Biogenic isoprene plays an important role in tropospheric chemistry. We use HCHO column measurements by the Global Ozone Monitoring Experiment (GOME) to constrain isoprene emissions. Using the global Goddrad Earth Observing SystemChemistry (GEOS-Chem) as the forward model, a Bayesian inversion of GOME HCHO observations from September 1996 to August 1997 is conducted. Column contributions to HCHO from 12 sources including 10 terrestrial ecosystem groups, biomass burning, and industry are considered and inverted for 8 geographical regions globally. The a posteriori solution reduces the model biases for all regions, and estimates the annual global isoprene emissions of 566 Tg C yr-1, ~50% larger than the a priori estimate. Compared to the Global Emissions Inventory Activity (GEIA) inventory (~500 Tg C yr-1), the a posteriori isoprene emissions are generally higher at mid latitudes and lower in the tropics. This increase of global isoprene emissions significantly affects tropospheric chemistry, decreasing the global mean OH concentration by 10.8% to 0.95106 molecules/cm3. The atmospheric lifetime of CH3CCl3 increases from 5.2 to 5.7 years. Positive matrix factorization (PMF), an advanced method for source apportionment, is applied to TRAnsport of Chemical Evolution over the Pacific (TRACE-P) measurements and it is found that cyanogenesis in plants over Asia is likely an important emission process for CH3COCH3 and HCN. This approach also is applied to estimate source contributions to the tropospheric ozone (O3) with Tropospheric Ozone Production about the Spring Equinox (TOPSE) and TRACE-P measurements. The corresponding GEOS-Chem simulations are applied to the same factor-projected space in order to evaluate the model simulations. Intercontinental transport of pollutants is most responsible for increasing trend of springtime O3, while stratospheric influence is the largest contributions to troposperic O3 variability at northern middle and high latitudes. On the other hand, the overall tropospheric contributions to O3 variability are more important at northern low latitudes by long-range transport, biomass burning, and industry/urban emissions. In general, the simulated O3 variabilities are comparable with those of observations. However, the model underestimates the trends of and the contributions to O3 variability by long-range transport of O3 and its precursors at northern middle and high latitudes.

Atmospheric aerosol is an important component of our atmosphere influencing human health, regional and global atmospheric chemistry and climate. The organic component of submicron aerosol contributes around 50% of its mass and is a complex mixture of tens of thousands of compounds. Real-time aerosol mass spectrometry was the major measurement tool used in this work. The Aerodyne High Resolution Time of Flight Aerosol Mass Spectrometer (HR-ToF-AMS) can quantitatively measure the chemical composition and size distribution of non-refractory submicron aerosol (NR-PM1). The mass spectra provided by the instrument every few minutes contain information about aerosol sources and processes. This thesis uses the HR-ToF-AMS measurements in two areas of Greece to quantify the contributions of organic aerosol sources to the corresponding organic aerosol levels. Local and regional air pollution sources were monitored and characterized in two sites during intensive campaigns. The first campaign took place during the fall of 2011 (September 24 to October 23) in Finokalia, Crete, a remote-background coastal site without any major human activity. The aim of the study was to quantify the extent of oxidation of the organic aerosol (OA) during autumn, a season neither too hot nor cold, with reduced solar radiation in comparison to summer. The second one took place during the winter of 2012 (February 26 to March 5), in the third major city of Greece, Patras. The measurements were conducted in the campus of the Technological Educational Institute of Patras (TEI), in order to quantify the severity of the wintertime air pollution problem in the area and its sources. The contributions of traffic and residential wood burning were the foci of that study. The Finokalia site is isolated and far away from anthropogenic sources of pollution, making it ideal for the study of organic aerosol coming from different directions, usually exposed to high levels of atmospheric oxidants. The fine PM measured during the Finokalia Atmospheric Measurement Experiment (FAME-11) by the AMS and a Multi Angle Absorption Photometer (MAAP) was mostly ammonium sulfate and bisulfate (60%), organic compounds (34%), and BC (5%). The aerosol sampled originated mainly from Turkey during the first days of the study, but also from Athens and Northern Greece during the last days of the campaign. By performing Positive Matrix Factorization (PMF) analysis on the AMS organic spectra for the whole dataset the organic aerosol (OA) composition could be explained by two components: a low volatility factor (LV-OOA) and a semi-volatile one (SV-OOA). Hydrocarbon-like organic aerosol (HOA) was not present, consistent with the lack of strong local sources. The second field campaign took place in the suburbs of the city of Patras, 4 km away from the city center during the winter of 2012. During this 10-day campaign, organics were responsible for 70% during the day and 80% during the evening of the total PM1. The OA mean concentration during that period was approximately 20 μg m-3 and reaching hourly maximum values as high as 85 μg m-3. Sulfate ions and black carbon followed with 10% and 7% of the PM1. PMF analysis of the organic mass spectra of PM1 explained the OA observations with four sources: cooking (COA), traffic (HOA), biomass burning (BBOA), and oxygenated aerosol (OOA), related to secondary formation and long range transport. On average, BBOA represented 58% of the total OM, followed by OOA with 18%, COA and HOA, with the last two contributing of the same percentage (12%). / --

Nos últimos anos, a deterioração da qualidade do ar urbano devido ao material particulado atmosférico está recebendo atenção significativa e continuamente ameaça a qualidade de vida dos habitantes das áreas urbanas. A poluição do ar pelas partículas atmosféricas nas zonas urbanas é causada principalmente pelas emissões de fontes antropogênicas em sua maioria veiculares. Além disso, a poluição causada por partículas atmosféricas não está apenas relacionada com a sua concentração, mas também com a distribuição dos seus diferentes diâmetros. As partículas na fração estudada, < 1 μm, apresentam maior risco porque podem penetrar nos pulmões, afetam a função alveolar e ocasionam efeitos nocivos na saúde humana. Contudo, as partículas atmosféricas podem carregar diferentes compostos que são tóxicos e/ou cancerígenos, produzindo riscos para a saúde, como os Hidrocarbonetos policíclicos aromáticos – HPAs. Os HPAs são um grupo de diversos compostos orgânicos complexos, constituídos por carbono e hidrogênio junto com dois ou mais anéis benzênicos condensados. Portanto, foi desenvolvido um procedimento científico apto para estudar material particulado atmosférico < 1 μm (MP1) com a finalidade de analisar quantitativa e qualitativamente os HPAs associados a esta fração, a concentração em número das partículas e a distribuição de tamanho de partículas na Região Metropolitana de Porto Alegre usando técnicas analíticas e de sensoriamento remoto. As amostras foram coletadas em filtros de PTFE nos municípios de Sapucaia do Sul e Canoas, pertencentes à Região Metropolitana de Porto Alegre, usando o amostrador sequencial automático PM162M da Environnement S.A. As amostras foram extraídas utilizando o método EPA TO-13A para analisar 16 HPAs, utilizando um cromatógrafo gasoso acoplado a um espectrômetro de massa (CG-EM). A distribuição do tamanho de partícula nas frações PR1 (0.3-1.0 μm), PR2.5 (1.0-2.5 μm) e PR10 (2.5-10 μm) foi obtida utilizando o analisador de partículas CPM em Sapucaia do Sul. Os dados das concentrações de poluentes atmosféricos relacionados com MP10, óxidos de nitrogênio (NO, NOx, NO2) e ozônio (O3) foram obtidos utilizando os analisadores MP101M, AC32M e O342M da Environnement, respectivamente. Dados das variáveis meteorológicas como velocidade do vento, direção do vento, umidade relativa, radiação solar e temperatura ambiente foram medidos simultaneamente de modo concomitante. Os espectros de emissividade e transmitância, através da espectroscopia no infravermelho, foram obtidos utilizando espectrômetro FTIR D&P e o BOMEM MB-series FTIR-Hartmann & Braun Michelson, respectivamente. A determinação dos resultados usando cromatografia mostraram que no inverno as concentrações de HPAs foram significativamente maiores do que no verão, mostrando assim uma variação sazonal. A identificação das fontes de emissão, aplicando razões diagnóstico, confirmou que os HPAs na área de estudo são originários de fontes móveis, especialmente, das emissões de diesel e da gasolina. A análise por modelo receptor PMF também mostrou a contribuição dessas duas fontes principais, seguido pela combustão de carvão, combustão incompleta/petróleo não queimado e da combustão de madeira. Os fatores tóxicos equivalentes foram calculados para caracterizar o risco de câncer por exposição ao HPA em amostras de MP1, e benzo[a]pireno e dibenzo[ah] antraceno que dominaram os níveis de BaPeq. Com exceção do O3, a análise de tendência do NO, NO2 e NOx mostrou um aumento da concentração destes compostos no inverno. Também a correlação destes poluentes com os parâmetros meteorológicos permitiu evidenciar a influência das fontes móveis na área de estudo. Os resultados das assinaturas espectrais no infravermelho das amostras de MP1 comparando com os padrões e com outros trabalhos mostraram que o maior número de bandas de fortes intensidades ocorreu na região espectral de 680-900 cm-1, devido às deformações angulares CC fora do plano e deformações angulares CH fora do plano dos HPAs. Bandas de média intensidade na região de 2900-3050 cm-1, também foram observadas devido ao estiramento CH, característico de compostos aromáticos. A presente pesquisa foi o ponto de partida para obter um banco de dados das concentrações de HPAs associados à fração MP1 e dos poluentes NOx/NO2/NO/MP10/O3; caracterizar a distribuição de tamanho de partículas atmosféricas, que são de grande importância e preocupação atual; avaliar a sua variação sazonal e sua relação com as condições meteorológicas usando técnicas estatísticas; e aprofundar o conhecimento do comportamento espectral dos HPAs, poluentes cancerígenos e mutagênicos, presentes no material particulado atmosférico na fração fina e ultrafina. / In recent years, the urban air quality deterioration due to atmospheric particulate matter is receiving significant attention; also, it continually threatens the life quality of urban residents. Air pollution by atmospheric particles in urban areas is mainly caused by emissions from anthropogenic sources, mostly vehicular sources. Moreover, the pollution caused by atmospheric particles is not only related to its concentration, but also with the size distribution. The particles studied in the fraction <1μm have a greater risk because they can penetrate into the lungs, affect cellular function and cause adverse effects on human health. However, atmospheric particles can carry different compounds that are toxic and/or carcinogenic, producing health risks, such as polycyclic aromatic hydrocarbons - PAH. PAHs are a group of several complex organic compounds consisting of carbon and hydrogen along with two or more fused benzene rings. Consequently, a scientific procedure was developed to study the atmospheric particulate matter < 1 μm (PM1) in order to analyze qualitatively and quantitatively the PAHs associated with this fraction, also the particle number concentration and particle size distribution in the Metropolitan Region of Porto Alegre using remote sensing techniques. PM1 samples were collected in PTFE filters in Sapucaia South and Canoas sites, in the Metropolitan Region of Porto Alegre using the automatic sequential sampler PM162M of Environnement S.A. The samples were extracted using the EPA Method TO-13A and 16 PAHs were analyzed using a gas chromatograph coupled to a mass spectrometer (GC-MS). The particle size distribution of fractions PR1 (0.3 - 1.0 μm), PR2.5 (1.0 - 2.5 μm) and PR10 (2.5 – 10 μm) was obtained using the particulate analyzer CPM. The data of related air pollutants concentrations such as PM10, nitrogen oxides (NO, NOx, NO2), ozone (O3) were obtained using the analyzers MP101M, AC32M, O342M of Environnement, respectively. Data from meteorological variables, wind speed, wind direction, relative humidity, solar radiation and ambient temperature were continuously measured and simultaneously. The emissivity and transmittance spectra through infrared spectroscopy were obtained using FTIR spectrometer D&P and the Bomem MB-series FTIR-Hartmann & Braun Michelson, respectively. The results showed that in winter, the concentrations of PAHs were significantly higher than in summer, thus showing their seasonal variation. The identification of emission sources, applying diagnostic ratios confirmed that PAHs in the study area originate from mobile sources, especially diesel and gasoline emissions. The analysis by PMF receptor model also showed the contribution of these two sources, followed by coal combustion, incomplete combustion/unburned petroleum and wood combustion. The toxic equivalent factors were calculated to characterize the risk of cancer from PAH exposure to PM1.0 samples, and benzo[a]pyrene and dibenz[ah]pyrene dominated BaPeq levels. The trend analysis of O3, NO, NO2, NOx showed a trend of increased concentration at winter, except O3. Also the correlation of these pollutants with meteorological parameters has demonstrated the influence of mobile sources in the study area. The results of the IR spectral signatures of the PM1 samples compared to the standards and other studies showed that the greatest number of strong bands occurred in the spectral region of 680-900 cm- 1 due to the CC out-of-plane angular deformation and CH out-of-plane angular deformation of PAHs. Bands of medium intensity in the 2900-3050 cm-1 region were also observed due to the CH stretch, characteristic of aromatic compounds. This research was the starting point for a concentrations database of PAHs associated fraction PM1 and pollutants NOx/NO2/NO/PM10/O3, characterize the size distribution of atmospheric particles that are of great importance and current concern. Furthermore, to assess their seasonal variation and its relationship with meteorological conditions, using statistical techniques. Also to deepen the knowledge of the spectral behavior of PAHs that are carcinogenic and mutagenic pollutants present in atmospheric particulate matter in the fine and ultrafine fraction.

Nos últimos anos, a deterioração da qualidade do ar urbano devido ao material particulado atmosférico está recebendo atenção significativa e continuamente ameaça a qualidade de vida dos habitantes das áreas urbanas. A poluição do ar pelas partículas atmosféricas nas zonas urbanas é causada principalmente pelas emissões de fontes antropogênicas em sua maioria veiculares. Além disso, a poluição causada por partículas atmosféricas não está apenas relacionada com a sua concentração, mas também com a distribuição dos seus diferentes diâmetros. As partículas na fração estudada, < 1 μm, apresentam maior risco porque podem penetrar nos pulmões, afetam a função alveolar e ocasionam efeitos nocivos na saúde humana. Contudo, as partículas atmosféricas podem carregar diferentes compostos que são tóxicos e/ou cancerígenos, produzindo riscos para a saúde, como os Hidrocarbonetos policíclicos aromáticos – HPAs. Os HPAs são um grupo de diversos compostos orgânicos complexos, constituídos por carbono e hidrogênio junto com dois ou mais anéis benzênicos condensados. Portanto, foi desenvolvido um procedimento científico apto para estudar material particulado atmosférico < 1 μm (MP1) com a finalidade de analisar quantitativa e qualitativamente os HPAs associados a esta fração, a concentração em número das partículas e a distribuição de tamanho de partículas na Região Metropolitana de Porto Alegre usando técnicas analíticas e de sensoriamento remoto. As amostras foram coletadas em filtros de PTFE nos municípios de Sapucaia do Sul e Canoas, pertencentes à Região Metropolitana de Porto Alegre, usando o amostrador sequencial automático PM162M da Environnement S.A. As amostras foram extraídas utilizando o método EPA TO-13A para analisar 16 HPAs, utilizando um cromatógrafo gasoso acoplado a um espectrômetro de massa (CG-EM). A distribuição do tamanho de partícula nas frações PR1 (0.3-1.0 μm), PR2.5 (1.0-2.5 μm) e PR10 (2.5-10 μm) foi obtida utilizando o analisador de partículas CPM em Sapucaia do Sul. Os dados das concentrações de poluentes atmosféricos relacionados com MP10, óxidos de nitrogênio (NO, NOx, NO2) e ozônio (O3) foram obtidos utilizando os analisadores MP101M, AC32M e O342M da Environnement, respectivamente. Dados das variáveis meteorológicas como velocidade do vento, direção do vento, umidade relativa, radiação solar e temperatura ambiente foram medidos simultaneamente de modo concomitante. Os espectros de emissividade e transmitância, através da espectroscopia no infravermelho, foram obtidos utilizando espectrômetro FTIR D&P e o BOMEM MB-series FTIR-Hartmann & Braun Michelson, respectivamente. A determinação dos resultados usando cromatografia mostraram que no inverno as concentrações de HPAs foram significativamente maiores do que no verão, mostrando assim uma variação sazonal. A identificação das fontes de emissão, aplicando razões diagnóstico, confirmou que os HPAs na área de estudo são originários de fontes móveis, especialmente, das emissões de diesel e da gasolina. A análise por modelo receptor PMF também mostrou a contribuição dessas duas fontes principais, seguido pela combustão de carvão, combustão incompleta/petróleo não queimado e da combustão de madeira. Os fatores tóxicos equivalentes foram calculados para caracterizar o risco de câncer por exposição ao HPA em amostras de MP1, e benzo[a]pireno e dibenzo[ah] antraceno que dominaram os níveis de BaPeq. Com exceção do O3, a análise de tendência do NO, NO2 e NOx mostrou um aumento da concentração destes compostos no inverno. Também a correlação destes poluentes com os parâmetros meteorológicos permitiu evidenciar a influência das fontes móveis na área de estudo. Os resultados das assinaturas espectrais no infravermelho das amostras de MP1 comparando com os padrões e com outros trabalhos mostraram que o maior número de bandas de fortes intensidades ocorreu na região espectral de 680-900 cm-1, devido às deformações angulares CC fora do plano e deformações angulares CH fora do plano dos HPAs. Bandas de média intensidade na região de 2900-3050 cm-1, também foram observadas devido ao estiramento CH, característico de compostos aromáticos. A presente pesquisa foi o ponto de partida para obter um banco de dados das concentrações de HPAs associados à fração MP1 e dos poluentes NOx/NO2/NO/MP10/O3; caracterizar a distribuição de tamanho de partículas atmosféricas, que são de grande importância e preocupação atual; avaliar a sua variação sazonal e sua relação com as condições meteorológicas usando técnicas estatísticas; e aprofundar o conhecimento do comportamento espectral dos HPAs, poluentes cancerígenos e mutagênicos, presentes no material particulado atmosférico na fração fina e ultrafina. / In recent years, the urban air quality deterioration due to atmospheric particulate matter is receiving significant attention; also, it continually threatens the life quality of urban residents. Air pollution by atmospheric particles in urban areas is mainly caused by emissions from anthropogenic sources, mostly vehicular sources. Moreover, the pollution caused by atmospheric particles is not only related to its concentration, but also with the size distribution. The particles studied in the fraction <1μm have a greater risk because they can penetrate into the lungs, affect cellular function and cause adverse effects on human health. However, atmospheric particles can carry different compounds that are toxic and/or carcinogenic, producing health risks, such as polycyclic aromatic hydrocarbons - PAH. PAHs are a group of several complex organic compounds consisting of carbon and hydrogen along with two or more fused benzene rings. Consequently, a scientific procedure was developed to study the atmospheric particulate matter < 1 μm (PM1) in order to analyze qualitatively and quantitatively the PAHs associated with this fraction, also the particle number concentration and particle size distribution in the Metropolitan Region of Porto Alegre using remote sensing techniques. PM1 samples were collected in PTFE filters in Sapucaia South and Canoas sites, in the Metropolitan Region of Porto Alegre using the automatic sequential sampler PM162M of Environnement S.A. The samples were extracted using the EPA Method TO-13A and 16 PAHs were analyzed using a gas chromatograph coupled to a mass spectrometer (GC-MS). The particle size distribution of fractions PR1 (0.3 - 1.0 μm), PR2.5 (1.0 - 2.5 μm) and PR10 (2.5 – 10 μm) was obtained using the particulate analyzer CPM. The data of related air pollutants concentrations such as PM10, nitrogen oxides (NO, NOx, NO2), ozone (O3) were obtained using the analyzers MP101M, AC32M, O342M of Environnement, respectively. Data from meteorological variables, wind speed, wind direction, relative humidity, solar radiation and ambient temperature were continuously measured and simultaneously. The emissivity and transmittance spectra through infrared spectroscopy were obtained using FTIR spectrometer D&P and the Bomem MB-series FTIR-Hartmann & Braun Michelson, respectively. The results showed that in winter, the concentrations of PAHs were significantly higher than in summer, thus showing their seasonal variation. The identification of emission sources, applying diagnostic ratios confirmed that PAHs in the study area originate from mobile sources, especially diesel and gasoline emissions. The analysis by PMF receptor model also showed the contribution of these two sources, followed by coal combustion, incomplete combustion/unburned petroleum and wood combustion. The toxic equivalent factors were calculated to characterize the risk of cancer from PAH exposure to PM1.0 samples, and benzo[a]pyrene and dibenz[ah]pyrene dominated BaPeq levels. The trend analysis of O3, NO, NO2, NOx showed a trend of increased concentration at winter, except O3. Also the correlation of these pollutants with meteorological parameters has demonstrated the influence of mobile sources in the study area. The results of the IR spectral signatures of the PM1 samples compared to the standards and other studies showed that the greatest number of strong bands occurred in the spectral region of 680-900 cm- 1 due to the CC out-of-plane angular deformation and CH out-of-plane angular deformation of PAHs. Bands of medium intensity in the 2900-3050 cm-1 region were also observed due to the CH stretch, characteristic of aromatic compounds. This research was the starting point for a concentrations database of PAHs associated fraction PM1 and pollutants NOx/NO2/NO/PM10/O3, characterize the size distribution of atmospheric particles that are of great importance and current concern. Furthermore, to assess their seasonal variation and its relationship with meteorological conditions, using statistical techniques. Also to deepen the knowledge of the spectral behavior of PAHs that are carcinogenic and mutagenic pollutants present in atmospheric particulate matter in the fine and ultrafine fraction.

Nos últimos anos, a deterioração da qualidade do ar urbano devido ao material particulado atmosférico está recebendo atenção significativa e continuamente ameaça a qualidade de vida dos habitantes das áreas urbanas. A poluição do ar pelas partículas atmosféricas nas zonas urbanas é causada principalmente pelas emissões de fontes antropogênicas em sua maioria veiculares. Além disso, a poluição causada por partículas atmosféricas não está apenas relacionada com a sua concentração, mas também com a distribuição dos seus diferentes diâmetros. As partículas na fração estudada, < 1 μm, apresentam maior risco porque podem penetrar nos pulmões, afetam a função alveolar e ocasionam efeitos nocivos na saúde humana. Contudo, as partículas atmosféricas podem carregar diferentes compostos que são tóxicos e/ou cancerígenos, produzindo riscos para a saúde, como os Hidrocarbonetos policíclicos aromáticos – HPAs. Os HPAs são um grupo de diversos compostos orgânicos complexos, constituídos por carbono e hidrogênio junto com dois ou mais anéis benzênicos condensados. Portanto, foi desenvolvido um procedimento científico apto para estudar material particulado atmosférico < 1 μm (MP1) com a finalidade de analisar quantitativa e qualitativamente os HPAs associados a esta fração, a concentração em número das partículas e a distribuição de tamanho de partículas na Região Metropolitana de Porto Alegre usando técnicas analíticas e de sensoriamento remoto. As amostras foram coletadas em filtros de PTFE nos municípios de Sapucaia do Sul e Canoas, pertencentes à Região Metropolitana de Porto Alegre, usando o amostrador sequencial automático PM162M da Environnement S.A. As amostras foram extraídas utilizando o método EPA TO-13A para analisar 16 HPAs, utilizando um cromatógrafo gasoso acoplado a um espectrômetro de massa (CG-EM). A distribuição do tamanho de partícula nas frações PR1 (0.3-1.0 μm), PR2.5 (1.0-2.5 μm) e PR10 (2.5-10 μm) foi obtida utilizando o analisador de partículas CPM em Sapucaia do Sul. Os dados das concentrações de poluentes atmosféricos relacionados com MP10, óxidos de nitrogênio (NO, NOx, NO2) e ozônio (O3) foram obtidos utilizando os analisadores MP101M, AC32M e O342M da Environnement, respectivamente. Dados das variáveis meteorológicas como velocidade do vento, direção do vento, umidade relativa, radiação solar e temperatura ambiente foram medidos simultaneamente de modo concomitante. Os espectros de emissividade e transmitância, através da espectroscopia no infravermelho, foram obtidos utilizando espectrômetro FTIR D&P e o BOMEM MB-series FTIR-Hartmann & Braun Michelson, respectivamente. A determinação dos resultados usando cromatografia mostraram que no inverno as concentrações de HPAs foram significativamente maiores do que no verão, mostrando assim uma variação sazonal. A identificação das fontes de emissão, aplicando razões diagnóstico, confirmou que os HPAs na área de estudo são originários de fontes móveis, especialmente, das emissões de diesel e da gasolina. A análise por modelo receptor PMF também mostrou a contribuição dessas duas fontes principais, seguido pela combustão de carvão, combustão incompleta/petróleo não queimado e da combustão de madeira. Os fatores tóxicos equivalentes foram calculados para caracterizar o risco de câncer por exposição ao HPA em amostras de MP1, e benzo[a]pireno e dibenzo[ah] antraceno que dominaram os níveis de BaPeq. Com exceção do O3, a análise de tendência do NO, NO2 e NOx mostrou um aumento da concentração destes compostos no inverno. Também a correlação destes poluentes com os parâmetros meteorológicos permitiu evidenciar a influência das fontes móveis na área de estudo. Os resultados das assinaturas espectrais no infravermelho das amostras de MP1 comparando com os padrões e com outros trabalhos mostraram que o maior número de bandas de fortes intensidades ocorreu na região espectral de 680-900 cm-1, devido às deformações angulares CC fora do plano e deformações angulares CH fora do plano dos HPAs. Bandas de média intensidade na região de 2900-3050 cm-1, também foram observadas devido ao estiramento CH, característico de compostos aromáticos. A presente pesquisa foi o ponto de partida para obter um banco de dados das concentrações de HPAs associados à fração MP1 e dos poluentes NOx/NO2/NO/MP10/O3; caracterizar a distribuição de tamanho de partículas atmosféricas, que são de grande importância e preocupação atual; avaliar a sua variação sazonal e sua relação com as condições meteorológicas usando técnicas estatísticas; e aprofundar o conhecimento do comportamento espectral dos HPAs, poluentes cancerígenos e mutagênicos, presentes no material particulado atmosférico na fração fina e ultrafina. / In recent years, the urban air quality deterioration due to atmospheric particulate matter is receiving significant attention; also, it continually threatens the life quality of urban residents. Air pollution by atmospheric particles in urban areas is mainly caused by emissions from anthropogenic sources, mostly vehicular sources. Moreover, the pollution caused by atmospheric particles is not only related to its concentration, but also with the size distribution. The particles studied in the fraction <1μm have a greater risk because they can penetrate into the lungs, affect cellular function and cause adverse effects on human health. However, atmospheric particles can carry different compounds that are toxic and/or carcinogenic, producing health risks, such as polycyclic aromatic hydrocarbons - PAH. PAHs are a group of several complex organic compounds consisting of carbon and hydrogen along with two or more fused benzene rings. Consequently, a scientific procedure was developed to study the atmospheric particulate matter < 1 μm (PM1) in order to analyze qualitatively and quantitatively the PAHs associated with this fraction, also the particle number concentration and particle size distribution in the Metropolitan Region of Porto Alegre using remote sensing techniques. PM1 samples were collected in PTFE filters in Sapucaia South and Canoas sites, in the Metropolitan Region of Porto Alegre using the automatic sequential sampler PM162M of Environnement S.A. The samples were extracted using the EPA Method TO-13A and 16 PAHs were analyzed using a gas chromatograph coupled to a mass spectrometer (GC-MS). The particle size distribution of fractions PR1 (0.3 - 1.0 μm), PR2.5 (1.0 - 2.5 μm) and PR10 (2.5 – 10 μm) was obtained using the particulate analyzer CPM. The data of related air pollutants concentrations such as PM10, nitrogen oxides (NO, NOx, NO2), ozone (O3) were obtained using the analyzers MP101M, AC32M, O342M of Environnement, respectively. Data from meteorological variables, wind speed, wind direction, relative humidity, solar radiation and ambient temperature were continuously measured and simultaneously. The emissivity and transmittance spectra through infrared spectroscopy were obtained using FTIR spectrometer D&P and the Bomem MB-series FTIR-Hartmann & Braun Michelson, respectively. The results showed that in winter, the concentrations of PAHs were significantly higher than in summer, thus showing their seasonal variation. The identification of emission sources, applying diagnostic ratios confirmed that PAHs in the study area originate from mobile sources, especially diesel and gasoline emissions. The analysis by PMF receptor model also showed the contribution of these two sources, followed by coal combustion, incomplete combustion/unburned petroleum and wood combustion. The toxic equivalent factors were calculated to characterize the risk of cancer from PAH exposure to PM1.0 samples, and benzo[a]pyrene and dibenz[ah]pyrene dominated BaPeq levels. The trend analysis of O3, NO, NO2, NOx showed a trend of increased concentration at winter, except O3. Also the correlation of these pollutants with meteorological parameters has demonstrated the influence of mobile sources in the study area. The results of the IR spectral signatures of the PM1 samples compared to the standards and other studies showed that the greatest number of strong bands occurred in the spectral region of 680-900 cm- 1 due to the CC out-of-plane angular deformation and CH out-of-plane angular deformation of PAHs. Bands of medium intensity in the 2900-3050 cm-1 region were also observed due to the CH stretch, characteristic of aromatic compounds. This research was the starting point for a concentrations database of PAHs associated fraction PM1 and pollutants NOx/NO2/NO/PM10/O3, characterize the size distribution of atmospheric particles that are of great importance and current concern. Furthermore, to assess their seasonal variation and its relationship with meteorological conditions, using statistical techniques. Also to deepen the knowledge of the spectral behavior of PAHs that are carcinogenic and mutagenic pollutants present in atmospheric particulate matter in the fine and ultrafine fraction.

Atmospheric aerosols have adverse effects on human health, air quality, and visibility and frequently result in severe pollution events, particularly in urban areas. However, the sources of aerosols and the processes governing their behaviour in the atmosphere, including those which lead to high concentrations, are not well understood thus limit our ability to accurately assess and forecast air quality. Presented here are the first long-term chemical composition measurements from an urban environment using an Aerodyne compact Time-of-Flight Aerosol Mass Spectrometer (cToF-AMS). Organic aerosols (OA) were observed to account for a significant fraction (44%) of the total non-refractory submicron mass during 2012 at the urban background site in North Kensington, London, followed by nitrate (28%), sulphate (14%), ammonium (13%), and chloride (1%). The sources and components of OA were determined using Positive Matrix Factorisation (PMF) and attributed as hydrocarbon-like OA (HOA), cooking OA (COA), solid fuel OA (SFOA), type 1 oxygenated OA (OOA1), and type 2 oxygenated OA (OOA2), where HOA, COA, and SFOA were observed to be of equal importance across the year. The concentration of secondary OA increased during the summer yet the extent of oxidation, as defined by the oxygen content, showed no variability during the year. The main factors governing the diurnal, monthly, and seasonal trends observed in all organic and inorganic species were meteorological conditions, specific nature of the sources, and availability of precursors. Regional and transboundary pollution influenced total aerosol concentrations and high concentration events were observed to be governed by different factors depending on season. High-Resolution ToF-AMS measurements were used to further probe OA behaviour, where two SFOA factors were derived from PMF analysis in winter, which likely represent differences in burn conditions. In the summer an OA factor was identified, likely of primary origin, which was observed to be strongly associated with organic nitrates and anthropogenic emissions. This work uses instruments and techniques that have not previously been used in this way in an urban environment, where the results further the understanding of the chemical components of urban aerosols. Aerosol sources are likely to change in the future with increases in solid fuel burning as vehicular emissions decrease, with significant implications on air quality and health. Thus it is important to understand aerosol sources and behaviour in order to develop effective pollution abatement strategies.

Die Etablierung einer Infektion mit Salmonella Typhimurium (S. Typhimurium) ist das Ergebnis des Inputs verschiedener Virulenzfaktoren und genetischer Schaltkreise, die miteinander interagieren, um eine erfolgreiche Infektion und eine effiziente Ressourcennutzung sicherzustellen. Kleine (sRNAs) spielen eine wichtige Rolle, da sie schnell auf Umweltveränderungen reagieren und die Genexpression modulieren können. Im ersten Teil dieser Arbeit zeigen wir, dass die Überexpression von HilD, dem Masterregulator der Salmonella Pathogenitätsinsel 1 (SPI-1), zu einem Motilitätsdefekt von S. Typhimurium führt. Dieser Defekt steht im Zusammenhang mit der Expression von SPI-1-Virulenzgenen; dies führt zu einer Reduktion der protonenmotorischen Kraft (PMF), die wiederum für die Flagellenrotation notwendig ist. Zudem stellen wir eine Hochregulation mehrerer Adhäsine bei Überexpression von HilD fest. Die Kombination aus Erhöhter Expression von Adhäsinen und einer Reduktion der PMF ermöglicht es S. Typhimurium vermutlich, bei Erreichen der Invasionsstelle im Wirt die Motilität zu modulieren und das Andocken an das Darmepithel und die nachfolgende Injektion von Effektorproteinen zu erleichtern. Im zweiten Teil identifizierten wir mehrere in vivo differenziell regulierte sRNAs, die das virulenzassoziierte Typ-III-Sekretionssystem der SPI-1 (vT3SS-1) regulieren konnten. Weitergehende Untersuchungen der vielversprechendsten sRNAs ergaben Zielgene für STnc4160 und RybD. Diese Zielgene waren mit Stoffwechselprozessen, nicht jedoch mit regulatorischen oder strukturellen Komponenten des vT3SS-1 assoziiert. Unsere Ergebnisse deuten darauf hin, dass sRNAs Stoffwechselwege von S. Typhimurium in Reaktion auf die Umgebungsbedingungen im Wirt umprogrammieren; dies verschafft S. Typhimurium vermutlich einen Fitnessvorteil und erlaubt es, die residente Mikrobiota zu verdrängen. Zudem regulieren sRNAs vT3SS-1 und erleichtern die Invasion der Darmepithelien und die Etablierung der Infektion. / The establishment of a Salmonella Typhimurium (S. Typhimurium) infection results from an input from different virulence factors and genetic circuits. These crosstalk with each other to coordinate their efforts towards a successful infection and a wise use of resources. Other key players include small RNAs (sRNAs), which can quickly respond to environmental changes and modulate the gene expression accordingly. In the first part of this thesis, we show that the overexpression of HilD, the master regulator of the Salmonella pathogenicity island 1 (SPI-1), results in a motility defect in S. Typhimurium. This motility defect is related to SPI-1 virulence gene expression, which results in the dissipation of the proton motive force (PMF), which in turn is needed for powering the flagellar rotation. We also report the upregulation of several adhesins upon HilD overproduction. Thus, the combination of adhesins upregulation and PMF depletion likely helps S. Typhimurium to rapidly modulate motility upon reaching their target site inside the host and to facilitate the docking of bacteria to the surface of host intestinal epithelial cells and injection of effector proteins, subsequently. In the second part, we identified a number of in vivo differentially regulated sRNAs, which are able to regulate the virulence-associated type-III secretion system of SPI-1 (vT3SS-1). Further analyses of the promising sRNAs revealed a number of target genes for STnc4160 and RybD. The identified targets for both sRNAs were related to metabolic processes rather than to regulatory or structural components of the vT3SS-1. Our results suggest that sRNAs respond to the host environment by rewiring metabolic pathways of S. Typhimurium, which likely imparts a fitness advantage to it and enables it to outcompete the resident microbiota. Additionally, sRNAs can regulate vT3SS-1, thus modulating the invasion of intestinal epithelia by S. Typhimurium and accordingly the establishment of an infection.

Ma thèse s'inscrit dans le cadre du programme POLCA (Pollution des Capitales Africaines). Elle a pour principal objectif de caractériser la pollution particulaire sur des sites " trafic " de deux capitales africaines Dakar (Sénégal) et Bamako (Mali) et d'étudier son impact toxicologique sur l'appareil respiratoire. La pollution particulaire urbaine, bien supérieure aux normes imposées par l'organisation mondiale de la santé, est mise en exergue en lien avec un trafic automobile anarchique et d'intenses combustions domestiques. Dans ce contexte, les questionnements scientifiques suivants ont pu être abordés : - Quelle est la spéciation chimique par classes de tailles des aérosols de combustion (carbone suie, carbone organique, inorganiques, métaux traces...) pour les sites " trafic " de Dakar et Bamako ? - Quelles sont les sources prédominantes agissant sur la composition chimique en aérosols ? Quelle est la toxicité de ces aérosols et le niveau de stress oxydant ? - Quels sont les liens entre composition des aérosols différenciés en tailles et marqueurs d'inflammation pour chaque type de source ? - Quels sont les liens entre expositions aux aérosols et doses dans l'appareil respiratoire ? - Pour traiter ces questions, je me suis attaché à l'étude des résultats des campagnes intensives de 2009 à Dakar et à Bamako auxquelles j'ai participé, principalement à l'analyse chimique complète des aérosols par classes de tailles, à la caractérisation physico-chimique complète de l'aérosol pour chaque site mais également à la détermination de ses différentes sources par des modèles multivariés (ACP et PMF). Ces études ont été associées à des mesures toxicologiques in vitro effectuées sur les aérosols prélevés sur ces mêmes sites. Ce croisement mesures physcico-chimique/mesure santé a permis d'approfondir les liens sources d'émissions/chimie de l'aérosol/granulométrie et impacts biologiques associés. Enfin, en parallèle aux mesures expérimentales développées dans POLCA, la thèse a permis la mise en œuvre du modèle DEPCLUNG (DEPosition, Clearance, LUNG) afin de convertir spéciation de l'aérosol par classe de taille ou EXPOSITIONS en concentrations d'espèces par classe de taille ou DOSES dans les divers compartiments de l'appareil respiratoire (trachée, bronches, bronchioles, alvéoles). C'est la conjonction des trois thèmes, caractérisation de la pollution urbaine particulaire en Afrique de l'Ouest et ses sources, son impact toxicologique et la modélisation des doses dans l'appareil respiratoire, qui constitue le caractère pluridisciplinaire innovant de la thèse.

Att utöva turism- och fritidsaktiviteter är en väsentlig del i många människors liv, men för personer med funktionsnedsättningar (PmF) är genomförandet av sådana aktiviteter långt från lika självklara. Frågan om aktivt deltagande och inkludering av PmF i samhällets alla delar lyfts allt mer och kraven på tillgänglighet ökar. Därav syftar denna studie till att undersöka på vilka sätt turism- och aktivitetsföretag i Jämtlands län arbetar med att anpassa sina aktiviteter för att kunna inkludera individer med fysisk funktionsnedsättning. För att uppnå syftet var en kvalitativ ansats med semistrukturerade intervjuer studiens huvudsakliga metodologiska verktyg för insamling av empiriska data. Resultatet tyder på att majoriteten av verksamheterna inte erbjuder aktiviteter som är specifikt anpassade för PmF men att en del av utbudet går att kan anpassa om efterfrågan skulle uppstå. Marknadens efterfrågan styr verksamhetens utbud av aktiviteter och en bristande efterfrågan från PmF på tillgängliga aktiviteter har identifierats. Studiens slutsats beskriver att den bristande efterfrågan från PmF ligger till grund för det bristande utbudet av tillgängliga aktiviteter samt att verksamheterna anger resurser såsom kunskap och ekonomiska faktorer som utmanade vid utvecklingen av tillgänglighetsanpassade aktiviteter. / Tourism and leisure activities are an essential part of many people's lives, but for people with disabilities (PwD), their involvement can be highly conditional. The issue of active participation and the inclusion of PwD in all parts of society is increasingly being raised and the need for accessibility is growing. This study aims to investigate how tourism and activity companies in Jämtland County works to adapt and customize their activities to include individuals with physical disabilities. The study had a qualitative method with semi-structured interviews as the key focus for collecting empirical data. The result indicates that the majority of businesses do not currently offer activities that are specifically tailored to PwD, but for most of the companies these activities can be adjusted if there is a demand for it. Market demand controls the companies’ range of activities and a lack of demand from PwD for accessible activities has been identified. The conclusion describes that the absence of demand from PwD is the reason for the lack of accessible activities  and that the companies specify resources such as knowledge and financial factors as challenging for the development of accessible activities. / <p>2020-06-08</p>

In this Dissertation, systematic work has been carried out to study the road-deposited sediment and its adsorbed pollutants from a stormwater pollution perspective. Solid-phase concentration, surface load, source apportionment, risk assessment, and desorption dynamics of polycyclic aromatic hydrocarbons and/or heavy metals in road-deposited sediments (RDS) were investigated. In order to provide data to assist potential strategies of stormwater pollution mitigation and integrated catchment management to minimise the adverse impacts of RDS adsorbed pollutants on stormwawter quality, the following specific topics were addressed. ⑴ The influences of traffic load and antecedent dry-weather period on pollution level and ecological risk of heavy metals in RDS were analyzed. ⑵ The build-up dynamics and chemical fractionation of metals were determined. ⑶ The potential source contributions and risk assessment of polycyclic aromatic hydrocarbons in size-fractionated RDS were firstly determined by a Principal component analysis - Multiple linear regression receptor model. ⑷ The qualitative and quantitative source apportionments of polycyclic aromatic hydrocarbons were subsequently investigated through a combined qualitative Molecular Diagnostic Ratio and quantitative Positive Matrix Factorization source apportionment with an extended data set. ⑸ The exposure risk of polycyclic aromatic hydrocarbons were evaluated and calculated by incremental lifetime cancer risk models. ⑹ Then, a novel ecological risk assessment approach to the RDS adsorbed toxic substances was developed, which was explored exclusively for the study of RDS for a water pollution aspect. ⑺ Finally, the effects of rainwater, major wastewater constituents of dissolved organic matter and surfactant on the leaching of heavy metals from RDS were carried out.