A presente pesquisa trata de calibrar, a ferir e utiliza em laboratório um detetor de fotoionização (método de campo) proveitoso na caracterização de áreas contaminadas por vazamentos de gasolina; comparar as informações do detetor com os resultados obtidos com balança analítica; comparar os resultados de fluxo de massa medido com o previsto pelo modelo JURY contido no software APIDSS 2.0 O detetor mostrou-se útil como primeira ferramenta na caracterização de áreas contaminadas recentemente (até 100 dias). Para áreas onde a contaminação esteja em uma fase mais avançada o aparelho mostrou-se útil na detecção de alterações; os modelos desenvolvidos com base nos resultados obtido com balança e com o detetor de fotoinização apresentaram resultados satisfatórios para o período de ensaio; as comparações realizadas com o software APIDSS 2.0 serviram para a confirmação dos resultados obtidos. / The present research aims at gauging, checking and using a photoionization detector (field method) in laboratory advantageous to the characterization of areas polluted by leaks of gasoline; to compare the information of the detector with the results obtained in the analytic scale; to compare the results of the measured mass flow with those foreseen by the model JURY of the software APIDSS 2.0. The detector showed to be useful as a first tool in the characterization of areas recently contaminated (up to 100 days). To areas where the contamination is in a more advanced phase, the apparel showed to be useful in the detection of alterations; the development of models based on the results obtained with a scale and with the photoionization detector presented satisfactory results for the rehearsal period; the comparisons accomplished by the software APIDSS 2.0 confirmed the obtained results.

Orientador: Wanilson Luiz Silva / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Geociências / Made available in DSpace on 2018-08-22T15:39:08Z (GMT). No. of bitstreams: 1 Nizoli_EricoCasare_D.pdf: 3439410 bytes, checksum: 6e05f3840a6ddac0203d12e536c08876 (MD5) Previous issue date: 2013 / Resumo: Durante as últimas décadas, efluentes industriais têm sido lançados no sistema estuarino de Santos-Cubatão, onde os rios Cubatão e Morrão são os principais receptores das descargas industriais. Diversos estudos foram realizados nos sedimentos do rio Morrão, já sendo bem conhecida a geoquímica da concentração total dos elementos neste ambiente. Os elevados níveis de ferro e fósforo de origem antrópica nestes sedimentos colocam este ambiente em um patamar científico cujos processos físico-químicos dominantes ainda são desconhecidos. No presente estudo, buscou-se identificar os processos que ocorrem na partição água intersticial-sedimentos em ambientes estuarinos impactados e o papel que a alta concentração de ferro e fósforo desempenha na variabilidade geoquímica tempo-espacial desta partição. Para tanto, foram investigados a dinâmica multi-elementar nos sedimentos, nas águas intersticiais, características fisico-químicas, matéria orgânica, sulfetos volatilizados por acidificação (AVS) e metais simultaneamente extraídos (SEM), granulometria e mineralogia mensalmente durante o período de onze meses, em dois ambientes do rio Morrão, sistema estuarino de Santos-Cubatão. Adicionalmente, foi desenvolvido um dispositivo para amostragem temporal de água intersticial por equilíbrio difusivo com sistema de coleta de amostra/recarga e uma proposta de mini-coluna para extração em fase sólida para a determinação de metais por ICP-MS em águas salinas. Os resultados obtidos demonstraram que o amostrador de água intersticial por equilíbrio difusivo proposto neste estudo é adequado para o emprego em trabalhos onde se pretende coletar temporalmente água intersticial sem perturbar os sedimentos e onde há a necessidade de um maior volume de amostra, o que não pode ser conseguido empregando amostradores apresentados pela literatura com funcionamento semelhante. Os dados do estudo sobre extração em fase sólida para determinação de metais em águas salinas por ICP-MS demonstraram que a mini-coluna com resina quelante proposta neste trabalho é eficaz em remover a matriz salina, apresentando precisão e exatidão adequadas aos níveis de analito presentes nas amostras. Já os resultados obtidos no estudo sobre a partição água intersticial-sedimentos em ambientes estuarinos impactados mostraram a existência de variações geoquímicas espaço-temporais para elementos maiores, menores e traços nos sedimentos. Assinaturas geoquímicas discriminantes foram observadas entre as populações de amostras VG (sedimentos expostos durante menor maré - borda do canal) e CN (sedimentos permanentemente submersos). Foi observado ainda que os elementos estudados se agrupam (análise de componente principal - PCA) de acordo com três fontes distintas (natural, indústrias siderúrgica e de fertilizantes). Variação espacial e temporal também foi identificada para a água intersticial, indicando que a autigênese de vivianita e magnetita estão entre os principais fatores controladores dos metais na água intersticial nos diferentes ambientes. Fases secundárias sulfetos (AVS) também exercem ação controladora dos metais na interface sedimento-água intersticial. Contudo, magnetita e vivianita apresentam-se como importantes retentores de metais na fase sólida, cuja cristalização autigênica é decorrente de introdução antrópica de Fe e P em grande escala no ambiente sedimentar do estuário do rio Morrão / Abstract: During the last decades, industrial effluents have been discharged into the estuary of Santos-Cubatão, where Cubatão and Morrão rivers are the main receivers of industrial discharges. Several studies were made in sediments of Morrão River, being already well known the geochemistry of the total concentration of the elements in this environment. The high levels of iron and phosphorus of anthropogenic origin in sediments, putting the environment on a scientific level in which dominant physical and chemical processes are still unknown. In the present study, we sought to identify the processes that occur in the pore water-sediment partition in estuaries impacted and the role that the high concentration of iron and phosphorus plays in the time and spatial geochemical variability. Therefore, we investigated the multi-elemental dynamics in sediments, interstitial waters, physico-chemical, organic matter, AVS and SEM, particle size and mineralogy, monthly, during the period of eleven months, in two places of Morrão river, Santos-Cubatão estuarine system. Additionally, we developed a device for temporal sampling of interstitial water by diffusive equilibrium system with sampling/recharging and a proposal for a mini-column for solid phase extraction for the determination of metals by ICP-MS in saline waters. The results showed that the pore water sampler for diffusive equilibrium proposed in this study is suitable for employment in investigations where it is necessary to collect temporally pore water without disturbing sediment and when there is a need for a larger sample volume, which cannot be achieved by employing samplers presented in the literature that operate similarly. Data from the study of solid phase extraction for the determination of metals in saline waters by ICP-MS showed that the mini-chelating resin column proposed in this study is effective in removing the salt matrix, with adequate accuracy and precision levels of analyte present the samples. Since the results obtained in the study of the pore water-sediment partition in estuaries impacted showed the existence of spatial and temporal geochemical variations for major, minor and trace elements in sediments. Discriminant geochemical signatures were also observed among the sample populations VG (sediments exposed during low tide - canal edge) and CN (permanently submerged sediments). It was also observed that the studied elements are grouped (Principal component analysis - PCA) according to three separate sources (natural, steel and fertilizer industries). Spatial and temporal variation was also identified for the interstitial water, indicating that the authigenesis of vivianite and magnetite are the main controlling factors of metals in the pore water in different environments. Secondary sulfide phases (AVS) also exert controlling metals in the interface sediment-pore water. However, magnetite and vivianite present themselves as important scavengers of metals, which authigenic crystallization is due to anthropogenic introduction of Fe and P large-scale sedimentary environment in the Morrão estuary / Doutorado / Geologia e Recursos Naturais / Doutor em Ciências

Orientador: Sueli Yoshinaga Pereira / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Geociências / Made available in DSpace on 2018-08-22T00:31:48Z (GMT). No. of bitstreams: 1 Arcaro_NathaliaPozzi_M.pdf: 2439576 bytes, checksum: 7988db46a010845295ed8c71b1cbb79c (MD5) Previous issue date: 2013 / Resumo: A vinhaça constitui um efluente proveniente da indústria sucro-alcooleira, utilizado principalmente na fertirrigação de lavouras de cana-de-açúcar, por. Contudo, diversos trabalhos indicam que a aplicação e disposição de vinhaça em solo ocasionam a contaminação destes meios por sais e metais, além de proporcionar a alteração de características físico-químicas e biológicas do solo. O objetivo do presente estudo visou avaliar a qualidade do solo em um tanque/lagoa de disposição de vinhaça, sem impermeabilização, e que foi utilizada por 20 anos e há 8 anos se encontra inativo. Foram realizadas 2 sondagens dispostas no interior do tanque de vinhaça e em uma área de background com profundidades de 24 e 32 metros. As amostras de solo foram coletadas em intervalos de 1 metro até o nível d'água. As análises de solo foram realizadas por fluorescência de raios x para determinação das frações em massa de óxidos e elementos traços, além de ensaios de perda ao fogo e análise microbiológica de solo para fungos e leveduras. Também foram realizados ensaios de lixiviação com água deionizada e ácida nítrico, analisada por cromatografia e ICP-MS. Os resultados das amostras de solo e dos ensaios de lixiviação indicam que as amostras de solo coletadas no interior do tanque de vinhaça apresentaram indícios de salinização em comparação com as amostras de solo de controle. Os resultados das análises microbiológicas indicaram a diferença entre o número de isolamentos de unidades formadoras de colônia entre as amostras coletadas no interior do tanque de vinhaça e as amostras de controle. Concluiu-se que o solo do antigo tanque/lagoa avaliado ainda apresenta os efeitos da disposição inadequada de vinhaça, que interfere nas propriedades químicas e microbiológicas do solo / Abstract: The vinasse is an effluent from the ethanol industry, mainly used in fertirrigation of crops of sugar cane. However, several studies indicate that the application and disposal of vinasse on soil cause the contamination by salts and metals, in addition to providing the change of physical, chemical and biological soil properties. The aim of this study was to evaluate the quality of the soil in a vinasse dam without impermeabilization, that was used for 20 years and it's inactive for 8 years. Two boreholes were drilled in the vinasse dam and in a background area at depths of 24 and 32 meters. Soil samples were collected at one meter interval until the depth of the water level. Soil analyses were performed using XRF method to determine the mass fractions of oxides and trace elements, as well as loss on ignition test and microbiological analysis of soil for fungi and yeasts. Also leaching tests were performed with deionized water and nitric acid, and the leachates were analyzed by chromatography and ICP-MS. The results of the soil samples and leach tests indicated that the leaching of soil samples collected inside the vinasse dam showed evidence of salinization compared to control soil samples. The results of the microbiological analyses indicated a difference between the number of isolated colony forming units among samples collected in the vinasse dam and control samples. It was concluded that the soil of the old vinasse dam still shows the effects of improper disposal of vinasse, which interferes with chemical and microbiological properties of the soil / Mestrado / Geologia e Recursos Naturais / Mestra em Geociências

Submitted by Biblioteca da Faculdade de Farmácia (bff@ndc.uff.br) on 2017-04-07T17:48:18Z No. of bitstreams: 1 José, Kelly Fernanda Campos [Dissertação, 2014].pdf: 955086 bytes, checksum: 84564fe3de6240b8248fb1dbad2cf5ec (MD5) / Made available in DSpace on 2017-04-07T17:48:18Z (GMT). No. of bitstreams: 1 José, Kelly Fernanda Campos [Dissertação, 2014].pdf: 955086 bytes, checksum: 84564fe3de6240b8248fb1dbad2cf5ec (MD5) / O pescado é um alimento de excelente valor nutritivo devido às suas vitaminas, proteínas e ácidos graxos insaturados, no entanto, pode veicular uma variedade de microrganismos patogênicos ao homem, aumentando a preocupação com a qualidade sanitária. Nesse contexto, a formação de biofilme na indústria de alimentos representa uma preocupação por sua potencialidade em resistir a tratamentos sanitizantes, além da possibilidade de perda da qualidade por deterioração e/ou veiculação de patógenos, justificando assim, a importância de uma correta higienização na indústria. Neste estudo objetivou-se identificar microrganismos presentes nas superfícies de processamento de pescado, assim como avaliar a capacidade de formação de biofilmes bacterianos em equipamentos e sinalizar maneiras de evitar sua formação. Para tal, foi realizada a avaliação de superfícies através do método “swab”, com coleta de amostras das superfícies do tanque de lavagem, esteira de evisceração e descabeçamento e tanque de armazenamento de molho de cobertura, em uma indústria de pescado do Estado do Rio de Janeiro, através de três visitas aleatórias realizadas em diferentes meses do ano. As referidas amostras foram encaminhadas sob refrigeração para o Laboratório de Higiene e Microbiologia de Alimentos da Faculdade de Farmácia – UFF, onde foram processadas conforme métodos e recomendações oficiais. Em relação aos resultados foram constatadas não conformidades na lista de verificação, com situação mais crítica observada no item manipuladores. Na análise bacteriológica evidenciou-se elevadas contagens de bactérias heterotróficas aeróbias mesófilas, presença de Salmonela spp., Listeria spp., Bacillus spp., coliformes totais e Escherichia coli. Demonstrou-se capacidade de formação de biofilme por cepas de E. coli isoladas nas três visitas realizadas. Na avaliação da eficácia de sanitizantes de uso industrial, foram observados melhores resultados na exposição à biguanida polimérica e taxas elevadas de resistência ao quaternário de amônio. Diante dos resultados, constatou-se ausência de condições higiênico-sanitárias adequadas e circunstâncias propícias para formação de biofilmes bacterianos / Fish is a food of great nutricional value due to their vitamins, proteins and unsaturated fatty acids, however, can convey a variety of pathogenic microorganism to man increasing the concern about ensuring health standards. In this context, the formation of biofilms in the food industry represent a preoccupation because of its potencial to resist sanitizing treatments, besides the possibility of causing quality loss due to deterioration and/or transmission of pathogens, justifying the importance of proper hygiene in industry. This study aimed to identify microorganisms present on the surfaces of fish processing and assess the ability of formation of microbial biofilms on equipament and to signal ways to avoid their formation. In this sense, the evaluation of surfaces contact was performed from samples collected on the surfaces of the washing tank, gutting and beheading mat and of storing tank coverage sauce, at seafood industry in a state of Rio de Janeiro, through three randomized visits in different months of the year. These samples were sent under refrigeration to the Laboratory of Food Microbiology and Hygiene, Faculty of Pharmacy – UFF, which were processed by methods and official recommendations. Regarding the results, non-conformities were found by checklist, with more critical situation in the item handlers. Bacteriological analysis revealed a high count of aerobic mesophilic, presence of Salmonella spp., Listeria spp., Bacillus spp., total coliforms and Escherichia coli. It was demonstrated ability of biofilm formation by strains of E.coli isolated in three visits. In evaluating the effectiveness of sanitizers industrial use was observed better results in exposure to polymeric biguanide and high rates resistance to quaternary ammonium. Considering the results, it has been found a lack of adequate sanitary conditions and circumstances conducive to the formation of bacterial biofilms

M.Sc. (Nanoscience) / Polychlorinated biphenyls (PCBs) are endocrine disrupting compounds (EDCs) and are harmful to humans and the environment. These PCBs are grouped under chlorinated organic compounds (COCs). The PCBs find their way to the environment through human activity such as industrialization and farming. Such activity produces wastes and runoffs that eventually end up in the water we use for drinking, farming and sanitation. It has then become necessary for researchers to find viable methods to remove these compounds from the environment. This is because current water treatment methods are not effective in the removal of the PCBs from water. The stages in the conventional treatment methods may include sand filtration, advanced oxidative processes and coagulation among others. These methods need to be energetically eco-friendly to drive the PCB dechlorination processes. Researchers have used a variety of metallic nanoparticles including bimetallic nanoparticles for the removal of COCs from water. However, nanoparticles tend to agglomerate when not supported - leading to a decrease in their activity. Hence it has become necessary to stabilize or immobilize these nanoparticles on suitable support materials, such as, polymer solutions or solid substrates. Solid substrates including metal oxides, carbon and membranes, are currently being explored. Poly(vinylidene difluoride) microfiltration membranes are especially suitable for this function given the high porosity, chemical inertness and other outstanding physical properties. In this work, the objective was to modify commercially hydrophilized poly(vinylidine)difluoride (PVDF) membranes with poly(ethylene glycol) (PEG). PEG is a bidentate polymer with two –OH groups found on either side of the molecule. The -OH groups allows PEG binding to the PVDF polymer backbone and hence high ability to capture or chelate the metal ions followed by their reduction. Nano-zerovalent metal nanoparticles were formed from these metal ions and chelated into the PEG grafted PVDF membrane to give the composite PVDF-PEG-Fe0. Post addition of the secondary metal was then followed by the introduction of the precomposite to a Pd solution to give the final catalytic membrane (PVDF-PEG-Fe0/Pd0). The use of PEG in this system allows for an even dispersion of the nanoparticles in the composite. The resulting nanocomposite membrane was used for the dechlorination of a polychlorinated biphenyl (PCB 77). Attenuated total reflection- Fourier transform infra red spectroscopy (ATR-FTIR) showed that PEG was successfully grafted onto the PVDF backbone. Optical contact angle measurements (OCA) were taken to determine the change in hydrophilicity of the membrane upon modification. X-ray diffraction spectroscopy (XRD) proved that the Pd and Fe nanoparticles immobilized on the system were indeed zerovalent. Scanning electron microscopy (SEM) images and contact angle measurements suggested a less porous membrane and slightly decreased hydrophilicity after modification. On the SEM micrographs the nanoparticles were observed to be quite evenly distributed in the membrane. Transmission electron microscopy (TEM) showed that the nanoparticles were in the range 20-30 nm in diameter, confirming the particle size values as determined by SEM. For the preliminary dechlorination studies done under ambient conditions, two dimensional column gas chromatography- time of flight- mass spectrometry (GCxGC-TOF-MS) results showed a complete dechlorination of PCB 77. A comparative study of the bare PVDF and catalytic membranes showed a slight difference in adsorption of the total PCB 77 concentrations. The catalytic membrane maintained its activity towards the dechlorination of PCB 77 after multiple regeneration cycles.

>Magister Scientiae - MSc / The present study investigated the application of a multi-method approach to determine groundwater-surface water (GW-SW) interactions to quantify and characterize the quality of water resources in a fractured rock aquifer system in upper catchment of the Berg River (G10A). Demonstrating methods for improved understanding of groundwater and surface water interactions is important for informing development of strategies that ensure effective utilization and management of water resources. Applying a single method to inform innovative strategies for water resources has proved futile. The current study shows how the use of several methods can provide the basis for devising practical strategies for water resource utilization and management. The three methods were applied as follows: First, the base flow separation was used whereby the Chapman and Lynne & Hollick digital filter algorithms were applied to time-series streamflow data from four stream gauging stations in the catchment. The computation from algorithms on three sites (gauging stations) showed that the mean Base Flow Index (BFI) value ranged between 7%-8% for the 2012-2014 periods. This means that discharges from subsurface water storages dominate stream flows throughout the study period. Secondly, the quality of groundwater and surface water was sampled using standard methods. Piper Diagrams generated on Aquachem™ software and radial charts were used to identify the predominant hydrochemical facies. Results showed that Na-Cl was the predominant GW and SW water-type. This means that both GW and SW are mainly influenced by recharging surface water as well as interaction occurring between the rock matrices and infiltrating water. Multivariate statistical analyses were used to evaluate the factors controlling GW and SW chemistry in the upper Berg River catchment and the results showed that GW and SW are influenced by natural processes. Two main factors (a. & b.) were extracted which explained 71.8% of the variation in both GW and SW physicochemical parameters. These factors include water-rock interactions and the recharge of surface water. Cluster Analysis extracted four major clusters that grouped sites with similar physicochemical characteristics together. Finally, differential stream gauging was applied to a 600m reach above the Berg River Dam. Three 200m sub-reaches were used to compute differences in flows between sub-reaches. Stream flow at each sub-reach was estimated using mass balance equations with electrical conductivity measurements during instant salt tracer injection tests. Results indicated that during both the wet season (high flow) dry season (low flow), the river continuously lost water to the subsurface. This was demonstrated by the 0.91m³/s and 2.24m³/s decrease in stream flow along the 600m reach. Dry season flow decreases were less than wet season flow decreases, indicated by markedly lower flow loss in respect to the wet season. This confirms results of the analysis of base flow separation, which indicated that discharges from subsurface storages dominate stream flows during low flow periods. The differential stream gauging approach did not provide distinct points along the selected stream reach where GW-SW interaction occurred; rather it provided a holistic representation of seasonal flow variations along the selected reach. This study showed that upper Berg River catchment is dependent on discharges from subsurface water storages to maintain dry season flows. Furthermore, this study showed that infiltration of surface water and discharge of subsurface water transfers the respective chemical signature of the contributor, meaning that the transfer of water of suitable quality will reduce contamination in the receiving water body (i.e. surface water). Transfer of water between subsurface and surface water contributed an average of 8% of the gauged flows in the catchment between 2012 and 2014, suggesting that the groundwater recharge process dominates this catchment.

Fungal exposure had been repeatedly associated with a wide range of harmful health effects. The first association between mould exposure and asthma exacerbations was reported almost 300 years ago and since then, they are numerous data on the link between mould sensitization and asthma severity. Most of the data on fungi and asthma concern A. alternata, C. herbarum and A. fumigatus. However, some mould species are known for their more pronounced indoor tropism and since people tend to increase their time spent indoors, the impact of exposure to these “indoor” species cannot be neglected. In the first part of this work, we developed and validated a dot-blot assay for the detection of mould sensitizations against a panel of species. We worked with the classical A. alternata, C. herbarum and A. fumigatus but in addition, we included indoor-related species such as P. chrysogenum, P. brevicompactum, C. sphaerospermum, C. cladosporioides, A. versicolor and more ubiquitous A. niger, and A. flavus. The development of such an assay allowed us to detect sensitizations against species that are not routinely investigated or not available for testing with classical methods such as skin prick tests or CAP tests. In addition, to cope with cross-reactions, a well-described phenomenon with regard to response against moulds, we developed and validated the concept of “major sensitization”, defined as the antigenic response with the highest difference as compared to the variation of response of the negative control. As there are few data on mould sensitization in healthy individuals, the dot-blot assay was used in a large cohort of healthy subjects. The most frequent sensitizations were observed against A. alternata, A. flavus and A. niger and the commonest “major sensitizers” were A. niger and A. alternata. Of note, in this cohort, no “major sensitization” against A. fumigatus was detected while “major sensitization” against a group of species more specifically linked to the indoor environment (Penicillium spp, A. versicolor, C. cladosporioides) reached more than 25.1% of all sensitizations.These findings were quite surprising and since our laboratory had previous expertise with mouse-model of A. alternata-induced asthma, we investigated the inflammatory and allergenic properties of several fungal species to determine if they display different inner inflammatory potential. Six species were included in the panel A. alternata, A. fumigatus, C. cladosporioides, C. sphaerospermum, A. versicolor and P. chrysogenum. Results showed real differences between moulds and while the classification is not clear-cut, A. fumigatus or P. chrysogenum triggered a typical pro-Th2 response, A. alternata and C. sphaerospermum rather induced a neutrophilic inflammation and A. versicolor and C. cladosporioides induced a mixed Th2/Th17 response. In parallel, the sensitization rates and profile were also investigated in a group of mould-sensitized asthmatics and they both differed notably with the healthy cohort. Indeed, in asthmatic patients, the two most frequent major sensitizations were against A. fumigatus (32%) and A. alternata (28%). The last part of the work consisted in a case-control study to evaluate and compare asthma severity markers and indoor mould exposure between the group of mould-sensitized asthmatics (cases) and a group of asthmatics without mould sensitization (controls). Some interesting findings emerged from this study. First, the overall mould contamination (airborne, in settled dust or through visible mould marks) was very high and more than 90% of the visited dwellings were contaminated by at least one mould species/genus (Penicillium spp, A. versicolor, A. fumigatus and C. sphaerospermum) in at least one type of sample (air, dust and visible mould imprints). Of note, overall “indoor mould exposure” was not associated with markers of asthma severity. Second, exposure and sensitization but also sensitization alone to A. fumigatus in asthmatics were associated with asthma severity markers compared to the absence of mould sensitization which confirmed its noxious potential. This contrasted with the absence of significant severity markers associated with other sensitizations. Lastly, we observed a positive link between overall indoor exposure to Penicillium spp and a reduced lung function in asthmatics even in the absence of sensitization. / Doctorat en Sciences biomédicales et pharmaceutiques (Médecine) / info:eu-repo/semantics/nonPublished

Main objective of the diploma thesis was to observe the concentrations of selected types of drugs in the environment around the area of the village Horní Beřkovice. This goal was achieved by monitoring of the drugs concentration in surface and ground waters at Horní Beřkovice site. Monitoring system allowed to detect the passage of pollution from the source of the contamination, through sewage treatment plant, the unsaturated zone and aquifer to a potential user of contaminated groundwater. The diploma thesis is based on the field data from TACR project. I have analyzed data from the six samplings at the area of the village Horní Beřkovice with regard to the observed drugs or their residues in surface and ground waters. I have compared the results with data from the sewage treatment plants in the river basin of Želivka. Keywords: ground water, surface water, sewage treatment plant, drugs, contamination

M.Sc. (Nanoscience) / Ochratoxin A and Aflatoxin B1 are important food contaminates as they are known to be mutagenic, genotoxic, nephrotoxic, hepatotoxic, immunosuppressive and teratogenic to both animals and humans. These mycotoxins are associated with the contamination of food stuff such as grapes, maize, red pepper, meat, milk, beans and processed products from contaminated raw material. Current physical, biological and chemical methods employed to improve the safety of food often compromise the nutritional value and result in huge losses. The alternative to these treatments are addition of supplements with protective properties to reduce the toxicity of mycotoxins or prevent their formation. The work presented in this dissertation reports an attempt to develop such materials to prevent damage caused by ochratoxin A and aflatoxin B1. This was done through the synthesis; characterisation and cytotoxicity study of chitosan nanoparticles with methanolic plant extracts (L. leonurus, M. longifolia and A. montanus). Inhibition of cellular damage due to mycotoxins for possible application in prevention of cellular damage by mycotoxins also presented. Chitosan nanoparticles were synthesised using an ionic gelation method with sodium triphosphate as the cross linker. The methanolic medicinal plants extracts were incorporated into the chitosan solution before synthesising nanoparticles, and nanoparticle synthesis initiated by the addition of sodium triphosphate solution. The synthesised products were characterised using zetasizer, transmission electron microscopy, x-ray diffraction and Fourier-transform infrared spectroscopy. The extracts’ antioxidant ability was evaluated before incorporation into chitosan using 2, 2-diphenyl- 1-picrylhydrazy (DPPH) radical scavenging assay. This assay was performed using UVvis spectroscopy. The cytotoxicity of the synthesised nanoparticles was assessed using a Vero cell line and by evaluating the cell viability with an MTS assay. The nanoparticles were successfully synthesised and showed the presence of different functional groups as expected. Plain chitosan nanoparticles were roughly spherical shaped and had smooth surfaces, nanoparticles containing extracts similarly were spherical in shape as well but had rougher surfaces when visualised under TEM. All nanoparticles had positive zeta potentials between 26 – 28 mV. The average particle sizes ranged between 31 – 65 nm as measured using TEM and average particle sizes obtained using zetasiser was 78 – 190 nm. The cytotoxicity studies of plain nanoparticles and nanoparticles with extract showed that the synthesised nanomaterials were not toxic even at concentration of 500 μg/ml and less than 20% of the Vero cells were affected under these conditions.

D.Tech. (Biomedical technology) / The majority of the South African rural black population remain is exposed to HIV/ AIDS and other chronic diseases, tuberculosis, malaria and cancer. The effect of single and combined mycotoxins on their health and particularly their immune system is unknown and remain of concern as these populations are on daily basis exposed more than one mycotoxin at once. The aim of this study was to evaluate the exposure of South African rural black populations to mycotoxins via animal products in comparison to urban populations and to assess the effect of the major mycotoxins (fumonisin B1 (FB1), aflatoxin B1 (AFB1) and ochratoxin A (OTA)) mostly present in their food on human and animals (pigs) mononuclear cells and by extrapolation, evaluate possibilities of these mycotoxins on the immune system. To achieve this, animal feed and animal products (milk, serum, and tissues) obtained from selected rural and commercial farms in selected areas of South Africa were analysed for fungal and mycotoxins contamination. It was found in this study that almost all of the samples from both areas were contaminated with the major mycotoxin producing fungal strains (Fusarium, Aspergillus and Penicillium spp.) with the most prominent among them being Aspergillus flavus (87%), A. parasiticus (43%), A. niger (69%), A. ochraceus (42%), A. candidus (23%), F. verticillioides (98%) F. graminearum (67%) and P. Verrucosum (48.9%) and in commercial samples A. flavus (98%), A. parasiticus (51%), A. ochraceus (65%), A. niger (31%), A. candidus (21%), F. verticillioides (F. moniliforme) (68%), F. graminearum (43%) and P. verrucosum (7%). While, the three main mycotoxins were also present and contaminated most samples with fumonisins (FBs) 0in rural and commercial samples at 90.6% and 93.3% respectively with respective means values of 10136.4 ppb and 1045.4 ppb. Aflatoxins (AFs) contamination was of 92.0% in rural samples and 96.2% in commercial samples with means concentrations of 168.8 ppb and 294.1 ppb respectively. While 85.4% and 83.7% of rural and commercial samples respectively were contaminated with ochratoxin A (OTA), with mean concentrations of 67.6 ppb and 89.4 ppb respectively. Zearalenone (ZEA) concentrations were of 43.6 ppb in rural samples and 62.7 ppb in commercial samples with respective contamination of 50.6% and 55.3%. In addition, a co-occurrence of fungi and mycotoxins contaminations was found in both rural and commercial samples. It was found that, 50.5% of rural and 53% of commercial samples were contaminated with all four analyzed mycotoxins. (FBs, AFs, OTA and ZEA), whereas, 81.2% and 79.5% of samples respectively from rural and commercial farms were contaminated with FBs, AFs and OTA mycotoxins simultaneously. The above-obtained results are of significance in this study as they confirm the hypothesis of fungal contamination and mycotoxin co-occurrence in South African feed and their possible combined effects on consumers.