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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.
121

1H NMR-based Metabolomics for Elucidating the Mode of Action of Ccontaminants in the Earthworm Eisenia Fetida after Sub-lethal Exposure

Lankadurai, Brian 08 August 2013 (has links)
There is a growing need to develop rapid and cost-effective ecotoxicological tools for risk assessment because traditional methods examine endpoints such as mortality, which do not provide any insight into the mode of action (MOA) of the chemical. Research presented within this thesis illustrates the potential of 1H NMR-based metabolomics as a rapid and routine ecotoxicological tool that can elucidate a chemical’s MOA and also aid in the identification of metabolites of exposure. Metabolomics involves measuring the fluctuations in the endogenous metabolites of an organism within a cell, tissue, bio-fluid or whole organism in response to an external stressor. We focused on the model polycyclic aromatic hydrocarbon (PAH) phenanthrene, and the perfluoroalkyl acids (PFAAs) perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS), due to their recalcitrant nature and widespread prevalence in soil environments. 1H NMR-based metabolomics analysis of the exposure of Eisenia fetida earthworms to sub-lethal phenanthrene exposure via filter paper contact tests revealed a concentration-dependent two-phased MOA: a linear correlation between the metabolic response and exposure concentration at low concentrations followed by a plateau in the responses at high concentrations. Alanine, glutamate, maltose, cholesterol and phosphatidylcholine emerged as potential indicators of phenanthrene exposure. An increased energy demand and an interruption in the conversion of succinate to fumarate in the Krebs cycle were observed due to phenanthrene exposure. Sub-lethal PFOA and PFOS exposure to E. fetida via contact tests for two days revealed heightened responses with higher PFOA and PFOS concentrations. Leucine, arginine, glutamate, maltose, and ATP were identified as potential indicators of PFOA or PFOS exposure. E. fetida responses were then investigated after exposure for two, seven and fourteen days to an artificial soil that was spiked with sub-lethal PFOS concentrations. An exposure time-dependent operation of two separate MOAs were identified. Both the contact tests and artificial soil exposure studies identified an elevation in fatty acid oxidation, a disruption in energy metabolism and biological membrane structure, and also an interruption of ATP synthesis following PFOA and PFOS exposure. This thesis illustrates the promise of NMR-based metabolomics as a routine tool for ecotoxicological assessment of contaminated sites.
122

Tracking Oil from the Deepwater Horizon Oil Spill in Barataria Bay Sediments

Dincer, Zeynep 03 October 2013 (has links)
In April 2010, approximately 4.9 million barrels of oil were accidentally released into the Gulf of Mexico during the Deepwater Horizon Macondo Mc252 Oil Spill. Some of the surface oil was carried by prevailing winds and currents and reached the coast of Louisiana impacting marsh and marine ecosystems. One and a half years after this incident, a set of oiled marsh samples (2 grab samples) coupled with nearby subtidal and intertidal cores (12 cores) were collected from Barataria Bay, Louisiana to determine the probable source of petroleum residues present and to characterize the chemical composition of the oil. Plus, pre-spill core which was collected from Barataria Bay in 2007 was analyzed to identify the background hydrocarbon composition of the area. Polycyclic aromatic hydrocarbons (PAH), total petroleum hydrocarbons (TPH), biomarker, and stable carbon isotope compositions of selected samples were detected using a GC-MS and an elemental analyzer Conflo system coupled to a DeltaPlusXP isotope ratio mass spectrometer. The comprehensive chemical data allowed us to classify the pre and post-spill samples into 4 Groups. According to this classification, Group 1 and Group 2 samples had the highest concentrations of petroleum-derived hydrocarbons. Group 3 and background samples, on the other hand, was dominated by biogenic signatures. Although a direct connection between the detected and spilled Macondo oils results are complicated due to confounding factors (e.g., already present hydrocarbons and weathering processes), our biomarker data indicates that both oils have similar signatures. This close genetic relationship was also identified by stable carbon isotope analysis. The impact of the Macondo Mc252 Oil Spill in Barataria Bay appears to be limited to areas closer to the source. The oil has undergone moderate weathering and has penetrated into, the at least, the top 9 cm sediments. Additionally, to examine the decadal-scale history of sedimentation in these marshes, a sediment core was analyzed for the radioisotope 137Cs. The observed sedimentation rate of 0.39 cm/yr shows that oil pollutant input into Barataria Bay has been ongoing for at least 50-60 years.
123

Investigation Of Polycyclic Aromatic Hydrocarbon (pah) Deposition In Ankara

Gaga, Eftade Odaman 01 April 2004 (has links) (PDF)
In this work, wet deposition samples were collected at Middle East Technical University campus, Ankara, between December 2000 and May 2002. Snow samples were collected from 50 grids in January, 2001 in Ankara to investigate dry deposition of PAHs. The collected samples were preconcentrated by Solid Phase Extraction and ultrasonic extraction tecniques. Extraction methodologies were improved prior to analysis of samples. Extracted samples were analyzed by Gas Chromotography-Mass Spectrometry for 14 Polycyclic Aromatic Hydrocarbons. Selected Ion Monitoring mode was used throughout the analysis. Phenanthrene, fluoranthene, pyrene and benzo (b+k) fluoranthene were found to be dominant PAHs in wet deposition samples. Seasonal variation of PAHs were observed having higher concentrations in winter period. Meterological parameters were also examined together with PAH concentrations. Contribution of PAHs coming from North East and South West direction were found to be dominant. Wet deposition fluxes were calculated and compared with other urban sites. Wet deposition fluxes are lower than industrial sites and comparable with urban sites in Europe. PAH ratios and factor analysis results demostrated combustion and traffic emissions are major sources of pollutants in the city. Dry deposition of PAHs were invesigated using snow as a natural collecting surface. Dry deposition fluxes calculated using snow surface are compareble with other similar sites. Dry deposition pollution maps of PAHs were drawn by MapInfo software and it was observed that the major pollution regions are the localities where low income families live and low quality coal used for heating purpose. Ratio calculations showed that the central parts of the city is mostly affected from traffic emissions while coal emissions are dominating at the other parts of the city. Factor analysis applied to data set and 6 factors distinquished as coal, soil, traffic, oil combustion, mixed combustion and road dust.
124

Desenvolupament i Aplicació de Bioassaigs per a la Monitorització Ambiental de Lligands del Receptor d’hidrocarburs d’Aril (AhR, Compostos Tipus Dioxina)

Olivares Polo, Alba 25 November 2011 (has links)
Els contaminants ambientals capaços d’unir-se al Receptor d’hidrocarburs d’Aril i induir la seva activació ectòpica són molt diversos i es troben àmpliament distribuïts per tota la biosfera. L’exposició continuada a aquest tipus de compostos s’ha vist relacionada amb l’augment de malalties cardiovasculars i càncer, entre d’altres efectes adversos. D’aquesta manera, la seva monitorització en zones amb fonts de contaminación continues és necessària per tal d’assegurar que no es sobrepassen els límits establerts. La utilització de bioassaigs per a determinar l’activitat tipus dioxina dels contaminants. a més de la seva composició química, permet una valoració més acurada dels riscos que representen. Aquesta tesis presenta com a objectius el disseny i la validació de bioassaigs basats en un llevat recombinant i embrions de peix zebra que permeten, en el cas dels llevat, una valoració ràpida i econòmica i, en el cas de l’embrió de peix zebra, un estudi més complert i amb la possibilitat d’observar efectes adversos directes. Per tal de dur a terme la seva validació. aquests bioassaigs es van utilitzar en diversos estudis medi ambientals de zones possiblement contaminades per compostos tipus dioxina (PAHs, Organoclorats, etc.) que representen les diferents tipus de matrius on es solen trobar aquests contaminants: sediment fluvial (part baixa del riu Ebre, des de l’Embassament de Flix fins a la desembocadura) i marí (Estuari d’Urdaibai), particulat de l’aire (Vall del Po, al nord d’Itàlia) i sòl (residus miners al districte de Datong a Xina). Els resultats d’aquests estudis han permès establir els nivells de contaminació de cada zona així com observar que la resposta obtinguda pels nostres bioassaigs té un perfil similar a l’observada per altres bioassaigs ja establerts així com amb la composició química. A més, destaquen la importància de combinar l’anàlisi química amb l’activitat biològica per tal d’obtenir una informació més complerta sobre compostos que no s’han tingut en compte o que es desconeix la seva presència a les mostres. / Title: Development and application of bioassays for environmental monitoring Aryl hydrocarbon Receptor ligands (AhR, dioxin-like compounds). Environmental pollutants able to bind and induce ectopic activation of the Aryl hydrocarbon Receptor (AhR) are diverse and widely distributed throughout the biosphere. Continuous exposure to these compounds has been associated with increased cardiovascular disease and cancer, among other effects. Thus, their monitoring in potentially polluted areas is still necessary to ensure that safety limits are not exceeded. The use of bioassays to determine dioxin-like activity, along with chemical analysis, allow an accurate assessment of the risks they represent. This thesis presents the design, objectives and validation of bioassays based on a recombinant yeast and zebrafish embryos that allow, in the case of yeast, a rapid and economic assessment and, in the case of the zebrafish embryo, a more complete one and with the possibility of observing direct effects. To perform validation, these bioassays were used in studies of environmental areas presumably contaminated by dioxin-like compounds (PAHs, Chlorinated, etc..) that represent different types of matrices where these contaminants are found: fluvial sediment (lower part of the river Ebro, from the Flix Dam to the mouth) and marine (estuary Urdaibai), particulate air (Po Valley, northern Italy) and soil (mining waste in the district of Datong in China). The results of these studies have established pollutions levels present in each area and show a correlation with chemical data as well as a similar response between our bioassays and other more standardized. Besides, those results highlight the importance of combining chemical and biological analysis in order to obtain a complete information of the samples.
125

Determination of degradative gene frequencies applications in polycyclic aromatic hydrocarbon contaminated sediments /

Mumy, Karen Lynn. January 2004 (has links)
Thesis (Ph. D.)--Miami University, Dept. of Microbiology, 2004. / Title from second page of PDF document. Includes bibliographical references (p. 133-140).
126

Avaliação da distribuição de metais, selênio e hidrocarbonetos policíclicos arométicos (HPAs) em tecidos do camarão Litopenaeus vannamei (Boone, 1931) cultivados no Estado da Bahia

Silva, Edevaldo da January 2007 (has links)
Submitted by Ana Hilda Fonseca (anahilda@ufba.br) on 2016-08-30T15:51:23Z No. of bitstreams: 1 Edevaldo da Silva - Dissertação de Mestrado - AVALIAÇÃO DA DISTRIBUIÇÃO DE METAIS, SELÊNIO E HIDR.pdf: 2884849 bytes, checksum: fa7b35ee716d9dafe11da9dc385d97ef (MD5) / Approved for entry into archive by Vanessa Reis (vanessa.jamile@ufba.br) on 2016-09-02T15:19:40Z (GMT) No. of bitstreams: 1 Edevaldo da Silva - Dissertação de Mestrado - AVALIAÇÃO DA DISTRIBUIÇÃO DE METAIS, SELÊNIO E HIDR.pdf: 2884849 bytes, checksum: fa7b35ee716d9dafe11da9dc385d97ef (MD5) / Made available in DSpace on 2016-09-02T15:19:40Z (GMT). No. of bitstreams: 1 Edevaldo da Silva - Dissertação de Mestrado - AVALIAÇÃO DA DISTRIBUIÇÃO DE METAIS, SELÊNIO E HIDR.pdf: 2884849 bytes, checksum: fa7b35ee716d9dafe11da9dc385d97ef (MD5) / CNPq / O consumo de crustáceos vem crescendo rapidamente, graças à expansão da cultura de camarão. As fazendas de camarão são geralmente localizadas próximas da costa e utilizam a água na criação de camarões, a qual pode estar contaminada por vários tipos de poluentes químicos. Nesse trabalho, foi investigada a concentração e distribuição de metais, selênio e Hidrocarbonetos Policíclicos Aromáticos (HPAs) em diferentes tecidos, e em ambos os sexos, da espécie de camarão Litopenaeus vannamei. As amostras foram coletadas entre outubro de 2005 e janeiro de 2006 em carciniculturas ao redor da Baía de Todos os Santos (BTS), em Salvador, e em carcinicultura de águas do Rio São Francisco na cidade de Paulo Afonso, Bahia. Os metais e selênio foram quantificados por Espectroscopia de Emissão Óptica com Plasma indutivamente Acoplado (ICP OES) e os HPAs quantificados por Cromatografia Gasosa com Espectrômetro de Massa (CG MS). Os resultados da maioria dos metais e do selênio indicaram variações significativas entre os tecidos - músculos, vísceras e exoesqueleto – das amostras, assim como variações entre níveis de concentrações entre camarões de localidades diferentes. Não foi verificada variação entre os sexos, com exceção do selênio. Os metais com valores limítrofes estabelecidos pela ANVISA apresentaram níveis abaixo dos limites máximos aceitáveis para consumo. Os HPAs apresentaram níveis baixos de concentração, sendo mais altas em Salinas da Margarida. HPAs de baixa massa molecular se apresentaram em predominância nas amostras analisadas, indicando provável origem petrogênica, com exceção das amostras de Salinas da Margarida, cuja origem provável seja pirolítica. / The consumption of crustaceans has been growing rapidly, thanks to expansion of carciniculture. The farms of shrimps are generally localized near of coast and their water is use in the culture of shrimps, these waters can be contaminated with many kinds of chemical pollutants. In this work was investigated the concentration and distribution of metals, selenium and polycyclic aromatic hydrocarbons (PAHs) in differents tissues, and in both sex, of specie Litopenaeus vannamei. The samples were collected between November/2005 and January/2006 at carcinicultura around of Baía of Todos os Santos (BTS), in Salvador and at carciniculture of São Francisco River water’s in the city of Paulo Afonso, Bahia. The metals and selenium were quantified by Inductively Coupled Plasma Optical Emission Spectrometry (ICP OES) and the PAHs quantified by gas chromatography coupled to mass spectrometry (GC MS). The results of major of metals and selenium indicated significatives variations between the tissues – muscle, viscera and exoskeleton – of samples, as well as the variations in the level of concentrations between samples of different localities. There weren’t significatives variations between the males and females, except for selenium. The metals with maximum values determined by ANVISA shown reduced of acceptable limits for consumption. The PAHs shown levels below of concentration, the higher values were found in Salinas da Margarida. PAHs of below molecular weight were majority in the samples, indicating probable petrogênic origin, except for the sample of Salinas da Margarida that be probably of pirolitic sources
127

Approche préventive pour une réduction des Hydrocarbures Aromatiques Polycycliques (HAP) dans les fours à pyrolyse : application à la cémentation gazeuse à basse pression / Preventive approach for a reduction of Polycyclic Aromatic Hydrocarbons (PAHs) in pyrolysis furnaces : Application to low-pressure gas carburizing

Bensabath, Tsilla 19 June 2017 (has links)
La cémentation gazeuse à basse pression est un procédé de traitement de surface qui consiste à renforcer des pièces en acier par diffusion d’atomes de carbone provenant de la pyrolyse d’hydrocarbures gazeux. Une partie de l’hydrocarbure craqué est adsorbée sur le métal mais une autre partie réagit en phase gazeuse et conduit, entre autres, à la formation de HAP. Or, de nombreux HAP sont toxiques, voire cancérigènes, et les salariés en charge du nettoyage ou de la maintenance des fours de cémentation peuvent y être exposés. Des expériences de pyrolyse d’acétylène ont été réalisées à 900°C et 8 kPa, conditions proches de celles des procédés de cémentation gazeuse à basse pression. Un réacteur auto-agité par jets gazeux et des réacteurs tubulaires ont été utilisés. A la sortie de la zone réactionnelle, les produits de la pyrolyse ont été analysés. Entre autres, 16 HAP considérés comme des polluants prioritaires par l’Agence de Protection de l’Environnement aux Etats-Unis (US EPA) ont été observés. L’influence du taux de dilution du réactif en entrée et du temps de passage dans le réacteur a été étudiée. Les résultats expérimentaux ont été comparés à ceux obtenus avec un modèle cinétique détaillé. Ce modèle a été développé dans le but de décrire la formation des HAP lors de la pyrolyse d’hydrocarbures légers. Une attention particulière a été portée aux voies de formation des premiers cycles aromatiques et des 16 HAP de la liste de l’EPA. En plus des données expérimentales obtenues dans le cadre de cette étude, le modèle a été validé à partir de données expérimentales de la littérature. Le but de l’étude est de comprendre les phénomènes de formation et de croissance des HAP afin de trouver des conditions opératoires permettant de rendre plus surs les procédés de cémentation gazeuse à basse pression / Low-pressure gas carburizing is a heat treatment process used to harden surface of steel by enriching the metal with carbon atoms coming from pyrolysis of hydrocarbons. At the same time, a wide variety of molecules and radicals are also formed in the gas phase. They react together, leading to the formation of PAHs. PAHs are toxic and even carcinogenic, and activities such as furnace maintenance may thus represent a risk to workers. Experiments of acetylene pyrolysis were carried out in conditions close to low-pressure gas carburizing processes, at 900°C and 8 kPa. Two kinds of reactors were used: a jet stirred reactor and tubular reactors. At the outlet of the reaction zone, products of pyrolysis were analyzed. Among other products, 16 PAHs classified as priority pollutants by the United States Environmental Protection Agency (US EPA) were observed. Influence of residence time and of reactant dilution was studied. Experimental results were compared to those obtained with a detailed kinetic model. This model was developed in order to describe PAH formation during light hydrocarbon pyrolysis. The focus was placed on formation pathways of the first aromatic rings and of the 16 EPA-PAHs. In addition to the experimental data obtained in this study, the model was validated using experimental data from the literature. The aim of the study is to understand the phenomena of PAH formation and growth in order to find operating conditions to make safer the low-pressure gas carburizing processes
128

Mutagenicidade de solos como estratégia na avaliação de riscos de área contaminada

Pohren, Roberta de Souza January 2011 (has links)
O solo é um dos compartimentos mais atingidos pelo acúmulo de poluentes de origem antrópica, pois atua como depósito de poluentes e como fonte para outros ambientes de interface. Este estudo investigou sítio contaminado com resíduos da indústria de preservativos de madeira como fonte de compostos mutagênicos; definiu rotas e abrangência na dispersão desses contaminantes pela remobilização de partículas e deposição atmosférica, associando riscos ambientais e à saúde. Foram selecionados locais de amostragem para solos e poeira domiciliar a distâncias gradativas a partir de SI (pool de solo da área industrial), SR150 (150m), SR500 e SR1700; para poeira foi coletado um pool em área de risco, DR385 (385m) e em DR1700. Foi avaliada a atividade mutagênica através do ensaio Salmonella/microssoma, método de microssuspensão, em linhagens que detectam erro no quadro de leitura (TA98 e TA97a), substituição de pares de bases do DNA (TA100), em presença e ausência de metabolização hepática de ratos (S9mix) e YGs 1041, 1042 e 1024 para a definição de nitroderivados. Foram preparados extratos ácidos, visando definir os efeitos de compostos inorgânicos como metais pesados e de extratos orgânicos para avaliar principalmente hidrocarbonetos policíclicos aromáticos (HPAs) e nitroderivados. Os extratos foram testados também quanto à concentração dos 16 HPAs considerados poluentes prioritários pela USEPA, quanto a metais pesados de interesse e quanto ao contaminante pentaclorofenol (PCP) como marcador específico da atividade do sítio industrial. Através das análises de metais pesados foi detectado um gradiente de respostas, onde tanto a concentração de metais totais quanto a fração biodisponível de Cr e Cu apresentaram valores mais altos para SI em relação aos solos de entorno; para As, apenas na avaliação da concentração total do elemento, SI foi superior. Em relação aos efeitos mutagênicos decorrentes da mistura de compostos inorgânicos as respostas não permitiram uma gradação entre as diferentes distâncias. O solo fonte SI mostrou mutagênese nas diferentes linhagens, em especial em TA97a na ausência de S9mix. As amostras de entorno apresentaram potência mutagênica em pelo menos duas cepas, mas apenas uma consonante com SI. O solo SR500, mostrou mutagênese diferenciada e resposta expressiva na linhagem TA98 com S9 mix. No entanto, o local SR1700 mostrou ausência de influência a partir da área contaminada caracterizando uma área de referência. Nos extratos orgânicos, as respostas de mutagênese mostram um padrão de contaminação nas áreas de influência semelhante ao apresentado por SI, parecendo indicar a mobilidade de compostos orgânicos a partir da fonte para as áreas de entorno. Houve um predomínio de compostos de ação indireta, sendo os valores de SI entre 107 a 1455 rev/g de solo. Nos locais de entorno, observou-se padrão similar em SR150; já em SR500 valores elevados de mutagênese de ação direta foram evidenciados em TA97a; SR1700, embora apresentando mutagênese do tipo erro no quadro de leitura em presença de S9 mix, mostrou um decréscimo de efeitos. Os testes com as linhagens YG indicaram que compostos nitrados têm ação significativa na mutagênese direta encontrada, com exceção de SR500. Foi detectada ainda a presença de hidroxiamino-compostos em todas as amostras de solos através da linhagem YG1024. Na investigação da poeira residencial de entorno foram observadas respostas mutagênicas nas diferentes cepas testadas em DR385, mono e dinitroarenos do tipo substituição de pares de bases (YG1042) e hidroxiamino-compostos (YG1024); em DR1700 não foi observada resposta positiva. Concentrações de HPAs potencialmente carcinogênicos se estendem no solo da área interna até o do local de referencia, bem como na poeira domiciliar da área de risco indicando gradiente de concentrações e efeitos. A concentração de PCP no pool de poeira (DR385) foi (0,491 mg/Kg), similiar a observada em SI, (0,431 mg/Kg), definindo uma rota efetiva de dispersão a partir da área industrial para regiões do entorno. Ficou evidenciada a possibilidade de dispersão de mutágenos da área contaminada para regiões de entorno, sendo possível detectar gradientes de distância, favorecendo estimativas de risco. O estudo mostrou que é fundamental avaliar a extensão da contaminação a partir de fontes de solo impactado, visando delimitar qualquer medida de remediação dos ambientes atingidos e evitar danos potenciais ao equilíbrio ecológico e à saúde humana. / Soil is one of the compartments most affected by the accumulation of anthropic pollutants, since it acts as a deposit for pollutants and as a source for other interface environments. This study investigated a site contaminated with residues of the wood preservative industry as a source of mutagenic compounds; it defined the routes and area covered by dispersion of these contaminants through the remobilization of particles and atmospheric deposition, associating environmental and human health risks. Sampling sites were selected for soils and dusts at gradually increasing distances from SI (pool of soil from the industrial area), SR150 (150m), SR500 and SR1700; a pool was of residential dust was collected in the area of risk, DR385 (385m) and at DR1700. Mutagenic activity was evaluated by the Salmonella/microsome assay, microsuspension method, in strains that detect frameshift error (TA98 and TA97a), DNA base pair substitution (TA100), in the presence and absence of hepatic metabolization of rats (S9 mix) and YGs 1041, 1042 and 1024 to sough nitroderivates. Acid extracts were prepared to define the effects of inorganic compounds such as heavy metals, and organic extracts in evaluating mainly polycyclic aromatic hydrocarbons (PAHs) and nitroderivates. The extracts were tested also for the concentration of the 16 PAHs considered priority pollutants by USEPA, for heavy metals of interest and for contaminant pentachlorophenol (PCP) as a specific marker of the industrial site activity. A gradient of responses was detected through analyses of heavy metals , where both the concentration of heavy metals and the bioavailable fraction of Cr and Cu presented higher values for SI compared to the surrounding soils; for As, SI was superior only to evaluate the total concentration of the element. As to the mutagenic effects of the mixture of inorganic compounds, the responses did not allow a grading between the different distances. The source soil SI presented mutagenesis in the different strains, especially in TA97a in the absence of S9mix. The samples from the surrounding area presented mutagenic potency in at least two strains, but only one in accordance with SI. Soil SR500 showed differentiated mutagenesis and an expressive response in the TA98 strain with S9 mix. However, site SR1700 showed no influence from the contaminated area, characterizing an area of reference. In the organic extracts, the mutagenesis responses showed a pattern of contamination of the areas of influence similar to that presented by SI, and appear to indicate the mobility of organic compounds from the source to the surrounding areas. Indirect action compounds predominated, and the values of SI were from 107 to 1455 rev/g soil. At the surrounding sites, a similar pattern was observed in SR150; on the other hand, in SR500 high values of direct action mutagenesis were evidenced in TA97a; SR1700, although presenting mutagenesis in frameshift strains in the presence of S9 mix, showed diminished effects. Tests with YGs strains indicate that the nitrated compounds exert a significant action on the direct mutagenesis found, except for SR500. Further, hydroxyamine-compounds were detected in all soils samples through strain YG1024. Investigating residential dust from the surrounding area, mutagenic responses were observed in the different strains tested in DR385, mono and dinitroarenes of the pair substitution mutation type (YG1042) and hydroxyamine-compounds (YG1024); no positive response was observed in DR1700. Potentially carcinogenic PAHs concentrations are on the soil from the internal area until the site of reference, and also in the residential dust of the risk area, indicating a gradient of concentrations and effects. PCP concentration in the dust pool (DR385) was (0.491 mg/Kg), similar to that observed in SI, (0.431 mg/Kg), defining an effective dispersion route from the industrial area to the surrounding regions. The possibility of mutagen dispersion from the contaminated area to the surrounding regions was shown, and gradients of distance favoring risk estimates were detected. The study showed that it is essential to evaluate the extent of contamination from the sources of soil that have been impacted, with a view to delimiting any remedial measure for the environments affected and avoiding potential damage to the ecological balance and human health.
129

Hidrocarbonetos policíclicos aromáticos associados ao PM10 na atmosfera do Recôncavo Baiano: variação sazonal, caracterização de fontes e avaliação de risco

Silva, Sonilda Maria Teixeira January 2009 (has links)
152 f. / Submitted by Ana Hilda Fonseca (anahilda@ufba.br) on 2013-04-04T15:44:44Z No. of bitstreams: 1 TESE COMPLETA_SONILDA TEIXEIRA.pdf: 3246757 bytes, checksum: c41c8741042ef35b54690019e768753b (MD5) / Approved for entry into archive by Ana Hilda Fonseca(anahilda@ufba.br) on 2013-05-09T16:28:03Z (GMT) No. of bitstreams: 1 TESE COMPLETA_SONILDA TEIXEIRA.pdf: 3246757 bytes, checksum: c41c8741042ef35b54690019e768753b (MD5) / Made available in DSpace on 2013-05-09T16:28:03Z (GMT). No. of bitstreams: 1 TESE COMPLETA_SONILDA TEIXEIRA.pdf: 3246757 bytes, checksum: c41c8741042ef35b54690019e768753b (MD5) Previous issue date: 2009 / CAPES / Amostras de material particulado (PM10) foram coletadas no Recôncavo Baiano (RB) e em uma estação controle (Arembepe), de Agosto de 2007 a Abril de 2008, utilizando um amostrador de grandes volumes. Foram medidas as concentrações dos 16 HPAs classificados como poluentes prioritários pela Agência de Proteção Ambiental dos Estados Unidos (US-EPA), em duas campanhas de amostragem intensivas, nas estações chuvosa e seca, pelo período de 24 h durante 5-6 dias consecutivos, nos três sítios localizados na parte norte e nordeste da Baía de Todos os Santos (BTS) e em Arembepe (litoral norte da Bahia) tomado como sítio controle. Os filtros de fibra de vidro foram extraídos por microondas (MAE) utilizando um protocolo otimizado no qual a extração ocorreu em 10 min e consumiu 20 mL de DCM/acetona (1:1) antes da análise por cromatografia a gás/espectrometria de massas com detector de massas (GC/MS/MS). O somatório das concentrações médias dos 16 HPAs variou de 0,036 ng m-3 (Arembepe) a 108 ng m-3 (próximo a refinaria de petróleo e indústria de eletrodos de Carbono), apresentando uma variação sazonal (razão inverno/verão) na faixa de 0,2-306. Os HPAs potencialmente carcinogênicos representaram 53-74% da concentração total nos sítios do RB. Os HPAs predominantes foram os de alta massa molecular, do Fluoranteno ao Benzo(ghi)perileno, representando 90-99 % do total de HPAs no RB. Em Candeias as concentrações elevadas encontradas no inverno foram provavelmente causadas por emissões locais de fontes estacionárias. Para facilitar a identificação das fontes de HPAs no PM10 foi aplicada a análise de componentes principais (PCA) juntamente com o estudo das razões diagnósticas entre HPAs específicos. Na região estudada as emissões veiculares e industriais foram as principais contribuintes para os HPAs associados ao PM10. As concentrações de benzo(a)pireno equivalente (BaPeq) foram estimadas usando a relação de fatores de equivalência tóxica (TEFs) com valores de 0,1 a 22 ng m-3. Concentrações elevadas de BaPeq para os HPAs de 5 a 6 anéis no ar ambiente alertam para uma situação de aumento de riscos para a saúde humana e para a qualidade ambiental na região do RB, principalmente em Candeias e Madre de Deus / Salvador
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Qualidade ambiental da sub-bacia do Baixo Taquari influenciada por sítio contaminado em processo de remediação

Gameiro, Paula Hauber January 2015 (has links)
A contaminação do solo é uma das fontes pela qual os contaminantes são escoados para os ecossistemas aquáticos, afetando a qualidade dos sedimentos. Neste compartimento alguns compostos são capazes de bioacumular e interferir nos fluxos de energia e de nutrientes da cadeia biológica, gerando efeitos agudos, crônicos e genotóxicos para as comunidades que vivem ou entram em contato com este local. A região de estudo está localizada em área às margens do rio Taquari, no município de Triunfo, RS, próxima a um sítio com solo contaminado por preservantes de madeira, com passivo ambiental identificado (creosoto, pentaclorofenol e a hidrossal CCA). Esta área foi submetida à primeira fase do processo de intervenção para retirada das principais fontes ativas. Em estudos anteriores foi definido o provável escoamento de contaminantes para o rio a partir do solo contaminado. Para avaliar a qualidade dos sedimentos, nas diferentes fases de intervenção da área, foi utilizado o ensaio Salmonella/microssoma, para avaliar mutagênese, além da dosagem de HPAs nos extratos orgânicos de sedimentos. Foram testados quatro áreas de coleta, identificadas pela distância em Km a partir da foz, abrangendo local a montante do sítio, Ta032, em frente, Ta010, e a jusante, Ta006 e Ta004. As coletas foram nas fases, antes (inverno e verão), durante (verão) e após (verão) o processo de intervenção. A mutagênese foi avaliada através de linhagens que medem erro no quadro de leitura (TA98 e Ta97a) e substituição de pares de bases (TA100), na presença e ausência de S9mix (±S9) em extratos de compostos moderadamente polares de sedimento. Os resultados indicaram presença de pró-mutágenos em todas as amostragens na área Ta010, sendo mais elevada na anterior à intervenção (verão) para TA100+S9 (1672 rev/g) decrescendo durante e após este processo. Foram também observados valores constantes de HPAs totais e presença das espécies com potencial cancerígeno nos diferentes períodos avaliados. O local Ta006, após a intervenção, foi o que mostrou mutagênese mais alta (764 rev/g), sendo que as espécies consideradas cancerígenas foram detectadas em maiores concentrações, em especial o benzo(b+k) fluoranteno, que também esteve elevado, neste período, em Ta004. Presença de mutagênese e HPAs em arroio interno ao sítio, a montante de Ta010, marcaram uma das rotas de dispersão dos contaminantes. A presença de contaminação em frente ao sítio, após a intervenção, pode estar relacionada com a técnica escolhida para retirada das fontes ativas, contribuindo na presença de contaminantes a jusante deste rio, Ta006 e Ta004. / Soil contamination is one fo the sources of contaminant runoff into acquatic system, affecting sediment quality. In this compartment some compounds can bioaccumulate and interfere in the energy and nutrient flux of the biological chain with acute, chronic and genotoxic effects on the communities who live there or have contact with this place. The region studied is located on the area on the banks of Taquari river, in the municipality of Triunfo, RS, close to a site with soil contaminated by wood preservatives and identified environmental liabilities (creosote, pentachlorophenol and hydrosalt CCA). This area was submitted to the first stage of the intervention process to remove the main active sources. Previous studies defined the probable runoff of contaminants into river from contaminated soil. In order to evaluate the sediment quality in the different phases of intervention in the area, the Salmonella/microsome assay was used to evaluate mutagenesis, besides the dosage of PAHs in the sediment organic extracts. Four collection areas were tested, identified by the distance in km from the mouth, covering a location upstream from the site, Ta032, in front, Ta010, and downstream, Ta006 and 004. The collections were performed in the phases, before (winter and summer), during (summer) and after (summer) the intervention process. Mutagenesis was evaluated using frameshift (TA98 and Ta97a) and base pair substitution (TA100) strains in the presence and absence of S9mix (±S9), in extracts of moderately polar sediment compounds. The results indicate the presence of promutagens in all samplings in the Ta010 area, and it is higher before the intervention (summer) for TA100+S9 (1672 rev/g) decreasing during and after this process. Constant values of total PAHs and presence of species with a carcinogenic potential were also observed in the different periods evaluated. Site Ta006, after intervention, showed the highest mutagenesis (764 rev/g), and the species considered carcinogenic were detected at higher concentrations, especially benzo(b+k) fluoranthene, which was also high during this period at Ta004. The presence of mutagenesis and PAHs in a stream inside the site, upstream from Ta010 marks one of the contaminant dispersion routes. The presence of contamination in front of the site after intervention may be related to the technique chosen to remove the active sources, contributing to the presence of contaminants downstream of this river, Ta006 and Ta004.

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