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Silva, Joice de Oliveira Epif?nio da. "A inser??o de pessoas com defici?ncia no mercado de trabalho: os sentidos da Lei de Cotas para os gestores de Recursos Humanos da regi?o metropolitana do Rio de Janeiro." Universidade Federal Rural do Rio de Janeiro, 2017. https://tede.ufrrj.br/jspui/handle/jspui/2456.
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Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES
Law No. 8213/91, known as the Quota Law was formulated as a tool to implement the National Policy on Employment Dues for Persons with Disabilities. This law today is one of the main means for the insertion of PCDs (Persons with Disabilities) into the labor market. However, the implementation of this law occurs in the face of some difficulties, such as accessibility, for example, in addition to prejudice regarding PCDs in the social environment, which ultimately interferes with its effectiveness. The purpose of this paper is to understand the meanings attributed to the Quota Law by HR Managers who act or have acted in organizations that apply the Quota Law. In order to achieve this goal, nine interviews were conducted, of which eight interviews were conducted with managers, some of whom were in full exercise until the date of the interview, and others who had recently left the organization in which they performed HR functions, and was also interviewed the coordinator of the State Nucleus for Assistance to the Disabled (NEAD). Besides the interviews, this work made use of the technique of observation and the analysis of the collected material occurred through the Nuclei of Meaning. The results show that the managers interviewed still perceive the Quota Law as a merely punitive Law, however, they understand the Quota Law also, as an important one, if not unique, tool for the insertion of PCDs into the labor market. With this, it can be said that the meanings that managers attribute to the Quota Law are loaded with prejudice and the way the Quota Law is signified by these managers reflects in the way they execute this Law, and it can be affirmed that the issue is cultural.
A lei n? 8213/91, conhecida como Lei de Cotas foi formulada como ferramenta para implementar a Pol?tica Nacional de Cotas Empregat?cias para Portadores de Defici?ncia. Esta lei hoje ? um dos principais meios para a inser??o das PCDs (Pessoas com Defici?ncia) no mercado de trabalho. Contudo, a implementa??o desta lei ocorre diante de algumas dificuldades, como a acessibilidade, por exemplo, al?m do preconceito no que tange ?s PCDs no meio social, o que acaba interferindo na efetividade da mesma. Este trabalho tem como objetivo, compreender os sentidos atribu?dos ? Lei de Cotas pelos Gestores de RH que atuam, ou atuaram, em organiza??es que se aplica a Lei de Cotas. Para atingir este objetivo foram realizadas nove entrevistas, sendo oito entrevistas realizadas com gestores, dos quais alguns estavam em pleno exerc?cio da fun??o at? a data da entrevista e outros que haviam sa?do recentemente da organiza??o em que exercia a fun??o de gestor de RH, e ainda, foi entrevistada a coordenadora do N?cleo Estadual de Atendimento ao Deficiente (NEAD). Al?m das entrevistas este trabalho fez uso da t?cnica de observa??o e a an?lise do material levantado ocorreu por meio dos N?cleos de Significa??o. Os resultados mostram que os gestores entrevistados ainda percebem a Lei de Cotas como uma Lei meramente punitiva, entretanto, entendem a Lei de Cotas tamb?m, como uma importante, sen?o ?nica, ferramenta para a inser??o das PCDs no mercado de trabalho. Com isso, pode-se afirmar que os sentidos que os gestores atribuem a Lei de Cotas s?o carregados de preconceito e a forma como a Lei de Cotas ? significada por esses gestores reflete na forma como executam essa Lei, e ainda, pode-se afirmar que a quest?o ? cultural
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Xu, Weiguang. "Risk assessment of dietary exposure to PCDD/PCDFs, DL-PCBs and NDL-PCBs of Hong Kong residents." HKBU Institutional Repository, 2012. https://repository.hkbu.edu.hk/etd_ra/1407.
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Matos, Norberto. "Os desafios da capacitação técnica das Pessoas com Deficiência (PcDs) no mercado de trabalho: um estudo de caso CEFET-RJ." Universidade Federal Fluminense, 2017. https://app.uff.br/riuff/handle/1/4108.
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Apesar do relativo avanço no sentido de manter a igualdade entre os cidadãos, a sociedade brasileira ainda não atende às necessidades específicas de alguns grupos, como: idosos, enfermos, crianças, gestantes e pessoas com deficiência (PcDs). Porém, no caso das PcDs, atualmente existem leis que visam incluí-las no mercado de trabalho, o que vem contribuindo para a sua contratação. Este trabalho objetivou investigar os principais desafios encontrados no processo de capacitação de PcDs pertencentes ao quadro efetivo do Centro Federal de Educação Tecnológica Celso Suckow da Fonseca (Cefet-RJ), que é uma instituição pública destinada ao ambiente educacional com formação humana, científica e tecnológica. Foi realizada uma pesquisa bibliográfica a partir dos conceitos-chave que auxiliaram na identificação de publicações da temática estudada. A metodologia utilizada foi o estudo de caso com aplicação de questionários, os quais foram respondidos por grupos de funcionários com deficiência, de seus gestores, e também do setor de capacitação, sendo todos servidores públicos pertencentes ao quadro de profissionais do Cefet-RJ. O tratamento dos dados foi realizado através da análise de conteúdo. O trabalho de campo mostrou o envolvimento do profissional PcD com a instituição. Os objetivos almejados nesta pesquisa foram atingidos e direcionados para propostas de melhorias nos processos de inserção, contratação e adaptação das PcDs em seu ambiente de trabalho.
Despite relative efforts in order to sustain citizen equality, Brazilian society still remains inattentive to some groups’ especial needs, such as the elderly, children, pregnant, sick and people with disability (PwD). However, concerning the PwDs, a current legislation aiming to insert them in the labor market actually exists and have been contributing to their hiring. This paper focused on the main challenges found during the PwDs capacitation process in the Centro Federal de Educação Tecnológica Celso Suckow da Fonseca (Cefet-RJ) full-time staff. Cefet-RJ is a public institution destined to be an education environment for human, scientific and technological formation. From key concepts that helped identify publications for this studied theme, a bibliographical research was achieved. We used the case study methodology, in addition of questionnaires, answered by groups of employees with disability, their managers and also by the resource and training center. All questioned employees are from Cefet’s full-time staff. The data handling was done by analyzing the content. The fieldwork showed PwDs’ involvement with the Institution. The targets were achieved and the results directed as improvement proposals for insertion, hiring and adaptation processes in the working environment.
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Gaus, Caroline, and n/a. "Dioxins in the Marine Environment: Sources, Pathways and Fate of Polychlorinated Dibenzo-p-dioxins and Dibenzofurans in Queensland, Australia." Griffith University. School of Public Health, 2003. http://www4.gu.edu.au:8080/adt-root/public/adt-QGU20030624.144111.
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Polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans(PCDFs) are two groups of lipophilic, persistent organic pollutants that are produced as by-products of various anthropogenic and industrial processes. Due to their relatively high toxic potencies and potential to bioaccumulate and biomagnify in organisms and through the food chain, the contemporary widespread distribution of these compounds is a concern to the health of the environment, wildlife and humans. This study determined the distribution, pathways and fate of PCDD/Fs in the coastal zone of Queensland, Australia, including the inshore marine environment of the World Heritage Great Barrier Reef Marine Park. This ecosystem supports unique fauna and flora such as the marine herbivorous mammal dugong (Dugong dugon) and its food source, seagrass. Elevated PCDD/Fs were present in soils and sediments along the entire Queensland coastline. Highest concentrations were found in soil from agricultural irrigation drains and in sediments near the mouths of major rivers. Elevated concentrations were associated with rural and urban types of land-use, and PCDD/Fs were present even in locations remote from anthropogenic activities. PCDD/F congener-specific analysis revealed an unusual profile in all samples, dominated by OCDD, with PCDFs present in low concentrations or below the limit of detection. Distinct HxCDD isomer patterns were observed, with the 1,2,3,7,8,9-HxCDD/1,2,3,4,6,7-HxCDD isomer pair dominating the 2,3,7,8-substituted HxCDDs. Similar congener and isomer characteristics were reported in sediments, soil and clay samples from other continents, but could not be attributed to any known source. Possible PCDD/F sources in Queensland were assessed using segmented estuarine sediment cores, for which radiochemical chronologies were established for each depth. Variations of PCDD/F concentrations in the sediment cores over several centuries of depositional history were relatively small. Elevated PCDD levels were still present in sediment slices from the early 17th century. PCDD/F homologue profiles in sediments deposited during the last 350 years were almost identical and correlated well to the characteristic profiles observed in surface sediments and soils from the entire Queensland coastline. These results suggested the presence of an unidentified PCDD source prior to the production of commercial organochlorine products. To investigate the formation of the unusual PCDD/F profiles, congener and isomer specific analyses were undertaken in soils, sediments and dated sediment cores. The results demonstrated that specific transformation processes in the environment have resulted in the observed PCDD profile characteristics. Dechlorination of OCDD was proposed to result in distinct 1,4-pattern characteristics (i.e. formation of isomers chlorinated in the 1,4,6,9-positions). Consequently, the environmental samples do not reflect the signatures of the original source. An alternative hypothesis to natural formation is discussed evaluating these processes and their implications for possible source contributions. This hypothesis explores the potential for the influence of anthropogenic PCDD precursors (e.g. pentachlorophenol) during the 1940s to 1990s. Transport of PCDD/Fs from the land-based source via impacted tributary river systems, and subsequent deposition processes are proposed to result in PCDD/F accumulation in the inshore marine ecosystem. The extent of the sediment PCDD/F contamination governs the concentrations in the extensive inshore marine seagrass meadows of Queensland. Partitioning processes in the sediment-seagrass system lead to increased toxic equivalency (TEQ) in the seagrass, compared to sediment.The relationship between contaminated inshore sediments, seagrass and dugongs were evaluated using six dugong habitat regions along the coastline. PCDD/F body burdens in dugongs are governed by sediment (and seagrass) PCDD/F concentrations in their habitat. High seagrass (and incidental sediment) ingestion rates, selective retention of toxicologically potent congeners and relatively low PCDD/F elimination capacities in dugongs are proposed to result in elevated PCDD/F concentrations and TEQ levels in adult animals. Transfer efficiencies of 4 and 27% of maternal TEQ levels to foetuses and calves (respectively) during gestation and lactation result in relatively high exposure potentials to offspring. Compared to no-observed-adverse-effect-levels in other mammals, and based on the results of this study, a tolerable daily intake (TDI) of 10-24 pg TEQ kg-1 day-1 was estimated for dugongs. The results of the present study found that dugongs from some regions along the coastline of Queensland exceed this TDI by up to 20 fold, suggesting that these populations may be at risk from PCDD/F contamination in their habitat. These results have important implications for the health of the environment, wildlife and humans and were used to develop a conceptual understanding of the sources, pathways and fate of dioxins in Queensland, Australia.
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Yang, Yun. "Temperature dependent PCDD/PCDF product distributions from phenols." Diss., Georgia Institute of Technology, 1999. http://hdl.handle.net/1853/20182.
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Sewart, Andrew Paul. "The fate and behaviour of polychlorinated dibenzo-p-dioxins, dibenzofurans and polychlorinated biphenyls in sewage sludge : amended agricultural soils and their potential transfer into terrestrial foodchain via lactating cattle." Thesis, Lancaster University, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.261004.
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Harrad, Stuart J. "Levels and sources of PCDDs and PCDFs in UK soils." Thesis, University of East Anglia, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.327955.
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Del, Rio Gomez Iliana Maria. "Reproductive outcomes in people contaminated by PCBs/PCDFs, organohalogens in the Yucheng accident." Thesis, London School of Hygiene and Tropical Medicine (University of London), 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.407767.
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Hess, Philipp. "The determination and environmental significance of planar aromatic compounds in the marine environment." Thesis, Robert Gordon University, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.388494.
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Prange, Joelle, and n/a. "Origin of Dioxins in Queensland: Investigations into the Distribution and Sources of Polychlorinated Dibenzo-P-Dioxins in the Queensland Terrestrial Environment." Griffith University. School of Public Health, 2004. http://www4.gu.edu.au:8080/adt-root/public/adt-QGU20040615.161651.
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Polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs) are persistent organic pollutants of global concern as they are persistent, toxic and can biomagnify through the food chain. PCDD/Fs are generally regarded as trace contaminants in a number of chemical products and they are formed as by-products from various industrial, chemical and combustion processes. The pollution with PCDD/Fs occurs with the release of these chemicals into the environment, resulting in the contamination of various compartments including; air, soil, sediment and biota. Studies that have investigated the distribution of PCDD/Fs in the environment suggest that the highest concentrations of these pollutants are found in locations with a history of industrial or chemical PCDD/F sources. Queensland is the north-eastern state of Australia. Queensland has a low population density, few industrial activities and is considered predominantly rural. Therefore it was somewhat surprising that elevated concentrations of PCDD/Fs (in particular the higher chlorinated PCDDs) have been observed in soil and sediments samples collected from various locations along the Queensland coast. The concentrations of PCDDs in Queensland samples were comparable to or higher than concentrations in similar matrices from highly polluted regions elsewhere. To investigate the origin of PCDDs in Queensland, the geographical distribution of PCDD/Fs in topsoil was investigated in the coastal and inland environments to provide information on the potential sources and to estimate the extent of the PCDD contamination. Distinct east-west gradients were detected in topsoil collected from bushland areas across the state with elevated PCDD concentrations confined to the coastal region. Within the coastal region, the contamination could not be associated with specific land uses. In fact, the PCDD/F congener profile was similar in the majority of samples from the coastal region, with a dominance of the higher chlorinated PCDDs (in particular OCDD), whereas PCDFs were low or below the limit of detection. The similarity in the PCDD/F congener profiles in the soils along the coastal region indicated that a source of PCDDs of similar origin has resulted in the contamination of soil extending more than 3000 km and estimations suggest that more than 50 tonnes of OCDD is stored in the topsoil of Queensland.s coastal region. Investigation into the vertical distribution of PCDDs in Queensland coastal soils revealed elevated concentrations of PCDDs, (in particular OCDD) in soils to at least 3.5 m. These results indicated that the extent of the PCDD contamination is significantly greater than anticipated and it was estimated that there is in the order of 3 000 tonnes of OCDD stored in Queensland's coastal soils. The specific PCDD/F congener profile in Queensland coastal soils is unlike known PCDD/F source profiles which led to the suggestion that some yet unidentified formation mechanism may have resulted in the contamination. Potential natural sources of PCDD/Fs, including forest fires, geogenic and biogenic processes were assessed as possible origins for the PCDD contamination in Queensland. Elevated concentrations of PCDDs were detected in the atmosphere during a 'prescribed burn'. This study demonstrated that although forest fires influence atmospheric PCDD/F concentrations substantially, forest fires are not the source of PCDDs in Queensland; rather they are an important mechanism for the redistribution of PCDDs and may have attributed to the widespread PCDD contamination. In this study geological materials (oil shale and kaolin) were analysed as a proxy to assess a geogenic origin of PCDDs. Elevated concentrations of PCDDs were observed in the kaolin samples, however similar and higher concentrations were detected in surface and sub-surface soils, suggesting that specific geogenic formation processes investigated are not the source of PCDDs in Queensland. A preliminary indication for a biogenic origin of PCDDs was identified during the anaerobic incubation of sugarcane irrigation sediments. An increase in the concentration of OCDD in the anaerobic treatment, compared to the control was observed after incubation for 90 days. In these same experiments, a dechlorination of OCDD to lower chlorinated (1,4,6,9-substituted) PCDDs was also observed. Similar transformation processes were observed in other anaerobic environments in Queensland, which led to the suggestion that a biogenic formation of PCDDs (possibly from a precursor) may be responsible for the origin of PCDDs in Queensland.
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Mohr, Susana. "RESÍDUOS DE POLUENTES ORGÂNICOS PERSISTENTES EM MEL DE ABELHAS: REPERCUSSÕES DA CONTAMINAÇÃO AMBIENTAL." Universidade Federal de Santa Maria, 2013. http://repositorio.ufsm.br/handle/1/3407.
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Coordenação de Aperfeiçoamento de Pessoal de Nível SuperiorPersistent Organic Pollutants (POPs) are chemical substances that are widely distributed throughout the environment, accumulate in the fatty tissue of living organisms, are found at higher concentrations in the food chain and are toxic to both humans and wildlife. In the present work, POPs were determined in honey samples from different geographic regions, evaluating both the quality and safety of honey as food, and the environmental contamination of the studied regions. Organochlorine pesticides were analysed in 186 samples from the South region of Brazil, with concentrations between
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Phan, Duong Ngoc Chau. "The relationship between fly ash chemistry and the thermal formation of polychlorinated pollutants during waste incineration." Doctoral thesis, Umeå universitet, Kemiska institutionen, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-80186.
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The thermal formation of polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs), biphenyls (PCBs), and naphthalenes (PCNs) is a major problem in waste incineration. Ideally, rather than relying on air cleaning systems and treatment techniques, their formation should be minimized or, if possible eliminated. The work presented in this thesis was conducted to obtain a deeper understanding of the thermal formation of PCDDs, PCDFs, PCBs, and PCNs during incineration using a 5 kW laboratory scale incinerator and two artificial wastes that were designed to reflect regional differences in waste composition. The first part of the thesis focuses on the validation of a recently-developed flue-gas sampling probe with enhanced cooling capabilities. Artifact formation of PCDDs and PCDFs can occur during the sampling of hot flue gases if the cooling is insufficient. The new probe was successfully used to collect samples at 700 °C without biasing the measured POP levels. The thermal formation of PCDDs, PCDFs, PCBs, and PCNs in the post-combustion zone of the incinerator was then studied by collecting flue gas samples at 400 °C, 300 °C, and 200 °C during the incineration of the two artificial wastes. Highly chlorinated POPs were formed in larger quantities when burning the waste with the higher content of metals and chlorine, which suggests that high metal levels in the waste favor the chlorination of less chlorinated POPs or otherwise facilitate the formation of highly chlorinated polyaromatics, possibly via the condensation of highly chlorinated phenols. The concentrations of these pollutants and the abundance of highly chlorinated homologues increased as the flue gas cooled. Fly ash particles play an important role in thermal POP formation by providing essential elements (carbon, chlorine, etc.) and catalytic sites. The chemical and mineralogical properties of fly ash samples were studied by X-ray diffraction (XRD), Fourier Transform Infrared (FTIR), Scanning Electron Microscopy/Energy Dispersive X-ray (SEM/EDX), and X-ray photoelectron spectroscopy (XPS) to determine their impact on thermal POP formation. Orthogonal Partial Least Squares (OPLS) modeling was used to identify correlations between the observed POP distributions and the physicochemical data. This investigation provided new insights into the impact of fly ash chemistry on thermal POP formation. In addition, the POP isomer distribution patterns generated during waste combustion were examined. These patterns are used to “fingerprint” mechanisms of POP formation. It was found that wastes containing large quantities of metals and chlorine favored the formation of highly chlorinated homologues including the very toxic 2,3,7,8-congeners. The data suggest that reducing fly ash emissions might increase the SO2 content of the flue gas and thereby suppress the Deacon process and the formation of harmful highly chlorinated aromatic species.
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Johnston, Elise. "The Role of the Speech Language Pathologist in Concussion Management: A Survey Analysis." Thesis, University of Oregon, 2018. http://hdl.handle.net/1794/23718.
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Primary objective. The goals of this project were to review the current literature regarding the role of the speech-language pathologist (SLP) in concussion management and to conduct a survey of SLPs with experience in concussion care to determine their current practices and perspectives.
Design and methods. An online survey consisting of 41 questions was emailed to SLPs throughout the U.S. and Canada. Responses were anonymously collected from 60 SLPs, and the responses were analyzed.
Results and conclusions. Results showed that SLPs who work in concussion care are generally knowledgeable and confident despite how recently concussion has become part of SLP practice. There has been improvement in the types of assessment tools used in concussion cases, but there is a need for more sensitive instruments. Findings point to the need for increased availability of concussion training for SLPs and the need for continued research into current clinical practices.
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Moore, Paul 1962. "The Analysis of PCDD and PCDF Emissions from the Cofiring of Densified Refuse Derived Fuel and Coal." Thesis, University of North Texas, 1990. https://digital.library.unt.edu/ark:/67531/metadc330690/.
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The United States leads the world in per capita production of Municipal Solid Waste (MSW), generating approximately 200 million tons per year. By 2000 A.D. the US EPA predicts a 20% rise in these numbers. Currently the major strategies of MSW disposal are (i) landfill and (ii) incineration. The amount of landfill space in the US is on a rapid decline. There are -10,000 landfill sites in the country, of which only 65-70% are still in use. The Office of Technology Assessment (OTA) predicts an 80% landfill closure rate in the next 20 years. The development of a viable energy resource from MSW, in the form of densified Refuse Derived Fuel (dRDF), provides solutions to the problems of MSW generation and fossil fuel depletions. Every 2 tons of MSW yields approximately 1 ton of dRDF. Each ton of dRDF has an energy equivalent of more than two barrels of oil. At current production rates the US is "throwing away" over 200,000,000 barrels of oil a year. In order to be considered a truly viable product dRDF must be extensively studied; in terms of it's cost of production, it's combustion properties, and it's potential for environmental pollution. In 1987 a research team from the University of North Texas, in conjunction with the US DOE and Argonne National Laboratory (ANL), cofired over 550 tons of dRDF and bdRDF with a high sulfur Kentucky coal in a boiler at ANL. This work examines the emission rates of polychlorinated dioxins (PCDDs) and furans (PCDFs) during the combustion of the dRDF, bdRDF, and coal. Even at levels of 50% by Btu content of dRDF in the fuel feedstock, emission rates of PCDDs and PCDFs were below detection limits. The dRDF is shown to be an environmentally acceptable product, which could help resolve one of the major social and environmental problems facing this country today.
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Weber, P. [Verfasser]. "Der Chlortransfer bei der Bildung von polychlorierten organischen Spurenstoffen (PCDD/PCDF) in industriellen thermischen Prozessen (Müllverbrennung) / P. Weber." Karlsruhe : KIT-Bibliothek, 2000. http://d-nb.info/1198219823/34.
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Martínez, Guijarro Karell. "Policlorodibenzo-p-dioxinas, policlorodibenzofuranos (PCDD/Fs) y bifenilos policlorados (dl-PCBs) en la gestión de residuos y el medio ambiente." Doctoral thesis, Universitat de Barcelona, 2014. http://hdl.handle.net/10803/132001.
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En esta Tesis se han realizado diversos estudios relacionados con la presencia de dioxinas y bifenilos policlorados en el ámbito de la gestión de residuos y la problemática ambiental que de ello se deriva. Para poder llevar a cabo las tareas incluidas en los diferentes proyectos ha sido preciso incidir en algunos aspectos relacionados directamente con la metodología analítica empleada en la determinación de estas sustancias.
A modo de resumen, se ha actualizado la metodología analítica de PCDD/Fs y dl- PCBs utilizada anteriormente en nuestro laboratorio, con el objetivo de disponer de un procedimiento que nos permitiera analizar ambas familias de compuestos en fracciones separadas y en el caso de los dl-PCBs en un único análisis instrumental. Asimismo, ha sido posible realizar un estudio de validación de esta metodología analítica y determinar la incertidumbre de los resultados obtenidos en muestras ambientales objeto de estudio.
Esta metodología analítica ha permitido caracterizar fangos procedentes de plantas de tratamiento de aguas residuales para su eventual aplicación en suelos agrícolas, de acuerdo a directrices y criterios sujetos a un marco regulatorio europeo, habiéndose observado que en la mayoría de los casos se cumplían los requisitos en cuanto a presencia de dioxinas y furanos.
Se han determinado los niveles de estos contaminantes en muestras de suelo de una zona de gran impacto industrial (Campo de Gibraltar), como parte de un estudio multidisciplinario llevado a cabo en esta zona, que ha permitido descartar la influencia de las PCDD/Fs en la elevada incidencia de enfermedades cancerígenas diagnosticada entre los habitantes residentes dentro del área de influencia.
Por último, se ha realizado un programa de vigilancia ambiental en Cataluña que nos ha permitido conocer los niveles de PCDD/Fs en muestras de aire ambiente, observándose un descenso promedio del 70% entre los años 1997 y 2004. Como aspecto novedoso cabe señalar la introducción de manera exitosa de un captador de aire ambiente direccional para el estudio de estos contaminantes en la atmósfera.In this thesis various studies have been conducted about the presence of dioxins and PCBs in the field of waste management and environment. In the same way, some aspects related to the analytical methodology for the determination of PCDD/Fs and dl-PCBs in environmental samples have been studied. In summary, the analytical methodology of PCDD/Fs and dl-PCBs previously used in our laboratory has been updated, in order to have a procedure to analyze both families of compounds in separated fractions and dl-PCBs in a unique instrumental analysis. Also, it has been possible to validate the analytical method and determine its uncertainty in environmental samples. PCDD/F have been analyzed in sludges from wastewater treatment plants prone to be used as fertilizers in agricultural soils, noting that in most cases the PCDD/F concentrations determined in these samples met the requirements stated in the European regulatory framework. On the other hand, the levels of these contaminants in soil samples from an area with a high industrial impact (Campo de Gibraltar), have been determined as part of a multidisciplinary study carried out in this zone, which has made it possible to rule out the influence of the PCDD/Fs in the high incidence of cancer diseases diagnosed among the resident inhabitants within the area of influence. Finally, an environmental monitoring program has been carried out in Catalonia to determine the levels of PCDD/Fs in ambient air samples, observing an average decline of 70% between 1997 and 2004. To conclude, a novel directional ambient air sampler has been successfully evaluated for the determination of PCDD/Fs and dl-PCBs in the atmosphere.
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Danielsson, Conny. "Trace analysis of dioxins and dioxin-like PCBs using comprehensive two-dimensional gas chromatography with electron capture detection." Doctoral thesis, Umeå universitet, Kemiska institutionen, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-963.
Full textAbstract:
Polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs), two groups of struc-turally related chlorinated aromatic hydrocarbons, generally referred to as “dioxins” are of great concern due to their extreme toxicity and presence in all compartments of the environment. Since they occur at very low levels, their analysis is complex and challenging, and there is a need for cost-efficient, reliable and rapid analytical alternatives to the expensive methods in-volving use of gas chromatography high-resolution mass spectrometry (GC-HRMS). It is im-portant to routinely monitor food and feed items to detect contaminations at an early stage. For the regulation of dioxins and dioxin-like PCBs in food and feed according to current legis-lation, large numbers of samples have to be analysed. Furthermore, soils at many industrial sites are also contaminated with dioxins and need remediation. In order to optimize the cost-efficiency of reclamation activities it is important to acquire information about the levels and distribution of dioxins in the contaminated areas. The aim of the studies underlying this thesis was to investigate the potential of comprehen-sive two-dimensional gas chromatography with a micro-electron capture detector (GC × GC-µECD) as a cost-effective method for analysing dioxins and dioxin-like PCBs in food, feed, fly ash and contaminated soils. Quantification studies of dioxins and dioxin-like PCBs were con-ducted and results were compared with GC-HRMS reference data. Generally, there was good agreement between both the congener-specific results and data expressed as total toxic equiva-lents (TEQs). The developed GC × GC-µECD method meets the European Community (EC) requirements for screening methods for control of dioxins and dioxin-like PCBs in food and feed. The presented results also indicate that GC × GC-µECD has potential to be used as a routine method for the congener-specific analysis of 2,3,7,8-PCDD/Fs and dioxin-like PCBs in matrices such as food and feed, fly ash and soil. However, to fully exploit the potential of the GC × GC-µECD technique, it should be combined with a fast and cost-efficient sample preparation procedure. Therefore, a number of certified reference materials (CRMs) were extracted using a new shape-selective pressurized liquid extraction technique with integrated carbon fractionation (PLE-C), and the purified extracts were analysed for PCDD/Fs using GC × GC-µECD. The results compared well with the certified values of a fly ash and a sandy soil CRM, but they were much too high for a com-plex clay soil CRM. It was concluded that this combination of techniques was very promising for screening ash and highly permeable soils. Further assessments and method revisions are still required before GC × GC-µECD can be used on a routine basis, and available software packages need to be refined in order to accelerate the data-handling procedures, which currently restrict the sample throughput.
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Larsson, Daniel. "Mobilisation of soil-bound dioxins at an old sawmill area : Impact of excavation on groundwater levels of PCDF/PCDDs at Norrbyskär." Thesis, Umeå universitet, Kemiska institutionen, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-124420.
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Holma-Suutari, A. (Anniina). "Harmful agents (PCDD/Fs, PCBs, and PBDEs) in Finnish reindeer (Rangifer tarandus tarandus) and moose (Alces alces)." Doctoral thesis, Oulun yliopisto, 2014. http://urn.fi/urn:isbn:9789526206646.
Full textAbstract:
Abstract In Finland there is a food monitoring program which has found elevated dioxin and polychlorinated biphenyl concentrations in the muscle of semi-domesticated reindeer (Rangifer tarandus tarandus) calves. This led to further research on the concentrations of persistent organic pollutants in reindeer muscle, liver, and other internal organs. The research was further expanded on wild moose (Alces alces) muscle and liver. The main objective of this thesis is to increase knowledge of polychlorinated dibenzo-p-dioxin (PCDD), polychlorinated dibenzofuran (PCDF), polychlorinated biphenyl (PCB), and polybrominated diphenyl ether (PBDE) pollution levels in the Finnish terrestrial environment, and in semi-domesticated reindeer and wild moose in particular. The research gives information of exposure conditions in the reindeer’s food chain, as well as species differences and individual variation in accumulation and distribution of pollutants in reindeer and moose. Local differences between the contaminant concentrations were explored. Toxic equivalencies (TEQs) set by the World Health Organization (WHO) of PCDD/Fs and PCBs were calculated in order to assess the validity of selling reindeer and moose tissue. It was observed that there is a species-, individual-, and tissue-specific accumulation of dioxins, dioxin-like PCB, and PBDE compounds in reindeer and moose. Varying exposure conditions mainly explain the differences, although taking into account the age of an individual animal, its metabolic patterns have a role, too. Reindeer placenta and milk proved to be important factors in the transporting of compounds from hind to calf. The highest PCDD/F and PCB concentrations (as WHO-TEQs) were observed in reindeer calves in the study area in which animals are fed in natural pastures only. Despite the findings, it was concluded that it is safe to eat reindeer and moose meat since the concentrations of dioxins and dioxin-like PCBs in the muscle are relatively low, and because of the low fat content in these animals. Reindeer liver, for its part, had quite a lot of dioxin-like compounds that may compromise its safety as food, at least on a regular basis. The study shows that Finnish semi-domesticated reindeer and wild moose are good indicator species of POP contamination in a terrestrial environment, reindeer describing the situation in northern parts of the country especiallyTiivistelmä Suomalaisessa ruokamonitorointitutkimuksessa löydettiin kohonneita dioksiinien ja polykloorattujen bifenyylien pitoisuuksia puolivillin poron vasojen lihaksista. Se johti lisätutkimuksiin pysyvien orgaanisten yhdisteiden pitoisuuksista poron lihaksessa, maksassa ja muissa sisäelimissä. Tutkimus laajeni koskemaan myös hirven (Alces alces) lihasta ja maksaa. Väitöskirjatyö lisää tietämystä polykloorattujen dibentso-p-dioksiinien (PCDD), polykloorattujen dibentsofuraanien (PCDF), polykloorattujen bifenyylien (PCB) ja polybromattujen difenyylieettereiden (PBDE) pitoisuuksista suomalaisessa maaympäristössä ja erityisesti porossa ja hirvessä. Tutkimus antaa tietoa yhdisteille altistumisesta sekä viitteitä lajien- ja yksilöiden välisistä eroavai¬suuksista yhdisteiden kertymisessä ja niiden jakaantumisessa eri kudosten välillä. Alueellista vaihtelua yhdisteiden pitoisuuksissa selvitettiin myös. Maailman terveysjärjestön (WHO) asettamia PCDD/F- ja PCB-yhdisteiden toksisuusekvivalenttiarvoja (TEQ) tarkasteltaessa pystyttiin arvioimaan kemiallista elintarvikekelpoisuutta suhteessa EU:n antamiin sallittuihin pitoisuuksiin. Työssä havaittiin laji-, yksilö-, ikä- ja kudosspesifistä dioksiinien, dioksiinienkaltaisten PCB- ja PBDE-yhdisteiden kerääntymistä porossa ja hirvessä. Tämä on todennäköisimmin seurausta vaihtelevasta altistumisesta yhdisteille, mutta myös lajien metabolisissa toiminnoissa yksilön eri ikäkausina voi olla eroavaisuuksia. Poron istukan ja maidon havaittiin olevan tärkeitä yhdisteiden kulkeutumisessa emolta sikiölle ja vasalle. Korkeimmat dioksiinien ja dioksiinien kaltaisten PCB-yhdisteiden konsentraatiot (WHO-TEQ-pitoisuuksina) havaittiin poron vasoilla tutkimusalueella, jossa eläimet olivat laiduntaneet ainoastaan luonnonlaitumilla. Huolimatta havaituista haitta-ainepitoisuuksista todettiin, että sekä luonnostaan vähärasvaisen poron että hirvenlihan syönti on turvallista suhteellisen alhaisten dioksiinien ja dioksiininkaltaisten PCB-yhdisteiden pitoisuuksien perusteella. Poron maksa puolestaan sisälsi melko korkeita dioksiinien kaltaisten yhdisteiden pitoisuuksia, mikä voi vaikuttaa sen turvalliseen käyttöön elintarvikkeena ainakin usein syötynä. Suomalainen puolivilli poro ja villi hirvi sopivat hyvin POP-kontaminoitumisen indikaattoreiksi maaympäristössä; poron erityisesti kuvaten tilannetta maan pohjoisosissa
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Stark, Marie Luise [Verfasser]. "Transfer von Dioxinen (PCDD), Furanen (PCDF) und polychlorierten Biphenylen (PCB) aus dem Futter in ausgewählte Gewebe wachsender Schafe / Marie Luise Stark." Berlin : Freie Universität Berlin, 2021. http://nbn-resolving.de/urn:nbn:de:kobv:188-refubium-31051-8.
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Pieters, Rialet. "An assessment of dioxins, dibenzofurans and PCBs in the sediments of selected freshwater bodies and estuaries in South Africa / R. Pieters." Thesis, North-West University, 2007. http://hdl.handle.net/10394/1892.
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Harsha, Prahladh 1976. "Robust PCPs of proximity and shorter PCPs." Thesis, Massachusetts Institute of Technology, 2004. http://hdl.handle.net/1721.1/26720.
Full textAbstract:
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2004.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Includes bibliographical references (p. 179-185).
by Prahladh Harsha.
Ph.D.
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Quinn, Laura Penelope. "Persistent organic pollutants (POPs) in soil associated with an active incinerator in Potchefstroom, South Africa / L.P. Quinn." Thesis, North-West University, 2005. http://hdl.handle.net/10394/1013.
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POPs are a group of chemicals that have been extensively studied over the last few
years. The main reason that these chemicals have received so much scientific
attention is the myriad of negative effects they have on the environment and human
health. The properties that cause the deleterious effects include a high molecular
stability, rendering them highly persistent. Added to this is the lipophilic and
hydrophobic nature of the compounds. POPs will thus tend to bio-accumulate and
bio-magnify in the environment, causing a direct threat to humans and wildlife. To
address this threat, the Stockholm Convention on Persistent Organic Pollutants,
under the supervision of United Nations Environment programme (UNEP), was
initiated and became legally binding on 17 May 2004. All countries, including South
Africa, which ratified this agreement, will be expected to monitor and regulate the
formation of POPs.
Polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs)
and polychlorinated biphenyls (PCBs) are all members of the dioxin-like family of
POPs. This family of chemicals pose serious health threats such as carcinogenic
effects and negative effects on reproduction. These substances, with the exception of
PCBs, are formed unintentionally as by-products of industrial and thermal processes.
One of the main sources of dioxin-like chemicals is medical waste incinerators.
In this project the area surrounding a medical waste incinerator was monitored using
a bio-assay technique. The determination of dioxin concentrations is usually
preformed by chemical analysis, however, bio-assays have proven themselves to be
a cheaper and time-saving screening method. The Toxic Equivalency Quotient
(TEQs) determined through bio-assays can support chemical analysis in determining
biologically-relevant risk assessments since bio-assay data has ecotoxicological
relevance. These assays represent an integrated biological response to chemical
pollutants, where biological effects are accounted for which is not possible in
chemical analyses. One of the bio-assays used in the determination of the dioxin-like
chemical TEQ is the H411 E reporter gene bio-assay. This assay is based on the Ah-receptor
mediated toxicity of dioxin-like chemicals. Using this technique the TEQs for
areas surrounding an active incinerator were determined, to indicate the distribution
of these substances. The TEQs for the soil samples collected ranged between nondetectable
and 154 ngTEQ/kg. There was no clear distributional pattern and the total
organic carbon content in the soil did not seem to play a crucial role in the distribution
of dioxin-like chemicals. Although a decrease in soil tillage showed a corresponding
increase in TEQ. The predominant wind direction was taken into account but no
correlation could be seen. However, meteorological parameters such as the ambient
temperature and low precipitation in the area may have contributed to lower TEQ
values. Cytotoxicity excluded data points and the phenomenon has to be addressed.
High TEQ values in a residential area where free-range chickens are raised pose a
serious concern to the level of dietary dioxin-like chemical intake. Eggs in the area
could theoretically contain between 2.75 and 28.75 pgTEQ/g egg fat. Further studies
are needed to determine how much dioxin-like chemicals are being transferred to
humans through the consumption of free-range eggsThesis (M. Environmental Science)--North-West University, Potchefstroom Campus, 2006.
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Lundin, Lisa. "Formation and degradation of PCDD/F in waste incineration ashes." Doctoral thesis, Umeå : Department of Chemistry, Umeå University, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-1395.
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Gao, Qiuju. "Dioxins and dioxin-like compounds in thermochemical conversion of biomass : formation, distribution and fingerprints." Doctoral thesis, Umeå universitet, Kemiska institutionen, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-118861.
Full textAbstract:
In the transition to a sustainable energy supply there is an increasing need to use biomass for replacement of fossil fuel. A key challenge is to utilize biomass conversion technologies in an environmentally sound manner. Important aspects are to minimize potential formation of persistent organic pollutants (POPs) such as dioxins and dioxin-like compounds. This thesis involves studies of formation characteristics of polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs) and naphthalenes (PCNs) in microwave-assisted pyrolysis (MAP) and torrefaction using biomass as feedstock. The research focuses are on their levels, distributions, fingerprints (homologue profiles and isomer patterns) and the underlying formation pathways. The study also included efforts to optimize methods for extracting chlorinated aromatic compounds from thermally treated biomass. The overall objective was to contribute better understanding on the formation of dioxins and dioxin-like compounds in low temperature thermal processes. The main findings include the following: Pressurized liquid extraction (PLE) is applicable for simultaneous extraction of PCDDs, PCDFs, PCNs, polychlorinated phenols and benzenes from thermally treated wood. The choice of solvent for PLE is critical, and the extraction efficiency depends on the degrees of biomass carbonization. In MAP experiments PCDDs, PCDFs and PCNs were predominantly found in pyrolysis oils, while in torrefaction experiments they were mainly retained in solid chars with minor fractions in volatiles. In both cases, highly chlorinated congeners with low volatility tended to retain on particles whereas the less chlorinated congeners tended to volatize into the gas phase. Isomer patterns of PCDDs, PCDFs and PCNs generated in MAP were more selective than those reported in combustion processes. The presence of isomers with low thermodynamic stability suggests that the pathway of POPs formation in MAP may be governed not only by thermodynamic stabilities but also by kinetic factors. Formation of PCDDs, PCDFs and PCNs depends not only on the chlorine contents in biomass but also the presence of metal catalysts and organic/metal-based preservatives. Overall, the results provide information on the formation characteristics of PCDDs, PCDFs and PCNs in MAP and torrefaction. The obtained knowledge is useful regarding management and utilization of thermally treated biomass with minimum environmental impact.
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Neugebauer, Julia [Verfasser], Michael [Gutachter] Wilhelm, and Beate [Gutachter] Pesch. "Der Einfluss der prä- und perinatalen Exposition mit PCDD/Fs, PCBs und Blei auf die Aufmerksamkeit von Schulkindern / Julia Neugebauer ; Gutachter: Michael Wilhelm, Beate Pesch." Bochum : Ruhr-Universität Bochum, 2017. http://d-nb.info/1129451879/34.
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Awad, Andrew Magdi. "Particulate and gas-phase PCBs and OH-PCBs in Chicago air." Thesis, University of Iowa, 2015. https://ir.uiowa.edu/etd/2038.
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This study extends the work we have previously done by reporting on both gas-phase and particulate phase PCB concentrations in Chicago air as well as giving a first report on airborne OH-PCBs in Chicago. Gas phase PCB concentrations ranged from 43.1 pg/m³ to 2250 pg/m³, with an average concentration of 594 pg/m³ ± 445 pg/m³, and exhibited strong temporal trends. Particulate phase PCBs accounted on average for 4.3% of total PCBs in a sample. OH-PCBs were detected in both the gas and particulate phase and exhibit characteristics of either emission sources or atmospheric reactions depending on the congener.
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Karlson, Johan, and Pernilla Vedenbrant. "Att leva med PCOS." Thesis, Linnéuniversitetet, Institutionen för hälso- och vårdvetenskap, HV, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-12004.
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Aim: To describe the lived experience of women with polycystic ovary syndrome (PCOS). Method: Eight scientific articles of appropriate quality were found, analyzed, condensed and synthesized. Different experiences by women with PCOS were found and ordered into themes. The findings were then anchored in associated literature and discussed. Results: Four different themes were found: Feeling different; Disturbing symptoms; Searching for answers; Care treatment. Each of these themes offered areas of improvement in regard to nursing care. Conclusions: Extra attention to the psychosocial aspects of health for women with PCOS should be taken to improve nursing care. The exchange of information between nursing staff and patients needs to be better adapted to the individual informational needs of women with PCOS.
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Afsarmanesh, Tehrani Rouzbeh. "AEROBIC BACTERIAL DEGRADATION OF HYDROXYLATED PCBs: POTENTIAL IMPLICATIONS FOR NATURAL ATTENUATION OF PCBs." Diss., Temple University Libraries, 2013. http://cdm16002.contentdm.oclc.org/cdm/ref/collection/p245801coll10/id/216532.
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Civil EngineeringPh.D.
Polychlorinated biphenyls (PCBs) are toxic and persistent chemicals that have been largely dispersed into the environment. The biological and abiotic transformations of PCBs often generate hydroxylated derivatives, which have been detected in a variety of environmental samples, including animal tissues and feces, water, and sediments. Because of their toxicity and widespread dispersion in the environment, hydroxylated PCBs (OH-PCBs) are today increasingly considered as a new class of environmental contaminants. Although PCBs are known to be susceptible to microbial degradation under both aerobic and anaerobic conditions, bacterial degradation of OH-PCBs has received little attention. The overall objective of this study is therefore to evaluate the transformation of mono-hydroxylated PCBs by the well characterized aerobic PCB-degrading bacterium, Burkholderia xenovorans LB400. In order to achieve our overall objective, a series of model mono-hydroxylated PCBs have been selected and they are used to determine the toxicity of hydroxylated congeners toward the bacterium B. xenovorans LB400. The biodegradation kinetics and metabolic pathways of the selected OH-PCBs by B. xenovorans LB400 are then characterized using GC/MS. To understand further the molecular basis of the metabolism of OH-PCBs by B. xenovorans LB400, gene expression analyses are conducted using reverse-transcription real-time (quantitative) polymerase chain reaction (RT-qPCR) and microarray technology. More formally, the specific aims of the proposed research are stated as follows: (1) To evaluate the toxicity of selected mono-hydroxylated derivatives of lesser-chlorinated PCBs toward the bacterium B. xenovorans LB400. (2) To assess the degradation of the selected OH-PCBs by B. xenovorans LB400. (3) To gain further understanding of the molecular bases of the metabolism of the selected OH-PCBs by B. xenovorans LB400. Three hydroxylated derivatives of 4-chlorobiphenyl and 2,5-dichlorobiphenyl, including 2'-hydroxy-, 3'-hydroxy-, and 4'-hydroxy- congeners, were significantly transformed by Burkholderia xenovorans LB400 when the bacterium was growing on biphenyl (biphenyl pathway-inducing conditions). On the contrary, only 2'-OH-4-chlorobiphenyl and 2'-OH-2,5-dichlorobiphenyl were transformed by the bacterium growing on succinate (conditions non-inductive of the biphenyl pathway). Gene expression analyses showed that only exposure to 2'-OH-4-chlorobiphenyl and 2'-OH-2,5-dichlorobiphneyl resulted in induction of key genes of the biphenyl pathway, when cells grown on succinate. These observations suggest that 2'OH-PCBs were capable of inducing the genes of biphenyl pathway. These results provide the first evidence that bacteria are able to cometabolize PCB derivatives hydroxylated on the non-chlorinated ring. Genome-wide transcriptional analyses using microarrays showed that 134 genes were differentially expressed in cells exposed to biphenyl, 2,5-dichlorobiphenyl, and 2'-OH-2,5-dichlorobiphneyl as compared to non-exposed cells. A significant proportion of differentially expressed genes were simultaneously expressed or down regulated by exposure to the three target compounds i.e., biphenyl, 2,5-DCB, and 2'-OH-2,5-DCB, which suggests that these structurally similar compounds induce similar transcriptional response of B.xenovorans LB400. Results of this study may have important implications for the natural attenuation of PCBs and fate of OH-PCBs in the environment. The recalcitrance to biodegradation and the high toxicity of some OH-PCBs may provide a partial explanation for the persistence of PCBs in the environment.
Temple University--Theses
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Swiegelaar, Caitlin Reneé. "The effect of different sample preparatory protocols on the induction of the aryl hydrocarbon receptor (AhR) in the H4IIE-luc reporter gene bio-assay / Caitlin Reneé Swiegelaar." Thesis, North-West University, 2012. http://hdl.handle.net/10394/9702.
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Concern on a global scale gave rise to the founding of the Stockholm Convention on persistent organic pollutants (POPs) with a view to restrict the use and production of these toxic chemicals. As a signatory, South Africa is legally bound to abide to the Convention’s objectives, including participating in relevant research and monitoring. However, developing countries such as South Africa have limited information concerning POPs, partially because these countries do not have sufficient analytical capabilities, and thus method development and refinement are necessary. One group of POPs consisting of polychlorinated dibenzo-pdioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and dioxin-like polychlorinated biphenyls (dl-PCBs), collectively referred to as dioxins, are of particular concern due to their high toxicity and persistence. Additionally, the analysis of dioxins is recognised as one of the most analytically challenging of its kind. This study investigated the effect of different preparatory protocols on the semi-quantification of dioxins using the H4IIE-luc-reporter gene assay. The protocols evaluated were either Soxhlet or pressurised liquid extraction (PLE) combined with a manual acid digestion, gel permeation chromatography (GPC) and Florisil fractionation clean-up procedure as well as the automated Total Rapid Prep™(TRP) system which makes use of a PLE combined with a multi-layer silica, alumina and carbon column clean-up procedure. To evaluate the protocols, an eight point matrix matched calibration curve, two soil samples and a certified reference material (CRM) were used. The extracts were semi-quantified by the H4IIE-luc bio-assay. During the course of the assay, the appropriateness of different standards was investigated, and a mixed standard containing all 17 toxic PCDD/Fs was chosen for quantification. During the data review process, higher bioassay equivalent (BEQ) values were obtained from PLE compared to Soxhlet extraction, while no statistically significant difference (Kruskal-Wallis ANOVA: p > 0.05) was found between the assay quantifications for the different preparatory techniques. However, the results of the H4IIE bio-assay were larger than the expected values. The identity of the chemicals that were in all likelihood responsible for the higher response was investigated through instrumental analysis using comprehensive two-dimensional gas chromatography coupled to time of flight mass spectrometry (GCxGC-TOFMS). Instrumental results indicated a high level of PAHs in the extracts, which could lead to super induction of the aryl hydrocarbon receptor (AhR) and therefore, to a positive bias in the results. Instrumental screening proved that all selected preparatory protocols were inadequate at removing interfering compounds and not sufficiently selective for PCDD/Fs, although the TRP was more successful in removing interferences. The high matrix interference hindered peak identification. Additionally, as indicated by instrumental analysis, the weak recovery of PCDD/Fs could be ascribed to high evaporation temperatures. The effect of different reference standards in the H4IIE bio-assay used during semi-quantification needs further investigation; similarly, the optimisation of extraction, evaporation and clean-up protocols and the use of different GCxGC-TOFMS column combinations aimed at more efficient separation needs to be investigated.
The assistance of the National Metrology Institute (funded through the Department of Trade and Industry) towards this research is hereby acknowledged.Thesis (MSc (Environmental Sciences))--North-West University, Potchefstroom Campus, 2013.
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Weidemann, Eva. "Waste incineration residues : Persistent organic pollutants in flue gas and fly ash from waste incineration." Doctoral thesis, Umeå universitet, Kemiska institutionen, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-92765.
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Modern societies produce large quantities of municipal solid waste (MSW), which is commonly disposed of by incineration. This has several advantages: it reduces the waste’s volume and sterilizes it while also enabling energy recovery. However, MSW incineration has some notable disadvantages, the most widely debated of which is probably the production and release of persistent organic pollutants (POP) such as polychlorinated dibenzofurans (PCDF), dibenzo-p-dioxins (PCDD), biphenyls (PCB) and naphthalenes (PCN). Of the 210 PCDF and PCDD congeners, 17 are toxic, with hormone-disrupting and carcinogenic properties. Twelve of the 209 PCB congeners and at least 2 of the 75 PCN also exhibit such properties. These POP form in the post-combustion zones of MSW incineration plants and are removed from the flue gas using filtering devices that trap them in the fly ash This thesis concerns the formation and degradation of POP in processes related to MSW incineration. The first paper describes a case study in which PCDD were forming in filters designed to remove them from flue gases, causing emission-related issues in a full-scale MSW incineration plant. It was shown that the PCDD formation was probably due to chlorophenol condensation on the filters’ surfaces. The second paper describes the validation of a cooling probe designed to prevent POP formation during high temperature (>450 °C) flue gas sampling. The results obtained also confirmed that PCDF and PCDD formation takes place at temperatures below 600 °C. In the third paper, three different fly ashes were subjected to thermal treatment under an inert atmosphere in a rotary kiln and in sealed ampoules at 400 °C. The concentrations, degrees of chlorination and congener profiles of the POP in the treated ashes and emitted gases were compared to those for the untreated ashes. The trends observed for PCDF mirrored those for PCN, while the trends for PCDD closely resembled those for PCB. The PCDF congener profiles of the kiln ash were similar regardless of the initial ash composition, suggesting that the mechanisms of PCDF formation were similar in all cases. The fourth paper describes the surface characterization of the three fly ashes studied in paper three by SEM, EDX, XPS and XRD. In addition, the thermal desorption and subsequent degradation of POP from the ashes was studied at temperatures of 300-900 °C. The composition of the gases released as the temperature increased differed between the ashes and depended on their composition. Doping experiments using isotopically labelled PCDF and PCDD suggests that PCDD desorbed at lower temperatures than PCDF. This thesis examines several problems relating to POP formation during MSW incineration, from sampling to the ultimate fate of incineration residues. The results obtained illustrate the wide range of processes that contribute to thermal POP formation and degradation during and after MSW incineration.Förbränning av hushållssopor är en vanlig metod för att hantera ett växande avfallsproblem. Metoden har flera fördelar, såsom minskning av volym och vikt, sterilisering och energiåtervinning. Sopförbränning har dock vissa nackdelar och det mest debatterade är sannolikt utsläpp av persistenta organiska föroreningar (POPs) som polyklorerad dibensofuran (PCDF), dibenso-p-dioxin (PCDD), bifenyl (PCB) och naftalen (PCN). Det finns totalt 210 PCDF- och PCDD- kongener, med mellan ett till åtta klor på kolskelettet, varav 17 är giftiga med hormonstörande och cancerframkallande egenskaper. Även tolv av totalt 209 PCB-kongener samt minst två av totalt 75 PCN-kongener uppvisar liknande egenskaper. Dessa klorerade organiska föroreningar bildas då rökgaserna kyls ner i sopförbränningsanläggningarna och avlägsnas från rökgaserna med hjälp av filter och hamnar i flygaskan. Denna avhandling handlar om bildning och nedbrytning av POPs i sopförbränningsrelaterade processer. Den första artikeln är en fallstudie där PCDD bildas i filtren i en fullskalig sopförbränningsanläggning. Bildningen ledde till förhöjda halter organiska föroreningar i rökgaserna, vilket ledde till ökade utsläpp. Den funna bildningsvägen för PCDD i filtren befanns sannolikt bero på kondensation av klorfenoler på filterytorna. Den andra artikeln är en valideringsstudie av en kylprob avsedd att användas vid rökgasprovtagning vid hög temperatur (> 450 °C) för att undvika bildning av POPs under provtagningen. Studien bekräftade att majoriteten av PCDF- och PCDD- bildning i rökgaser från sopförbränning sker vid temperaturer under 600 °C. I den tredje artikeln berättas om behandling av tre olika flygaskor från olika sopförbränningsanläggningar. Askorna behandlades vid 400 °C i inert atmosfär i både en roterugn och i förseglade ampuller. De resulterande koncentrationerna, kloreringsgraderna och kongenprofilerna av de organiska föroreningarna jämfördes. Likheter hittades mellan PCDF och PCN, medan PCDD och PCB betedde sig på ett annat sätt. Studien fann också att PCDF kongenprofiler i aska som behandlats i roterugnen liknade varandra, oberoende av askornas sammansättning, vilket tyder på en liknande bildningsväg. För den fjärde artikeln, genomfördes ytkarakterisering (SEM, EDX, XPS och XRD) på de tre flygaskorna från artikel tre som sedan hettades upp från 30 °C till 900 °C i vacuum. Det som frigjordes på grund av uppvärmningen samt nedbrytningsprodukter från askorna studerades med hjälp av masspektrometri och infraröd spektroskopi. Studien fann att de gaser som frigjordes när temperaturen ökade skilde mellan askorna, beroende på deras sammansättning. Studien fann också att när aska dopad med isotopmärkt PCDF och PCDD utsattes för samma behandling, frigjordes PCDD vid lägre temperatur än PCDF. Denna avhandling berör flera aspekter av problematiken kring klorerade organiska föroreningar som bildas vid sopförbränning, från provtagning till hur man ska hantera flygaskan. Avhandlingen belyser även olika typer av bildning och nedbrytning av POPs i varma processer kopplade till sopförbränning.
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Wicks, Tony. "Design and implementation of PCAS filters." Thesis, University of Warwick, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.308510.
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Harsha, Prahladh 1976. "Small PCPs with low query complexity." Thesis, Massachusetts Institute of Technology, 2000. http://hdl.handle.net/1721.1/86448.
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Vale, Luiz Américo da Silva do. "Hidrodescloração catalítica de bifenilas policloradas (PCBs)." Universidade de São Paulo, 2008. http://www.teses.usp.br/teses/disponiveis/46/46132/tde-26112008-121816/.
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Bifenilas policloradas (PCBs) foram produzidas comercialmente entre 1929 e meados da década de 1980 para propósitos industriais. As mesmas propriedades que despertaram o interesse industrial, tais como: inércia química, alta constante dielétrica, resistência à queima; foram responsáveis pelo espalhamento dos PCBs em todos os compartimentos ambientais, de tal forma que são encontrados em amostras de tecidos adiposos de animais e humanos, leite, sedimentos dentre outras matrizes. Enormes quantidades de PCBs continuam em uso ou estão estocadas a espera de uma destinação final. No presente estudo demonstramos o uso da reação de hidrodescloração catalítica como forma de destruição/destoxificação de bifenilas policloradas. Para tanto, a reação foi estudada em amostras reais de PCBs (óleo dielétrico - Ascarel®), amostras comerciais (Aroclor® 1242 e 1254) e amostra sintética (2,4-diclorobifenila). O estudo se baseia no uso de solventes orgânicos como meio reacional e paládio suportado em carvão ativado como catalisador, devido à sua seletividade para a reação desejada, bem como sua baixa capacidade de hidrogenar compostos aromáticos. xii A condição experimental ótima para a hidrodescloração foi determinada a partir da aplicação de planejamento experimental do tipo Doehlert. Esta condição ótima foi aplicada com sucesso a PCBs contidos em outras matrizes. A cinética da reação é apresentada para o 2,4-diclorobifenila como estudo de caso e uma proposta de mecanismo da reação de hidrodescloração de PCBs é apresentada baseada nos resultados experimentais.Polychlorinated biphenyls (PCBs) were produced between 1929 and the 1980s for industrial applications. The same properties that make it a chemical of interest for industrial applications, such as: chemical inertness, high dielectric constant, fire resistance; were responsible for the widespreading of PCBs over all enviornmental compartments. They can be found in samples of fat tissues of humans and animals, milk, sediments, among other matrices. Enormous quantities of PCBs are still in use or stocked waiting for a final destination. In the present study, we have shown the use of catalytic hydrodechlorination as an alternative for the destruction/detoxification of polychlorinated biphenyls. For this, the reaction was studied in real samples of PCBs (dielectric oil - Ascarel®), commercial samples (Aroclor® 1242 e 1254) and pure chlorinated biphenyls (2,4-dichlorobiphenyl). The study is based in the use of organic solvents as reactional media and palladium supported in activated carbon as catalyst, due to its selectivity for the desired reaction and to its low capacity to hydrogenate aromatic compounds. xiv The optimal hydrodechlorination condition was determined through the application of a Doehlert experimental planning. This optimal condition was applied with success to PCBs contained in other matrices. The reaction kinetics for 2,4-dichlorobiphenyl was presented as a case study and a mechanistic proposal was presented for the hydrodechlorination of PCBs based on these experimental conditions.
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Wood, David L. "Abnormal Uterine Bleeding, Amenorrhea and PCOS." Digital Commons @ East Tennessee State University, 2017. https://dc.etsu.edu/etsu-works/5172.
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Badji, Aisha. "A PCOS-like Drosophila Melanogaster model." Thesis, Högskolan i Skövde, Institutionen för hälsa och lärande, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:his:diva-17845.
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Polycystic ovary syndrome (PCOS) is a female endocrine disorder defined by high androgen levels and presence of polycystic ovaries. PCOS is characterized by menstrual irregularities, anovulation, infertility, hyperandrogenism, insulin resistance, abdominal obesity, chronic inflammation and increased hair growth. The diagnosis is based on 2003/2004 Rotterdam criteria, which is based on the presence of the following phenotypes: anovulation, clinical and biochemical marks of hyperandrogenism and polycystic ovarian morphology. Theoretical causes could be genetical, environmental or maternal imprinting. Drosophila Melanogaster, a model used broadly in disease research, could bear promising insights to this syndrome. Besides having a lifecycle characterized by a 12 days metamorphism, these species of flies have the ecdysone (steroid) hormone, similar to the human testosterone and the body systems similar to those of the human body. This laboratory work involved the development of a PCOS-like drosophila fly model through exposure to 10mg/ml of testosterone after 24 hours of starvation. Data collection comprised measurements of weight and length, anovulation, triglyceride quantification and RT-qPCR for quantification of inflammatory and PCOS-related genes. Results showed significant differences in response to physical stress among the four groups of flies. Variation in weight and length values, as well as in fecundity, triglyceride assay and relative expression levels were also observed. Although the expression levels of inflammatory and PCOS- related genes were not significantly affected, homeostasis was clearly affected by metabolic disturbances. These observations lead to the conclusion that further experiments should be done in order to establish a more comprehensive definition of the syndrome.
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Aurell, Johanna. "Effects of Varying Combustion Conditions on PCDD/F Formation." Doctoral thesis, Umeå universitet, Kemi, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-1795.
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Polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) are by-products emitted from combustion sources such as municipal solid waste (MSW) incineration plants. These organic compounds are recognized as toxic, bioaccumulative and persistent in the environment. PCDD/Fs are removed from flue gases before released from MSW incineration. However, the PCDD/Fs are not destroyed but retained in the residues, thus in the environment. Understanding the pathways that lead to their formation is important in order to develop ways to suppress their formation and prevent their release into the environment. Suppressing the formation can also allow less expensive air pollution control system to be used, and/or the costs of thermally treating the residues to be reduced. The main objective of the studies underlying this thesis was to elucidate process, combustion and fuel parameters that substantially affect the emission levels and formation of PCDD/Fs in flue gases from MSW incineration. The experiments were conducted under controllable, realistic combustion conditions using a laboratory-scale reactor combusting artificial MSW. The parameter found to most strongly reduce the PCDD/F emissions, was prolonging the flue gas residence time at a relatively high temperature (460°C). Increasing the sulfur dioxide (SO2) to hydrogen chloride (HCl) ratio to 1.6 in the flue gas was also found to reduce the PCDF levels, but not the PCDD levels. Fluctuations in the combustion process (carbon monoxide peaks), high chlorine levels in the waste (1.7%) and low temperatures in the secondary combustion zone (660°C) all tended to increase the emission levels. The PCDD/PCDF ratio in the flue gas was found to depend on the chlorine level in the waste, fluctuations in the combustion process and the SO2:HCl ratio in the flue gas. The formation pathways were found to be affected by the quench time profiles in the post-combustion zone, fluctuations in the combustion process and addition of sulfur. In addition, increased levels of chlorine in the waste increased the chlorination degrees of both PCDDs and PCDFs. A tendency for increased SO2 levels in the flue gas to increase levels of polychlorinated dibenzothiophenes (sulfur analogues of PCDFs) was also detected, however the increases were much less significant than the reduction in PCDF levels.
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Geng, Dawei. "Gas chromatography-atmospheric pressure chemical ionization-tandem mass spectrometry methods for the determination of environmental contaminants." Doctoral thesis, Örebro universitet, Institutionen för naturvetenskap och teknik, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:oru:diva-51727.
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The recent developments and improvements of instrumental methods for the analyses of the environmental contaminants, especially the persistent organic pollutants (POPs), have made it possible to detect and quantify these at very low concentrations in environmental and biotic matrices. The main objective of this thesis is to demonstrate the capability of the atmospheric pressure chemical ionization technique (APCI), using gas chromatography coupled to tandem mass spectrometry for the determination of a wide range of environmental contaminants, including the POPs regulated by Stockholm Convention, such as polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), but also the derivates of PBDEs and novel brominated flame retardants (NBFRs). The APCI was operated in charge transfer condition, preferably producing molecular ions. Multiple reaction monitoring (MRM) experiments were optimized by adjusting cone voltage, collision energy and dwell time. Optimization of source parameters, such as gas flows and temperatures was also performed. Low concentration standards were analyzed, achieving a visible chromatographic peak for 2 fg 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) demonstrating the excellent sensitivity of the system. Adequate linearity and repeatability were observed for all the studied compounds. The performance of APCI methods was validated against the conventional methods using gas chromatography coupled to high resolution mass spectrometry for chlorinated compounds in a wide range of matrices including environmental, air, human and food matrices. The GC-APCI-MS/MS method was successfully applied to a set of 75 human serum samples to study the circulating levels of POPs in epidemiologic studies. Moreover the method was utilized to establish temporal trends of POPs in osprey eggs samples collected during the past five decades.
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Ebhogiaye, Ijeoma N. "An economics advisor on test strategy planning for complex electronic boards." Thesis, Brunel University, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.310056.
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Chewe, Derrick. "Analytical methods for the congener specific determination of polychlorinated biphenols in environmental and food samples." Thesis, Nottingham Trent University, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.363328.
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Mills, Andrew G. "An investigation into the extraction and analysis of polychlorinated biphenyls from various foodstuffs." Thesis, University of Bath, 1994. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.261036.
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Aytekin, Banu. "Vibration Analysis Of Pcbs And Electronic Components." Master's thesis, METU, 2008. http://etd.lib.metu.edu.tr/upload/3/12609444/index.pdf.
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In this thesis, vibration analyses of electronic assemblies that consist of an electronic box, printed circuit board and electronic components are presented. A detailed vibration analysis of a real electronic assembly is performed by finite element methods and vibration tests. Effects of component addition and component modeling are investigated by finite element analysis in detail. Results are compared in order to identify the most efficient, reliable and suitable method depending on the type of problem. Experimental results for the vibration of an electronic box, PCB and components are presented and discussed. Furthermore, an analytical model that represents a printed circuit board and electronic component is suggested for fixed and simply supported boundary conditions of the PCB. Different types of electronic
components are modeled analytically to observe different dynamic characteristics. The validity of the analytical model is computationally checked by comparing results with those of finite element solution.
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Stemm, Divinia Nolasco. "INTERACTIONS BETWEEN SELENIUM AND POLYCHLORINATED BIPHENYLS (PCBs)." UKnowledge, 2005. http://uknowledge.uky.edu/gradschool_diss/472.
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This study investigated the interaction between polychlorinated biphenyls (PCBs) and selenium to explain the mechanism involved that could affect selenium metabolism and its anti-cancer property. PCBs congeners and mixtures were previously found to reduce hepatic Se and Se-dependent glutathione peroxidase activity. I hypothesized that certain PCB congeners affect selenium metabolism in the rat liver resulting in diminished antioxidant capacity of selenoproteins, which could alter the ability of Se to protect against PCBs induced tumor promotion. In the first study, the influence of 3,3,4,4-tetrachlorobiphenyl (PCB 77) on hepatic Se and glutathione peroxidase (GPx1) activity as well as cytochrome P450 1A1 induction was examined by employing a time-course study, which showed that PCB 77 significantly reduced the hepatic selenium level and GPx1 activity and that this effect was influenced by gender. The next study explored how PCB 77 could deplete hepatic selenium by determining selenium concentrations in different tissues, feces and urine. This study demonstrated that PCB-77 decreased hepatic Se by increased excretion of Se in urine but not in feces. Unlike glutathione peroxidase, thioredoxin reductase activity was not affected by PCB 77. The third study investigated the effect of selenium supplementation on the tumor promoting activity of PCB 77 and 2,2,4,4,5,5-hexaclorobiphenyl (PCB 153) using a 2-stage carcinogenesis model. Se supplementation did not diminish the induction of altered hepatic foci by coplanar PCB 77 or ortho-substituted PCB 153. Instead of protection, the number of foci per cubic centimeter and per liver among the PCB-77 treated rats was increased as the selenium dietary level increased. PCB 153 did not show the same selenium dose-response effect; nevertheless, selenium supplementation did not confer protection against foci development. On the other hand, supranutritional selenium reduced the mean focal volume. Supranutritional selenium or PCBs did not affect cell proliferation or thioredoxin reductase activity. Lastly, the use of the Zeeman graphite furnace atomic absorption spectrometry (GFAAS) method and closed microwave digestion technique for selenium determination of biological samples was compared with the neutron activation analysis and fluorometry methods. I found that GFAAS was not as reliable as the other methods.
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Vyas, Nikhil S. M. Massachusetts Institute of Technology. "Imperfect gaps in Gap-ETH and PCPs." Thesis, Massachusetts Institute of Technology, 2019. https://hdl.handle.net/1721.1/122771.
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Thesis: S.M., Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science, 2019Cataloged from PDF version of thesis.
Includes bibliographical references (pages 45-47).
In this thesis we study the role of perfect completeness in probabilistically checkable proof systems (PCPs) and give a new way to transform a PCP with imperfect completeness to a PCP with perfect completeness, when the initial gap is a constant. In particular, we show that PCP[subscript c,s][r, q] [mathematical symbol] PCP[subscript 1,s'][r + 0(1), q+ 0 (r)] for c - s = [omega](1) which in turn implies that one can convert imperfect completeness to perfect in linear-sized PCPs for NTIME[0(n)] with a 0(log n) additive loss in the query complexity q. We show our result by constructing a "robust circuit" using threshold gates. These results are a gap amplification procedure for PCPs (when completeness is imperfect), analogous to questions studied in parallel repetition [21] and pseudorandomness [141. We also investigate the time complexity of approximating perfectly satisfiable instances of 3SAT versus those with imperfect completeness. We show that the Gap-ETH conjecture without perfect completeness is equivalent to Gap-ETH with perfect completeness; that is, MAX 3SAT(1 - [epsilon], 1 - [delta]) for [delta] > [epsilon] has 2⁰([superscript n])-time algorithms if and only if MAX 3SAT(1, 1 - [delta]) has 2⁰([superscript n])-time algorithms. We also relate the time complexities of these two problems in a more fine-grained way, to show that T₂ (n) by Nikhil Vyas.
S.M.
S.M. Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science
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Wilhelmsson, Diana. "Thermal analysis of PCBs for airborne applications." Thesis, KTH, Mekanik, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-213129.
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Saab develops and manufactures Printed Circuit Board (PCB) for airborne applications. Since the cooling supply often is limited and power dissipation is high the thermal performance of the PCBs is an important parameter to evaluate. This thesis is a step in a larger evaluation of the Finite Element Methods (FEM) used for thermal analysis of the cards. The evaluation aims to create greater understanding of the uncertainties in current models and to provide new proposals on how the models can be improved.SAAB tar fram och tillverkar kretskort för flygande ändamål. Då kylförsörjningen inte sällan är begränsad och effektförlusten hög är kretskortens termiska prestanda en viktig parameter att utvärdera. Detta examensarbete är ett steg i en större utvärdering av de Finita Element Modellerna (FEM) som används vid termisk analys av korten. Utvärderingen syftar till att skapa större förståelse för osäkerheter i nuvarande modeller samt att ge nya förslag på hur modellerna kan förbättras.
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Chenot, David. "ORGANIZATIONAL CULTURE AND RETENTION IN PUBLIC CHILD WELFARE SERVICES ORGANIZATIONS." Case Western Reserve University School of Graduate Studies / OhioLINK, 2007. http://rave.ohiolink.edu/etdc/view?acc_num=case1169849653.
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Penteado, José Carlos Pires. "Metodologia analítica para análise de PCBs em fígado de peixe do Rio Paraíba do Sul." Universidade de São Paulo, 2000. http://www.teses.usp.br/teses/disponiveis/46/46133/tde-25062008-092101/.
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Os bifenilos policlorados (PCBs) são compostos organoclorados que apresentam 209 congêneres sendo que alguns deles são muito tóxicos. Foram produzidos por mais de 30 anos sendo utilizados principalmente no setor eletroeletrônico. Devido à legislação brasileira não prever substituição de equipamentos, ainda em funcionamento, que contenham PCBs estes podem tomar-se fontes potenciais de contaminação no ambiente. Neste aspecto a região do Vale do Paraiba, por ter um parque industrial diversificado (químico, eletrônico e mecânico) iniciado na década de 50, pode apresentar essas fontes. O rio Paraíba do Sul é o principal recurso hídrico sendo utilizado para captação de água para abastecimento e também como receptor de efluentes industriais e esgotos domésticos. Nele também é praticada a pesca de subsistência pela população ribeirinha. Devido às características de bioconcentração no fígado de peixe por organoclorados, decidiu-se utilizá-lo como bioindicador. Assim pode ser verificada a presença de PCBs na região avaliando-se os níveis de contaminação que podem colocar em risco as populações ribeirinhas. Na metodologia analítica proposta, foram encontrados de 48 a 159 ng/g de PCBs totais para a traíra e 12 a 34 ng/g de PCBs totais para o mandi. A recuperação alcançada foi na faixa de 50 a 100%. Os valores do limite de detecção para os 13 congêneres estudados se encontraram na faixa de 1 a 3 ng/g. Os congêneres mais genotóxicos (PCB 77 e 126) foram encontrados principalmente na traira com 20 ± 9 ng/g (PCB 77) e 21 ± 3 ng/g (PCB126), enquanto que o mandi apresentou principalmente o PCB 77 com 8 ± 2 ng/g. Estas avaliações são preliminares e necessitam de maiores estudos para se determinar a extensão do grau de contaminação e as possíveis fontes de contaminação por estes compostos.The chlorinated biphenyls are organochlorinated compound with around 209 congeners some them are very toxic. They were produced during 30 years and used mainly in the eletronic equipment (transformers and capacitors). Brazilian legislation don\'t obligate the substitution of equipaments containing PCBs that are still being used. So this could be a signifincat source of environrnent contamination. The industries have settled the Paraíba Valley since 50\'s that can represent the major source of PCBs. The South Paraíba river main hidric source that has been used caption for water suplly and subsistent fishing. It receives also industrial efluents and domestic sewer. In spite of bioconcentration characteristics of organochIorinated in fishes\'liver, this organ was decided to be used as bioindicator. PCB\' s level can be avaliated indiretly, analysing the exposure of some species of fishes, and arevall contamination around the fish population. From this proposed analytical method total PCBs from traira here found nearly 32 to 143 ng/g in liver and 8 to 26 ng/g in mandi\'s liver. The aproached recuperation were about 50 to 100%, the limit detection for these 13 congeners were around 1 to 3ng/g. The most genotoxic congeners were found in traira (PCB 77 20 ± 9ng/g and PCB 12621 ± 3ng/g) and other hand, it was only in mandi PCB 77 8 ± 2ng/g. These evalutions are preliminar and necessites further studies to determine the extension of contarnination and the possibly source these compound\' s contamination.
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Koenig, Brenda Grace. "Latitudinal patterns of polychlorinated biphenyls (PCBs) in zooplankton." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/nq22914.pdf.
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Khmyl, Aliaksei L. "Phytoremediation of soil contaminated with polychlorinated biphenyls (PCBs)." Virtual Press, 2003. http://liblink.bsu.edu/uhtbin/catkey/1265088.
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Edgar, Petrena Joyce. "Biogeochemistry of polychlorinated biphenyls (PCBs) in estuarine sediments." Thesis, University of the West of Scotland, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.343348.
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