Made available in DSpace on 2014-06-11T19:29:06Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-08-26Bitstream added on 2014-06-13T20:38:18Z : No. of bitstreams: 1 ferrizzi_vc_me_sjrp.pdf: 1611524 bytes, checksum: dc7ddb08f93a8a08f46ca06614d12b8d (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Hidrocarbonetos Policíclicos Aromáticos (HPA) fazem parte de uma classe de compostos denominados Substâncias Tóxicas Persistentes, tendo como principais características elevada toxicidade e persistência no ambiente, sendo as fontes petrogênicas, pirogênicos e biogênicas as que mais contribuem para o aporte destes compostos. A Bacia Hidrográfica do Turvo/Grande (BHTG) é caracterizada por pequenos parques industriais e intensa atividade agrícola com destaque a cana-de-açúcar, que vem acompanhada por processos de queimadas. Neste contexto, este trabalho teve como principal objetivo utilizar a determinação de 1-hidróxipireno em bílis de peixes como biomarcador de exposição para HPA e também determinar o histórico destes em sedimentos de rios da BHTG. As coletas de amostras de peixe (160 amostras) e sedimento (superficial e profundidade) nos rios Preto (CAPRP), Turvo (PORTUR e RTURG) e Grande (RGRANDE) foram feitas em dois períodos distintos: fevereiro e julho de 2010. A determinação do 1-hidroxipireno nas amostras de bílis de peixes foi realizada de acordo com o método proposto por Ariase et alii (1993). Os HPA dos sedimentos foram extraídos de acordo com o método 3540C (EPA) e a quantificação foi realizada empregando Cromatografia Líquida de Alta Eficiência com detector de Fluorescência (HPLC-DF). As concentrações do 1-hidróxipireno no ponto RTURG da coleta de fevereiro de 2010 variaram na faixa de 210 a 1025 µg L-1, com valor médio de 780 ± 281 µg L-1. Para as amostras de peixes coletadas em julho de 2010 no ponto CAPRP, os valores estiveram na faixa de 397 - 6463 µg L-1, com valor médio de 1300 ± 1130 µg L-1. Para os pontos PORTUR e RTURG, os valores médios de concentração de 1-hidróxipireno na bílis dos peixes foram... / Polycyclic Aromatic Hydrocarbons (PAHs) constitute a class of compounds denominated as Persistent Toxic Substances, having as main characteristics high toxicity and persistence in the environment, being that the sources petrogenic, pyrogenic and biogenic contribute most to the intake of these compounds. Turvo/Grande watershed (BHTG) is characterized by a small industrial facilities and intensive agriculture especially sugarcane activity, which is accompanied by the burning process. In this context, this work aimed to use the determination of 1-hydroxypyrene in fish bile as a biomarker of exposure to PAHs and also determine the history of these in the sediments from BHTG rivers. The sampling of fish (160 samples) and sediment (surface and deep) in the Preto (CAPRP), Turvo (PORTUR e RTURG) e Grande (RGRANDE) rivers, were made in two distinct periods: February and July of 2010. The determination of 1-hydroxypyrene in fish bile samples was performed according to the method proposed by Ariase et alii (1993). PAHs were extracted of the sediments according to the method 3540C (EPA) and the quantification was performed using high performance liquid chromatography with fluorescence detector (HPLC-FD). Concentrations of 1-hydroxypyrene is fish bile samples collected in RTURG (February 2010) ranged from 210 to 1025 µg L-1, the average values 780 ± 281 µg L-1. For fish samples collected in CAPRP in July 2010 , values ranged 397-6463 µg L-1, with an average of 1300 ± 1130 µg L-1. For PORTUR and RTURG, the mean concentration of 1-hydroxypyrene in fish bile were 1643 ± 744 µg L-1 and 588 ± 183 µ g L-1, respectively. PAHs concentration along the sediment profile showed similar behavior. In general, for all PAHs there was a trend of reduction with increasing depth in sediment cores. The total concentration... (Complete abstract click eletronic access below)

Made available in DSpace on 2014-10-09T12:33:05Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:06:06Z (GMT). No. of bitstreams: 0 / O Parque Estadual Marinho da Laje de Santos (PEMLS) é considerado um dos melhores pontos de mergulho do Brasil além de apresentar grande importância ecológica para a região. Está localizado a 40 km de uma das áreas costeiras mais contaminada do Brasil, o Sistema Estuarino de Santos e São Vicente (SESSV) que apresenta como principais fontes de contaminação as atividades industriais e o maior porto da América Latina. O presente estudo teve como objetivo avaliar o gradiente de contaminação por metais e hidrocarbonetos alifáticos (AH) e policíclicos aromáticos (HPA) nos sedimentos desde o SESSV até o PEMLS para identificar o grau de contaminação e as possíveis fontes dos contaminantes. Amostras de sedimento superficial foram coletadas em pontos distribuídos por todo SESSV, na baia de Santos, na zona marinha adjacente e no PEMLS. Os resultados foram comparados aos valores da qualidade dos sedimentos (VGQS) propostos na literatura para avaliar o grau de contaminação nos sedimentos. De acordo com os resultados, a contaminação por metais e hidrocarbonetos nos sedimentos do SESSV é elevada, acima dos limites estabelecidos nos VGQS, principalmente na porção interna do estuário próximo as atividades industriais. As principais fontes de emissão de contaminantes para o SESSV são os efluentes industriais e a queima de combustíveis fósseis. A zona marinha adjacente, onde está localizada a área de descarte do material dragado, apresentou, depois do estuário, as maiores concentrações de metais e hidrocarbonetos. Essas concentrações foram mais elevadas que as encontradas na baia de Santos. No PEMLS foram registrados indícios de contaminação por Cr, Hg, Ni, Pb e Zn, os quais tem origem de fontes localizadas na costa, que exportam os contaminantes até a região do PEMLS através das correntes marinhas e ainda fontes locais como barcos de operadoras de mergulho e o tráfego de navios. O Ni apresentou concentrações que estiveram acima dos limites do VGQS. Os hidrocarbonetos não apresentaram concentrações elevadas nos sedimentos do PEMLS. Sendo assim, é importante que seja realizado um controle de poluição no SESSV a fim de remediar as áreas mais contaminadas e um monitoramento continuo do gradiente de contaminação desde a zona de costa até o PEMLS para garantir a preservação desse ecossistema que já apresenta indícios de contaminação. A criação de um plano de manejo específico para o PEMLS auxiliaria na proteção dessa Unidade de Conservação. / Dissertação (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous environmental pollutants which are of concern due to their potential human toxicity. They are formed during numerous combustion processes, including biomass burning and diesel vehicular emissions, which are of relevance in developing countries. A novel analytical screening method for atmospheric polycyclic aromatic hydrocarbons (PAHs) was developed in this study based on laser induced fluorescence (LIF) of samples on quartz multi-channel polydimethylsiloxane (PDMS) traps. A tunable dye laser with a frequency doubling crystal provided the excitation radiation, and a double monochromator with a photomultiplier tube detected emitted fluorescence. The method allowed for the rapid (<5 min), cost effective analysis of samples. Those yielding interesting results could be further analysed by direct thermal desorption-gas chromatography-mass spectrometry (TD-GC-MS, with limits of detection of ~0.3 ng.m-3), as photodegradation was minimal (<10% over 5 min irradiation). Without any signal optimization, a LIF detection limit of ~1 ìg.m-3 was established for naphthalene using a diffusion tube (diffusion rate of 2 ng.s-1) and 292 nm excitation. Gas standards which facilitated the uniform distribution of analyte across each of the 22 PDMS tubes were provided by easily constructed diffusion tubes for naphthalene and by a gas chromatographic fraction collection method for the less volatile target PAHs. The methods developed were successfully tested in a number of applications which are of relevance to southern Africa, as emissions from sugar cane burning, household fires, diesel vehicles and industries were monitored. The LIF method allowed for the differentiation between impacted and non-impacted industrial sites, and the importance of naphthalene as an indicator for atmospheric PAHs was verified in that this PAH was the most abundant in the various applications which were investigated. The multi-channel silicone rubber traps were also evaluated theoretically and practically in the denuder configuration, in order to monitor PAHs in both the gas and particle phases, which is important in terms of human health effects. The novel LIF method developed in this study has the potential to serve as a screening tool to avoid the comprehensive and costly analysis of samples which do not contain appreciable levels of PAHs. The experimental procedure is simple and rapid, with acceptably low limits of detection, even with the initial, unoptimized optical arrangement and without extensive time-averaging. LIF also provides selectivity without the need for sample clean-up and separation processes. The LIF method could be further optimized by improving the laser energy stability, as well as by the investigation of possible time resolution techniques. As equipment cost considerations were important, it is possible that the LIF screening method could find application in a centralized environmental laboratory for the southern African region. This would facilitate the widespread monitoring of atmospheric PAHs in a cost effective manner. / Thesis (PhD)--University of Pretoria, 2010. / Chemistry / unrestricted

Human exposures to polycyclic aromatic hydrocarbons (PAHs) occur as components of complex mixtures. Evaluations of health risks posed by complex mixtures containing PAHs rely on the toxicological knowledge of prioritized PAH mixture components, assuming that these PAHs share a common mode of action and that the sum of the contributions of these PAHs equals the toxic potency of the mixture (i.e., additivity). Traditional toxicity testing methods emphasizing apical endpoints have had limited success at evaluating the validity of these assumptions. Toxicogenomic tools that are able to rapidly generate toxicologically-relevant and mechanistic information have gained acceptance in the regulatory arena for individual chemicals; however, the applicability of these tools for chemical mixtures has been inadequately addressed. This thesis used toxicogenomic tools to (1) improve the understanding of mechanisms underlying the adverse, toxicological responses induced by individual PAHs and (2) evaluate the contention that transcriptional profiles and pathway information can be used to critically examine interactions between individual PAHs in PAH-containing mixtures, and the assumption of additivity. Microarrays were used to profile gene expression changes (transcriptomes) in forestomach, liver, and lung tissues (targets of PAH exposure) from mice orally exposed to three doses of eight individual PAHs, two defined PAH mixtures, and one complex PAH-containing mixture (coal tar). The results revealed that each PAH induced transcriptional changes that were significantly associated with several pathways implicated in carcinogenesis. However, despite a uniform ability to induce DNA damage (i.e., DNA adducts), mutations, and increases in enzyme activity, the pathways differ across PAHs and tissues. A novel strategy that employs single-PAH transcriptome data to models of additivity revealed that the assumption of additivity in PAH mixtures is valid at the pathway level; however, the independent action model of additivity yielded better estimates compared to concentration addition (used in human health risk assessment of PAH mixtures) or generalized concentration addition. Additionally, predicted and observed coal tar-induced transcriptional benchmark doses were comparable to those derived from previously published coal tar-induced murine lung tumour incidence data. Overall, this thesis demonstrates the utility of toxicogenomic data to expand the current understanding regarding the toxic potential of individual PAHs and PAH-containing complex mixtures.

Exposure to combustion emissions poses a threat to human health due to the complex mixture of toxic compounds. Polycyclic aromatic hydrocarbons (PAHs) are one group of compounds found within this mixture, and have known carcinogenic and mutagenic properties. Rates of exposure to PAHs depend on a wide range of variables including, but not limited to, demographic, geographical location, dietary habits, smoking habits, and occupation. Understanding magnitude of exposure to these compounds in various groups is imperative to highlight at-risk populations and provide appropriate exposure reduction recommendations. Here, urinary biomarkers are used as a non-invasive, convenient way to assess an individual’s exposure to combustion emissions. Urinary measurements of metabolites of individual PAHs as well as compounds indicative of a physiological condition resulting from combustion emission exposure are used to infer exposure. Pairing urinary data with information from questionnaires collecting data on possible sources of combustion by-product exposure was used to determine situations of high exposures. This thesis investigated the influence of demographic, lifestyle, and occupational factors on urinary levels of PAH metabolites and/or urinary mutagenicity. More specifically, statistical methods were used to analyze population data compiled for the Canadian Health Measures Survey (CHMS). Smoking, age, and sex were identified as the variables most predictive of urinary PAH metabolite concentrations in Canadians. Together with the other demographic and lifestyle variables examined, 24-50% of the variation in the various PAH metabolites was explained. Furthermore, the results obtained illustrated that utilizing PAH metabolites other than the traditionally used 1-hydroxypyrene may be more suitable for certain exposure scenarios (e.g., fluorene metabolites for tobacco smoke exposure). Occupational exposures to combustion emission were investigated in firefighters as they experience above average risk of cancer, thus paired with their obvious involvement with combustion, are an ideal population to apply the use of urinary biomarkers to assess PAH and combustion exposure. The effect of participating in fire suppression activities (i.e., firefighting) on urinary levels of selected PAH metabolites and organic mutagens was examined. Levels of external PAH exposures were assessed using personal air monitoring and surface wipes of skin. Significant increases in urinary PAH metabolites and mutagenicity were seen after fire suppression events. Empirical relationships between urinary PAH metabolites and duration of fire event and skin concentrations of PAHs suggested that dermal contamination during live fire events is a major route of exposure. Overall, the results from both studies identified factors that may affect an individual’s concentrations of urinary biomarkers of combustion emission exposure. This may be used to identify at-risk populations and/or determine effective exposure reduction techniques to these hazardous compounds.

Flat dendrimers, consisting of a hexavalent aromatic core and rigid ethynyl units locked in place by ether connections were developed based upon the divergent synthetic method. Alternating functional groups were adopted on each site of the hexa-substituted benzene, in order to avoid undesired cyclization pathways. The flat structures of conjugated dendrimers would allow investigation on the discotic liquid crystal properties. In addition, these ethylnyl dendrimers are expected to show directed energy and electron transfer with a highly conjugated system, and thus are effective in the preparation of photoreactive materials such as electronic sensors or light harvesting materials. Conjugated polycyclic aromatic hydrocarbons, consisting of naphthalene, anthracene, pyrene, and phenanthrene groups connected via 1,3,5-triethynylbenzene cores, were synthesized. These molecules exhibited luminescence properties and the π-complexation with a mercury trifunctional lewis acid are expected to enhance the phosphorescence in the presence of the heavy metal due to the spin-orbit coupling. Besides, owing to the presence of heavy metal atom in the Au (I) complexes linked by s-bonded triethynyltriphenylene luminophore, the phosphorescence occurs from a metal-centered emission. The conjugated organic luminophores have been developed to produce excellent quantum efficiencies, brightness, and long lifetimes.

Among current technologies used for the treatment of polycyclic aromatic hydrocarbons (PAHs) -contaminated media, adsorption has been reported to offer relatively high PAH removal efficiency while being rapid and cost-effective. Therefore, the main goal of this research was to assess and optimize the adsorption process for the removal of PAHs from contaminated water and soil using recoverable magnetic activated carbon-based composites. In the first phase, 6 different composites, 3 magnetic powder activated carbon (MPAC) composites and 3 magnetic granular activated carbon (MGAC) composites, were synthesized, and then, characterized using XRD, FE-SEM, EDS, and FTIR methods. The adsorption experiments revealed that all the recoverable MPACs and MGACs were capable of removing the PAHs from water, with removal percentages ranging from 87.2 to 99.3%. The PAH-loaded MPAC and MGAC with the highest PAH removal efficiency were also subjected to a series of desorption studies. The results indicated that the PAHs desorption was in the range 38.1-60.1% for low molecular weight (LMW) PAHs and 23.4 to 57.2% for the high molecular weight (HMW) PAHs. In the second phase, the adsorption kinetics and isotherms studies were performed on MPAC synthesized by a precipitation (MPAC-Prec.) method, which showed the highest PAH removal efficiency among the prepared magnetic activated carbons (MACs). The PAHs adsorption by MPAC-Prec. was rapid, reaching equilibrium in 6 h with the removal efficiency ranging from 95.6 to 100.0% under the conditions of this study. Among the studied kinetics models, pseudo-second order fitted the experimental data very well, implying that all the MPAC adsorption sites had an equal affinity for PAHs. The results of the kinetic studies also indicated that the greater molecular weight PAHs had a slower adsorption rate due to the slower transfer of their molecules to the MPAC adsorption sites. With an R2 in the range 0.73-0.96, the Langmuir model described the isotherms adsorption of LMW and HMW PAHs better than the other isotherms models. Furthermore, according to the Langmuir model, the maximum adsorption capacity of MPAC-Prec. was determined to be between 8.7 and 11.4 µg/mg for the LMW PAHs, and 8.4 and 20.2 µg/mg for the HMW PAHs. In the third phase, a series of soil washing tests using MGAC synthesized by co-precipitation (MGAC-CoP) method, were carried out to explore the effect of MAC on the PAHs removal from soil. The employed MGAC was the second most efficient MAC in the PAHs adsorption experiments (first phase of research), and it showed greater recovery from soil washing mixture compared to the MPAC-Prec. in the preliminary tests. The MGAC-CoP composite had a surface area and total pore volume of 837.9 m2/g and 0.5 cm3/g, respectively, which were approximately 10% lower than the bare GAC, according to BET test results. Soil washing parameters were optimized for the treatment of a real contaminated soil, which were MGAC-CoP dose of 2% (w/w), washing time of 24 h, liquid to soil ratio of 15:1, stirring speed of 100 rpm, pH of 8.3, and temperature of 25 ˚C. Under these optimized conditions, an average PAHs removal of 47.4% was obtained. Among the LMW and HMW PAHs, anthracene (ANT), and fluoranthene (FLUO) showed the highest affinity to MGAC during the treatment process, with 57.7% and 67.1% removal from soil, respectively. The thermodynamic studies revealed that the adsorption of the LMW and HMW PAHs onto MGAC in soil washing was non-spontaneous and endothermic as the values of Gibbs free energy (∆G˚>0) and Enthalpy change (∆H˚>0) were positive. In the fourth phase, the efficiency of MGAC-CoP in surfactant-enhanced soil washing for the PAH removal and the recovery of the surfactant solution was studied. The effective parameters of soil washing with the surfactant (Tween 80) were assessed using a real contaminated soil sample, and the results showed that 5% Tween 80, a liquid to soil ratio of 10:1, and a 72-hour washing time at 20°C were optimum operating conditions. Under these conditions, the average PAHs removal efficiency was 67.6%, which was higher than the 47.4% obtained for the same soil with no surfactant addition in phase 3. The possibility of recycling and reusing the Tween 80 solution was investigated by adding MGAC-CoP to the soil and surfactant solution mixture during the soil washing process. For this purpose, 5% Tween 80 and 2% (w/w) MGAC were used in 7 successive washing cycles, with no regeneration process for the MGAC composite. The results revealed that the combination of surfactant and MGAC was capable of removing 68.6, 70.7, 70.3, 61.6, 55.5, 50.2, and 39.4% of the PAHs from soil in the 7 washing cycles, respectively. Furthermore, the recycled Tween 80 and non-regenerated MGAC did not produce any waste or effluent after 6 times reuse in the treatment process, while successfully recovered and reused. This implies that soil washing with Tween 80 and MGAC is a very affordable, efficient, and practical method for remediation of PAH-contaminated soils.

Polycyclic aromatic hydrocarbons (PAH) are important environmental pollutants originating from a wide variety of natural and anthropogenic sources. Because many of them are highly suspect as etiological agents in human cancer, chemical analysis of PAH is of great environmental and toxicological importance. Current methodology for PAH follows the classical pattern of sample preparation and chromatographic analysis. Sample preparation preconcentrates PAH, simplifies matrix composition, and facilitates analytical resolution in the chromatographic column. Among the several approaches that exist to pre-concentrate PAH from water samples, the Environmental Protection Agency (EPA) recommends the use of solid-phase extraction (SPE). High-performance liquid chromatography (HPLC) and gas chromatographymass spectrometry (GC-MS) are the basis for standard PAH identification and determination. Ultraviolet (UV) absorption and room temperature fluorescence detection are both widely used in HPLC, but the specificity of these detectors is modest. Since PAH identification is solely based on retention times, unambiguous PAH identification requires complete chromatographic resolution of sample components. When HPLC is applied to "unfamiliar" samples, the EPA recommends that a supporting analytical technique such as GC-MS be applied to verify compound identification and to check peak-purity HPLC fractions. Independent of the volume of extracted water, the approximate time required to separate and determine the sixteen "priority pollutants" (EPA-PAH) via HPLC is approximately 60min. If additional GC-MS analysis is required for unambiguous PAH determination, the total analysis time will reach 2-3 hours per sample. If the concentrations of target species are found to lie outside the detector’s response range, the sample must be diluted and the process repeated. These are important considerations iv when routine analysis of numerous samples is contemplated. Parent PAH are relatively inert and need metabolic activation to express their carcinogenicity. By virtue of the rich heterogeneous distribution of metabolic products they produce, PAH provide a full spectrum of the complexity associated with understanding the initial phase of carcinogenesis. PAH metabolites include a variety of products such as expoxides, hydroxyl aromatics, quinines, dihydrodiols, dioepoxides, tetrols and water soluble conjugates. During the past decades tremendous efforts have been made to develop bio-analytical techniques that possess the selectivity and sensitivity for the problem at hand. Depending on the complexity of the sample and the relative concentrations of the targeted metabolites, a combination of sample preparation techniques is often necessary to reach the limits of detection of the instrumental method of analysis. The numerous preparation steps open ample opportunity to metabolite loss and collection of inaccurate data. Separation of metabolites has been accomplished via HPLC, capillary electrophoresis (CE) and GC-MS. Unfortunately, the existence of chemically related metabolic products with virtually identical fragmentation patterns often challenges the specificity of these techniques. This dissertation presents significant improvements in various fronts. Its first original component – which we have named solid-phase nano-extraction (SPNE) - deals with the use of gold nanoparticles (Au NPs) as extracting material for PAH. The advantages of SPNE are demonstrated for the analysis of PAH in water samples via both HPLC1 and Laser-Excited TimeResolved Shpol’skii Spectroscopy (LETRSS).2 The same concept is then extended to the analysis of monohydroxy-PAH in urine samples via SPE- HPLC3 and In-Capillary SPNE-CE.4 The second original component of this dissertation describes the application of Shpol’skii Spectroscopy to the analysis of polar PAH metabolites. The outstanding selectivity and v sensitivity for the direct analysis of PAH at trace concentration levels has made Shpol’skii spectroscopy a leading technique in environmental analysis.5 Unfortunately, the requirement of a specific guest-host combination - typically a non-polar PAH dissolved in an n-alkane - has hindered its widespread application to the field of analytical chemistry. This dissertation takes the first steps in removing this limitation demonstrating its feasibility for the analysis of polar benzo[a]pyrene metabolites in alcohol matrixes.6

Human bodies are in constant interaction with materials containing known and unknown chemicals of hazardous behavior. One group of chemicals are polycyclic aromatic compounds (PACs) which can be present in both indoor and outdoor materials, commonly in plastics. PACs are known for their cancerogenic behavior and thus should be considered and studied in an attempt to decrease human exposure. The following project reports the execution and results from chemical analysis of 48 PACs including parent polycyclic aromatic hydrocarbons (PAHs), alkylated PAHs and dibenzothiophenes (S-PAC), searched for in different materials commonly found indoors. Eleven samples were prepared and analyzed using GC/MS target analysis. 23 out of the 33 parent PAHs targeted were detected and quantified. In addition, 12 out of 15 alkylated PAHs including four dibenzothiophenes (S-PAC) were detectable in the samples. The contents of parent PAHs ranged from 105 ng/g to 6700 ng/g in the samples, with the highest value being present in a laminated artificial leather sample. The alkylated PAHs ranged from 34 ng/g to 3000 ng/g, and a recycled hard plastic contained the highest amount. Amongst the parent PAHs, the dominating compound in the samples was phenanthrene. For the alkylated PAHs, 2-methylnaphtalene was the compound present in the highest mass fraction. When comparing the samples, most similarities in PAC composition could be seen in the artificial leather samples excluding a high content of naphthalene in the laminated leather. The recycled plastic material consisted of the highest variety of PACs. The results presented that none of the samples exceeded the limit values set by EU regulation regarding eight PAHs (PAH8) in consumer products. However, poor recovery in addition to poor resolution of the majority of the high molecular mass compounds suggest further investigation of method optimization.

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