neurobehavioral performance was examined. A cross-sectional study was carried out in The Gambia to identify rural residents’ knowledge about pesticide hazards and practices while handling pesticides. Relationships between participants’ knowledge, characteristics, and practices were examined. Occupational exposure scores were developed to quantify participants’ chronic pesticide exposures using the study’s questionnaire. In addition, participants provided information on neurological symptoms associated with pesticide use and a neurobehavioral test battery was administered to assess cognitive function. The relationships between occupational exposure scores and neurological symptoms and neurobehavioral performance were examined. In the orchard community, OP detection frequencies and concentrations were higher in agricultural households compared to non-agricultural households. Significant associations were found between higher OP concentrations in dust and the following: (1) homes with a parent working in an agricultural field and/or orchard, (2) homes with ≥ 2 agricultural workers living in the home, and (3) homes located in close proximity to an agricultural field or orchard. Having air conditioning in the home had a protective effect on OP concentrations. Results suggested that deficits in learning, or less improvement, on the neurobehavioral tests from the first visit to the second visit were found in agricultural children compared to non-agricultural children. In The Gambia, the majority of participants reported risky practices while handling pesticides such as: not wearing any protective clothing or equipment; mixing with bare hands; applying with their bare hands, plastic bags, or leaves; storing pesticides in the home; inadequately disposing of empty pesticide containers; and wearing shoes into the home after working with pesticides. They also reported having concerns about the adverse effects of pesticides on their health. Participants having had farm or pesticide safety training reported having less risky pesticide handling practices and behaviors. Participants with high occupational exposure scores experienced more symptoms and had worse performance on several of the neurobehavioral tests, including tests of motor function and dexterity, compared to participants with low exposure scores. Results from these studies suggest neurobehavioral impairments were found in participants with higher pesticide exposures compared to participants with lower exposures in the two populations. Further research is needed to identify successful strategies for reducing pesticide exposure in the home environment and while handling pesticides.

Pesticides have been used to control various types of pests, including plants and insects, for thousands of years, however the impact of exposure to these toxic chemicals, with respect to environmental and health consequences, is not fully understood. Two pesticides of interest, molinate and dieldrin, have been shown to cause neurotoxicity in humans, but their mechanisms of toxicity are still unknown. In order to better understand how exposure to these chemicals can cause toxicity, the structure-activity relationship (SAR) was defined to determine how specific changes to the structure of each pesticide affects the toxicity profiles of each of these compounds. Results of this study demonstrated that oxidation of molinate to molinate sulfoxide, and then further to molinate sulfone, a more potent inhibitor of aldehyde dehydrogenase. The sulfone metabolite is capable of covalently modifying the active-site cysteine residue of aldehyde dehydrogenase, accounting for the observed enzyme inhibition. These results indicate that the compound responsible for the toxicity from molinate exposure is not the parent compound, but rather one of the sulfoxidation metabolites. When the SAR of dieldrin was investigated with respect to a Parkinson's disease model, it was determined that the compounds that were previously found to be the least potent insecticides were the most toxic with respect to dopaminergic cells. Each of the compounds tested was observed to disrupt dopamine metabolism in accordance with their toxicity profiles in dopaminergic cells. In combination, these results implicate important structural features responsible for the toxicity with respect to Parkinson's disease. This information is critical for the development of new pesticides, and will be important to increase the selective toxicity for insects while minimizing adverse/off-target effects. This can lead to the development of safer, more effective pesticides that will be essential for future environmental and human health.

Detection of organic molecules present on the surface of dust particles is important in homeland security, agriculture, and several other applications. The research presented reports the ability of the aerosol mass spectrometer (AMS) to detect molecules on the surface of dust particles without detecting the particle core. Experiments were carried out to detect semi-volatile organic compounds adsorbed onto the surface of particulates without interference from the dust particle core. Methyl salicylate, oleic acid, and organophosphorus pesticides such as Malathion were detected on the surface of particles representative of dust-type materials. Zeolite powders were used as aerosol support, representative of a typical silica mineral aerosol present in the atmosphere. Mass spectral fingerprint information was gained by first directly detecting atomized species to record their clean electron impact mass spectrum. This facilitated detection during later experiments of organic molecules coated on an inorganic support. Spectra obtained give mass spectrometric signatures of molecules coated on inorganic particles without detection of the particle core. An important feature of the AMS is the ability to equate an ion rate detected in the mass spectrometer to a mass concentration of a given chemical species in a sample using its ionization efficiency. Based on an average inlet flow rate of 1.2 cm 3sec -1 the ionization efficiencies obtained were 5.89x10-5, 1.15x10-6, and 1.62x10-5 for Malathion, methyl salicylate, and oleic acid, respectively. These experiments and the results obtained show that detection and characterization of organic species adsorbed onto inorganic dust particles are possible at µg m-3 concentrations using the AMS.