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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
241

Développement et sélection de métabolites urinaires des Hydrocarbures Aromatiques Polycycliques en tant que biomarqueur d’exposition des populations / Development and selection of Polycyclic Aromatic Hydrocarbons urinary metabolites as exposure biomarkers for human biomonitoring

Lutier, Simon 16 January 2017 (has links)
Les hydrocarbures aromatiques polycycliques (HAP) sont des polluants ubiquitaires cancérogènes émis dans l’atmosphère sous forme gazeuse ou particulaire et constituent des mélanges complexes issues de sources multiples. Les biomarqueurs d’exposition urinaires sont le plus couramment utilisés pour effectuer la surveillance biologique de l’exposition (SBE) aux HAP, notamment le 1-hydroxypyrène (1-OHP). Sa seule utilisation pour estimer l’exposition aux mélanges de HAP est aujourd’hui controversée. Le 3-hydroxybenzo(a)pyrène (3-OHBaP) est récemment utilisé car il est issu du benzo(a)pyrène (BaP), le seul HAP classé cancérogène certain pour l’homme. Les métabolites monohydroxylés des HAP gazeux les plus abondants sont utilisés pour la SBE. Ce travail a pour objectif de développer et sélectionner un ensemble de biomarqueurs permettant une SBE pertinente et efficace de l’exposition aux HAP tant au niveau professionnel qu’environnemental. Dans un premier temps, les biomarqueurs d’exposition aux HAP cancérogènes (essentiellement contenus dans la phase particulaire) qui sont le 1-OHP et le 3-OHBaP ont été étudiés. La variabilité des mélanges atmosphérique émis, notamment l’abondance relative de la phase gazeuse par rapport à la phase particulaire font que le 1-OHP n’est pas spécifique de l’exposition aux HAP cancérogènes qui sont contenu dans la phase particulaire. En effet, les concentrations urinaires de 1-OHP dépendent des niveaux atmosphériques de pyrène, un HAP non cancérogène émis sous forme gazeuse et particulaire. L’étude de la cinétique d’élimination urinaire du 3-OHBaP a permis de confirmer que le prélèvement d’urine dans le cadre de la SBE en milieu professionnel soit réalisé en fin de poste plus 16h de par la cinétique d’élimination urinaire atypique. Ainsi, il est recommandé de l’effectué en début de poste du dernier jour travaillé. L’étude des modes de correction de la diurèse a confirmé la nécessité de prendre en compte le degré de dilution des urines pour le 1-OHP et le 3-OHBaP et que la correction par la créatinine urinaire est un moyen adapté. La faible abondance urinaire du 3-OHBaP ne permet pas d’effectuer de la SBE dans des milieux professionnels avec de faibles niveaux d’expositions. Dans un deuxième temps, nous avons sélectionné des biomarqueurs pour les faibles expositions professionnelles parmi les différents métabolites monohydroxylés des HAP gazeux. Parmi les métabolites comparés, le 2-hydroxyfluorène et le 2-hydroxyphenanthrène sont ceux qui reflètent au mieux l’exposition professionnelle mais ne sont pas spécifiques de l’exposition aux HAP cancérogènes contenus dans la phase particulaire. Enfin, nous avons développé une méthode de dosage urinaire du (±)trans-anti-BaP-tétraol (Tetraol-BaP) applicable en routine avec un limite de quantification de 0,02 ng/L. Le Tetraol-BaP urinaire est au moins aussi abondant que le 3-OHBaP. Les premières analyses indiquent que le Tetraol-BaP pourrait être un biomarqueur d’exposition intéressant pour estimer le risque cancérogène. En effet, il est plus proche de l’effet toxique que le 3-OHBaP car il est issu des voies de métabolisation toxique du BaP. Ce travail de thèse souligne que l’évaluation de l’exposition aux mélanges de HAP à partir d’un seul métabolite est difficilement interprétable à cause de la variabilité des mélanges émis et propose différents biomarqueurs qui permettraient de caractériser l’exposition à l’échelle du mélange de HAP. / Polycyclic Aromatic Hydrocarbons (PAHs) are ubiquitous carcinogenic pollutants emitted into the atmosphere in complex mixtures constituted of gaseous PAHs and particulate PAHs. Urinary exposure biomarkers are most commonly used in order to perform human biomonitoring (HB) to PAHs, especially the 1-hydroxypyrene (1-OHP) that is considered as the golden standard. However, its use to characterized mixture exposure is controversial. The 3-hydroxybenzo(a)pyrene (3-OHBaP) is recently used because it is a metabolite of the benzo(a)pyrene (BaP), the only PAH classified as carcinogenic to humans. Monohydroxylated metabolites of the most abundant gaseous PAHs are also used to perform HB. The aim of this thesis was to develop and select a set of exposure biomarkers that enables a relevant and effective HB for both environmental and occupational exposures. Firstly, the 1-OHP and the 3-OHBaP which are used as exposure biomarkers of carcinogenic PAHs (mainly contained in the particulate phase) were studied. The variability of the emitted atmospheric mixtures, especially the relative abundance between the gaseous and the particulate phases complicates the use of the 1-OHP to assess specific carcinogenic PAH exposure. Indeed, 1-OHP urinary concentrations depend on atmospheric pyrene concentrations (a non-carcinogenic PAH) which is present in both phases. The study of urinary elimination kinetic of the 3-OHBaP revealed atypical elimination kinetics (as in rats) and confirmed that sampling time should be done 16 hours after the end of the shift. Thus, sampling is recommended at pre-shift of the last day worked. The study of diuresis adjustment confirmed the need to take into account the urine’s degree of dilution and that urinary creatinine adjustment is suitable to correct concentrations of the 1-OHP and the 3-OHBaP. HB in occupational sectors with low exposure can’t be performed with 3-OHBaP due to its low urinary abundance. Secondly, monohydroxylated metabolites of gaseous PAHs were compared to select relevant biomarkers for low occupational exposure. Among the compared metabolites, the 2-hydroxyfluorene and the 2-hydroxyphenanthrene were proposed because they are those that best reflect occupational exposure. However, these two metabolites were not specific of carcinogenic PAH exposure in the particulate phase. Finally, an analytical method of the (±)trans-anti-BaP-tetraol (Tetraol-BaP) was developed for routine application (the limit of quantification was 0,02ng/L). The first urinary analysis indicated that the Tetraol-BaP is at least as abundant as the 3-OHBaP and that it could be a relevant biomarker to assess carcinogenic risk. Indeed, the Tetraol-BaP is a product of toxic metabolism pathways of the BaP, which allows it to be closer to the toxic effect than the 3-OHBaP. This thesis highlights the difficulty to use a single biomarker to assess PAH mixture exposure due to their important variability and suggests different biomarkers that would characterize mixture PAH exposure.
242

TOXICITY OF SEDIMENTS CONTAINING COAL-TAR PAVEMENT SEALANTS TO NOTOPHTHALMUS VIRIDESCENS AND AMBYSTOMA MACULATUM, SURROGATE SPECIES FOR EURYCEA SOSORUM

Bommarito, Thomas 01 January 2009 (has links)
The Barton Springs salamander (Eurycea sosorum) is a federally endangered species that is endemic to Barton Springs in Austin, Texas. Development within the Barton Springs watershed threatens the continued existence of E. sosorum. A factor that may be contributing to its decline is contamination from polycyclic aromatic hydrocarbons (PAHs). Nearby asphalt parking lots paved with coal-tar and asphalt sealants can be sources of PAHs. Unaltered parent compounds of PAHs can have toxic effects, but oxidation and ultraviolet radiation can create degradation products 100 times more toxic than the parent compounds. The objective of this project was to determine if PAHs are potentially harmful to E. sosorum using two surrogate species. Adult eastern newts (Notophthalmus viridescens) and larval spotted salamanders (Ambystoma maculatum) were exposed to sediments with nominal concentrations of total PAHs that ranged from 0 to 1500 mg/kg under UV (290 - 400 nm) and visible (400 - 700 nm) light to determine concentration/response relationships. No statistically significant mortality occurred under any treatment. Exposure to both coal-tar sealant and UV light resulted in sublethal effects such as decreased righting ability and swimming speed. Difficulty in performing such movements would make it difficult to catch prey and increase susceptibility to predation. Exposure to UV light also resulted in elevated numbers of micronucleated erythrocytes and white blood cells. This study shows that simultaneous exposure to PAHs and UV light result in sublethal effects that could make the population of E. sosorum vulnerable to further decline.
243

Influência da fuligem da queima de palha de cana-de-açucar na presença de HPA em hortaliças de consumo humano

Sugauara, Lucy Elaine [UNESP] 17 January 2014 (has links) (PDF)
Made available in DSpace on 2014-12-02T11:16:38Z (GMT). No. of bitstreams: 0 Previous issue date: 2014-01-17Bitstream added on 2014-12-02T11:21:05Z : No. of bitstreams: 1 000748808_20160131.pdf: 1145880 bytes, checksum: 9fb3124f890c373c2a716642bfa96e7a (MD5) Bitstreams deleted on 2016-02-01T10:15:55Z: 000748808_20160131.pdf,. Added 1 bitstream(s) on 2016-02-01T10:16:45Z : No. of bitstreams: 1 000748808.pdf: 4286658 bytes, checksum: 8f952ac5669d4bfdeb244e9023369477 (MD5) / Os HPA são contaminantes orgânicos formados tanto na queima da palha de cana-de-açúcar quanto de combustível fóssil e por suas características físicoquímicas estão associados ao material particulado fino, podendo assim ser transportado a longas distâncias em um curto espaço de tempo dependendo das condições climáticas. Pelas características de mutagenicidade, carcinogecidade e alteração endócrina são substâncias que tem merecido interesse dos pesquisadores na avaliação da exposição humana por diversas vias, sendo a via alimentar a menos explorada atualmente. Este trabalho teve por objetivo otimizar e validar um método para determinação de HPA em hortaliças e avaliar a presença destas substancias em alface, couve e rúcula , em localidades com e sem a influência da queima de cana-de-açúcar (Araraquara e Itu). O método otimizado e validado neste trabalho envolve extração por banho de ultrassom e detecção por HPLC/FLU, possui valores aceitáveis de LD e LQ de acordo com a União Européia, 0,3 e 0,9 µg kg-1 respectivamente e valores de CV (<11,6%) e recuperação (70~119%), de acordo com os valores preconizados pela ANVISA. Amostras de alface, rúcula e couve cultivados em duas cidades em três diferentes locais, Araraquara (zona rural e zona urbana) e Itu (zona urbana) no período correspondente a safra (agosto de 2012) e entressafra (março 2013) da cana-de-açúcar foram analisadas. As concentrações de HPA encontradas nestas hortaliças situaram-se abaixo dos níveis reportados na literatura em folhas de diferentes espécies vegetais. No entanto, quando considerada a ingestão de 200g/dia, metade do preconizado pela OMS (Organização Mundial de Saúde) para ingestão diária recomendada de legumes, frutas e verduras, infere-se que a quantidade de HPA ingerida por esta via corresponderia a uma dieta de alta exposição MOE (Margin of Exposure) <10 000 próximos aos limites considerados preocupantes pela União Européia. / The PAH are a class of organic contaminants which are formed in burning of sugarcane and fossil fuel. The physicochemical properties are associated with their affinity for fine particulate matter and can therefore be transported over long distances in a short time depending on the weather. The PAH have characteristics of mutagenicity, carcinogenicity and endocrine disruption, because of these characteristics they are substances that have earned interest of researchers in the evaluation of human exposure via differents routes of uptake, and currently the dietary is the less explored. This study aimed to optimize and validate a method for the determination of PAH in vegetables and evaluate the presence of these substances in lettuce , kale and arugula, in locations with and without the influence of sugarcane burning (Araraquara and Itu). The optimized and validated method in this work involves extraction by ultrasound bath and detection by HPLC/FLU, also has acceptable values of LOD and LOQ in accordance with the European Union , 0.3 and 0.9 μg kg- 1 respectively , and the CV (<11.6%) and recovery values (70 ~ 119 %), are also in accordance to the values recommended by ANVISA . Samples of lettuce , arugula and kale grown in two different cities on three sites , Araraquara (rural and urban areas) and Itu (urban area) corresponding to the harvest period (August 2012) and sugarcane off season (March 2013) were analyzed. Concentrations of PAH found in these vegetables were below the levels reported in the literature in leaves of different plant species . However, when considering the intake of 200g/day, half the daily intake of fruits and vegetables recommended by WHO (World Health Organization ) it is inferred that the amount of PAH ingested in this way corresponds to a High exposure diet with MOE ( Margin of exposure) < 10 000 near the limits considered worrisome by the European Union.
244

Determinação de compostos orgânicos em material particulado emitido em queimadas de cana de açúcar

MAGALHAES, DULCE 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:51:07Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:00:15Z (GMT). No. of bitstreams: 1 11246.pdf: 3725307 bytes, checksum: a030a8c41a665ad1a01941e5275544f5 (MD5) / Dissertacao (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
245

Estudo preliminar do comportamento de hidrocarbonetos policiclicos aromaticos (HPAs) em solo por isotermas de sorcao

D'AGOSTINHO, ADRIANA 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:49:43Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:01:21Z (GMT). No. of bitstreams: 1 09991.pdf: 5492615 bytes, checksum: ba479cf83ce76514f63501df3fa92374 (MD5) / Dissertacao (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
246

A variação sazonal na concentração de hidrocarbonetos policíclicos aromáticos e material particulado MPsub(10) na atmosfera de São Paulo

SOUZA, DAVI Z. de 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:51:58Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:07:31Z (GMT). No. of bitstreams: 0 / Dissertação (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP
247

Estudo de hidrocarbonetos policíclicos aromáticos nos estuários de Santos e São Vicente - SP utilizando diatomito como material absorvente / Polycyclyc aromatic hydrocarbons study at São Vicente and Santos Estuaries SP using diatomite as adsorbent material

POLAKIEWICZ, LILIAN 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:54:47Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:07:30Z (GMT). No. of bitstreams: 0 / Dissertação (Mestrado) / IPEN/D / Instituto de Pesquisas Energéticas e Nucleares - IPEN/CNEN-SP
248

Estudo do efeito do processamento na contaminação de cana-de-açucar e derivados por hidrocarbonetos policiclicos aromaticos / Study of the process effect on the contamination of sugar cane and its products by polycyclic aromatic hydrocarbons

Tfouni, Silvia Amelia Verdiani 12 February 2005 (has links)
Orientador: Maria Cecilia de Figueiredo Toledo / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-05T13:48:10Z (GMT). No. of bitstreams: 1 Tfouni_SilviaAmeliaVerdiani_D.pdf: 392240 bytes, checksum: 6b63e5c3f72ce75847b3087c1e16bbe8 (MD5) Previous issue date: 2005 / Doutorado / Ciência de Alimentos / Doutor em Ciência de Alimentos
249

Determinação de benzo(a) pireno em pescados comercializados em Campinas-SP / Determination of benzo (a) pyrene in fish sold in Campinas, Sao Paulo

Azeredo, Antonio 27 July 2018 (has links)
Orientador : Maria Cecilia de Figueiredo Toledo / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-07-27T22:01:59Z (GMT). No. of bitstreams: 1 Azeredo_Antonio_M.pdf: 1864873 bytes, checksum: 56f9b654732a9202de6eae08d42b64af (MD5) Previous issue date: 2001 / Resumo: Hidrocarbonetos policíclicos aromáticos (HPAs), entre os quais o benzo(a)pireno (B[a]P) é um doa mais estudados, são contaminates formados pela pirólise incompleta da matéria orgânica tecnológicos. Estes compostos estão presentes no meio ambiente e nos alimentos e caracterizam-se por apresentarem elevada toxicidade / Abstract: Polycyclic aromatic hydrocarbons (PAHs), including benzo (a) pyrene (B [a] P) is a donates most studied, are incomplete Contaminat formed by pyrolysis of organic material technology. These compounds are present in the environment and in foods and are characterized by high toxicity present / Mestrado / Mestre em Ciência de Alimentos
250

Desenvolvimento e validacao de metodologia analitica para determinacao de hidrocarbonetos policiclicos aromaticos (HPAS) em sedimentos. Avaliacao da represa do Parque Pedroso, Santo Andre, SP / Development and validation of analytical methodology for determination of polycyclic aromatic hydrocarbons (PAHS) in sediments. Assessment of Pedroso Park dam, Santo Andre, SP

BRITO, CARLOS F. de 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:27:05Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T13:56:15Z (GMT). No. of bitstreams: 0 / Os hidrocarbonetos policíclicos aromáticos (HPAs) por serem considerados contaminantes persistentes, pela sua ubiqüidade no meio ambiente e pelo reconhecimento de sua genotoxicidade, têm estimulado atividades de pesquisa com o objetivo de determinar e avaliar as origens, transporte, transformação, efeitos biológicos e a acumulação em compartimentos de ecossistemas aquático e terrestre. Nesta dissertação, a matriz estudada foi o sedimento coletado na represa do Parque Pedroso em Santo André, SP. A técnica analítica empregada foi a cromatografia líquida em fase reversa com detector UV/Vis. O tratamento dos dados foi estabelecido durante o processo de desenvolvimento da metodologia para que houvesse confiabilidade nos resultados. As etapas envolvidas foram avaliadas usando o conceito da Validação de Ensaios Químicos. Os parâmetros selecionados para a validação analítica foram Seletividade, Linearidade, Intervalo de Trabalho, Sensibilidade, Exatidão, Precisão, Limite de Detecção, Limite de Quantificação e Robustez. Esses parâmetros apresentaram resultados satisfatórios, o que permite a aplicação da metodologia desenvolvida, sendo ainda um método simples que permite a minimização da contaminação e da perda de compostos por excesso de manipulação. Para os HPAs estudados não foram encontrados resultados positivos, acima do limite de detecção, em nenhuma das amostras coletadas na primeira fase. Já na segunda coleta foram encontradas pequenas alterações principalmente em acenaftileno, fluoreno e benzo[a]antraceno. Embora a área se encontre preservada, já se notam pequenos sinais de contaminação. / Dissertacao (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP

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