A poluição marinha por petróleo e seus derivados é uma preocupação crescente de caráter global. O litoral norte do estado de São Paulo é hoje caracterizado como a região mais altamente impactada por esses contaminantes de toda a costa Sul e Sudeste do país. Dentre as substâncias que compõem esses produtos estão os Hidrocarbonetos Aromáticos Policíclicos (HPAs), como o fenantreno, que apresentam potencial de alterar o sistema endócrino de peixes, gerando desajustes hormonais de alto risco para o processo reprodutivo dos animais expostos. Com base nestes fatos, o presente trabalho buscou verificar efeitos do fenantreno como desregulador endócrino em juvenis de E. marginatus. Essa espécie se caracteriza pelo hermafroditismo protogínico, de modo que os juvenis costumam apresentar altas concentrações de esteroides gonadais, o que gera preocupação quanto os efeitos reprodutivos decorrentes de alterações no padrão de produção de esteroides, especialmente em uma espécie que já vem sofrendo declínios populacionais por conta da sobrepesca. A CL50 encontrada para juvenis de E. marginatus foi 1,51 mg⁄L. Em seguida, foi realizado um bioensaio subletal (96h) com quatro grupos experimentais (n=5) em duplicata: grupo controle; duas concentrações distintas de fenantreno (0,1 mg⁄L e 1 mg⁄L) e grupo exposto ao veículo de diluição (0,004% de etanol). Foram dosadas as concentrações de 17β-estradiol (E2), testosterona (T) e 11-cetotestosterona (11-KT) plasmáticos por ELISA. Gônadas, fígado e baço foram processados para análise histológica. Foi conduzido bioensaio in vitro com incubação de fragmentos gonadais sob ação de fenantreno (50μM) ou etanol. Os níveis dos mesmos esteroides também foram dosados por ELISA. A exposição in vivo ao fenantreno resultou em aumento na área dos hepatócitos, bem como no número de centro melanomacrofágicos e hemossiderose no baço. O etanol induziu efeitos similares no baço. Os níveis de E2 e T não se alteraram no plasma ou no meio de incubação in vitro. O fenantreno reduziu a concentração de 11-KT in vitro e in vivo. No plasma, o etanol também causou esse decréscimo. Considerando a importância do 11-KT no desenvolvimento dos ovários em teleósteos, o fenantreno parece causar desregulação da esteroidogênese em juvenis de E. marginatus, possivelmente gerando disfunções durante a inversão sexual / Marine pollution by crude oil and its residual products is a growing global concern. The Northern coast of São Paulo is characterized as the highly impacted area by these contaminants through Brazil\'s South and Southeast coast. Polycyclic aromatic hydrocarbons (PAH), such as phenanthrene, are the main crude oil components and have a significant toxic potential to biota, acting as endocrine disruptors (ED) and negatively impacting reproduction. This study aimed to investigate the effects of phenanthrene as ED on gonadal steroidogenesis in E. marginatus juveniles. As a hermaphrodite protogynous species, E. marginatus juveniles maintain high levels of plasma steroids as substrates for sex inversion, which causes concern about reproductive effects of disruptions in steroid production patterns, especially in an overfished species. LD50 to E. marginatus exposed to phenanthrene was established in 1.51 mg⁄L. An in vivo sublethal exposure (96 h) to phenanthrene was carried out at two concentrations (0.1mg⁄L and 1 mg⁄L); exposure to the vehicle (ethanol) was also performed. Plasma levels of 17β-estradiol (E2), testosterone (T) and 11-ketotestosterone (11-KT) were measured by ELISA. Gonads, liver and spleen were processed for histological analysis. In an in vitro bioassay, gonad fragments were incubated with phenanthrene (50μM) or ethanol. Steroid levels in the culture media were also measured by ELISA. The in vivo exposure to phenanthrene triggered an increase of the area of the hepatocytes, increased number of melanomacrophagic centers and hemosiderosis in the spleen. Ethanol also induced similar effects on spleen. E2 and T levels did not change neither in plasma nor in vitro media. Phenanthrene sharply reduced 11-KT levels in vitro and in vivo. In plasma, ethanol also decreased 11-KT levels. Considering the importance of 11-KT in fish developing ovaries, phenanthrene seems to disrupt steroidogenesis in juvenile grouper, possibly being able to cause dysfunctions during sex change

Os hidrocarbonetos policíclicos aromáticos (HPA) são poluentes formados por dois ou mais anéis aromáticos que podem causar efeitos mutagênicos, carcinogênicos e teratogênicos aos seres humanos. Os HPA não são suscetíveis à degradação pela maioria dos micro-organismos devido a sua baixa solubilidade em água e a sorção destes poluentes na parte mineral e orgânica do solo. Uma forma de tratamento é o uso de processos oxidativos que podem degradar inúmeros contaminantes orgânicos e minerizá-los a gás carbônico e água. Neste trabalho foi avaliada a eficiência da degradação do isômeros fenantreno e antraceno, dois tipos de HPA, em areia padrão, utilizando-se como oxidantes o permanganato, peróxido de hidrogênio e persulfato ativado. De acordo com a matriz e o contaminante, após 24 horas de tratamento, verificou-se a degradação de 95 a 98% utilizando-se como oxidantes permanganato e de 34 a 62% utilizando-se a reação de Fenton. Foi identificada a antraquinona como produto do antraceno, independentemente do oxidante utilizado. Dentre os oxidantes, avaliou-se o persulfato ativado com ferro para a aplicação em solos arenosos contaminados com HPA. Quando se utilizou persulfato ativado com ferro em areia padrão houve a decomposição, após 24 horas de tratamento, de 60 e 95%, de fenantreno e antraceno, respectivamente. Em solos arenosos utilizando-se o persulfato, a degradação dos contaminantes foi predominantemente inferior devido ao possível efeito de matriz. Em contrapartida praticamente não houve a decomposição das substâncias húmicas. Esta é característica favorável, pois não houve a competição da matéria orgânica com o contaminante pelo persulfato, além de não promover alterações no teor de carbono presente no solo / Polycyclic aromatic hydrocarbons (PAH) are pollutants formed by two or more aromatic rings that can be mutagenic, carcinogenic and teratogenic to humans. PAH do not undergo degradation by most microorganisms due to this low water solubility and adsorption in the mineral and organic soil phase. One form of treatment is the use of oxidative processes that can degrade numerous organic contaminants and mineralize them to carbon dioxide and water. In this study, it was evaluated the efficiency of phenanthrene and anthracene degradation, in standard sand soil using permanganate, hydrogen peroxide and activated persulfate as oxidants. Depending on the contaminant and the matrix, over 24h of treatment, it was found the degradation 95 to 98% using permanganate and 34 to 62% using reaction Fenton. Anthraquinone was identified as product of anthracene, independent of the oxidant used. Among the oxidants, persulfate activated with iron was evaluated in the degradation of PAH in sandy soils. In standard sand, this process promoted,over 24 hours of treatment, a degradation level up to 60 % phenanthrene and 95% for anthracene. In sand soils, the degradation of the contaminants was lower due to possible matrix effect. In constrast there was no decomposition of humic substances, indicating no competition between the organic matter and the PAH by persulfate, and no change in the soil carbon content

Die vorliegende Dissertation berichtet über die Untersuchung von selbst-aggregierten Einfach- und Mehrfachschichten aus Nanographenen-Derivate mit Hilfe der Rastertunnelmikroskopie (RTM) an Fest-Flüssig-Grenzflächen. Die -Konjugation bringt einzigartige elektronische Eigenschaften mit sich, so dass die Nanographen-Derivate viel versprechende Bausteine für eine molekulare und organische Elektronik sind, da sie maßgeschneidert und kostengünstig prozessiert werden können, und leicht und flexibel sind. Für elektronische Anwendungen ist es notwendig, die Nanographene in ultradünnen Filmen mit geordneten supramolekularen Strukturen zu organisieren. Nanostrukturen werden für Nanographene-Derivate auf hoch orientiertem pyrolytischem Graphit (HOPG) untersucht, wie zum Beispiel alkylierte Hexi-peri-hexabenzocoronene (HBCs) unterschiedlicher Symmetrie und dreiecksförmige polyzyklische aromatische Kohlenwasserstoffe (PAK). Es zeigt eine erstaunliche Vielfalt von supramolekularen Strukturen, z.B. Zick-Zack-, Blumen- oder Honigwaben-Muster. Eine faszinierende Besonderheit besteht in den Honigwaben Strukturen, die sich durch Selbstaggregation dreieckiger alkylierter Phenyl-PAKs bilden, und die damit Nanotemplate für Gastmoleküle darstellen. In vielen Fällen bilden Nanographene-Derivate nicht nur Monoschichte sondern auch Multischichten auf Graphit. Die Selbstorganisation von Doppelschichten aus einer HBC-Stern-Verbindung bietet das Potenzial für Baustelemente in der organischen Elektronik, zum Beispiel für Nanodrähte. Die alkylierten Phenyl-HBCs bilden polykristalline Strukturen sowohl in der "face-on"-Anordnung in Monoschichten auf Graphit wie in der "edge-on"-Anordnung in Multischichten, die sich in einem äußeren elektrischen Feld bilden. Beides kann nützlich sein, da für die mögliche Anwendung in einer Photovoltaik-Zelle die "face-on"-Orientierung auf Oberflächen erforderlich ist, während für organische Feldeffekt-Transistoreneine "edge-on" Nanostruktur benötigt wird. / This thesis reports on the investigation of self-assembled mono- and multilayers from nanographene derivatives via scanning tunneling microscopy (STM) at solid-liquid interfaces. Because of the unique electronic properties associated with their -bonded topology, nanographenes are promising building blocks for molecular and organic electronics, which provide the possibility of tunability together with low-cost processing, light weight, and flexibility. For the application in electronics it is necessary to organize nanographenes in ultrathin films with well-ordered supramolecular structures. Nanostructures of monolayers on Highly Oriented Pyrolytic Graphite (HOPG) are studied for different nanographene derivatives, such as alkylated hexa-peri-hexabenzocoronenes (HBCs) with different symmetries, and triangle-shaped polycyclic aromatic hydrocarbons (PAHs). They exhibit a surprising diversity of supramolecular structures, for example zigzag, flower-like or honeycomb shapes. A fascinating peculiarity provides the honeycomb structures which are self-assembled from triangle-shaped alkylated phenyl PAHs, which provide nanotemplates to accommodate guest molecules. In many cases, nanographene derivatives not only form monolayers but also multilayers on HOPG. Star-shaped HBC molecules self organize into bilayers in polar solvents, which exhibit the potential for the formation of building blocks of organic electronics, for instance nanowires. The alkylated phenyl HBCs form polycrystalline structures both in the “face-on” arrangement in a monolayer on HOPG, and “edge-on” in multilayers within an external electric field. Both may be useful for potential applications, since in a photovoltaic cell, the “face-on” orientation on surfaces is required, while for the purpose to be applied in organic field-effect transistors, the “edge-on” nanostructure on the electrodes is necessary.

Dois milhões de toneladas por ano de resíduos plásticos são gerados no Brasil. Apenas 16,5% em massa deste resíduo plástico são mecanicamente reciclados, a maior parte restante é levada a aterros ou lixões. Todo este material poderia ser incinerado e, desta forma reduzir em até 90% a massa do volume aterrado, e seu conteúdo energético seria usado para gerar vapor ou energia. Esta investigação foi feita sobre os produtos de combustão incompleta emitidos da pirólise e combustão em estado estacionário do polietileno e poliestireno em um forno vertical de dois estágios, eletricamente aquecido. Separadamente, os polímeros na forma pulverizada foram pirolisados em temperatura constante de 1000°C e, depois da mistura com N2/O2, os produtos de pirólise foram queimados a 900, 1000 e 1100°C. Os testes foram conduzidos com 21% de O2 em volume no forno de oxidação. Diferentes razões de combustível e ar foram usadas no forno de combustão, pela variação da taxa de alimentação de polímero no forno de pirólise. A motivação para a combustão indireta de PE e PS foi obter a combustão nominalmente pré-misturada dos gases de pirólise com ar, assim, obtendo menores emissões dos produtos de combustão incompleta comparativamente à combustão direta do polímero sólido. Este trabalho examinou os efeitos da temperatura de combustão e a razão equivalente de ar e combustível. Os efluentes da pirólise e combustão foram analisados, e as emissões de CO, CO2, O2, hidrocarbonetos leves, hidrocarbonetos policíclicos aromáticos e materiais particulados foram mensurados. Ainda, o material particulado foi caracterizado quanto ao tamanho das partículas. Foi observado que enquanto a quantidade de gás de pirólise diminuiu com o aumento da taxa de alimentação do polímero, sua composição permaneceu praticamente independente da taxa de alimentação. As emissões de CO2 foram máximas perto da razão equivalente 1, enquanto as emissões de CO aumentaram com o aumento da razão equivalente. As emissões totais de hidrocarbonetos leves e PAH na combustão aumentaram tanto com o aumento da razão equivalente, quanto do aumento da temperatura. A maior parte do material particulado teve o tamanho menor que um micrometro. No geral, as emissões de PAH e material particulado da combustão indireta de PE e PS foram uma ordem de grandeza menor que a emissão correspondente da combustão direta e heterogênea do polímero sólido, obtida em outros trabalhos. Como a pirólise destes polímeros requer uma entrada nominal de calor mínima em relação à quantidade de calor gerada na sua combustão, a implantação desta técnica pode ser vantajosa. / Two millions tons/year of plastic wastes are generated in Brazil. Only 16.5% of this plastic waste is mechanically recycled, the rest is mostly landfilled. All these material could be incinerated, in a way to reduce by 90% the volume of landfilled waste, and use its energy content to supply energy. This investigation was conducted on pollutants emitted from steady-flow pyrolysis and combustion of polyethylene and polystyrene in a two-stage electrically-heated vertical furnace. Separately, the polymers, in pulverized form, were first pyrolyzed at constant temperature of 1000°C and subsequently their pyrolyzates were burned at 900, 1000 and 1100°C, upon mixing with air. Tests were conducted with 21% of O2 and different fuel to air equivalence ratios in the oxidizer furnace, by keeping the flow of gases and changing the feed rate of polymer in the pyrolyzer furnace. The motivation for this indirect combustion of PE and PS was to attain nominally-premixed combustion of the pyrolyzate gases with air, thereby achieving lower pollutant emissions than those from direct combustion of the solid polymer. This work examined the effects of the combustion temperature, as well as of the polymer feed rate and the resulting fuel to air equivalence ratio. The effluents of pyrolysis and combustion were analyzed for fixed gases (CO, CO2, O2), light hydrocarbons, polycyclic aromatic hydrocarbons and particulate matter. It was found that whereas the amount of pyrolysis gas decreased with increasing polymer feed rate, its composition was nearly independent of the feed rate. CO2 emissions peaked at an equivalence ratio near unity, while the CO emissions increased with increasing equivalence ratio. The total light hydrocarbon and PAH emissions of combustion increased both with increasing equivalence ratio and with temperature. The generated particulates were mostly submicronmeter in size. Overall, PAH and soot emissions from indirect burning of PE and PS were an order of magnitude lower than corresponding emissions from direct heterogeneous burning of the solid polymer, obtained elsewhere. As pyrolysis of these polymers requires a nominal heat input that amounts to a diminutive fraction of the heat released during its combustion, implementation of this technique is deemed advantageous.

Os hidrocarbonetos policíclicos aromáticos (HPA) são poluentes formados por dois ou mais anéis aromáticos que podem causar efeitos mutagênicos, carcinogênicos e teratogênicos aos seres humanos. Os HPA não são suscetíveis à degradação pela maioria dos micro-organismos devido a sua baixa solubilidade em água e a sorção destes poluentes na parte mineral e orgânica do solo. Uma forma de tratamento é o uso de processos oxidativos que podem degradar inúmeros contaminantes orgânicos e minerizá-los a gás carbônico e água. Neste trabalho foi avaliada a eficiência da degradação do isômeros fenantreno e antraceno, dois tipos de HPA, em areia padrão, utilizando-se como oxidantes o permanganato, peróxido de hidrogênio e persulfato ativado. De acordo com a matriz e o contaminante, após 24 horas de tratamento, verificou-se a degradação de 95 a 98% utilizando-se como oxidantes permanganato e de 34 a 62% utilizando-se a reação de Fenton. Foi identificada a antraquinona como produto do antraceno, independentemente do oxidante utilizado. Dentre os oxidantes, avaliou-se o persulfato ativado com ferro para a aplicação em solos arenosos contaminados com HPA. Quando se utilizou persulfato ativado com ferro em areia padrão houve a decomposição, após 24 horas de tratamento, de 60 e 95%, de fenantreno e antraceno, respectivamente. Em solos arenosos utilizando-se o persulfato, a degradação dos contaminantes foi predominantemente inferior devido ao possível efeito de matriz. Em contrapartida praticamente não houve a decomposição das substâncias húmicas. Esta é característica favorável, pois não houve a competição da matéria orgânica com o contaminante pelo persulfato, além de não promover alterações no teor de carbono presente no solo / Polycyclic aromatic hydrocarbons (PAH) are pollutants formed by two or more aromatic rings that can be mutagenic, carcinogenic and teratogenic to humans. PAH do not undergo degradation by most microorganisms due to this low water solubility and adsorption in the mineral and organic soil phase. One form of treatment is the use of oxidative processes that can degrade numerous organic contaminants and mineralize them to carbon dioxide and water. In this study, it was evaluated the efficiency of phenanthrene and anthracene degradation, in standard sand soil using permanganate, hydrogen peroxide and activated persulfate as oxidants. Depending on the contaminant and the matrix, over 24h of treatment, it was found the degradation 95 to 98% using permanganate and 34 to 62% using reaction Fenton. Anthraquinone was identified as product of anthracene, independent of the oxidant used. Among the oxidants, persulfate activated with iron was evaluated in the degradation of PAH in sandy soils. In standard sand, this process promoted,over 24 hours of treatment, a degradation level up to 60 % phenanthrene and 95% for anthracene. In sand soils, the degradation of the contaminants was lower due to possible matrix effect. In constrast there was no decomposition of humic substances, indicating no competition between the organic matter and the PAH by persulfate, and no change in the soil carbon content

Les hydrocarbures aromatiques polycycliques (HAPs) sont des polluants organiques persistants (POP) émis essentiellement par les activités humaines suite à la combustion incomplète de la matière organique (industrie, chauffage, trafic routier...). En raison de leur faible taux de dégradation, de leur toxicité et de leur bioaccumulation, les HAPs font l'objet de plusieurs études d'écotoxicologie. La présente thèse, entreprise dans ce contexte par le biais d'une étude microcosmique se propose d'évaluer l'impact des HAPs sur la microflore et la méiofaune et d'appliquer différentes techniques de bioremédiation (biostimulation, bioaugmentation et combinaison des deux techniques) dans le but de dégrader les HAPs. Nos résultats ont montré que les HAPs sont toxiques aussi bien pour la microflore que pour la méiofaune de la lagune de Bizerte. Sur la microflore, l'effet toxique de ces contaminants s'est manifesté par l'inhibition de l'activité bactérienne à l'interface eau–sédiment et par la modification profonde de la structure des communautés bactériennes. En ce qui concerne la méiofaune, les HAPs ont entrainé une altération de la structure des communautés nématologiques. En effet, nous avons pu caractériser des espèces indicatrices de pollution par les HAPs. Ainsi, l'espèce Spirinia parasitifera dont la densité s'accroît dans tous les microcosmes contaminés par les HAPs paraît être une espèce “opportuniste” à la pollution par les HAPs. Cependant, Oncholaimus campylocercoïdes, fortement dominante dans tous les microcosmes témoins, a diminué de densité dans tous les microcosmes contaminés et a été considérée comme HAP-sensible. En analysant la structure des communautés microbiennes et méiofaunistiques, nous avons observé que la méiofaune joue un rôle structurant dans le maintien d'une communauté microbienne peu sensible aux effets des HAPs. Ce rôle structurant a été moins prononcé dans le cas d'ajout des sels nutritifs par la technique de biostimulation ; technique qui a présenté des effets non significatifs vis-à-vis des communautés nématologiques et a semblé plus efficace dans la minéralisation des HAPs et par conséquent à la réduction de leur effet toxique sur les organismes benthiques. Ces résultats suggèrent que la bioremédiation serait une alternative prometteuse à la dégradation des HAPs. / Polycyclic aromatic hydrocarbons (PAHs) are persistent organic pollutants (POP) emitted mainly by human activities due to the incomplete combustion of organic matter (industry, heating, traffic ...). Because of their low rate of degradation, their toxicity and their bioaccumulation, PAHs are main of concern in ecological studies. In this context, the objectives of this thesis were to assess the impact of PAHs on the benthic microflora and meiofauna and apply different techniques of bioremediation (biostimulation, bioaugmentation and combination of both treatments) in order to degrade PAHs, using experimental approach with microcosms.Our results showed that PAHs are toxic for microflora but also for meiofauna of Bizerta lagoon. The toxic effects of these contaminants were demonstrated by the inhibition of bacterial activity in the sediment/water interface and by profound changes in the structure of bacterial communities. PAHs provoked significant changes on meiofaunal community with the selection of nematode species that could be proposed as bioindicators of PAH pollution. Thus, Spirinia parasitifera which significantly (p<0.05) increased in PAH contaminated microcosms, suggesting that it is an "opportunistic» species to PAH pollution. In contrast, Oncholaimus campylocercoïdes, strongly dominant in control microcosms, decreased in PAH contaminated microcosms and seemed to be a ‘‘PAH-sensitive'' species.By analyzing the structure of microbial and meiofaunal community, we observed that the structural role of meiofauna on bacteria community structure was still evident even under PAH contamination despite the toxic effects on meiofauna. However, this structural role of meiofauna disappeared when nutrients were added to the sediment resulting in an almost complete removal of PAHs. Biostimulation seemed to be the most effective bioremediation strategy in the reduction of PAH toxic effects on benthic organisms. Overall, these results suggest that bioremediation using nutrient addition is a promising alternative technique for the degradation of PAHs in coastal polluted environments.

A poluição marinha por petróleo e seus derivados é uma preocupação crescente de caráter global. O litoral norte do estado de São Paulo é hoje caracterizado como a região mais altamente impactada por esses contaminantes de toda a costa Sul e Sudeste do país. Dentre as substâncias que compõem esses produtos estão os Hidrocarbonetos Aromáticos Policíclicos (HPAs), como o fenantreno, que apresentam potencial de alterar o sistema endócrino de peixes, gerando desajustes hormonais de alto risco para o processo reprodutivo dos animais expostos. Com base nestes fatos, o presente trabalho buscou verificar efeitos do fenantreno como desregulador endócrino em juvenis de E. marginatus. Essa espécie se caracteriza pelo hermafroditismo protogínico, de modo que os juvenis costumam apresentar altas concentrações de esteroides gonadais, o que gera preocupação quanto os efeitos reprodutivos decorrentes de alterações no padrão de produção de esteroides, especialmente em uma espécie que já vem sofrendo declínios populacionais por conta da sobrepesca. A CL50 encontrada para juvenis de E. marginatus foi 1,51 mg&frasl;L. Em seguida, foi realizado um bioensaio subletal (96h) com quatro grupos experimentais (n=5) em duplicata: grupo controle; duas concentrações distintas de fenantreno (0,1 mg&frasl;L e 1 mg&frasl;L) e grupo exposto ao veículo de diluição (0,004% de etanol). Foram dosadas as concentrações de 17&beta;-estradiol (E2), testosterona (T) e 11-cetotestosterona (11-KT) plasmáticos por ELISA. Gônadas, fígado e baço foram processados para análise histológica. Foi conduzido bioensaio in vitro com incubação de fragmentos gonadais sob ação de fenantreno (50&mu;M) ou etanol. Os níveis dos mesmos esteroides também foram dosados por ELISA. A exposição in vivo ao fenantreno resultou em aumento na área dos hepatócitos, bem como no número de centro melanomacrofágicos e hemossiderose no baço. O etanol induziu efeitos similares no baço. Os níveis de E2 e T não se alteraram no plasma ou no meio de incubação in vitro. O fenantreno reduziu a concentração de 11-KT in vitro e in vivo. No plasma, o etanol também causou esse decréscimo. Considerando a importância do 11-KT no desenvolvimento dos ovários em teleósteos, o fenantreno parece causar desregulação da esteroidogênese em juvenis de E. marginatus, possivelmente gerando disfunções durante a inversão sexual / Marine pollution by crude oil and its residual products is a growing global concern. The Northern coast of São Paulo is characterized as the highly impacted area by these contaminants through Brazil\'s South and Southeast coast. Polycyclic aromatic hydrocarbons (PAH), such as phenanthrene, are the main crude oil components and have a significant toxic potential to biota, acting as endocrine disruptors (ED) and negatively impacting reproduction. This study aimed to investigate the effects of phenanthrene as ED on gonadal steroidogenesis in E. marginatus juveniles. As a hermaphrodite protogynous species, E. marginatus juveniles maintain high levels of plasma steroids as substrates for sex inversion, which causes concern about reproductive effects of disruptions in steroid production patterns, especially in an overfished species. LD50 to E. marginatus exposed to phenanthrene was established in 1.51 mg&frasl;L. An in vivo sublethal exposure (96 h) to phenanthrene was carried out at two concentrations (0.1mg&frasl;L and 1 mg&frasl;L); exposure to the vehicle (ethanol) was also performed. Plasma levels of 17&beta;-estradiol (E2), testosterone (T) and 11-ketotestosterone (11-KT) were measured by ELISA. Gonads, liver and spleen were processed for histological analysis. In an in vitro bioassay, gonad fragments were incubated with phenanthrene (50&mu;M) or ethanol. Steroid levels in the culture media were also measured by ELISA. The in vivo exposure to phenanthrene triggered an increase of the area of the hepatocytes, increased number of melanomacrophagic centers and hemosiderosis in the spleen. Ethanol also induced similar effects on spleen. E2 and T levels did not change neither in plasma nor in vitro media. Phenanthrene sharply reduced 11-KT levels in vitro and in vivo. In plasma, ethanol also decreased 11-KT levels. Considering the importance of 11-KT in fish developing ovaries, phenanthrene seems to disrupt steroidogenesis in juvenile grouper, possibly being able to cause dysfunctions during sex change

The overall objective of the research presented in this dissertation was to investigate molecular risk factors of susceptibility to estrogenic chemicals, polychlorinated biphenyls (PCBs), hormone replacement therapy, and oral contraceptives and how that leads to the development of pulmonary arterial hypertension (PAH). Environmental and molecular risk factors for PAH are not clearly understood. This is a major hurdle for the development of new therapy against PAH as well as understanding individual susceptibility to this disease. Gender has been shown to impact the prevalence of PAH. Although controversial, estrogens have been implicated to be a risk factor for PAH. Thus, we hypothesize that women exposed to estrogenic chemicals are at increased risk of developing PAH when endocrine disrupting chemicals interact with unopposed estrogen to worsen pulmonary arterial disease. In support of this hypothesis, we have accomplished the following: Microarray data on PAH were collected and subsequent meta-analysis was conducted using genome-wide association and environment-wide association approaches on published studies as well as GEO and NHANES data. All PCB geometric mean concentrations found higher levels in people at risk of PAH than people not at risk of PAH. The sum of non-dioxin-like PCBs and the sum of dioxin-like PCBs were significantly higher in people at risk of PAH than people not at risk of PAH. Also, different levels of LOD (including PCBs concentration >LOD, > 50th percentile, 50th-75th percentile, and ≥75th percentile) were significantly higher in people at risk of PAH than people not at risk of PAH. We reported that females used estrogen pills and oral contraceptive were associated with risk of PAH. However, females used progestin and estrogen/progestin pills were not at risk of PAH. Molecular risk factor analysis using machine learning approaches revealed that VAMP2, LAMA5, POLR2C, VEGFB, and PRKCH genes are causal genes of PAH pathogenesis. Gene ontology and pathway analysis of PAH showed that genes involved in the apoptosis pathway, p53 pathway, Ras Pathway, T-cell activation, TGF-beta pathway, VEGF pathway, and Wnt pathway appear to be significantly associated with PAH. Documenting the exposure to estrogenic chemicals among the general U.S. population, and identifying agents and molecular risk factors associated with PAH have the potential to fill research gaps and facilitate our understanding of the complex role environmental chemicals play in producing toxicity in the lungs.

The Deepwater Horizon blowout occurred on April 20th, 2010, releasing 4.9 million barrels of Louisiana crude oil into the Gulf of Mexico (GoM). Subsequent to the Deepwater Horizon blowout, sediment cores revealed oil on the northern GoM seafloor and abnormal skin lesions were seen in GoM fishes. Exposure to polycyclic aromatic hydrocarbons (PAHs), a component of crude oil, in fish has been associated with many sublethal effects, including cancer and population-level effects. Using a biomarker of exposure to PAHs, this thesis evaluates inter-species, temporal and spatial differences in exposure to hydrocarbon contamination between three species of fish with varying levels of association with the sediment, that were potentially exposed to Deepwater Horizon crude oil: golden tilefish (Lopholatilus chamaeleonticeps), king snake eel (Ophichthus rex) and red snapper (Lutjanus campechanus), and examines patterns in these data using life history, behavior and environmental data. In 2011, 2012 and 2013, bile samples and biometric data were collected from fish via demersal longlining and bile was analyzed for three PAHs, naphthalene, phenanthrene and benzo[a]pyrene and their metabolites, using high performance liquid chromatography with fluorescence detection (HPLC-F). Bile of golden tilefish had significantly higher concentrations of naphthalene and phenanthrene metabolites, compared to red snapper and king snake eel. For biliary naphthalene metabolites, golden tilefish had an average concentration of 240 ug g-1, compared to 61 ug g-1 for red snapper and 38 ug g-1 for king snake eel, for the year 2012. Biliary naphthalene metabolite concentration has decreased 8% in golden tilefish samples, between 2012 and 2013, indicating continuous exposure to petrogenic pollution, while naphthalene metabolites decreased 49% over time for red snapper and 37% for king snake eel, indicating episodic exposure to elevated petrogenic pollution prior to 2011. The concentration of naphthalene metabolites measured in golden tilefish in this study are some of the highest concentrations measured in the GoM and internationally, while naphthalene metabolite concentrations for red snapper and king snake eel are similar to 1990's GoM data. In contrast, concentrations of benzo[a]pyrene metabolites were statistically similar for all three species, suggesting a difference in the disposition of or exposure to benzo[a]pyrene contamination. Concentrations of benzo[a]pyrene metabolites are relatively low when compared to other GoM and international data, for all three species. This study has identified a species of GoM fish, golden tilefish, that is exposed to a present-day source of petrogenic PAH pollution and certain fish species that were episodically exposed, in the years following the Deepwater Horizon blowout. With residual Deepwater Horizon oil still found in GoM sediments, coastal marshes and beaches, there is a need to identify these chronic exposures to persistent PAH pollution, monitor PAH concentrations in over time and evaluate the resulting sublethal effects to better understand the impacts of the Deepwater Horizon blowout on marine resources such as GoM fisheries.

De l'IR au submillimétrique, le spectre du milieu interstellaire (MIS) est dominé par l'émission des grains de poussière interstellaires. Les plus petits d'entre eux, les PAHs, sont en fait de grosses molécules aromatiques polycycliques hydrogénées. Leur présence est attestée par l'observation d'une série de bandes vibrationnelles dans l'IR moyen, caractéristiques de modes de vibration C-C et C-H sur des cycles aromatiques. Etant donnée l'importance des PAHs pour la physique et la chimie du MIS (chauffage du gaz, formation de H2), il est essentiel de trouver d'autres observables pour contraindre leurs propriétés. L'émission micro-onde des grains interstellaires qui sera observée prochainement avec le satellite Planck est de ce point de vue une opportunité. En effet, les efforts faits récemment dans le but de mesurer les fluctuations du fonds diffus cosmologique ont motivé une étude détaillée des émissions Galactiques dans le domaine micro-onde. Un excès d'émission inattendu a été découvert entre 10 et 90 GHz et ne peut être expliqué par aucun des mécanismes d'émission déjà connu dans ce domaine de fréquences. Cet excès, baptisé « émission anormale », s'est révélé être corrélé à l'émission IR des grains interstellaires. L'origine de l'émission anormale pourrait être l'émission dipolaire électrique de PAHs en rotation.<br /> L'objectif central de ma thèse est la compréhension de l'émission des PAHs interstellaires à grande longueur d'onde en vue de mieux contraindre leurs propriétés et de préparer l'analyse des données Planck-Herschel. Mon travail de thèse a consisté en deux parties complémentaires : modélisation de l'émission des PAHs interstellaires de l'IR proche au centimètre, puis confrontation de ce modèle aux observations disponibles dans le but d'obtenir un modèle physique.<br /> La première partie de mon travail de modélisation concerne l'émission rovibrationnelle des PAHs. J'ai adopté une section efficace déduite des observations ISO et Spitzer pour λ ≤ 20 µm. A plus grande longueur d'onde, trois modes vibrationnels ont été ajouté à partir des travaux théoriques de Malloci et al. (2007). Ce modèle permet de reproduire le spectre du milieu diffus et d'une région de photodissociation avec un mélange de PAHs neutres et ionisés. J'ai par ailleurs montré que si l'émission rovibrationnelle des PAHs dans l'IR moyen est proportionnelle à l'intensité du champ de rayonnement, ce n'est plus le cas pour λ ≥ 3 mm. La seconde partie a consisté en la modélisation de l'émission purement rotationnelle des PAHs. J'ai utilisé des propriétés moléculaires réalistes et traité les interactions avec les atomes et les ions du gaz interstellaire. L'excitation et le freinage par émission de photons rotationnels et rovibrationnels ont également été inclus. L'émission rotationnelle en bande large a été estimée pour une large gamme de conditions astrophysiques et de propriétés des grains. J'ai par ailleurs mis en évidence l'indépendance du spectre d'émission rotationnelle par rapport à l'intensité du champ de rayonnement G0 et à la densité du milieu dans lequel les grains se trouvent nH (G0 ≤ 100 et nH ≤ 30 cm-3).<br /> J'ai ensuite confronté les résultats de cette modélisation aux observations disponibles. La première étape a été l'extraction de l'émission anormale des données WMAP, à laquelle j'ai participé. Nous avons pu mettre en évidence l'existence d'une composante anormale forte, non polarisée, à 23 GHz. Elle a été incluse dans le Planck Sky Model. Pour la première fois, nous avons pu montrer que l'émission anormale est bien corrélée avec l'émission des poussières et que cette corrélation est meilleure à 12 µm (caractéristique des PAHs) qu'à 100 µm (caractéristique de grains plus gros). J'ai également montré l'indépendance de l'émission anormale par rapport à l'intensité du champ de rayonnement, une des prédictions du modèle. Les caractéristiques des grains déduites de l'émission anormale sont par ailleurs en accord avec celles déduites de l'émission IR. J'ai également étudié la région moléculaire G159.6-18.5 dans Persée et montré que son spectre d'émission anormale est bien ajusté avec une distribution de tailles bimodale, en accord avec les travaux théoriques de Le Page et al. (2003).