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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.
131

Exposição a substâncias organocloradas em São Paulo: níveis séricos em doadores de sangue e fatores associados / Exposure to organochlorine substances in São Paulo: serum levels in blood donors and associated factors

Felipe Parra do Nascimento 01 April 2016 (has links)
A utilização de pesticidas organoclorados é motivo de preocupação das entidades ligadas à área de saúde em todo o mundo. Apesar de as formas de contaminação serem bem conhecidas, não há um controle eficaz na fiscalização do seu uso no Brasil. Sabe-se que altos níveis séricos destes compostos nos organismos de seres humanos e animais acarretam sérios problemas de saúde. Tendo em vista essa realidade, foi realizado, em 2009, o Projeto Piloto do I Inquérito Nacional de Populações Expostas a Substâncias Químicas, cujo subprojeto \"doadores de sangue\" teve como objetivo mensurar as concentrações de substâncias químicas no sangue de 547 residentes da região metropolitana de São Paulo, dentre elas os pesticidas organoclorados. Este trabalho teve como objetivos avaliar as concentrações dos pesticidas hexaclorobenzeno (HCB), alfa-HCH, ?-HCH, beta-HCH, beta-HCH, heptacloro, heptacloro epóxido, dieldrin, mirex, o,p\'-DDT, p,p\'-DDT, o,p\'-DDE, p,p\'-DDE, o,p\'-DDD e p,p\'-DDD nesta população e compará-las com as encontradas em outros países e determinar fatores associados aos níveis mais elevados destas substâncias. O método analítico utilizado foi de cromatografia a gás. Os resultados deste estudo indicam que a população adulta de São Paulo não está exposta a níveis preocupantes de pesticidas organoclorados, pois dentre os compostos analisados, apenas o beta-HCH e o p,p\'-DDE tiveram um número significante de amostras acima do limite de quantificação, 10,7% e 31,2% das amostras respectivamente. Quando utilizada a metade do limite de quantificação para substituir os valores abaixo do limite de quantificação do método, o valor médio encontrado para o beta-HCH foi de 0,028 ug/dL e para o p,p\'-DDE foi de 0,045 ug/dL. Este estudo propôs dois modelos multivariados para explicar os fatores associados aos compostos beta-HCH e p,p\'-DDE no sangue dos doadores. Segundo o modelo de Regressão Logística Ordinal Multivariado, os fatores associados a níveis mais altos de beta-HCH foram ter idade entre 26 e 45 anos e ser do sexo feminino. Para o p,p\'-DDE os fatores associados a níveis mais altos foram ter idade entre 26 e 45 anos, ser do sexo feminino e ter trabalhado com pesticidas, enquanto receber renda mensal de 3 a 5 salários mínimos e consumir derivados de origem animal uma ou mais vezes por semana foram associados a níveis mais baixos de p,p\'-DDE. Segundo o modelo de Regressão Linear Múltipla, os fatores associados a níveis mais altos de beta-HCH foram o sexo feminino, ter contato prévio com pesticidas na região agrícola, ter trabalhado com pesticidas em campanhas de saúde pública, ter trabalhado em empresas de capacitores ou transformadores, ter trabalhado em indústrias de solventes clorados, ter renda mensal de 3 a 5 salários mínimos, consumo de carnes uma ou duas vezes por semana e consumo de frutos do mar uma ou duas vezes por semana, enquanto consumo frequente de cerveja e ter renda mensal de 1 a 3 salários mínimos foram associado a níveis menores de beta-HCH. Já para o p,p\'-DDE, os fatores associados a níveis mais elevados foram ser do sexo feminino, ser não branco, ter trabalhado com pesticidas e consumir água de fontes que não sejam minerais ou de rede, enquanto o consumo frequente de bebidas alcoólicas foi associado a níveis mais baixos de p,p\'-DDE / The use of organochlorine pesticides is a cause of concern to the entities of the health field worldwide. Although the ways of contamination are well known, there is no effective surveillance of its use on Brazil. It\'s known that high levels of these compounds on human beings and animals entails serious health problems. Foreseeing this reality, a Pilot study of the 1st National Inquiry of Populations Exposed to Chemical Compounds was carried out in 2009, in a subproject called \"blood donors\" had the objective to measure the concentrations of chemical compounds on serum from 547 residents of the metropolitan area of São Paulo, among them, the organochlorine pesticides. This study had as objectives to evaluate the levels of the pesticides hexachlorobenzene (HCB), alfa-HCH, beta-HCH, beta-HCH, beta-HCH, heptachlor, heptachlor epoxide, dieldrin, mirex, o,p\'-DDT, p,p\'-DDT, o,p\'-DDE, p,p\'-DDE, o,p\'-DDD e p,p\'-DDD on blood donors and compare these with the ones found on other countries and to find out factors associated with higher levels of those compounds in the population. The analytical method used was gas chromatography. The results of this study indicate that, overall, the population in São Paulo is not exposed to high levels of these compounds because of all compounds analyzed, only beta-HCH and p,p\'-DDE had a significative number of samples above the quantification limit, 10,7% and 31,2% of the samples respectively. Using the half of the quantification limit to substitute the values below the quantification limit, the beta-HCH mean level was 0.028 ug/dL and p,p\'-DDE mean level was 0.045 ug/dL. This study proposed two multivariate models to explain the factors associated with beta-HCH and p,p\'-DDE blood levels. According to the Multivariable Ordinal Logistic Regression model, the factors associated with higher levels of beta-HCH were age between 26 and 45 years and female gender. For the p,p\'-DDE, the associated factors with higher levels were age between 26 to 45 years, female gender and previous work with pesticides while having income of 3 to 5 minimum wages and consumption of derivates of animal origin at least once per week were associated to lower levels of p,p\'-DDE. According to the Multiple Linear Regression model, the factors associated with higher levels of beta-HCH were female gender, previous contact with pesticides on agricultural region, working with pesticides on campaigns of public health, in companies of capacitators or transformers, in companies of chlorinated solvents, having income of 3 to 5 minimum wages, consumption of meat once or twice per week, and consumption of seafood once or twice per week, while frequent consumption of beer and income of 1 to 3 minimum wages lead to lower levels of beta-HCH. Factors associated with higher levels of p,p\'-DDE were female gender, being non-white, previous work with pesticides and consumption of water from sources that not mineral or mains, while frequent consumption of alcohol were associated with lower levels of p,p\'-DDE
132

Analyse chimique des résidus des contaminants anthropiques dans les chaines alimentaires : influence du régime alimentaire chez les prédateurs / Chemical analysis of residues of anthropogenic contaminants in food chains : influence of diet in predators

Alomar, Hussein 25 October 2017 (has links)
Dans ce travail de thèse, nous avons analysé les résidus des plusieurs contaminants anthropiques dans des prédateurs de la chaîne alimentaire aquatique et des proies de la chaîne terrestre. En effet, la loutre, le grand cormoran et le silure sont prédateurs piscivores au sommet de la chaîne alimentaire, les pesticides organochlorés, les PCBs et les éléments traces métalliques (plomb, cadmium, cuivre et mercure) ont été détectés dans tous les foies de ces prédateurs prélevés dans les bassins de la Loire en France. Les PCBs sont les organochlorés les plus répandus dans les trois espèces, suivi des DDTs. Les valeurs maximales de PCBs ont atteint 1,61, 1,96 et 0,28 mg/kg de poids frais pour les cormorans, les loutres et les silures, respectivement. La concentration du mercure a dépassé la limite toxique pour plus de 40 % des cormorans analysés. L‘effet « cocktail » de ces contaminants sur les trois espèces n‘est pas étudié dans cette thèse. Cependant, Les concentrations des organochlorés et des éléments traces dans ces prédateurs sont généralement modestes ou faibles. Ainsi, Il nous semble que ces contaminants ne constituent pas une menace pour la conservation de ces espèces à court ou moyen terme. Par ailleurs, dans le réseau trophique terrestre, nous avons trouvé que trois rodenticides anticoagulants la chlorophacinone, la bromadiolone et le brodifacoum s‘accumulent dans les limaces de la manière rapide et stable au cours de temps, par contre aucune mortalité n‘a été observée chez les limaces. Le brodifacoum a été détecté dans plus de 90 % des limaces prélevées sur le terrain, et nous avons constaté que ces limaces représentaient un risque élevé d'empoisonnement secondaire pour trois de leurs prédateurs, le hérisson européen, la musaraigne commune et l'étourneau sansonnet. On pourrait donc confirmer que les invertébrés constituent une source non négligeable de rodenticides pour leurs prédateurs.L‘objectif de cette thèse est de montrer l‘influence du régime alimentaire sur la contamination des proies, des prédateurs et d‘évaluer les risques toxicologiques pour ces espèces / In this work, we analyzed the residues of several anthropogenic contaminants in predators of the aquatic food chain and prey of the terrestrial chain. The otter, the great cormorant and the catfish are piscivorous predators at the top of the food chain. Organochlorine pesticides, PCBs and trace elements (lead, cadmium, copper and mercury) were detected in all these predators collected from the basins of the Loire in France. Residue level of PCBs in these predators was the highest followed by DDTs and maximal PCB values reached 1.61, 1.96, and 0.28 mg/kg wet weight for cormorants, otters, and catfish, respectively. The concentration of mercury exceeded the toxic thresholds for more than 40% of the cormorants analyzed. The possible combined effect of these contaminants on the three species has not been studied in this thesis. However, the concentrations of organochlorines and trace elements are generally modest or low. Thus, it seems that these contaminants do not constitute a major threat to the conservation of these species for the short or medium term. Furthermore, in the terrestrial food chain, we found that three anticoagulant rodenticides chlorophacinone, bromadiolone and brodifacoum accumulate in slugs in a stable way over the time, whereas no mortality was observed in slugs. Brodifacoum was detected in more than 90% of the slugs collected in the field, and we found that these slugs represented a high risk of secondary poisoning for three of their predators, European hedgehog, common shrew and European starling. Therefore, it could be confirmed that invertebrates constitute a non-negligible source of rodenticides for their predators.The objective of this thesis is to show the influence of the diet on the contamination of prey, predators and to evaluate the toxicological risks for these species
133

Risk assessment of organochlorine pesticides and polycyclic aromatic hydrocarbons in fish collected from fish ponds in the Pearl River Delta

Kong, Kai Yip 01 January 2004 (has links)
No description available.
134

Etude des mécanismes histologiques et physiologiques du transfert de la chlordécone (insecticide organochlore) dans les vegetaux / Study of physiological and histochemical mechanisms of chlordecone transfer, an organochlorinated insecticide, in plant

Létondor, Clarisse 14 February 2014 (has links)
La chlordécone (CLD) est un insecticide organochloré qui a été utilisé principalement aux Antilles pour lutter contre le charançon du bananier (Cosmopolites sordidus). Sa faible dégradabilité dans le sol et sa dispersion dans les bassins versants entraînent une contamination durable des sols agricoles et des écosystèmes environnants. Cela pose un problème d’exposition pour l’Homme par la consommation de végétaux contaminés et pour l’environnement par le transfert de la molécule dans les chaînes alimentaires (bioamplification). Pour l’Homme, les principaux végétaux à risque sont les légumes-racines, en contact direct avec la CLD dans le sol, mais aussi les autres légumes car des résidus de CLD sont retrouvés dans les parties aériennes, tiges ou feuilles. Ce travail de thèse a porté sur le transfert sol-plante de la CLD, d’une part dans les tubercules des légumes-racines pour appréhender le risque sanitaire et d’autre part dans les graminées pour le risque environnemental. La lipophilie de la CLD joue un rôle majeur dans son transfert dans les plantes. La CLD a une affinité particulière pour les tissus lipophiles, notamment le périderme subérifié des tubercules et les parois cellulaires incrustées de lignine des vaisseaux du xylème. En outre, le transfert est dépendant de l’architecture de la plante, de sa physiologie et de l’histologie de ses organes. Nous avons mis en évidence deux voies de contamination des plantes par la CLD : l’absorption racinaire et l’adsorption sur le périderme des tubercules. Ces phénomènes sont suivis de la translocation de la molécule vers les tissus internes du tubercule par diffusion et vers la partie aérienne de la plante par évapotranspiration via les faisceaux vasculaires du xylème. Dans le cas des tubercules, nous avons distingué la part de contamination apportée par l’absorption racinaire de celle due à l’adsorption péridermique. Chez le radis, il a été montré que le phénomène prépondérant était la diffusion trans-péridermique. Une analyse du risque de contamination de tubercules couramment consommés aux Antilles (patate douce, dachine, igname) a été réalisée en se basant notamment sur l’architecture de la plante et l’histologie des tissus mis en place lors de la tubérisation. Concernant les graminées, la capacité de transfert de la CLD dans la partie aérienne de la plante a été étudiée chez plusieurs graminées usuelles. Le potentiel de contamination de la plante dépend de ses caractéristiques physiologiques (métabolisme) et de son cycle de vie (pérennité). Ces caractéristiques pourraient permettre d’orienter le choix de certaines graminées pour la phytoremédiation de la CLD. / Chlordecone (CLD) is an organochlorine insecticide mainly used in French West Indies to struggle against banana weevil (Cosmopolites sordidus). Its low degradability into soils and its spreading in catchment basins cause a sustainable contamination of agricultural soils and surrounding ecosystems. This leads to a human exposure risk, by food consumption of contaminated vegetables, and to an environmental risk by transfer of CLD in food chains. Main hazardous vegetables for human health are root-vegetables that are directly in contact of soil but also other vegetables because CLD residues are found in aerial parts of plant, leaves and shoots. The environmental risk seems to be the biomagnification of contamination in trophic chains due partly by consumption of contaminated plants. This work focused on the CLD soil-plant transfer, on the one hand in tubers of edible-roots for knowing the health risk and on the other hand in grasses for environmental risk. The CLD lipophilicity plays a major role in its transfer to plants. CLD exhibits a certain affinity for lipophilic tissues particularly for the suberised periderm of tubers and the xylem cell walls that are thickened by lignin. In addition, transfer depends on plant architecture, physiology and organ histology. Two ways of CLD plant contamination were highlighted: roots absorption and adsorption onto tuber periderm. These mechanisms are followed by CLD translocation towards internal tissues of tuber by diffusion and to above-ground parts of the plant within the transpiration stream occurring in vascular xylem vessels. For tubers, we distinguished between the contamination brought by roots absorption and the one brought by peridermic adsorption. In radish, the trans-peridermic diffusion was showed as the major way of contamination. A risk analysis mainly based on plant morphology and tissue histology set up during tuberization process was realized. For grasses, CLD transfer ability to aerial part of plant was studied in several usual gramineae (yam, sweet popato, dasheen). Plant contamination potential is mainly determined by its physiological traits (metabolism) and its life cycle (perenniality). These features could drive the choice of some gramineae to perform CLD phytoremediation.
135

A review of research and literature linking breast cancer to pesticides

Pellegrino-Peard, Patricia L. 01 January 1995 (has links)
No description available.
136

Primena sorpcionih parametara odabranih hidrofobnih organskih polutanata na organskoj materiji sedimenata za procenu njihove dostupnosti u sistemima sediment-voda / Application of the parameters ofsorption of selected hydrophobic organic compounds onto the sediment organic matter for the assessment of their availability in the sediment-water system

Tričković Jelena 25 May 2009 (has links)
<p>Prirodna organska materija zemlji&scaron;ta/sedimenata predstavlja glavnu oblast<br />za sorpciju hidrofobnih organskih jedinjenja, a njene osobine utiču na stepen<br />retencije i konsekventnu (bio)dostupnost organskih jedinjenja. Da bi se procenio<br />ekotoksikolo&scaron;ki rizik zagađenih zemlji&scaron;ta/sedimenata po okolinu, dizajnirala<br />odgovarajuća strategija remedijacije ili predvidela sudbina i transport organskih<br />polutanata u zagađenim zonama, neophodno je razumevanje mehanizma sorpcije i<br />desorpcije na nivou mehanizma uspostavljenih veza. U radu je izvr&scaron;eno ispitivanje<br />sorpcije i desorpcije odabranih hidrofobnih organskih polutanata, pentahlorbenzena<br />i lindana, na sekvencijalno ekstrahovanim huminskim kiselinama i huminima iz<br />jednog uzorka sedimenta u cilju pronalaženja veze između strukturnih<br />karakteristika izolovanih huminskih kiselina i humina i sorpcionih i desorpcionih<br />parametara. Afinitet za sorpciju, nelinearnost izotermi i prividna sorpciono-desorpciona histereza korelirani su&nbsp; sa osobinama sorbenata dobijenim iz<br />elementarne i FTIR spektroskopske analize. Predloženo je da je mehanizam<br />sorpcije na huminskim kiselinama rezultat odigravanja raspodele i specifične<br />adsorpcije, pri čemu se pri nižim koncentracijama pentahlorbenzena i lindana prvo<br />popune sorpciona mesta u kondenzovanoj aromatičnoj oblasti, a tek potom pri<br />vi&scaron;im koncentracijama sorpciona mesta u amorfnim alifatičnim oblastima.<br />Sveukupno vi&scaron;i koeficijenti nelinearnosti dobijeni za sorpciju pentahlorbenzena na huminskim kiselinama u odnosu na nelinearnost sorpcionih izotermi lindana, ukazuju na to da u ukupnoj sorpciji pentahlorbenzena veći značaj ima mehanizam raspodele i sme&scaron;tanje molekula pentahlorbenzena u hidrofobne &scaron;upljine huminskih kiselina, u odnosu na specifičnu adsorpciju. Ovi zaključci su potvrđeni rezultatima spektroskopskih istraživanja interakcija&nbsp; odabranih organskih jedinjenja i N-metilformamida. Predloženi mehanizam sorpcije ne može objasniti sorpciju pentahlorbenzena i lindana na uzorcima humina, većje pretpostavljeno da nelinearna sorpcija za uzorke humina može biti rezultat ostvarivanja povr&scaron;inskih interakcija, a visoki afinitet za sorpciju rezultat je raspodele organskih jedinjenja u amorfnim alifatičnim oblastima koje pružaju odlično okruženje za sorpciju.</p><p>U cilju daljeg proučavanja mehanizma sorpcije, izvr&scaron;eno je ispitivanje kinetike<br />desorpcije tri odabrana hidrofobna organskajedinjenja, pentahlorbenzena, lindana i<br />pentahloranilina, posredstvom&nbsp; čvrstog adsorbenta, XAD-4 makroporozne<br />jonoizmenjivačke smole. Na osnovu rezultata dobijenih za uzorak sedimenta i<br />frakciju &lt; 125 &micro;m za dva ravnotežna vremena (15 i 90 dana) i za sva odabrana<br />organska jedinjenja može se zaključiti da se za procenu potencijalne (bio)dostupne<br />frakcije organskih jedinjenja može koristiti jednostavna desorpcija u prisustvu<br />XAD-4 makroporozne jonoizmenjivačke smole i to na dva načina: (1) ekstrakcijom<br />sedimenta tokom 24 časa, kada frakcija koja se desorbuje odgovara frakciji<br />jedinjenja koja se nalazi u brzo-desorbujućem domenu organske materije, ili (2)<br />ekstrakcijom tokom 6 časova, kada frakcija koja se desorbuje odgovara polovini<br />one frakcije jedinjenja koja se nalazi u brzo-desorbujućem domenu organske<br />materije.</p> / <p>Natural organic matter of soil/sediment make the main region for&nbsp;sorption of hydrophobic organic compounds, ant its properties influence the degree&nbsp;of retention and, consequently, (bio)availability of organic compounds. In order to&nbsp;assess the ecotoxicological risks of contaminated soils/sediments to the&nbsp;environment and design the appropriate remediation strategy or predict the fate and&nbsp;transport of organic pollutants in contaminated zones, it is necessary to understand&nbsp;the mechanisms of sorption/desorption at the level of the mechanism of established&nbsp;bonds. Study of the sorption and desorption of selected hydrophobic organic&nbsp;pollutants, pentachlorobenzene and lindane, on sequentially extracted humic acids&nbsp;and humins from a single sediment sample with the aim of finding the relationship&nbsp;between the structural characteristics of the isolated humic acids and humin and&nbsp;sorption and desorption parameters. Sorption affinity, nonlinearity of isotherms,&nbsp;and apparent sorption-desorption hysteresis were correlated to the sorbent&nbsp;characteristics obtained from elemental analysis and FTIR spectroscopic data. The&nbsp;proposed sorption mechanism on humic acids assumes that at low concentrations&nbsp;of pentachlorobenzene and lindane the sorption sites in the condensed aromatic&nbsp;region are occupied first, and then, at their higher concentrations, the sorption sites&nbsp;in the amorphous and aliphatic regions. Generally higher nonlinearity coefficient obtained for the sorption of pentachlorobenzene on &nbsp;umic acids compared with the nonlinearity of sorption isotherms for lindane, indicate that in the overall sorption of pentachlorobenzene of higher significance is the &nbsp;echanism of distribution and insertion of pentachlorobenzene molecule into hydrophobic dips of humic acids, compared to specific adsorption. These conclusions were confirmed with the results of spectroscopic investigation of &nbsp;intermolecular interaction of chosen organic compounds and N-methylformamide.Since suggested sorption mechanism could not explain sorption of &nbsp;pentachlorobenzene and lindane onto humin samples, it is supposed that the nonlinearity can be a result of surface interactions, while the high sorption affinity is result of distribution of organic compounds in the amorphous aliphatic regions that offer an excellent environment for sorption.</p><p>With the aim of further insight into the sorption mechanism, investigation of&nbsp;desorption kinetics of three chosen hydrophobic organic compounds,&nbsp;pentachlorobenzene, lindane and pentachloroaniline, in the presence of &nbsp;soild&nbsp;adsorbent XAD-4 macroporous ion-exchange resin was performed. On the basis of&nbsp;the results obtained for sediment sample and fraction &lt; 125 &micro;m at two equilibrium&nbsp;times (15 and 90 days) and for all selected organic compounds, it can be concluded&nbsp;that the assessment of the potential (bio)avialable fraction of organic compounds&nbsp;may be obtained by using simple method of desorption in the presence of XAD-4&nbsp;macroporous ion-exchange resin, performed in two ways: (1) by sediment&nbsp;<br />extraction during 24 hours, when the desorbing fraction corresponds to the fraction&nbsp;of &nbsp;he compound that is found in the fast-desorbing domain of organic matter, or&nbsp;(2) by 6-hour extraction, when the desorbing fraction corresponds to one half of the&nbsp;fraction appearing in the fast-desorbing domain of the organic matter.</p>
137

Bioremediation of polychlorinated biphenyls (PCBs) on contaminated soils : a case study of Rietvlei Farm Borehole No. 11, Limpopo Province, South Africa

Sengani, David January 2015 (has links)
MENVM / Department of Ecology and Resource Management / Polychlorinated biphenyls (PCBs) are worldwide environmental pollutants which contaminate the environment through careless disposal practices and accidental spills or leakages from electrical transformers. These organic compounds are lipophilic chemicals soluble in fats, slightly soluble in water and readily bioaccumulated in the fatty tissues of fish, birds, animals and humans. The main objective of this study was to isolate and identify PCB degrading bacteria from PCB contaminated soils and test them for their degradation ability of PCBs in natural habitat conditions. Three bacteria species which comprise of Gram negative and Gram positive microorganisms were isolated and identified through biochemical tests, catalase tests, oxidase tests and morphological study and included Burkholderia cepacia, Pasteurella pneumotropica and Enterococcus faecalis. The results indicated that, there was an overall decrease of PCB concentration level and the readings ranged between -1.51 and -1.79 respectively for all the microorganisms. Enterococcus faecalis remove as much as 32% of PCBs in the contaminated soil samples. Whereas Pasteurella pneumotropica could remove 24% of PCBs, Burkholderia cepacia 21% of PCBs and the mixed culture removed 23%. Data showed that the 3 bacterial strains could tolerate high concentration of PCBs. The results provided the evidence that naturally occurring bacteria in soil contaminated with PCBs have the potential to degrade PCBs. Statistical analysis showed that there was a significant positive correlation between bacteria growth and treatment with a coefficient of (r) =0.1459 and p value <0.001.
138

Impact of polychlorinated biphenyl- and organochlorine pesticide exposure on faecal metabolome

Näsman, Maja January 2022 (has links)
The gut microbiota plays a major part in maintaining the health of a human host. Countless of crucial functions in the body, including immune responses, cell signaling and energy metabolism to name a few, are conducted by the gut microbiota and its metabolites. Accordingly, it is of interest to gain knowledge on what can alter the gut microbiota, as these alterations by extension can give rise to adverse health effects. In this study, the impact of polychlorinated biphenyl (PCB)- and organochlorine pesticide (OCP) exposure on tricarboxylic acid (TCA) cycle metabolites, short-chain fatty acids (SCFAs) and bile acids, as well as other polar and semi-polar metabolites, which are all related to the gut microbiota, were investigated. An in vitro fermentation of faecal samples exposed to a PCB/OCP mixture was performed, and liquid chromatography-time of flight mass spectrometry (LC-qToF-MS) targeted and non-targeted approaches were applied to the extracts. The results obtained suggested that PCBs and OCPs most likely have an effect on the levels of several features of the gut metabolome with either increased or decreased levels upon exposure. Bile acids and TCA metabolites appear to follow a trend of decreasing levels, while no apparent effects could be seen for the SCFAs. Furthermore, distinct concentrations of the PCB/OCP mixture appear to induce different changes in gut microbiota functioning, which highlights the importance of performing dose-response studies when exploring biological effects of these compounds. The identification of different metabolite profiles during fermentation also allows for the possibility of further investigation of potential biomarkers to assess PCB/OCP exposure.
139

Pinguim-de-Magalhães (Spheniscus magellanicus) como indicador da ocorrência de poluentes orgânicos persistentes / Magellanic Penguin (Spheniscus magellanicus) as a persistent organic pollutants indicator

Jorge, Paula Baldassin 04 June 2014 (has links)
O Pinguim-de-Magalhães, Spheniscus magellanicus, é o mais abundante dos pinguins que vivem em regiões temperadas da América do Sul, sendo um bom indicador de poluição ambiental. Poluentes orgânicos persistentes (POPs) foram detectados em fígado de Pinguins-de-Magalhães encontrados debilitados ou mortos nas praias do Brasil (Rio de Janeiro, São Paulo, Santa Catarina e Rio Grande do Sul) entre 2008 - 2012 e, do Uruguai e do Chile, em 2011. Os bifenilos policlorados (PCBs) predominaram em relação aos pesticidas organoclorados (DDTs &#8764; HCB &#8764; Drins) e aos éteres difenilos polibromados (PBDEs). O contaminante emergente fipronil não foi detectado apesar de seu uso na América do Sul. Entre os PCBs predominaram os congeneres penta, hexa e heptaclorados. Concentrações de POPs foram similares entre as áreas de migração e reprodução exceto para os PCBs que foram relativamente maiores na área de reprodução. Avaliação temporal (2008 - 2012) de POPs apresentou constância para os pesticidas organoclorados e tendência ao declínio para os PCBs. A glândula uropigiana de Pinguim-de-Magalhães mostrou-se um tecido alternativo adequado para análise de POPs em aves debilitadas. No geral, as regiões de reprodução e migração dos pinguins na América do Sul apresentam baixas concentrações de POPs com tendência constante ou indícios de declínio. / The Magellanic Penguin , Spheniscus magellanicus, is the most abundant penguin that live in temperate regions of South America and a good indicator of environmental pollution in that region. Persistent organic pollutants (POPs) were detected in the liver of Magellanic penguins found debilitated or dead on the beaches of Brazil (Rio de Janeiro, Sao Paulo, Santa Catarina and Rio Grande do Sul) between 2008 - 2012, and in Uruguay and Chile in 2011. Polychlorinated biphenyls (PCBs) were more prevalent than organochlorine pesticides (DDTs &#8764; HCB &#8764; Drins) and polybrominated diphenyl ethers (PBDEs). Fipronil, an emerging contaminant, was not detected despite its use in South America. Among PCBs, the congeners penta, hexa and heptaclorados were predominant. Concentrations of POPs are similar between the migration and reproduction areas except for PCBs that are relatively higher in the breeding area. At this time point (2008 - 2012) POPs showed constancy for organochlorine pesticides and PCBs tendency to decline. The Magellanic penguin uropygian gland has proved to be a suitable alternative for POPs tissue analysis in debilitated birds. Overall, southern South America has low concentrations of POPs with constant trend or decline evidence.
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Avaliação da contaminação por hidrocarbonetos e organoclorados em diferentes compartimentos do ambiente marinho do Estado do Rio de Janeiro / Evaluation of the contamination of several compartiments of marine environment of the State of Rio de Janeiro by hidrocarbons and organochlorine

Taniguchi, Satie 31 October 2001 (has links)
O ambiente marinho é o destino final de muitos contaminantes, como os PAHs, PCBs, DDTs e HCHs, que têm sido detectados em vários compartimentos do ambiente marinho, podendo trazer efeitos deletérios para o ecossistema. O objetivo deste trabalho foi a avaliação da contaminação por hidrocarbonetos alifáticos, PAHs, PCBs, DDTs e HCHs através da análise de 15 amostras de sedimento, 6 de mexilhão e 11 de fígado de peixe. Para isso, foi otimizada uma mesma metodologia para todas as matrizes bióticas. A amostragem foi feita ao longo da costa do estado do Rio de Janeiro, no período de 1996 a 1998, durante o Programa de Monitoramento do Ambiente do Meio Ambiente Marinho, promovido pela Marinha do Brasil. Os controles de qualidade analítica e confiabilidade dos dados gerados seguiram os padrões internacionais. A metodologia utilizada foi considerada satisfatória para análise dos organismos e sedimentos, de acordo com a avaliação feita através da análise de materiais de referência certificados. Os PCBs e DDTs apresentaram o fenômeno da magnificação com concentrações crescentes: sedimentos < mexilhões < peixes. Os HCHs apresentaram as maiores concentrações nos mexilhões. Os hidrocarbonetos alifáticos apresentaram concentrações similares nas três matrizes amostradas, o mesmo ocorrendo com os PAHs. As concentrações de hidrocarbonetos do petróleo indicam que as maiores introduções são próximas às áreas urbanas. Os PCBs e pesticidas também foram detectados em grande parte das amostras, mas em baixas concentrações. A fonte desses OCs para o ambiente marinho pode ser oriunda de outras regiões devido ao transporte e à deposição atmosférica. A comparação entre as matrizes mostrou a importância da análise simultânea de sedimentos e organismos em função da concentração de cada grupo de compostos e sua diferente acumulação. / The marine environment is the final recipient of many organic compounds that are widely found in seawater, sediments and organisms. The purpose of this study was the assessment of the contamination of aliphatic hydrocarbons, PAHs, PCBs, DDTs and HCHs through the analyses of 15 sediments, 6 mussels and 11 fish livers. The same methodology was optimized for biotic matrices. The sampling was performed from 1996 to 1998 along the Coast of the State of Rio de Janeiro, during the Brazilian Navy Environmental Monitoring Program. Quality assurance and quality control followed the international procedures. The methodology give satisfactory results in accord with the analyses of certified standard reference materials. Data of PCBs and DDTs from different matrices revealed increasing concentrations: sediment < mussel < fish. HCHs prevailed in mussels. Data of aliphatic hydrocarbons and PAHs were similar between sediments and organisms. Levels of petroleum hydrocarbons showed major inputs near the urban areas. PCBs and chlorinated pesticides were detected in the majority of samples but in low levels. These inputs can be attributed to long-range atmospheric transport. Comparison among the sampled matrices showed the importance of simultaneous analyses of sediments and organisms based in the concentration of each group of compounds and their different accumulations.

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