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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.
71

Detecção dos interferentes endócrinos estradiol e estriol em amostras ambientais e clínicas empregando eletrodos modificados com grafeno, nanopartículas metálicas e quantum dots / Detection of endocrine disruptors stradiol and estriol in environmental and clinical samples using modified electrodes with graphene, metal nanoparticles and quantum dots

Cincotto, Fernando Henrique 10 November 2016 (has links)
Para o desenvolvimento dos sensores aqui descritos foram utilizados materiais inovadores considerando relatos atuais da literatura, materiais estes: óxido de grafeno, óxido de grafeno reduzido, nanocompósitos de grafeno e nanopartículas (ródio, antimônio e sílica mesoporosa desordenada), materiais híbridos a base de grafeno e quantum dots de CdTe, além de biossensores incorporando a enzima lacase. Estes materiais foram sintetizados utilizando metodologias específicas e caracterizados por diversas técnicas analíticas como microscopia eletrônica de transmissão de alta resolução, microscopia de força atômica, espectroscopia Raman, difração de raios-X, espectroscopias de UV-Vis e fotoluminescência, e técnicas eletroquímicas. Posteriormente, os materiais foram utilizados para modificação em eletrodos de carbono vítreo e utilizados na determinação de interferentes endócrinos (os hormônios estriol e 17β-estradiol) como sensores eletroquímicos em amostras ambientais e clínicas. Em essência, os eletrodos desenvolvidos apresentaram importantes vantagens, tais como alta sensibilidade, boa reprodutibilidade, simples instrumentação, fácil preparação e procedimentos analíticos rápidos, apresentando baixos limites de detecção, na ordem de picomolar e nanomolar, com baixa taxa de interferência de outras espécies na mesma matriz da amostra. Concluindo assim que as técnicas eletroquímicas podem ser facilmente aplicadas na determinação de interferentes endócrinos em amostras reais. / For the development of the sensors described here innovators materials were used considering current literature reports, these materials: Graphene oxide, reduced graphene oxide, nanocomposites graphene and nanoparticles (rhodium and antimony), hybrid materials of graphene and CdTe quantum dots, and biosensors incorporating the laccase enzyme. These materials were synthesized using specific methodologies and characterized by several analytical techniques such as transmission electron microscopy, high resolution transmission electron microscopy, atomic force microscopy, Raman spectroscopy, X-ray diffraction, UV-Vis and photoluminescence spectroscopy and electrochemical techniques. Subsequently, the materials were used for modification of glassy carbon electrodes to the determination of endocrine disruptors (estriol and 17β-estradiol hormone) as electrochemical sensors for environmental and clinical samples. In essence, developed electrodes showed important advantages such as high sensitivity, good reproducibility, simple instrumentation, easy preparation and quick analytical procedures, with low detection limits in the range of picomolar and nanomolar, low interference rate of other species in same matrix sample. Finally, electrochemical techniques can be easily applied in the determination of endocrine disruptors in real samples.
72

Avaliação da atividade estrogênica em esgotos sanitários e águas de reúso na região metropolitana de São Paulo / Evaluation of estrogenic activity on sanitary wastewater and reclaimed reclaimed water of São Paulo metropolitan region

Lopes, Vania Rodrigues 03 December 2015 (has links)
Os esgotos sanitários concentram compostos que são interferentes endócrinos. Os tratamentos de esgotos convencionais por sistema de lodos ativados podem não remover totalmente estes compostos, os quais atingem os ecossistemas aquáticos e oferecem riscos ecológicos e à saúde humana. Neste trabalho, mediu-se a atividade estrogênica de compostos presentes em esgotos brutos, tratados e águas de reúso de duas estações de tratamento de esgotos (ETE) da região metropolitana de São Paulo, que operam por sistema de tratamento por lodos ativados e produzem águas de reúso para fins não potáveis por tratamento físico-químico. Nesse procedimento, as amostras foram preparadas por extração de fase sólida e utilizou-se o bioensaio BLYES (Bioluminescence Yeast Estrogen Screen) para a quantificação de efeito de atividade estrogênica em nanogramas de 17-estradiol equivalente (ng-EEQ/L). A estrogenicidade da amostra foi calculada por meio da EC50 (concentração efetiva em 50%), para isto foram utilizadas diluições seriadas para curva padrão com 17-estradiol e para cada amostra analisada. A toxicidade nos ensaios foi medida e monitorada pela levedura controle BLYR. A atividade estrogênica no esgoto bruto variou de 14,7 a 52,6 ng-EEQ/L Os resultados em esgotos tratados por sistema de lodos ativados variaram de abaixo o limite de quantificação do bioensaio de < 0,10 ng-EEQ/L a 11ng-EEQ/L, indicando eficiência de remoção entre 50% a 100%. As águas de reúso foram produzidas por filtração e cloração e na maioria dos resultados apresentaram atividade estrogênica de <0,10 ng-EEQ/L. Os resultados obtidos neste estudo foram comparáveis aos encontrados na literatura medidos pelo bioensaio YES. Os resultados demonstraram que o bioensaio BLYES foi viável para quantificar a estrogenicidade em todas as amostras testadas. As evidências acerca da atividade estrogênica das águas estudadas podem subsidiar ações integradas na gestão da qualidade das águas, o aprimoramento de condições operacionais e tecnológicas das ETEs / The wastewater concentrates compounds with endocrine disruptors. The conventional wastewater treatment by activated sludge are not able to completely remove these compounds, whose achieve aquatic ecosystems and offer ecologic risks and to human health. In this study we measured estrogenic activity on raw and treated wastewater and reclaimed water from two wastewater treatment plants (WWTPs) in the metropolitan region of São Paulo. These WWTPs treat wastewater by activated sludge process and produce reclaimed water for non potable purposes by physical chemical processes. By this procedure, the samples were collected on both WWTPs before and after described treatments and they were prepared by solid phase extraction (SPE). The samples after SPE were analyzed by the BLYES (Bioluminescence Yeast Estrogen Screen) bioassay for quantifying estrogenic activity measured by nanograms 17-estradiol equivalent per litre (ng-EEQ/L). The estrogenicity of sample was calculated by EC50 (half maximal effective concentration), for that were applied serial dilutions to 17-estradiol standard curve and for each sample. They were implemented serial dilutions for monitoring samples toxicity by BLYR yeast control. The estrogenic activity on raw wastewater ranged by 14,7 to 52,6 ng-EEQ/L. The treated wastewater by activated sludge presented results below the quantification of assay limit of < 0,10 ng-EEQ/L to 11ng-EEQ/L, indicating removal efficiency between 50% to 100%. The reclaimed water was produced by chlorination and filtration and presented results of estrogenic activity of < 0,10 ng-EEQ/L on majority analyzed samples. The results showed that BLYES bioassay was viable to quantify estrogenicity in all tested samples. The evidences on estrogenic activity in studied waters may offer subsidies for integrated actions on water quality management, improvements on operational conditions and technologies of WWTPs
73

Avaliação da atividade estrogênica em esgotos sanitários e águas de reúso na região metropolitana de São Paulo / Evaluation of estrogenic activity on sanitary wastewater and reclaimed reclaimed water of São Paulo metropolitan region

Vania Rodrigues Lopes 03 December 2015 (has links)
Os esgotos sanitários concentram compostos que são interferentes endócrinos. Os tratamentos de esgotos convencionais por sistema de lodos ativados podem não remover totalmente estes compostos, os quais atingem os ecossistemas aquáticos e oferecem riscos ecológicos e à saúde humana. Neste trabalho, mediu-se a atividade estrogênica de compostos presentes em esgotos brutos, tratados e águas de reúso de duas estações de tratamento de esgotos (ETE) da região metropolitana de São Paulo, que operam por sistema de tratamento por lodos ativados e produzem águas de reúso para fins não potáveis por tratamento físico-químico. Nesse procedimento, as amostras foram preparadas por extração de fase sólida e utilizou-se o bioensaio BLYES (Bioluminescence Yeast Estrogen Screen) para a quantificação de efeito de atividade estrogênica em nanogramas de 17-estradiol equivalente (ng-EEQ/L). A estrogenicidade da amostra foi calculada por meio da EC50 (concentração efetiva em 50%), para isto foram utilizadas diluições seriadas para curva padrão com 17-estradiol e para cada amostra analisada. A toxicidade nos ensaios foi medida e monitorada pela levedura controle BLYR. A atividade estrogênica no esgoto bruto variou de 14,7 a 52,6 ng-EEQ/L Os resultados em esgotos tratados por sistema de lodos ativados variaram de abaixo o limite de quantificação do bioensaio de < 0,10 ng-EEQ/L a 11ng-EEQ/L, indicando eficiência de remoção entre 50% a 100%. As águas de reúso foram produzidas por filtração e cloração e na maioria dos resultados apresentaram atividade estrogênica de <0,10 ng-EEQ/L. Os resultados obtidos neste estudo foram comparáveis aos encontrados na literatura medidos pelo bioensaio YES. Os resultados demonstraram que o bioensaio BLYES foi viável para quantificar a estrogenicidade em todas as amostras testadas. As evidências acerca da atividade estrogênica das águas estudadas podem subsidiar ações integradas na gestão da qualidade das águas, o aprimoramento de condições operacionais e tecnológicas das ETEs / The wastewater concentrates compounds with endocrine disruptors. The conventional wastewater treatment by activated sludge are not able to completely remove these compounds, whose achieve aquatic ecosystems and offer ecologic risks and to human health. In this study we measured estrogenic activity on raw and treated wastewater and reclaimed water from two wastewater treatment plants (WWTPs) in the metropolitan region of São Paulo. These WWTPs treat wastewater by activated sludge process and produce reclaimed water for non potable purposes by physical chemical processes. By this procedure, the samples were collected on both WWTPs before and after described treatments and they were prepared by solid phase extraction (SPE). The samples after SPE were analyzed by the BLYES (Bioluminescence Yeast Estrogen Screen) bioassay for quantifying estrogenic activity measured by nanograms 17-estradiol equivalent per litre (ng-EEQ/L). The estrogenicity of sample was calculated by EC50 (half maximal effective concentration), for that were applied serial dilutions to 17-estradiol standard curve and for each sample. They were implemented serial dilutions for monitoring samples toxicity by BLYR yeast control. The estrogenic activity on raw wastewater ranged by 14,7 to 52,6 ng-EEQ/L. The treated wastewater by activated sludge presented results below the quantification of assay limit of < 0,10 ng-EEQ/L to 11ng-EEQ/L, indicating removal efficiency between 50% to 100%. The reclaimed water was produced by chlorination and filtration and presented results of estrogenic activity of < 0,10 ng-EEQ/L on majority analyzed samples. The results showed that BLYES bioassay was viable to quantify estrogenicity in all tested samples. The evidences on estrogenic activity in studied waters may offer subsidies for integrated actions on water quality management, improvements on operational conditions and technologies of WWTPs
74

Polluants Organochlorés et Risque de Survenue du Cancer de la Prostate. Interactions Gène-Environnement / Organochlorine Pollutants and the Risk of Prostate Cancer. Gene-Environment Interactions

Emeville, Elise 17 December 2014 (has links)
Le cancer de la prostate (CaP) est la pathologie tumorale la plus fréquente chez les hommes dans les pays occidentaux. L’âge avancé, les origines ethno-géographiques et la présence d’antécédents familiaux de CaP sont les principaux facteurs de risque clairement établis. Les expositions aux substances chimiques issues de l’activité humaine, en particuliers ceux présentant des propriétés hormonales (perturbateurs endocriniens), sont suspectées. L’objectif général cette thèse est d’étudier le rôle de certains polluants universels présentant des propriétés hormonales, tels que le DDE (principal métabolite du DDT) et les PCBs, ainsi que celui des polymorphismes de gènes codant pour des enzymes intervenant dans le métabolisme des xénobiotiques (GSTM1, GSTT1) et des œstrogènes (CYP17, CYP19, CYP1B1, COMT, UGT1A1) dans la survenue du CaP ou de sa récidive après traitement par prostatectomie radicale. Ce projet s’appuie sur les données obtenues lors de l’étude cas-témoins en population générale en Guadeloupe (KARUPROSTATE) et de la file active des cas traités par prostatectomie radicale. / Prostate cancer (PCa) is the most frequent type of cancer in Western countries. Advanced age, ethno-geographic origin and the presence of a family history of CaP are the main clearly established risk factors. The effects of exposure to synthetic chemicals with hormonal properties, also called endocrine disruptors (EDCs), on PCa are also are suspected. The main objective of this thesis is to evaluate the relationships between plasma concentration of persistent organochlorine pollutants with hormonal properties, such as DDE (the main metabolite of DDT) and PCBs as well polymorphisms of selected genes involved in xenobiotic (GSTM1, GSTT1) and estrogens (CYP17, CYP19, CYP1B1, COMT, UGT1A1) metabolism, and the occurrence of PCa or its recurrence after treatment with radical prostatectomy. This project is based on data obtained from the population-based case-control study (KARUPROSTATE) in Guadeloupe and from cases treated by radical prostatectomy.
75

Effects of some Endocrine Disruptors on Human and Grey Seal Uterine Cells

Bredhult, Carolina January 2007 (has links)
<p>The effects of environmental contaminants in humans and animals are of great concern. Some contaminants are endocrine disruptors that may interfere with the endogenous hormonal signalling and disturb, for example, reproductive organs and functions.</p><p>Primary uterine myometrial cells originating from women and Baltic grey seals were exposed to some polychlorinated biphenyls (PCBs) and their metabolites. Even though human and Baltic grey seal myometrial cells responded differently to the tested PCBs, the results indicate that PCBs can influence myometrial cell proliferation <i>in vitro</i>.</p><p>The prevalence of uterine leiomyomas was investigated among 257 Baltic grey seals. Leiomyomas were only present in females older than 22 years, at a prevalence of 65%. Proliferation in leiomyoma cells was detected in individuals lacking ovarian proliferation support, suggesting the presence of an exogenous stimulant. By taking into account temporal alterations in the contaminant burden of the seals, PCB exposure was found to be associated with leiomyoma prevalence. In conclusion, PCB exposure may be related to uterine leiomyoma development and proliferation in Baltic grey seals <i>in vivo</i>.</p><p>Human endometrial endothelial cells (HEECs) were exposed to some endocrine disruptors, and the effects of the endocrine disruptors on cell proliferation and viability were studied. All evaluated endocrine disruptors decreased HEEC proliferation and most also decreased HEEC viability. Further studies revealed that the reduction in HEEC proliferation after exposure to o,p’-DDT was associated with differential expression of mRNA involved in proliferation, defence response, and lipid and cholesterol metabolism compared to untreated HEEC. </p><p>In conclusion, these studies suggest that endocrine disruptors affect cultured cells from the female reproductive tract of humans and grey seals, and may have deleterious effects on proliferation, viability, and genes involved in defence response, and lipid or cholesterol metabolism.</p>
76

Effects of some Endocrine Disruptors on Human and Grey Seal Uterine Cells

Bredhult, Carolina January 2007 (has links)
The effects of environmental contaminants in humans and animals are of great concern. Some contaminants are endocrine disruptors that may interfere with the endogenous hormonal signalling and disturb, for example, reproductive organs and functions. Primary uterine myometrial cells originating from women and Baltic grey seals were exposed to some polychlorinated biphenyls (PCBs) and their metabolites. Even though human and Baltic grey seal myometrial cells responded differently to the tested PCBs, the results indicate that PCBs can influence myometrial cell proliferation in vitro. The prevalence of uterine leiomyomas was investigated among 257 Baltic grey seals. Leiomyomas were only present in females older than 22 years, at a prevalence of 65%. Proliferation in leiomyoma cells was detected in individuals lacking ovarian proliferation support, suggesting the presence of an exogenous stimulant. By taking into account temporal alterations in the contaminant burden of the seals, PCB exposure was found to be associated with leiomyoma prevalence. In conclusion, PCB exposure may be related to uterine leiomyoma development and proliferation in Baltic grey seals in vivo. Human endometrial endothelial cells (HEECs) were exposed to some endocrine disruptors, and the effects of the endocrine disruptors on cell proliferation and viability were studied. All evaluated endocrine disruptors decreased HEEC proliferation and most also decreased HEEC viability. Further studies revealed that the reduction in HEEC proliferation after exposure to o,p’-DDT was associated with differential expression of mRNA involved in proliferation, defence response, and lipid and cholesterol metabolism compared to untreated HEEC. In conclusion, these studies suggest that endocrine disruptors affect cultured cells from the female reproductive tract of humans and grey seals, and may have deleterious effects on proliferation, viability, and genes involved in defence response, and lipid or cholesterol metabolism.
77

Auswirkungen von Östradiol, Bisphenol A und Octylmethoxycinnamat in östrogen-sensitiven Organen im Langzeitversuch an ovarektomierten Mäusen / Effects of estradiol, Bisphenol A and OMC on estrogen sensitive organs of ovarectomized mice under long-term treatment

Opitz, Carl Christian 28 August 2013 (has links)
No description available.
78

A Biography of Endocrine Disruptors: The Narrative Surrounding the Appearance and Regulation of a New Category of Toxic Substances

January 2018 (has links)
abstract: Endocrine disruptors are chemicals that interact with the hormone system to negative effect. They ‘disrupt’ normal processes to cause diseases like vaginal cancer and obesity, reproductive issues like t-shaped uteri and infertility, and developmental abnormalities like spina bifida and cleft palate. These chemicals are ubiquitous in our daily lives, components in everything from toothpaste to microwave popcorn to plastic water bottles. My dissertation looks at the history, science, and regulation of these impactful substances in order to answer the question of how endocrine disruptors appeared, got interpreted by different groups, and what role science played in the process. My analysis reveals that endocrine disruptors followed a unique science policy trajectory in the US, rapidly going from their proposal in 1991 to their federal regulation in 1996, even amid intense and majority scientific disagreement over whether the substances existed at all. That trajectory resulted from the work of a small number of scientist-activists who constructed a concept and category as scientific, social, and regulatory. By playing actors from each sphere against each other and advancing a very specific scientific narrative that fit into a regulatory and social window of opportunity in the 1990s, those scientist-activists made endocrine disruptors a national issue that few could ignore. Those actions resulted in the Endocrine Disruptor Screening Program, a heavily-criticized and ineffective regulatory program. My dissertation tells a story of the past that informs the present. In 2018, the work of researchers, public media, and policymakers in the 1990s continues to play out, evident in the deep scientific division over endocrine disrupting effects and the inability of the European Union to settle on even a definition of endocrine disruptors for regulation purposes. / Dissertation/Thesis / Doctoral Dissertation Biology 2018
79

Detecção dos interferentes endócrinos estradiol e estriol em amostras ambientais e clínicas empregando eletrodos modificados com grafeno, nanopartículas metálicas e quantum dots / Detection of endocrine disruptors stradiol and estriol in environmental and clinical samples using modified electrodes with graphene, metal nanoparticles and quantum dots

Fernando Henrique Cincotto 10 November 2016 (has links)
Para o desenvolvimento dos sensores aqui descritos foram utilizados materiais inovadores considerando relatos atuais da literatura, materiais estes: óxido de grafeno, óxido de grafeno reduzido, nanocompósitos de grafeno e nanopartículas (ródio, antimônio e sílica mesoporosa desordenada), materiais híbridos a base de grafeno e quantum dots de CdTe, além de biossensores incorporando a enzima lacase. Estes materiais foram sintetizados utilizando metodologias específicas e caracterizados por diversas técnicas analíticas como microscopia eletrônica de transmissão de alta resolução, microscopia de força atômica, espectroscopia Raman, difração de raios-X, espectroscopias de UV-Vis e fotoluminescência, e técnicas eletroquímicas. Posteriormente, os materiais foram utilizados para modificação em eletrodos de carbono vítreo e utilizados na determinação de interferentes endócrinos (os hormônios estriol e 17&beta;-estradiol) como sensores eletroquímicos em amostras ambientais e clínicas. Em essência, os eletrodos desenvolvidos apresentaram importantes vantagens, tais como alta sensibilidade, boa reprodutibilidade, simples instrumentação, fácil preparação e procedimentos analíticos rápidos, apresentando baixos limites de detecção, na ordem de picomolar e nanomolar, com baixa taxa de interferência de outras espécies na mesma matriz da amostra. Concluindo assim que as técnicas eletroquímicas podem ser facilmente aplicadas na determinação de interferentes endócrinos em amostras reais. / For the development of the sensors described here innovators materials were used considering current literature reports, these materials: Graphene oxide, reduced graphene oxide, nanocomposites graphene and nanoparticles (rhodium and antimony), hybrid materials of graphene and CdTe quantum dots, and biosensors incorporating the laccase enzyme. These materials were synthesized using specific methodologies and characterized by several analytical techniques such as transmission electron microscopy, high resolution transmission electron microscopy, atomic force microscopy, Raman spectroscopy, X-ray diffraction, UV-Vis and photoluminescence spectroscopy and electrochemical techniques. Subsequently, the materials were used for modification of glassy carbon electrodes to the determination of endocrine disruptors (estriol and 17&beta;-estradiol hormone) as electrochemical sensors for environmental and clinical samples. In essence, developed electrodes showed important advantages such as high sensitivity, good reproducibility, simple instrumentation, easy preparation and quick analytical procedures, with low detection limits in the range of picomolar and nanomolar, low interference rate of other species in same matrix sample. Finally, electrochemical techniques can be easily applied in the determination of endocrine disruptors in real samples.
80

Utilisation des biomarqueurs d'exposition en épidémiologie environnementale : application à l'étude des effets des expositions intra-utérines aux phénols et au phtalates sur la croissance pré-et post-natale / Biomarkers of Exposure in Environmental Epidemiology : the case of the effects of prenatal exposure to phenols and phthalates on pre- and post-natal growth.

Philippat, Claire 26 August 2013 (has links)
Contexte : Les phtalates et les phénols sont des perturbateurs endocriniens. Les données concernant leurs effets sur la croissance fœtale et durant l'enfance sont limitées et suggèrent un effet dépendant du sexe de certains phénols sur le poids de naissance. Une des limites de ces études est l'estimation de l'exposition, basée sur la mesure de leurs concentrations dans un petit nombre d'échantillons d'urine maternelle. En raison de la faible persistance de ces composés chimiques dans l'organisme, les concentrations urinaires varient dans le temps. Les concentrations dosées dans d'autres matrices comme le liquide amniotique pourraient être pertinentes pour estimer l'exposition fœtale.Objectifs : Les objectifs de la thèse étaient : 1) d'étudier les impacts potentiels de l'exposition prénatale aux phénols et aux phtalates sur la croissance du fœtus et de l'enfant ; 2) de caractériser la variabilité des concentrations urinaires de phénols au long de la grossesse et de comparer les concentrations de phénols dosées dans le liquide amniotique et l'urine maternelle recueillis le même jour ; 3) de caractériser le biais et l'impact sur la puissance statistique de l'utilisation d'un faible nombre d'échantillons urinaires pour estimer les expositions. Méthodes : Les associations entre les phénols, les phtalates et la croissance ont été étudiées parmi un sous-effectif de la cohorte mère-enfant EDEN ayant accouché de garçons (n =520). La croissance fœtale a été estimée à l'aide d'échographies réalisées pendant la grossesse et de mesures à la naissance. La croissance postnatale a été modélisée à partir de mesures répétées normalisées, réalisées entre la naissance et 3 ans. Les biomarqueurs d'exposition aux phtalates et phénols ont été dosés dans les urines maternelles recueillies une fois pendant la grossesse. La variabilité des concentrations urinaires de phénols et la correspondance avec les concentrations mesurées dans le liquide amniotique ont été étudiées chez 71 femmes enceintes recevant une amniocentèse au centre médical Mount Sinaï (NY, États-Unis). Un échantillon d'urine maternelle a été recueilli le jour de l'amniocentèse, et à deux autres reprises pendant la grossesse. L'étude concernant les biais est basée sur des données simulées. Résultats : Les concentrations de triclosan étaient négativement associées à tous les paramètres de croissance mesurés à la troisième échographie (p ≤ 0,16) et avec la périmètre crânien à la naissance (β = - 1,4 mm, IC 95%; -2.8; 0.0). Les parabènes étaient associés positivement avec le poids à la naissance (p < 0,05). Le méthyle et propyle parabènes étaient aussi positivement associés au poids et à la circonférence abdominale à 3 ans (p-valeurs comprises entre 0,02 et 0,14). En ce qui concerne la variabilité des concentrations urinaires pendant la grossesse, les coefficients de corrélation intra-classe (ICC) variaient entre 0,48 et 0,62 pour l'ensemble des phénols sauf le bisphénol A (ICC = 0,11). Seuls la benzophénone-3 et le propyle parabène ont été détectés dans au moins 50 % des échantillons de liquide amniotique. Pour ces composés les concentrations dosées dans l'urine maternelle et le liquide amniotique, recueillis le même jour, étaient positivement associés. Dans le cadre d'une simulation, nous avons estimé que 5 échantillons d’urine étaient nécessaires pour estimer correctement l’exposition aux produits chimiques ayant un ICC de 0,6, tandis que pour des produits chimiques avec un ICC de 0,15, environ 25 échantillons étaient nécessaires.Conclusion : Un seul échantillon d'urine était disponible pour évaluer les expositions des femmes de la cohorte EDEN et nos résultats peuvent être affectés d'un biais résultant d'erreurs de classification des expositions, notamment pour le bisphenol A pour lequel nous avons observé une variabilité importante des concentrations. Néanmoins, notre étude suggérait un effet de l'exposition prénatale à certains phénols sur la croissance pré- et post-natale. / Background: Phthalates and phenols belong to the family of short half-life endocrine disruptors. Data regarding their effects on fetal and early post-natal growth in Human are sparse and suggest a sex-specific effect of some phenols on birth weight. One of the limitations of these studies is exposure assessment usually based on the measurement of their concentrations in a small number of maternal urine samples collected during pregnancy. Because of their low persistence in the organisms and the likely episodic nature of the exposures, urinary concentrations of these chemicals are likely to vary. Chemical concentrations measured in alternative matrix, such as amniotic fluid, might be a relevant dosimeter of fetal exposure.Objectives: Objectives of the thesis were: to study the potential effects of prenatal exposures to phenols and phthalates on pre- and early post-natal growth; to characterize variability in maternal urine concentrations of phenols throughout pregnancy and to compare phenol concentrations in amniotic fluid to those measured in maternal urine collected same day; to characterize the impact of increasing the number of measurements to estimate exposure on bias and statistical power of epidemiological studies.Methods: Associations between phenols, phthalates and growth were studied among a subsample of pregnant women of the French EDEN cohort delivered boys (n =520). We measured fetal growth with ultrasound (three times during pregnancy) and birth measurements. We used standardized measures acquired between birth and 3 years of age to model postnatal growth. We measured biomarkers of phthalates and phenols in maternal urines collected once during pregnancy: 191 women were assessed in 2008 and 410 other women in 2012 (ntot = 601). Variability in phenol urine concentrations and relationship between concentrations measured in amniotic fluid and maternal urine collected on the same day were studied among 71 pregnant women presenting for an amniocentesis at the Mount Sinai Medical Center (NY, USA). Maternal urine was collected at the time of the amniocentesis appointment, and on two subsequent occasions. Urine and amniotic fluid were analyzed for nine phenols.The study aiming at characterizing bias was based on simulated data. Results: Among the subsample of 191 pregnant women from the EDEN cohort, we observed a negative association between dichlorophenols and birth weight and a positive association between benzophenone-3 and birth weight. The associations with dichlorophenols were not replicated in the larger subsample of the EDEN cohort (n = 520). Triclosan concentration was negatively associated with all of the growth parameters measured at the third ultrasound examination (p ≤ 0.16) and with head circumference measured at birth (β = - 1.4 mm, 95% CI; -2.8; 0.0). All of the parabens were positively associated with weight at birth (p < 0.05). These associations remained in childhood for methyl- and propyl-parabens. Regarding the variability in phenol urinary concentrations during pregnancy, the intraclass correlation coefficients (ICC) ranged between 0.48 and 0.62 for all phenols except bisphenol A (ICC = 0.11). Only benzophenone-3 and propylparaben were detectable in at least half of the amniotic fluid samples; for these phenols, concentrations in maternal urine and amniotic fluid were positively associated. In a simulation study, we estimated that 5 samples will be needed to correctly estimate exposure to chemicals with ICC of 0.6, while for chemicals with ICC of 0.15 around 25 samples would be needed.Conclusion: We only had spot urine sample to assess exposure in the EDEN cohort and findings may be affected by exposure misclassification, especially for bisphenol A for which we observed high variability in urine concentrations. Nevertheless, our study lends support to a potential effect of prenatal exposure to some phenols on pre- and early post-natal growth.

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