Thesis (Ph. D.)--Ohio State University, 2006. / Title from first page of PDF file. Includes bibliographical references (p. 355-382).

Orientador: Mary Rosa Rodrigues de Marchi / Banca: Christine Laure Marie Bourote / Banca: Annibal Duarte Pereira Netto / Banca: Nilva Ré Poppi / Banca: Roma Tauler / Resumo: No Brasil, a queima da cana de açúcar é utilizada para facilitar a colheita, mas este procedimento causa grande poluição ambiental devido a quantidade de fuligem lançada na atmosfera. O material particulado (MP) emitido contém inúmeros contaminantes, tais como: hidrocarbonetos policíclicos aromáticos (HPAs) e elementos. A cidade de Araraquara/SP possui cerca de 200.000 habitantes e é cercada por plantações de cana de açúcar, sendo que a prática de queimada é constante no período da safra (abril-novembro, todos os anos). Neste trabalho, determinou-se a concentração elementar e de HPAs em MP na cidade de Araraquara durante o período da safra (S) e da entre safra (E) da cana de açúcar. Foram coletadas 60 amostras (E) e 220 amostras (S) para a análise de HPAs, e 10 amostras (E) e 10 amostras (S) para a análise elementar. As amostras foram coletadas utilizando um amostrador dicotômico (vazão: 10 L min-1, 24 h) com filtros de PTFE (37 mm, 2 μm de tamanho de poro). Para a análise de HPAs, dez filtros de PTFE contendo o MP foram extraídos em banho de ultrassom com acetona/n-hexano (1:1 v/v), sendo que as análises foram efetuadas por HPLC/FLD. A análise elementar foi efetuada por fluorescência de raios X por energia dispersiva (EDXRF), sem tratamento prévio das amostras. A concentração mediana de HPAs totais foi de 1,9 ng m-3 (E) e 6,2 ng m-3 (S). A concentração mediana de benzo[a]pireno, HPA considerado carcinogênico, foi de 0,026 ng m-3 e 0,15 ng m-3 para os períodos de E e S, respectivamente. O risco potencial de câncer associado à exposição a HPAs por inalação, foi estimado com base na concentração de benzo[a]pireno equivalente (BaPeq), onde a toxicidade de uma mistura de HPAs é definida pela concentração de cada substância multiplicada pelo seu fator de equivalência de toxicidade relativa (FET). Os valores medianos encontrados para... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: In Brazil, the sugar cane crops are burned to facilitate the harvesting, this procedure causes environmental pollution from the large amounts of soot that are released into the atmosphere. This particulate matter (MP) contains numerous contaminants such as polycyclic aromatic hydrocarbons (PAHs) and metals. The city of Araraquara, located at central area from São Paulo State, has around 200,000 inhabitants and is surrounded by sugarcane plantations (46,994 ha of total cultivated area, in the harvest 2008/2009). In this study, PAHs concentrations and elemental composition in the MP were determined in Araraquara city during the sugarcane harvesting (HV) and non-harvesting (NHV) seasons. 60 samples were collected during the NHV and 220 samples during the HV seasons for the analysis of PAHs. 10 samples were collected during the NHV and 10 samples during the HV season for the analysis of Si, K, Ca, Ti, V, Fe, Sr, Cr, Ni, Mn, Cu, Zn, As, Cd, Pb, Sb, Al, S and Cl. The samples were collected using a dichotomous sampler (10 L min-1, 24 h) with PTFE filters. Ten filters sets were extracted (ultrasonic bath with hexane/acetone (1:1 v/v)) and analyzed by HPLC/FLD for the analysis of PAHs. Information concerning the bulk elemental concentration was provided by energy-dispersive x-ray fluorescence (EDXRF). The median concentration for total PAHs was 1.9 ng m-3 (NHV) and 6.2 ng m-3 (HV). Benzo[a]pyrene median concentration was 0.026 ng m-3 and 0.15 ng m-3 for the NHV and HV seasons, respectively. The potential cancer risk associated to inhalation exposure was estimated based on the benzo[a]pyrene toxic equivalence (BaPeq), where the overall toxicity of a PAH mixture is defined by the concentration of each compound multiplied... (Complete abstract click electronic access below) / Doutor

Les hydrocarbures aromatiques polycycliques (HAP) constituent un groupe de polluants organiques persistants (POP). Ils sont produits par la combustion incomplète de la matière organique et peuvent être transférés sur de longues distances. Leur nature organique et hydrophobe leur confère une affinité vis-à-vis des surfaces lipidiques et des compartiments contenant de la matière organiques. Ils peuvent donc s’adsorber sur les matrices végétales et sur la matière organique des sols. La canopée, du fait de sa rugosité aérodynamique importante, constitue un puits important de HAP. Dans cette étude, nous avons suivi l’évolution de la concentration en HAP, sur une période de 20 ans (de 1993 à 2011), dans la végétation (feuilles/aiguilles), les couches organiques (OL, OF et OH) et les couches organo-minérales (0 – 10 cm, 10 – 20 cm et 20 - 40 cm) des sites forestiers français suivis par le réseau RENECOFOR (Réseau National de suivi à long terme des ECOsystèmes FORestiers).14 sites répartis sur tout le territoire français ont été choisis selon des caractéristiques différentes (type de l’essence forestière, climat, altitude, latitude, longitude, type d’humus forestier, contenu en carbone organique, etc.). Ainsi, 14 HAP considérés comme prioritaires par l’agence de protection de l’environnement des Etats-Unis (US-EPA) ont été quantifiés.Cette étude a mis en évidence l’efficacité de la végétation dans l’enregistrement de l’historique de la qualité de l’air des sites forestiers. Une baisse générale de la concentration en HAP dans la végétation et dans l’atmosphère pendant les 20 dernières années a été constatée. La végétation joue le rôle d’une pompe qui accumule les HAP et les transferts vers les sols forestiers. Le contenu en carbone organique semble être le paramètre contrôlant l’accumulation des HAP dans les sols forestiers. Ainsi, la dynamique des HAP entre les différents compartiments forestiers semble dépendre de leurs propriétés physico-chimiques et de leur capacité à subir des mécanismes de dissipation (lixiviation, dégradation, etc). Enfin, cette étude montre que les couches organo-minérales des sols forestiers constituent un puits plus important de HAP (légers, intermédiaires et lourds) que la végétation et les couches organiques dans l’écosystème forestier. / Polycyclic aromatic hydrocarbons (PAHs) are a group of persistent organic pollutants (POPs). They are produced by incomplete combustion of organic matter and can be transported over long distances in the atmosphere. Because of their organic and hydrophobic nature they have a strong affinity for lipid surfaces and compartments containing organic matter. They can therefore be adsorbed on the plant matrices and on the organic matter of the soils. The canopy, due to its important aerodynamic roughness, constitutes an important sink for PAHs.In this study, we have monitored the evolution of PAHs concentrations over a period of 20 years (from 1993 to 2011) in 3 compartments of the forest ecosystem: vegetation (leaves / needles), organic layers (OL, OF and OH) and organo-mineral layers (0-10 cm, 10-20 cm and 20-40 cm) of French forest sites monitored by the RENECOFOR network (National Network for Long-term FOrest ECOsystem Monitoring).4 sites distributed throughout France were selected according to different characteristics (type of forest species, climate, altitude, latitude, longitude, type of forest humus, organic carbon content, etc.). Thus, 14 PAHs, considered as priority pollutants by the United States Environmental Protection Agency (U.S. EPA), were quantified.This study highlights the efficiency of vegetation in registering the history of air quality at forest sites. A general decrease in the concentration of PAHs in vegetation and in the atmosphere over the past 20 years has been observed.Vegetation plays the role of a pump that accumulates PAHs and transfers them to forest soils. Organic carbon content appears to be the most important parameter controlling PAHs accumulation in forest soils. Thus, PAHs transfer between the different forest compartments appears to depend on their physico-chemical properties and their ability to undergo dissipation mechanisms (leaching, degradation, etc.).Finally, this study shows that the organo-mineral layers of forest soils constitute a more important sink of (light, intermediate and heavy) PAHs than vegetation and organic layers in the forest ecosystem.

Ce manuscrit décrit la synthèse et les caractérisations physico-chimiques de nouveaux systèmes hétérocycliques π-conjugués contenant un atome de phosphore. Le chapitre d'introduction présente les différentes voies de synthèse du cycle phospholes pouvant être incorporé dans des systèmes π-conjugués. Le chapitre I décrit la synthèse et les propriétés physico-chimiques de dérivés du pyrène contenant soit un phosphole, soit un silole. La synthèse de ces nouvelles structures a été réalisée à l'aide de réactions métallo-catalysées. Deux types de régioisomères ont ainsi été synthétisés afin de déterminer l'impact de la nature de l'hétéroatome (P ou Si) sur leurs propriétés optiques et électrochimiques et sur l'organisation des molécules à l'état solide. Le chapitre II décrit la synthèse et les propriétés physico-chimiques de nouveaux complexes d'Ir(III) ortho-métallés contenant un ligand phosphole. La présence de deux centres stéréogènes induit la formation de diastéréoisomères, dont la formation peut être contrôlée par les conditions réactionnelles. De plus, les propriétés électroniques du ligand phosphole permettent de moduler à façon les propriétés redox et optiques du complexe. Le chapitre III se focalise sur l'utilisation de la phosphépine comme sous-unité pour la construction de nouveaux systèmes π-conjugués. Deux systèmes π-conjugués ont été synthétisés : un squelette de PAH contenant la phosphépine et les dithieno-phosphépines. Les propriétés optiques et redox de ces dérivés ont été étudiées et discutées dans le manuscrit. / This manuscript describes the synthesis and characterisation of new heterocyclic π-conjugated systems built around the phosphorus atom. Firstly, an introduction to the phosphole chemistry (synthesis methods and integration into π-conjugated systems) is presented. The chapter I describes the synthesis and physico-chemical properties of pyrene functionalised either by a phosphole or silole ring. The synthesis of these new structures was achieved by using a transition-metal catalysis. Two types of regioisomers were synthesised in order to study the effect of the heteroatom (P or Si) on the optical and electrochemical properties together with the impact on the solid-state organisation. The chapter II describes the synthesis and the physical properties of the first phosphole-based Ir(III) ortho-metallated complexes. The presence of two stereogenic centres in the complex induced diastereoselectivity issues that could be solved by carefully choosing the reaction conditions. Furthermore, it was demonstrated that the nature of the ligands can tune the optical and the redox properties. The chapter III describes the use of P-containing seven-membered rings (phosphepines) for the development of new π-conjugated systems. Two original π-systems have been synthesised and studied: (i) phosphepine based PAH and (ii) dithieno-phosphepines. The optical and redox properties have been investigated and discussed in the manuscript.

According to the Waste Framework Directie 2008/98/ES and the Czech law on waste 185/2001 Sb., waste preienton is the main priority in waste management. Using biodegradable plastcs seems to represent a suitable approach in fulflling the strategy. The subject of this diploma thesis is biodegradable lightweight polyurethanes (PURs), which might represent suitable materials for repellent fences in agricultural landscapes. Biodegradaton processes are assumed to begin in the agricultural soil afer their lifetme. The biodegradability of new lightweight PURs (BIO 8-10), presented as material mineralizaton, was tested in agricultural soil under laboratory conditons according to the ASTM Internatonal standard method D5988-03. Afer the nine-month experiment the material with the highest biodegradability (BIO 10) containing starch (28 wt. %) was mineralized to 42.0 ± 4.2 %. Cellulose (the positie control) was completely mineralized; thus, the ialidity criterion (positie control mineralizaton > 70 %) was accomplished. Afer the biodegradability test, degradaton products (residual PURs) were separated from the soil by a two-step method using fuidisaton and fotaton, according to a modifed procedure described in Nuelle et al. (2014). The procedure enabled a subsequent analysis of PUR residues with Fourier transform...

Les Hydrocarbures Aromatiques Polycycliques (HAP) sont responsables de cancers du poumon, de la vessie et de la peau. Parmi eux, seul le benzo(a)pyrène (BaP) est classé cancérogène certain pour l'homme. La surveillance biologique de leur exposition passe par le dosage du 1-hydroxypyrène urinaire (1-OHP), métabolite du pyrène non cancérogène. L'objectif de cette thèse était de développer un nouveau biomarqueur plus proche du risque cancérogène. Le 3-hydroxybenzo(a)pyrène (3-OHBaP) est apparu comme le meilleur candidat car c'est le métabolite majoritaire du BaP, car ses concentrations sont liées aux taux d'adduits à l'ADN mesurés dans le poumon de rat et car son dosage est réalisable dans les urines de sujets exposés. Nous avons développé une méthode analytique de routine associant l'extraction en phase solide à la chromatographie liquide avec une détection en fluorescence, qui nous a permis d'atteindre une limite de détection 0,02 ng/L. La médiane des concentrations de 3-OHBaP dans les urines de sujets fumeurs atteignait 0,02 nmole/mole de créatinine et était deux fois plus élevée que chez les non-fumeurs. Dans les secteurs de production du silicium, des cathodes et des anodes, de 30 à 70% des niveaux étaient supérieurs à la valeur recommandée en France, ce qui confirme le risque sanitaire lié à ces activités professionnelles. Lors d'une exposition répétée aux HAP pendant une semaine de travail, le prélèvement des urines doit être réalisé en fin de semaine fin de poste, du fait de l'atteinte d'un équilibre entre les doses de BaP absorbées et celles de 3-OHBaP éliminées. La corrélation entre les niveaux urinaires de 3-OHBaP et de 1-OHP est variable en fonction du secteur et des activités professionnelles. Ceci démontre la difficulté d'établir une seule valeur limite professionnelle en lien avec le risque cancérogène des HAP pour le 1-OHP et souligne tout l'intérêt de doser le 3-OHBaP. / Polycyclic Aromatic Hydrocarbons (PAH) are responsible for lung, skin and bladder cancers. Among them, only benzo(a)pyrene (BaP) is classified as carcinogenic to humans. Their biomonitoring is performed by the determination of urinary 1-hydroxypyrene (1-OHP), a metabolite of the non-carcinogenic pyrene. The aim of this thesis was to develop a new biomarker closest carcinogenic risk. The 3-hydroxybenzo(a)pyrene (3-OHBaP) seemed to be the best candidate because it is the major metabolite of BaP, these urinary levels are related to the rate of DNA adducts measured in the lung of rats and its analysis is achievable in the urine of exposed subjects. We have developed a simple analytical method combining solid phase extraction and liquid chromatography with fluorescence detection, which achieved a detection limit of 0.02 ng/L. The median concentrations of 3-OHBaP in the urine of smokers reached 0.02 nmol/mol of creatinine and was two times higher than among non-smokers. In the industries of silicon, cathodes and anodes, from 30 to 70 % of levels were above the recommended value in France, which confirms the health risk associated with these occupational activities. In case of repeated exposure to PAH during a workweek, urine sampling should be performed at the end of the shift the last workday, due to a balance between the amounts of BaP absorbed and those of 3-OHBaP eliminated. The correlation between urinary levels of 3-OHBaP and 1-OHP is variable depending on the sector and occupational activities. This demonstrates the difficulty of establishing a single limit value in connection with the carcinogenic risk of PAH for 1-OHP and highlights the interest of the 3-OHBaP.

O óleo extensor normalmente empregado em copolímeros à base de butadieno e estireno ( borracha SBR) da série 1712 é o extrato aromático (DAE). Nesta Dissertação, esse óleo foi substituído por óleos com baixos teores de policíclicos aromáticos em formulações de SBR. Esta substituição se deu em atendimento a Regulamentação REACH (EC No1907/2006 do Parlamento Europeu e do Conselho de 18 de Dezembro de 2006, Anexo XVII) que determina que a soma de hidrocarbonetos policíclicos aromáticos individuais (PAHs) deve ser abaixo de 10 mg/kg e o teor de benzo(a)pireno (BaP) não deve exceder 1 mg/kg. Os óleos empregados foram o extrato aromático residual tratado (TRAE) e dois óleos naftênicos de fornecedores diferentes (HN1 e HN2). As composições de SBR estendidas em DAE, TRAE, HN1 e HN2 tiveram suas propriedades térmicas avaliadas por análise termogravimétrica (TG) e calorimetria diferencial de varredura (DSC). As propriedades físicas foram determinadas por ensaios de tração, dureza, resistência à abrasão e resiliência. Foram ainda avaliadas as propriedades reométricas e reológicas, por viscosidade e relaxação Mooney, respectivamente. Ao final os resultados demonstraram que é possível a substituição do óleo extensor por quaisquer dos óleos testados sem prejuízos nas propriedades estudadas / The extender oil usually employed in compositions of rubbers based on sytrene and butadiene (SBR) 1712 is the aromatic extract DAE. In this Dissertation, this oil was substituted by oils with low levels of polycyclic aromatic hydrocarbons: the treated residual aromatic extract (TRAE) and two naphthenic oils from different suppliers (HN1 and HN2). This substitution was performed in response to REACH Regulation (EC No1907/2006 European Parliament and the Council of 18 December 2006, Annex XVII) which state that the sum of individual polycyclic aromatic hydrocarbons (PAHs) should be below 10 mg / kg and the levels of benzo (a) pyrene (BaP) should not exceed 1 mg / kg. SBR compositions extended with DAE, TRAE, HN1 and HN2 were characterized in terms of thermal properties by thermogravimetry (TG) and differential scanning calorimetry (DSC), rheometric properties, physical properties (tension tests, hardness, abrasion resistance and resilience) and rheological (viscosity and Mooney relaxation). The final results showed that it is possible to replace the extender oil DAE for any of the tested oils without loss in the studied properties

Made available in DSpace on 2016-12-23T14:41:52Z (GMT). No. of bitstreams: 1 Dissertacao de Luciana Brunhara Biazati.pdf: 848805 bytes, checksum: 4ed964a7ad50c362409f5ddb61fac503 (MD5) Previous issue date: 2009-03-06 / Os hidrocarbonetos policíclicos aromáticos (HPAs), derivados de petróleo, são substâncias cada vez mais preocupantes aos órgãos ambientais devido ao seu caráter tóxico, carcinogênico e mutagênico. Com o aumento da utilização de petróleo e seus derivados como fonte de energia, a contaminação do efluente líquido se expandiu, prejudicando a biota, incluindo seres humanos que de alguma forma fazem uso dessa água. É necessário que sejam desenvolvidos procedimentos eficazes na eliminação parcial ou total destes compostos. Uma técnica muito estudada atualmente no tratamento de efluentes líquidos é o processo Fenton. Ele se baseia na geração do radical hidroxila a partir da reação de íons Fe2+ e peróxido de hidrogênio. Devido ao seu elevado poder oxidante, o radical hidroxila degrada totalmente os compostos orgânicos, formando CO2, H2O e íons inorgânicos provenientes de heteroátomos. O presente trabalho estudou o processo Fenton na decomposição de HPAs (acenafteno, fluoreno, fluoranteno, benzo(a)pireno) em meio aquoso com a utilização de magnetitas puras ou dopadas com cobalto como fonte de íons Fe2+ e peróxido de hidrogênio. A análise da degradação e possível formação de intermediários foram acompanhadas por cromatografia gasosa/espectrometria de massa (CG/EM). Pôde-se observar que o percentual de degradação dos HPAs variou de 39 a 100%. O composto que mais degradou foi o acenafteno, com três anéis, enquanto que o benzo(a)pireno, com cinco anéis, teve a menor oxidação. Não foram encontrados intermediários acima do limite de detecção do equipamento. Além da CG/EM, foi utilizada a fluorescência como método de análise. O objetivo foi comparar a eficiência da magnetita pura e dopada com cobalto na degradação do fluoreno. Observou-se que o processo de degradação com a magnetita pura não foi significante. Já com a magnetita dopada com cobalto a degradação total ocorreu em cinco horas. Assim, o processo Fenton com utilização de magnetitas como fonte de ferro pode ser uma nova alternativa para o tratamento de HPAs em meio aquoso / The awareness regarding Polycyclics Aromatic Hydrocarbons (PAHs), petroleum derivatives, has been increasing over the years due to their toxic, carcinogenic and mutagenic characteristics. The increase on the use of petroleum and its derivatives as energy source has induced many accidents spilling liquid effluent in the environment, making harm to biota, including human beings. So that, developing efficient procedures is important on the partial or total elimination of these compounds. A common technique that has been used recently is the Fenton process. This is based on the generation of hydroxyl radical from the reaction of Fe2+ions and hydrogen peroxyde, forming CO2, H2O and inorganic ions from heteroatoms. This study evaluated PAHs (acenaphthene, fluorene, fluoranthene, benzo(a)pyrene) decomposition due to the fenton process in water by utilization of pure and doped magnetites (with Co as source of ions Fe2+) and hydrogen peroxyde. In order to compare the two kinds of magnetites, fluorene was degraded utilizing fluorescence to evaluate its concentration. We observed that reaction was not significant when pure magnetite was used, whereas doped one degraded fluorene completely after five hours. Because of this, only doped magnetite was used with the other compounds, but evaluating its efficience and intermadiaries formation by gas chromatography and mass spectrometry (GC/MS). The degradation of HPAs varied from 39 to 100%. Acenaphtene (with three rings) reacted more intensively whereas benzo(a)pyrene (with five) reacted less. No intermediate compounds were found above the detection limit. Beside GC-MS, fluorescence was utilized to analyse the compounds. Our goal was to compare the pure magnetite efficiency to that of doped one regarding fluorene degradation. We observed that the degradation using the former was not significant. Magnitite doped with cobalt degraded it within five hours. So, the method may be a new alternative of treating liquid efluents

Atualmente, um dos problemas ambientais mais graves é a contaminação dos solos e das águas subterrâneas. Na Europa, já foram identificadas 300.000 áreas contaminadas ou potencialmente contaminadas e estima-se que exista 1,5 milhão. Nos Estados Unidos da América, já foram identificadas mais de 63.000. No Brasil, 1.336 áreas contaminadas foram identificadas apenas no Estado de São Paulo. Das tecnologias de remediação de áreas contaminadas, a biorremediação tem a vantagem de destruir os poluentes. No entanto, para aplicação de tal tecnologia, é necessário determinar a biodegradação dos compostos orgânicos no solo. No Brasil, faltam estes dados, pois os solos tropicais possuem características bem diferentes dos solos de regiões de clima temperado. O método respirométrico de Bartha, adaptado de uma norma holandesa, é um método simples e economicamente viável para determinar a atividade microbiológica pela geração de gás carbônico e, indiretamente, a biodegradação de contaminantes orgânicos no solo. No presente trabalho, foi estudada a sua aplicabilidade para um latossolo, tipo de solo predominante no Estado de São Paulo, utilizando como contaminante orgânico, o fenantreno. A partir dos resultados obtidos, foi possível verificar que o gás carbônico gerado não era resultante apenas da biodegradação do contaminante, mas também de reações abióticas ocorridas no solo, principalmente as de equilíbrio do carbonato de cálcio, adicionado para neutralizar o pH. Tal constatação dificulta a análise dos resultados obtidos nos ensaios de respirometria, já que o procedimento descrito na norma brasileira NBR 14283/99 relaciona diretamente a geração do gás carbônico à biodegradação do contaminante. Apesar desta dificuldade, foi possível verificar a biodegradação do fenantreno por microrganismos indígenas, que resistiram ao processo de esterilização. Verificou-se ainda, neste trabalho de pesquisa, a dificuldade de esterilização do solo em autoclave, o que limita a avaliação de remoção de contaminantes por outros mecanismos, tais como volatilização e adsorção. / Nowadays, one of the most serious environmental problems is the contamination of soil and groundwater. In Europe, 300,000 contaminated or potentially contaminated sites have already been identified and there it is estimated that 1.5 million contaminated sites exist. In the United States of America, more than 63,000 have already been identified. In Brazil, 1,336 contaminated sites have been identified in the State of São Paulo. Of the remediation technologies that can be applied for the recovery of these sites, bioremediation has the advantage of destroying the contaminants, but it is necessary to determine the degree to which they biodegrade in the soil. In Brazil, this data is lacking, since tropical soil has different characteristics than the soil of regions with temperate climates. Bartha’s respirometric method, adapted from a Dutch norm, is a simple and economically viable method for determining carbon dioxide generation and, indirectly, the biodegradation of organic contaminants in the soil. In this research, this method’s applicability was studied for a typical tropical soil, predominant in the State of São Paulo, using phenantrene as an organic contaminant. Based on the results of this study, it was possible to verify that the carbon dioxide generated resulted not only from the biodegradation of the contaminant, but also from abiotic reactions that occurred in the soil, mainly from the balance of calcium carbonate, added to neutralize the pH. This fact makes the analysis of the results of the respirometric tests more difficult, since the procedure described in Brazilian norm NBR 14283/99 relates the generation of carbon dioxide directly to the biodegradation of the contaminant. Despite this difficulty, it was possible to verify the biodegradation of the phenantrene for indigenous microorganisms. Furthermore, this research verified the difficulty of sterilizing the soil, which would make it difficult to evaluate the removal of contaminants by other mechanisms, such as volatilization and adsorption.

O crescente mercado dos produtos naturais, fomentado pelo interesse dos consumidores por alimentos que auxiliem a promoção da saúde, tem pressionado a indústria alimentícia na oferta por novos alimentos. Dentre estes alimentos, encontram-se os óleos vegetais extraídos a frio, reconhecidos por preservarem compostos bioativos característicos e, alguns deles, serem fontes de ácidos graxos (AG) essenciais. A categoria dos óleos e gorduras apresenta, dentre outros alimentos, uma importante fonte de exposição aos hidrocarbonetos policíclicos aromáticos (HPAs), um grupo de contaminantes químicos orgânicos, alguns com ação carcinogênica. Este trabalho teve como objetivo avaliar os óleos vegetais extraídos a frio quanto aos parâmetros de identidade, de qualidade e à ocorrência de HPAs. Foram avaliadas 40 amostras, dez de cada tipo (coco, cártamo, prímula e linhaça), de diferentes marcas, adquiridas no comércio da cidade de São Paulo. Foram realizados os ensaios de perfil de AG, índice de acidez, índice de peróxido, p-anisidina, valor total de oxidação (totox) e HPAs (benzo(a)antraceno, criseno, benzo(b)fluoranteno e benzo(a)pireno). Quanto aos AG, catorze óleos (35 por cento ) não apresentaram perfis de ácidos graxos característicos que os declarados em seus rótulos, incluindo um de coco, quatro de cártamo e nove de prímula. Os valores para acidez estavam inadequados em relação a legislação para três óleos de linhaça (7,5 por cento ). Para o peróxido, quatro óleos (10 por cento ) estavam acima do limite da legislação, sendo dois de linhaça e dois de prímula. Os valores de p-anisidina variaram de <LQ a 12,98, sendo o menor valor encontrado nas amostras de coco e o maior em uma de prímula, que apresentava um odor alterado. No ensaio de totox, 37,5% das amostras apresentaram valores acima da recomendação da literatura, especialmente os óleos de cártamo e prímula. Já para os HPAs, pelo menos um dos hidrocarbonetos analisados foi detectado em 97,5% das amostras avaliadas; três amostras de prímula (7,5%) apresentaram níveis acima do permitido pela Comunidade Européia para BaP e, para a soma dos 4 HPAs, oito óleos (20%) estavam em desacordo: dois de cártamo, quatro de prímula e dois de linhaça. Este trabalho expõe os problemas relacionados aos parâmetros de identidade, qualidade e contaminação dos óleos vegetais comercializados como extraídos a frio e reforçam a importância de um contínuo monitoramento destes produtos. / The natural product market growth, stimulated by the interest of consumers in foods that support health promotion, has encouraged the food industry to supply new kinds of foods. Among these are the cold-pressed vegetable oils, recognized by preserving characteristic bioactive compounds and, some of them, are sources of essential fatty acids (FA). The category of oils and fats owns, within others foods, an important source of exposure to polycyclic aromatic hydrocarbons (PAHs), a group of organic chemical contaminants, some of them with carcinogenic activity. This study aimed at evaluating cold-pressed vegetable oils in relation to the PAHs occurrence, as well as the quality and identity parameters. Forty samples being ten of each type (coconut oil, safflower oil, evening primrose oil and flaxseed oil) of distinct brands, which were acquired in different markets from São Paulo, were evaluated. Fatty acids profile, acid value, peroxide value, p-anisidine value, total oxidation value (totox) and PAHs (benzo(a)anthracene, chrysene, benzo(b)fluoranthene and benzo(a)pyrene) were analyzed. As for FA, fourteen oils (35 per cent ) showed different fatty acids profiles according to the ones on their labels, including one of coconut oil, four of safflower oils and nine of evening primrose oils. The acid values were unsuitable towards the legislation to three flaxseed oils (7.5 per cent ). As for peroxide values, four of the oils (10 per cent ) were above the legislation limit, including two of flaxseed oils and two of evening primrose ones. The p-anisidine values ranged from <LOQ to 12.98, being the smallest value found in the coconut oils samples and the biggest ones in an evening primrose oil, which featured an altered odor. In the totox analysis, 37,5% of the samples presented values above the normal pattern according to literature, mailly the safflower and theevening primrose oils. Regarding the PAHs, at least one of the analyzed hydrocarbons was detected in 97,5% of the samples; three of the primrose samples (7,5%) had levels above those allowed by the European Community for BaP. According to the sum of 4 PAHs, eight oils (20%) were in disagreement: two of safflower oils, four of evening primrose oils and two of flaxseed oils. This study exposes problems related to identity and quality parameters, contamination of vegetable oils marketed as cold-pressed. It also aims at reinforcing the importance of a continuous monitoring os these products.