nÃo hà / O elevado consumo de pesticidas no Brasil e no mundo tem levado grupos de pesquisadores a relacionar essa exposiÃÃo a possÃveis danos genÃticos e agravos a saÃde do trabalhador rural. Estudos revelam que o cÃncer à considerado doenÃa genÃtica, vez que resulta do acÃmulo de mutaÃÃes em genes comprometidos com o controle da proliferaÃÃo e da diferenciaÃÃo celular ou de mutaÃÃes em genes envolvidos com os mecanismos de reparo do DNA. O objetivo dessa estudo foi realizar um biomonitoramento genÃtico em indivÃduos expostos ocupacionalmente a pesticidas avaliando a ocorrÃncias de danos cromossÃmicos, atravÃs do teste do MicronÃcleo em cÃlulas esfoliadas da mucosa bucal, teste Cometa e teste de AberraÃÃes CromossÃmicas em linfÃcitos de sangue perifÃrico. Como tambÃm alteraÃÃes hematolÃgicas e hepÃticas. A populaÃÃo estudada incluiu 32 agricultores moradores do povoado Vila Bessa, ConceiÃÃo do JacuÃpe, Bahia, expostos ocupacionalmente a pesticidas e 30 indivÃduos controle, sem historia de exposiÃÃo a pesticidas. O material para anÃlise do teste do micronÃcleo foi coletado por raspagem da mucosa bucal com escova cytobrush, confeccionado um esfregaÃo e posteriormente fixado em soluÃÃo de metanol/Ãcido acÃtico (3:1) e corados pelo mÃtodo FeÃlgen/Fast Green, as lÃminas foram analisadas em teste cego sob microscopia Ãptica em um mÃnimo de 1000 cÃlulas/indivÃduo. Para realizaÃÃo do teste Cometa e de AberraÃÃes, cromossÃmicas e das alteraÃÃes hematolÃgicas e hepÃticas foram coletadas 10 mL de sangue perifÃrico. O teste Cometa foi executado de acordo com a metodologia descrita por por Singh et al. (1988), foram contados 100 cometas por lÃmina e classificados, por anÃlise visual, dentre cinco categorias de danos (0, 1, 2, 3 e 4), e calculado o Ãndice e a FreqÃÃncia de dano. O teste de AberraÃÃes CromossÃmicas foi realizada atravÃs de culturas de linfÃcitos e obtenÃÃo de metÃfases pela interrupÃÃo da citocinese das cÃlulas. Foram analisados o hemograma, e as transaminases TGO, TGP E GGT que foram processados pelo laboratÃrio de anÃlise bioquÃmica de Escola Bahiana de Medicina e SaÃde PÃblica. NÃo houve diferenÃa significativa na ocorrÃncia de micronÃcleos entre os grupos avaliados (p = 0,163), mas alteraÃÃes nucleares indicativos de apoptose e necrose foram encontradas significantemente no grupo exposto a pesticidas (p = 0,001), indicando que uma maior injÃria celular do que simplesmente uma resposta a diferenciaÃÃo e maturaÃÃo do epitÃlio. AberraÃÃes CromossÃmicas numÃricas (3,3%) foi encontrada significantivamente para o grupo exposto (p = 0,001), foram encontrados danos ao DNA avaliados pelo teste Cometa no escore 1 (p< 0.001) no grupo exposto; alÃm do Ãndice de Dano cromossÃmico com mÃdia  SEM 4.032  0.3336 para o grupo controle e mÃdia  SEM 41.05  3.227 para o grupo exposto a pesticida (p<0,0001); e FreqÃÃncia de Dano: mÃdia  SEM grupo controle 4.081  0.3667 e mÃdia  SEM grupo exposto a pesticida 38.44  2.664, com diferenÃas significativas para o grupo exposto (p<0,0001). Os indivÃduos pesquisados estÃo expostos ao glifosato e ao paration-metÃlico, ambos tÃxicos para o organismo humano, e apresentavam-se anÃmicos (p=0,004) e com leucopenia (p < 0,001), porÃm sem alteraÃÃes nas avaliaÃÃes hepÃticas. ConcluÃmos que esses indivÃduos estÃo expostos a agentes potencialmente genotÃxicos, alÃm de apresentarem alteraÃÃes hematolÃgicas, e que a persistÃncia desse contato com os pesticidas poderà levar a desencadeamento dos fenÃmenos envolvidos na iniciaÃÃo e promoÃÃo do cÃncer. / The high consumption of pesticides in Brazil and all over the world have lead researches to relate this exposition to possible genetic and health damages in rural workers. Studies reveal that cancer is considered a genetic disease, once it results of the mutation accrual in genes involved with control of proliferation and cellular differentiation or mutations in genes involved with the DNA repair. The aim of this study was realize a genetic biomonitoring in individuals occupationally exposed to pesticides evaluating the occurrence of chromosomal damages, by the Micronucleus assay in exfoliated cells of buccal mucosa, Comet assay and Chromosome Aberration assay in peripheral blood lymphocytes. Hematologic and hepatic alterations were also evaluated. The studied population included 32 agriculturists living in the village of Vila Bessa, ConceiÃÃo do JacuÃpe, Bahia, occupationally exposed to pesticides, and 30 control individuals, with no history of pesticides exposition. For the micronucleus assay, the material was collected by scaling buccal mucosa with a cytobrush, the smear was made and then fixed in methanol/acetic acid solution (3:1) and colored by FeÃlgen/Fast Green Method, slides were analyzed in blind test by optic microscopy in a minimum of 1000 cells/individual. To realize the assay of Comet and Aberration, Chromosomal and hematologic and hepatic alterations, were collected 10 mL of peripheral blood. Comet test was made according the methodology described by Singh et al. (1988), were counted 100 comet by slides and classified, by visual analyses, into five categories of damages (0, 1, 2, 3 e 4), and then calculated the index and frequency of damage. Chromosome Aberration test was realized with a lymphocytes culture and obtaining of metaphases by interrupting the cells cytokinesis. The hemogram and the transaminases TGO, TGP and GGT were analyzed; those were processed by the biochemical analyses laboratory of Escola Bahiana de Medicina e SaÃde PÃblica. That wasnÂt statistical difference in the occurrence of micronucleus among the evaluated groups (p = 0.163), but nuclear alterations, indicative of apoptosis and necrosis, were significantly found in the pesticide exposed group (p = 0.001), indicating a major cellular injury than a simple answer to epitheliumÂs differentiation and maturation. Numeric Chromosome Aberrations (3.3%) were significantly found in the exposed group (p = 0.001), were found DNA damages evaluated by the Comet assay in score 1 (p<0.001) in the exposed group; as also index of chromosomal damage with media  SEM 4.032  0.3336 to the control group and media  41.05  3.227 to the pesticide exposed group (p<0.0001); and frequency of damage: media  SEM control group 4.081  0.3667 and media  SEM pesticide exposed group 38.44  2.664, with significant differences in the exposed group (p<0.0001). The studied individuals are exposed to glifosate and methyl parathion, both toxic to the human organism, and were anemics (p=0.004) and with leukopenia (p<0.001), however with no alterations in hepatic evaluations. We conclude that these individuals are exposed to potentially genotoxic agents, besides present hematologic alterations, and that the persistence of this contact with the pesticides can trigger to phenomenonâs involved with cancer initiation and promotion.

D.Sc. (Zoology) / The influence of some natural enemies and pesticides was studied on Tetranychus cinnabarinus (Boisduval), T. lombardinii Baker & Pritchard and T. ludeni Zacher (Acari: Tetranychidae). Two important predators were discovered, viz: Pardosa crassipalpis (Purcell) (Arachnida: Araneida) and Labidura riparia (Insecta: Dermaptera). Both are more susceptible to some acaricides, especially dimethoate, than the mites. It is proved that the injudicious use of these acaricides, also of DDT and carbaryl, can cause an outbreak of these mites. As to the biologies of the species, the appearance was noted of a fourth chrysalis stage during the development of three T. cinnabarinus females.

M.Sc. (Zoology) / Axenic cultures of Euglena gracilis in different basal medium concentrations, to simulate eutrophic conditions, were exposed to different concentrations of Monocrotophos and Dichlorvos to determine the effect of the pesticides on the growth reaction. The effect of the pesticides on the chlorophyll a content of test organisms exposed to equivalent toxicities of pesticides was determined. The amount of pesticide accumulated and me tabolised was determined by the choline esterase method and by gaschromatography. More pesticide was found to be accumulated and metabolised by organisms in the lower concentration of basal medium.

Puisque l'utilisation des pesticides augmente dans la pratique agricole (Gorse, 2015), il est inévitable que nous allons retrouver ces contaminants dans l'eau de surface qui se trouve à proximité des zones d'épandage. Il est certain que les pesticides ont plusieurs manières d'affecter notre organisme. Cependant, l'effet de ces pesticides sur les différents mécanismes cellulaires est peu étudié. En effet, il est connu que certains pesticides permettent l'activation de gènes régulés par le récepteur à l'hydrocarbure d’aryle (AhR), mais il n'y a peu de documentation par rapport à leur effet sur les dommages à l'ADN. De plus, ces pesticides sont la plupart du temps utilisés en combinaison lors de leur utilisation agricole, mais il n'y a quasiment aucune étude qui est faite sur leurs effets lorsqu'ils sont en combinaison. Ainsi, mon projet de maîtrise se base sur l'hypothèse que certains contaminants présents dans l’environnement ainsi que dans les eaux de surface peuvent, à court et à long terme, perturber deux voies cellulaires, soit celle du récepteur à l'hydrocarbure d’aryle et celle de p53. Pour la première partie de mon projet, je me suis intéressée principalement aux gènes CYP1A1 et CYP1B1, deux enzymes impliquées dans le métabolisme de ces contaminants environnementaux dont l'expression est régulée par AhR. L'activation de ces deux gènes a été mesurée suite à un traitement avec différents ingrédients actifs seuls à haute concentration ou en combinaison à faible concentration. Nous avons démontré que chacun des ingrédients actifs séparément permettent l'activation d’AhR. En plus, lorsque nous les combinons, nous observons une activation synergique d’AhR pour la plupart des combinaisons. Ainsi, leur effet en combinaison est beaucoup plus grand que celui qu'ils ont lorsqu'ils sont seuls. Nous avons aussi déterminé que les pesticides seuls ainsi que les combinaisons permettaient l'observation de l’interaction croisée entre AhR et le récepteur à l'oestrogène (ER[alpha]). Pour la deuxième partie de mon projet, j'ai vérifié si les pesticides utilisés à haute concentration ainsi que les différentes combinaisons à faible concentration entraînent l’activation du point de contrôle des dommages à l’ADN. Le carbaryl, le linuron et le bromoxynil sont les trois seuls pesticides permettant l’activation de ce point de contrôle à haute concentration. Toutes les combinaisons de pesticides à faibles concentrations ne permettent pas l’activation de ce point de contrôle. Ainsi, tous les pesticides testés à haute concentration permettent l’activation d’AhR, mais seulement certain d’entre eux permettent l’activation du point de contrôle des dommages à l’ADN. Cela montre donc que les pesticides ont plusieurs cibles dans la cellule et que selon le pesticide étudié, les cibles changent. La dernière partie de mon projet consistait à vérifier l’impact sur AhR des contaminants environnementaux présent dans la rivière Saint-François le 26 septembre 2016 sur AhR. Les contaminants ont été extraits et concentrés avant d'être testés sur des cellules en culture. Les contaminants présents dans l'eau de rivière permettent l'activation d’AhR. En conclusion, mes études permettent de mieux comprendre l'effet de ces cinq pesticides sur ces deux mécanismes cellulaires. Des études plus approfondies sont nécessaires afin de comprendre l'ensemble des mécanismes affectés par ces pesticides

Please read the abstract in the section 00front of this document / Dissertation (MSc (Entomology))--University of Pretoria, 2006. / Zoology and Entomology / unrestricted

Cryptophlebia leucotreta granulovirus (CrleGV-SA) is a baculovirus specifically pathogenic to the citrus pest false codling moth, Thaumatotibia leucotreta. CrleGV- SA is formulated as a commercial biopesticide, Cryptogran® (River Bioscience, South Africa). The virus has a stable, proteinaceous crystalline occlusion body (OB) that protects the nucleocapsid. The major limitation to the use of baculoviruses is their susceptibility to the ultraviolet (UV) component of sunlight, which rapidly and greatly reduces their efficacy as biopesticides. The UVA and UVB components are the most destructive to biological organisms. To date no publication has reported the effect of UV on the structure and virulence of CrleGV, or the effectiveness of the OB as a UV protectant. In this study the effect of UV irradiation on the structure and infectivity of pure CrleGV-SA and Cryptogran® was investigated using scanning electron microscopy (SEM), Raman spectroscopy, qPCR, and bioassays. The project included laboratory and field studies. In the laboratory, CrleGV-SA and Cryptogran® were exposed to either UVA or UVB for periods of 24 hours to 7 days before analysis. In the field, Cryptogran® was applied to trees in a citrus orchard with young fruit. The fruit were collected from 24 hours to 28 days after application and bioassays conducted to assess the effect of sunlight over time on virus structure and efficacy when applied to the northern or southern sides of the trees. No surface morphological changes to the virus were detected using SEM. However, small compositional changes were detected by Raman spectroscopy. qPCR and bioassays demonstrated that UV irradiation damaged the viral DNA, greatly reducing the infectivity of pure CrleGV-SA and Cryptogran®. Exposure to UVB reduced the virulence of the virus more than UVA. The field studies revealed that the activity of CrleGV-SA decreased more on the northern side of the trees than on the southern side.

Liquid phase catalytic hydrodechlorinations can provide a convenient and environmentally friendly method for treating organic chlorinated compounds in waste streams generated during the manufacturing of agrochemicals. During such treatment hydrochloric acid is generated as a by-product, which can be easily neutralized employing a base to yield an inorganic salt. This work describes the results obtained during the liquid phase hydrodechlorination of 2,6-dichlorophenol (2,6-DCP) and 2,4,6-trichlorophenol (2,4,6-TCP). The hydrodechlorination of these chlorinated phenolic compounds in a mixture of methanol and water was investigated using supported and unsupported palladium catalysts to yield lower chlorinated phenols or phenol. Various parameters were investigated such as catalyst concentration, ammonium formate concentration, effect of base addition and effect of temperature. During this study two methods of hydrodechlorination were also investigated such as hydride-transfer hydrogenolysis, using ammonium formate, and hydrogenolysis, using dihydrogen. These methods offer a mild treatment in terms of the reaction temperature with temperatures used below 800C. A comparison of the palladium catalyst systems using these methods also showed that Pd/C produced the best results in terms of the hydrodechlorination rate and the selectivity towards phenol. When the ammonium formate method was used, complete hydrodechlorination of both substrates was achieved in 1h of reaction time at a selectivity of 100 percent towards phenol. A comparison of the method using dihydrogen and Pd/C showed that the reaction rate and the selectivity towards phenol during the hydrodechlorination of 2,6-DCP were 87.92 percent and 93.30 percent. Similarly, the reaction rate and selectivity during 2,4,6- TCP hydrodechlorination were 63.77 percent and 70.57 percent. These results were achieved in a reaction time of 3 hours. A high catalyst loading increases the reaction rate at the expense of selectivity, due to the formation of cyclohexanone, formed during further hydrogenation of phenol. The formation of cyclohexanone was limited at high temperatures (ca. 800C) with none detected during the hydrodechlorination of 2,6-DCP and 0.19 percent during the hydrodechlorination of 2,4,6-TCP. Evaluation of the hydrodechlorination parameters showed that the catalytic efficiency of the Pd/C catalysts was inhibited as the reaction proceeded due to the formation of HCl as by-product. A significant increase in the reaction rate was achieved when the reaction was performed in the presence of an inorganic base, which neutralized HCl.

El DDT está íntimamente vinculado al siglo XX.  Su producción, uso y comercialización están prohibidos por ser un contaminante organoclorado persistente controlado por el Convenio de Estocolmo. / DDT is closely linked to the twentieth century.  Its production, use and marketing are now banned because it is a persistent organochlorine pollutant controlled by the Stockholm Convention.

Les expositions professionnelles agricoles, et notamment l’exposition aux pesticides, ont été associées à divers effets négatifs, sur la fertilité, le déroulement de la grossesse et le développement de l’enfant. Peu d’études se sont intéressées à des activités agricoles spécifiques excepté le travail sous serre et la floriculture et aucune n’a été à ce jour conduite en France. (1) L’interrogation de plus de 800 femmes, incluses dans la cohorte AGRIculture & CANcer (AGRICAN) et ayant eu une grossesse depuis l’inclusion (2005), grâce à 2 questionnaires rétrospectifs a montré un allongement du délai nécessaire à concevoir en lien avec l’emploi sur une exploitation agricole, le travail de nuit ou l’exposition à des vibrations. Des augmentations de risque d’avortements spontanés et de malformations ont également été observées mais restent à confirmer. (2) Le développement d’une méthode d’analyse multi-résidus a permis de mesurer 25 pesticides différents parmi 116 recherchés dans les urines de femmes travaillant sur des exploitations de poly-culture élevage. Les herbicides étaient les plus fréquemment détectés, notamment en lien avec la présence de maïs sur l’exploitation ou de tâches réalisées au contact des animaux d’élevage. Le glyphosate ou son métabolite AMPA étaient retrouvés dans 85% des échantillons.Un projet de recherche poursuivra les travaux engagés en s’intéressant au développement cognitif des enfants nés depuis 2005. / Agricultural exposures, including pesticide exposure, have been associated with several negative effects on fertility, pregnancy and child development. Few studies focused on specific agricultural activity excepted floriculture and working in greenhouse and none was conducted in France. (1) More than 800 women, enroled in the AGRIculture & CANcer (AGRICAN) cohort and who reported a pregnancy since enrolment (2005) agreed to fill in 2 questionnaires. An increase of time to pregnancy was observed for women who worked on a farm, for those exposed to night work and to vibrations. Increased risks of spontaneous abortions or abnormalities were also observed in relation to agricultural work but these results need to be confirmed. (2) Multi-residue analytical method was developed and applied to women of childbearing age, working in crop-livestock farms. Twenty-five pesticides or metabolites were detected among 116 measured in urine samples. Herbicides were the most frequently detected, especially when women worked on corn-crop farms or were involved in breeding tasks. Glyphosate or its metabolite AMPA were detected in 85% of urine samples.Future project will allow us to investigate cognitive development of children born since 2005.

Accurate solubility measurements for the pesticide l-naphthyl-N-methylcarbamate (carbaryl) in water, natural and artificial seawater, NaCl, Na2SO4, CaCl2 and (CH3)4NBr, at different temperatures covering the range 5-45 °C, were obtained using a combination of the generator column method and absorption spectroscopy techniques. As a rule, it was found that the solubility of carbaryl in water and in the electrolyte solution increased with an increase in temperature. The thermodynamic parameter ΔG°, ΔH°, ΔS°, and ΔC°p at 298.15 K, for the dissolution process carbaryl(s) to carbaryl(aq) and carbaryl(s) to carbaryl(aq. elect.), were calculated by fitting the solubility information to the Clarke and Glew equation. The results were consistent with the model which considers carbaryl and (CH3)4NBr to be solvent-structure-promoters and the rest of the electrolytes used in this work as solvent-structure-breakers. The salt-effect as a function of temperature on the nonelectrolyte pesticide was obtained by calculating the Setchenov constants for each one of the electrolyte solutions mentioned above. Salting-out was observed in solutions prepared with NaCl, Na2SO4, and CaCl2 was well as in natural and artificial seawater, while salting-in was obtained with (CH3)4NBr solutions. Pseudo-first order rate constants and half-life times for carbaryl in water were determined for different pH values ranging from 9.70 ± 0.02 to 11.60 ± 0.02 and covering the temperature range 25.5 ± 0.2 to 34.7 ± 0.2 °C. A direct relationship between SDS concentration and pesticide solubility was found by showing that the presence of micelles increased the solubility of an otherwise sparingly soluble molecule like carbaryl. Under high pressures (1356±34, 1797±34, and 2203±34 atm) and using NaCl as cosolute, carbaryl was readily degraded at 30 °C, giving deprotonated l-naphthol as one of the final products, in agreement with previous observations reported in the literature with esters and substituted phenols. Pseudo-first order high-pressure rate constants were calculated and, according to the results, it was found that there was a direct relationship between these constants and pressure.