Introdução: Os dados epidemiológicos e experimentais têm mostrado efeitos adversos da exposição pré e pós natal ao material particulado (MP2,5) sobre a saúde fetal e adulto. Entretanto, poucos estudos abordaram a toxicidade fetal da exposição gestacional à poluição do ar ambiental, bem como efeitos a longo prazo de adversos da exposição pré-natal sobre o desenvolvimento pós-natal e maturação de vários sistemas de órgãos. Objetivos: O objetivo deste estudo foi determinar se a exposição pré-natal e / ou pós-natal ao material particulado, influencia o desenvolvimento pulmonar e resposta vascular pulmonar em um modelo de camundongo suscetível a aterosclerose (LDLr-/- camundongos knockout). Métodos: Camundongos LDLr-/- foram expostos durante a gestação ao ar filtrado (AF) ou ar poluído (AC). Após o período de desmame, os filhotes foram subdivididos e novos quatro grupos foram formados de acordo com a exposição gestacional ou a exposição pós natal contínua no ar poluído. Atingindo a idade de 3 meses, esses grupos foram novamente subdivididos, formando um total de 8 grupos e uma dieta hipercolesterolêmica foi introduzida. Os seguintes parâmetros foram analisados: desfechos gestacionais, dosagem de colesterol total (CT) e triglicerídeos (TG) do fígado, avaliação de citocinas no LBA, e avaliação imunohistoquímica da resposta vascular pulmonar . Resultados: Nos grupos que receberam dieta hipercolesterolêmica (DH) os níveis de colesterol apresentaram-se aumentados (p=0,002); A expressão da IL6 no LBA mostrou-se elevada (p=0,01) somente no grupo que não foi exposto a poluição em nunhum período da vida e recebeu dieta postnatalmente. Diferenças significativas também foram observadas na expressão pulmonar vascular dos seguintes imunomarcadores: endotelina (p=0,05); ENOS (p=0,04); IL1? (p=0,005); INOS (p=0,002); ISOP (p=0,001); NOX2 (0,01) e ICAM (0,04) quando comparados ao grupo controle. O volume pulmonar total também se mostra alterado em decorrência do tratamento. Assim, conclui-se que a resposta do desenvolvimento pulmonar à exposição gestacional à poluição particulada do ar pode ser evidenciada mais tarde durante a vida adulta e agir como um fator modulador de insultos pós-natal devido à exposição a poluição do ar e a uma dieta hipercolesterolemica em individuos predispostos aterosclerose / Epidemiological and experimental data have shown adverse effects of gestational and post natal exposure to ambient particulate matter (PM) on the fetal and adult health. However, few studies addressed the fetal toxicity of gestational exposure to environmental air pollution as well as long-term adverse consequences of prenatal exposure on postnatal development and maturation of several organ systems. The aim of this study was to determine if prenatal and/or postnatal exposure to concentrated ambient particles influences lung development and pulmonary vascular response in an atherosclerosis susceptible mouse model (LDLr-/- knockout mice). LDLr-/- mice were exposed during the pregnancy to either filter (AF) or polluted air (CAP). After weaning period, pups were subdivided and new 4 groups formed according to gestational and continuous or not post natal exposure to air pollution. Reaching the age of 3 months these groups were again subdivided and a hypercholesterolemic (HC) diet introduced and a total of 8 groups were formed. Then the following parameters were analyzed: evaluation of the offspring outcomes, assessment of airway responsiveness, evaluation of cytokines in BALF, dosage of total cholesterol (TC) and triglycerides (TG) in the liver and pulmonary vascular response by immunohistochemistry. Results: Animals that received HC diet presented higher levels of cholesterol (p=0.002) when compared to those animals that received normal diet. Expression of IL-6 was only increased in the groups of mice exposed not exposed to particulate air pollution and that received the HC diet (p=0.01). Significant differences were also observed in vascular expression of immunomarkers in the lung endothelin (p=0.05); ENOS (p=0.04); IL1? (p=0.005); INOS (p=0.002); ISOP (p=0.001); NOX2 (0.01) e ICAM (0.04). Total lung volume was also different, there was an increase in those animals receiving a HC diet. In conclusion, the response of the lung development to gestational exposure to particulate air pollution can be evidenced later in life and act as a modulator factor for postnatal insults due to exposures to particulate air pollution and hypercholesterolemic diet in individual predisposed to atherosclerosis

Introdução: Os dados epidemiológicos e experimentais têm mostrado efeitos adversos da exposição pré e pós natal ao material particulado (MP2,5) sobre a saúde fetal e adulto. Entretanto, poucos estudos abordaram a toxicidade fetal da exposição gestacional à poluição do ar ambiental, bem como efeitos a longo prazo de adversos da exposição pré-natal sobre o desenvolvimento pós-natal e maturação de vários sistemas de órgãos. Objetivos: O objetivo deste estudo foi determinar se a exposição pré-natal e / ou pós-natal ao material particulado, influencia o desenvolvimento pulmonar e resposta vascular pulmonar em um modelo de camundongo suscetível a aterosclerose (LDLr-/- camundongos knockout). Métodos: Camundongos LDLr-/- foram expostos durante a gestação ao ar filtrado (AF) ou ar poluído (AC). Após o período de desmame, os filhotes foram subdivididos e novos quatro grupos foram formados de acordo com a exposição gestacional ou a exposição pós natal contínua no ar poluído. Atingindo a idade de 3 meses, esses grupos foram novamente subdivididos, formando um total de 8 grupos e uma dieta hipercolesterolêmica foi introduzida. Os seguintes parâmetros foram analisados: desfechos gestacionais, dosagem de colesterol total (CT) e triglicerídeos (TG) do fígado, avaliação de citocinas no LBA, e avaliação imunohistoquímica da resposta vascular pulmonar . Resultados: Nos grupos que receberam dieta hipercolesterolêmica (DH) os níveis de colesterol apresentaram-se aumentados (p=0,002); A expressão da IL6 no LBA mostrou-se elevada (p=0,01) somente no grupo que não foi exposto a poluição em nunhum período da vida e recebeu dieta postnatalmente. Diferenças significativas também foram observadas na expressão pulmonar vascular dos seguintes imunomarcadores: endotelina (p=0,05); ENOS (p=0,04); IL1? (p=0,005); INOS (p=0,002); ISOP (p=0,001); NOX2 (0,01) e ICAM (0,04) quando comparados ao grupo controle. O volume pulmonar total também se mostra alterado em decorrência do tratamento. Assim, conclui-se que a resposta do desenvolvimento pulmonar à exposição gestacional à poluição particulada do ar pode ser evidenciada mais tarde durante a vida adulta e agir como um fator modulador de insultos pós-natal devido à exposição a poluição do ar e a uma dieta hipercolesterolemica em individuos predispostos aterosclerose / Epidemiological and experimental data have shown adverse effects of gestational and post natal exposure to ambient particulate matter (PM) on the fetal and adult health. However, few studies addressed the fetal toxicity of gestational exposure to environmental air pollution as well as long-term adverse consequences of prenatal exposure on postnatal development and maturation of several organ systems. The aim of this study was to determine if prenatal and/or postnatal exposure to concentrated ambient particles influences lung development and pulmonary vascular response in an atherosclerosis susceptible mouse model (LDLr-/- knockout mice). LDLr-/- mice were exposed during the pregnancy to either filter (AF) or polluted air (CAP). After weaning period, pups were subdivided and new 4 groups formed according to gestational and continuous or not post natal exposure to air pollution. Reaching the age of 3 months these groups were again subdivided and a hypercholesterolemic (HC) diet introduced and a total of 8 groups were formed. Then the following parameters were analyzed: evaluation of the offspring outcomes, assessment of airway responsiveness, evaluation of cytokines in BALF, dosage of total cholesterol (TC) and triglycerides (TG) in the liver and pulmonary vascular response by immunohistochemistry. Results: Animals that received HC diet presented higher levels of cholesterol (p=0.002) when compared to those animals that received normal diet. Expression of IL-6 was only increased in the groups of mice exposed not exposed to particulate air pollution and that received the HC diet (p=0.01). Significant differences were also observed in vascular expression of immunomarkers in the lung endothelin (p=0.05); ENOS (p=0.04); IL1? (p=0.005); INOS (p=0.002); ISOP (p=0.001); NOX2 (0.01) e ICAM (0.04). Total lung volume was also different, there was an increase in those animals receiving a HC diet. In conclusion, the response of the lung development to gestational exposure to particulate air pollution can be evidenced later in life and act as a modulator factor for postnatal insults due to exposures to particulate air pollution and hypercholesterolemic diet in individual predisposed to atherosclerosis

Adverse health effects from exposure to air pollution, although at present only partly understood, are a global challenge and of widespread concern. Quantifying human exposure to air pollutants is challenging, as ambient concentrations of air pollutants at potentially harmful levels are ubiquitous and subject to high spatial and temporal variability. At the same time, individuals have their very own unique activity-patterns. Hence exposure results from intertwined relationships between environmental and human systems add complexity to the assessment process. It is essential to develop a deeper understanding of individual exposure pathways and situations occurring in people’s everyday lives. This is important especially with regard to exposure and health impact assessment which provide the basis for public health advice and policy development. This thesis describes the development and application of a personal monitoring method to assess exposure to fine particulate matter in a variety of microenvironments. Tools and methods applied are tested with respect to feasibility, intrusiveness, performance and potential for future applications. The development of the method focuses on the application in everyday environments and situations in an attempt to capture as much of the total exposure as possible, across a complete set of microenvironments. Seventeen volunteers took part in the pilot study, collected data and provided feedback on methodology and tools applied. The low-cost particle counter applied showed good agreement with reference instruments when studied in two different environments. Based on the assessment of the two instruments functions to derive particle mass concentration from the original particle number counts have been defined. The application of the devices and tools received positive feedback from the volunteers. Limitations are mainly related to the non-weatherproof design of the particle counter. The collection of time-activity patterns with GPS and time-activity diaries is challenging and requires careful processing. Resulting personal exposure profiles highlight the influence of individual activities and contextual factors. Highest concentrations were measured in indoor environments where people also spent the majority of time. Differences between transport modes as well as between urban and rural areas were identified.

Crankcase ventilation contributes significantly to diesel engine particulate emissions. Future regulations will not only limit the mass of particulate matter, but also the number of particles. Controlling the source of crankcase emissions is critical to meeting the perennial legislation. Deficiency in the understanding of crankcase emissions generation and the contribution of lubricating oil has been addressed in detail by the experimental study presented in this thesis. A plethora of high speed laser optical diagnostics techniques have been employed to deduce the main mechanisms of crankcase oil aerosol generation. Novel images have captured oil atomisation and passive oil distribution around the crankcase of an optically accessed, motored, four cylinder, off highway, heavy duty, diesel engine. Rayleigh type ligament breakup of oil films present on the surface of dynamic components, most notably the crankshaft, camshaft and valve rockers generated oil drops below 10 micrometers. Data illustrated not only crankcase oil aerosol generation at source, but it has provided valuable information on methods to control oil aerosol generation and improve oil circuit efficiency. The feasibility of utilising computational fluid dynamics to predict crankcase oil aerosol generation has been successfully assessed using the experimental data. Particle sampling has characterised the crankcase emissions from both a fired and motored diesel engine crankcase. The evolution of submicron crankcase particles down to 5 nm has been recorded from both engines, including the isolated contribution of engine oil, at a wide range of engine test points. Results have provided constructive insight into the generation and control of this complex emission. The main mechanism of crankcase oil aerosol generation was found to be crankshaft oil atomisation. This atomisation process has been analysed in detail, involving high speed imaging of primary and satellite drop generation and high speed digital particle image velocity of the crankshaft air flow. A promising mechanism of regulating and controlling crankcase oil aerosol emissions at source has been studied experimentally.

Earth observation satellites cover large areas with frequent temporal repetition and provide us with new insight into ocean and coastal processes. Ocean colour measurements from satellite remote sensing are linked to the bio-optics, which refers to the light interactions with living organisms and dissolved and suspended constituents in the aquatic environment. Human pressures have changed the aquatic ecosystems, by, for example, the increased input of nutrient and organic matter leading to eutrophication. This thesis aims to study and develop the link between bio-optical data and the remote sensing method to the monitoring and management of the Baltic Sea. The results are applied to the European Union’s Water Directives, and the Baltic Sea Action Plan from the Helsinki commission. In paper I indicators for eutrophication, chlorophyll-a concentration and Secchi depth were evaluated as a link to remote sensing observations. Chlorophyll-a measurements from an operational satellite service (paper I) were compared to conventional ship-based monitoring in paper II and showed high correlations to the in situ data. The results in paper I, II and IV show that the use of remote sensing can improve both the spatial and temporal monitoring of water quality. The number of observations increased when also using satellite data, thus facilitating the assessment of the ecological and environmental status within the European Union’s water directives. The spatial patterns make it possible to study the changes of e.g. algae blooms and terrestrial input on larger scales. Furthermore, the water quality products from satellites can offer a more holistic and easily accessible view of the information to decision makers and end-users. In paper III variable relationships between in situ bio-optical parameters, such as coloured dissolved organic matter (CDOM), dissolved organic carbon, salinity and Secchi depth, were found in different parts of the Baltic Sea. In paper IV an in situ empirical model to retrieve suspended particulate matter (SPM) from turbidity was developed and applied to remote sensing data. The use of Secchi depth as an indicator for eutrophication linked to the concentrations of chlorophyll-a and SPM and CDOM absorption was investigated in paper V. The variations in Secchi depth were affected differently by the mentioned parameters in the different regions. Therefore, one must also consider those when evaluating changes in Secchi depth and for setting target levels for water bodies. This thesis shows good examples on the benefits of incorporating bio-optical and remote sensing data to a higher extent within monitoring and management of the Baltic Sea. / <p>At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 4: Manuscript. Paper 5: Manuscript.</p>

L'étude des matières en suspension (MES) minérales est essentielle pour comprendre le fonctionnement des écosystèmes en Manche : les MES influencent la pénétration de la lumière dans la colonne d'eau, paramètre clé pour la production biologique, et sont susceptibles de transporter des polluants et nutriments. Lors de ce travail, la dynamique des MES minérales de surface en Manche est étudiée à l'aide de deux méthodes complémentaires : l'observation par satellite et la modélisation numérique tridimensionnelle. Dans un premier temps, les images satellite MODIS et MERIS, traitées par l'algorithme semi-analytique développé par l'IFREMER et représentant les MES non-algales de surface, sont analysées afin d'élaborer trois modèles statistiques permettant d'estimer la MES de surface en fonction de variables basiques telles que le coefficient de marée, la hauteur significative des vagues et la concentration moyenne en chlorophylle-a. Dans un deuxième temps, le modèle hydrosédimentaire multiclasse tridimensionnel ROMS (Regional Ocean Modeling System) est implémenté en Manche. Il prend en considération le forçage par la marée aux frontières ouvertes, la contrainte exercée par le vent à la surface de la mer, l'interaction houle-courant en couche limite de fond et l’hétérogénéité spatiale réaliste du lit sédimentaire. Les résultats du modèle statistique le plus sophistiqué sont également utilisés pour forcer la concentration en MES aux frontières ouvertes du domaine de calcul. Des tests de sensibilité sur les conditions limites montrent l'importance de considérer de manière réaliste les sédiments entrant en Manche par les frontières ouvertes lors de la modélisation numérique. L'influence de la biologie sur les MES minérales est testée en utilisant une formulation de la vitesse de chute et de la contrainte critique d'érosion variant saisonnièrement.Grâce à ces deux outils associés, les influences respectives de la marée, de la houle et de la biologie sur les MES minérales sont mises en avant et localisées en Manche. Le modèle numérique prédit que les MES de surface sont composées principalement de silts (>70%). Les silts en suspension en surface proviennent majoritairement du lit sédimentaire près des côtes en Manche orientale et des frontières ouvertes du domaine de calcul à l'ouest de la presqu'île du Cotentin et au large en Manche centrale et orientale. Les variations des MES de surface sont ensuite étudiées aux échelles des cycles de marée semi-diurnes, vive-eau/morte-eau et autour d'un épisode de houles. Enfin, l'évolution de la concentration de sédiments dans la zone de forte turbidité autour de l'île de Wight peut être analysée suivant les conditions hydrodynamiques afin d'évaluer les rôles respectifs des processus locaux d'érosion/dépot et d'advection dans la génération de ces turbidités remarquables. / Study of mineral suspended particulate matter (SPM) is essential to understand ecosystem dynamics. SPM influences light penetration which is closely related to primary production and carries pollutants and nutrients within the water masses. This work aims to study near-surface mineral SPM dynamics in the English Channel using two complementary methods: remote-sensing by satellites and numerical modelling.Firstly, MODIS and MERIS satellite images processed by the IFREMER semi-analytical algorithm and describing non-algal SPM, are analysed to build three statistical models which are able to estimate near-surface SPM using simple variables, e.g., tidal coefficient, significant wave height and mean chlorophyll-a concentration. Secondly, the three-dimensional hydrosedimentary model ROMS (Regional Ocean Modeling System) is applied in the English Channel. It considers tidal forcing along open boundaries, wind stress at the sea-surface, wave-current interactions in the bottom boundary layer and realistic heterogeneous bottom sediments. Results of the more sophisticated statistical model is also used to impose SPM concentrations at open boundaries. Sensitivity tests on SPM boundary conditions show the importance of prescribing realistic sediment concentrations to improve the model predictions. Biological influences on mineral SPM are also tested using settling velocity and critical shear stress for erosion which vary with seasons.Both statistical and numerical models highlight and locate respective influences of tide, waves and biology on mineral SPM. Numerical predictions indicate that near-surface SPM is mainly composed of silts (>70%). Near-surface suspended silts come largely from seabed resuspension alongshore in the Eastern Channel and from the open boundaries of our limited-area coastal model at the West of Cotentin Peninsula and offshore. Near-surface SPM variations are investigated at semi-diurnal, neap-spring tidal cycle time scales and during a wave event. Finally, dynamics of sediments in the turbidity maximum zone around the Isle of Wight is examined depending on hydrodynamical conditions in order to distinguish the role played by advection and local erosion/settling processes in this area.

Cette thèse porte sur l’étude de l’évolution de la qualité de l’air en Europe et en France dans les prochaines décennies à l’aide de simulations numériques. Dans les études des impacts de l’évolution du climat sur la qualité de l’air, les modèles de chimie atmosphérique utilisent des sorties de modèles climatiques globaux ou régionaux qui fournissent les « forçages », c’est-à-dire les conditions météorologiques simulées pour les périodes futures. Contrairement aux analyses météorologiques, qui représentent la variabilité jour à jour du temps, les sorties des modèles de climat doivent nécessairement être interprétées de manière statistique : elles ne représentent la météorologie que dans un sens climatologique. Afin de pouvoir commenter utilement les simulations futures de qualité de l’air, il est nécessaire d’évaluer au préalable et pour le climat présent, la qualité des simulations calculées avec des forçages climatiques par rapport aux références que constituent les simulations calculées avec des forçages analysés et, bien entendu, les observations. Trois simulations pluri-annuelles (6 ans) ont été lancées pour la période actuelle (2000-2010) et ont été comparées ; elles différent par l’utilisation d’analyses météorologiques ou de forçages de modèle de climat (pour les paramètres atmosphériques seuls et par ailleurs, pour les paramètres atmosphériques et le calcul des échanges en surface) en entrée du modèle de chimie-transport tridimensionnel de Météo-France, MOCAGE. Nous avons évalué ces différentes simulations par comparaison aux observations de la base de données européenne AirBase. Nous avons ensuite comparé les performances de ces simulations pour un grand nombre de scores quantitatifs, en analysant d’une part les effets liés aux champs météorologiques (température, vent, humidité, etc.) et d’autre part, ceux liés aux échanges en surface (comme les vitesses de dépôts, les émissions biogéniques) qui dépendent également de la météorologie. Nous avons ainsi évalué comment ces changements affectent les distributions horizontales et verticales des polluants. In fine, nous avons caractérisé la fiabilité des simulations de qualité de l’air reposant sur des forçages issus de modèles climatiques pour le climat présent : des indicateurs (biais moyens, biais moyens normalisés, RMSE, déviations standards) et des index de qualité de l’air (comme le dépassement de seuils) se distinguent et peuvent donc servir de base fiable pour l’interprétation des résultats pour les simulations du futur. Enfin dans une troisième partie, ces indicateurs considérés comme pertinents ont été utilisés pour étudier des simulations de qualité de l’air aux horizons 2030 et 2050 (5 ans). Comme attendu, l’évolution des paramètres météorologiques (température, précipitation, vent) modifie les quantités et la dispersion des polluants dans l’atmosphère, mais l’évolution des émissions en Europe et dans le reste du monde joue aussi un rôle important. Ainsi, face à l’évolution du climat et la hausse des émissions dans certains pays du monde, en Asie notamment, les effets des politiques Européennes pour réduire les émissions anthropiques sont mitigés selon les régions et les polluants, dépendant de l’influence relative des phénomènes locaux et du transport de polluant à longue distance. / This thesis aims at predicting how European and French air quality could evolve over the next decades using numerical modeling. In order to study the impacts of climate change up on regional air quality, atmospheric chemistry models rely on global or regional climate models to produce “forcings”, i.e. meteorological conditions for future periods. Unlike meteorological analyses, which can represent specifically each date and hour thanks to the assimilation of observations, climate model outputs need to be averaged and can only be interpreted in a climatological sense. And so are air quality hindcasts relying on them for their forcings. In order to properly interpret air quality simulations in a future climate, it is a pre-requisite to assess how realistic air quality hindcasts are when driven by forcings from climate models for the current period in comparison to the references, which are simulations with the same set-up but relying on meteorological analyses and observations. Three six-year simulations for the current climate (2000-2010) have been run with the three-dimensional chemistry transport model of Météo-France, MOCAGE. These simulations only differ by the meteorological forcings used, either operational meteorological analyses or outputs from climate simulations (for atmospheric parameters only ; for atmospheric parameters as well as surface exchanges, which depend also on the weather). We compared the three simulations and evaluated them against the European air quality database of the European Environment Agency, AirBase. Further, we investigated how statistical skill indicators compare in the different simulations, assessing the effects of meteorology on atmospheric fields (temperature, wind, humidity,...) and on the dependent emissions and deposition processes (such as deposition velocities, volatile organic compound emissions, ...) that depend upon meteorology. We have in particular studied how these factors affect the horizontal and vertical distributions of species. In the end, we have estimated how reliable are skill indicators for the simulations run with “climate” forcings : some indicators (mean bias, mean normalized bias, RMSE, deviation standards, number of exceedance days) are sufficiently close to the ones obtained with the reference configuration (relying on analysed meteorological forcings) to be considered reliable. They can thus be used to interpret simulations for future periods. We have run simulations of European air quality in the 2030s and 2050s (5 years for each period). They are discussed using the indicators previously indentified. As expected, the changes in meteorological parameters (temperature, precipitation, wind, ...) affect the quantities and distributions of pollutants in the atmosphere, but the future evolutions in European and global emissions also play a significant role. Faced with climate change and increased emissions in some countries in the world, as in Asia, the impacts of European policies for reducing anthropogenic emissions are mitigated, depending on the regions and the pollutants due to the respective influence of local emission and of long-range transport of pollutants.

This study was a population-based retrospective cohort of all singleton births in British Columbia for the years 2001 to 2006. The purpose of this dissertation is to examine how social and physical environment factors influence the risk of adverse pregnancy outcomes and whether they interact with each other or with maternal characteristics to modify disease risk. The main environmental factors examined include ambient particulate air pollution (PM2.5), neighbourhood socioeconomic status (SES), neighbourhood immigrant density, neighbourhood level of post-secondary education level and the urban-rural context. Census dissemination areas (DAs) were used as the neighbourhood spatial unit. The data (N=242,472) was extracted from the BC Perinatal Data Registry (BCPDR) from Perinatal Services BC (PSBC). The main perinatal outcomes investigated include birth weight and indicators of fetal growth restriction such as small-for-gestational age (SGA), term low birth weight (tLBW), and intrauterine growth restriction (IUGR), preterm birth (PTB) and gestational age, gestational diabetes mellitus (GDM) and gestational hypertension (GH). Collectively, this dissertation contributes to the perinatal epidemiological literature linking particulate air pollution and neighbourhood SES context to adverse pregnancy outcomes. Assumptions about the linear effect of PM2.5 and smoking on birth weight are challenged showing that the effects are most pronounced between low and average exposures and that the magnitude of their effect is modified by neighbourhood and individual-level characteristics. These results suggest that focusing exclusively on individual risk factors may have limited success in improving outcomes without addressing the contextual influences at the neighbourhood-level. This dissertation therefore also contributes to the public health, sociological and community-urban development literature demonstrating that context and place matters. / Graduate / 0766 / 0573 / 0768 / anderse@uvic.ca

Atmospheric haze, which builds up over South Africa including our study areas, Cape Town and the Mpumalanga Highveld under calm weather conditions, causes public concern. The scope of this study was to determine the concentration and composition of atmospheric aerosol at Khayelitsha (an urban site in the Western Cape) and Ferrobank (an industrial site in Witbank, Mpumalanga). Particulate matter was collected in Khayelitsha from 18 May 2007 to 20 July 2007 (i.e. 20 samples) using a Partisol-plus sampler and a Tapered Element Oscillating Microbalance (TEOM) sampler. Sampling took place at Ferrobank from 07 February 2008 to 11 March 2008 (6 samples) using a Partisol-plus sampler and an E-sampler. The gravimetric mass of each exposed sample was determined from pre- and post-sampling weighing. The elemental composition of the particulate matter was determined for 16 elements at Khayelitsha using Proton Induced X-ray Emission (PIXE). The concentration of the elements Al, Si, S, Cl, K, Ca, Ti, Cr, Mn, Fe, Cu, Zn, As, Br, Sn, and Pb was determined by analysing the PIXE spectra obtained. In similar manner, the elemental composition of the particulate matter was determined for 15 elements at Ferrobank (Al, Si, S, Cl, K, Ca, Ti, Cr, Mn, Fe, Cu, Zn, As, Br and Pb). The average aerosol mass concentrations for different days at the Khayelitsha site were found to vary between 8.5 μg/m3 and 124.38 μg/m3. At the Khayelitsha site on three occasions during the sampling campaign the average aerosol mass concentrations exceeded the current South African air quality standard of 75 μg/m3 over 24 h. At the Ferrobank site, there are no single days that exceeded the limit of the South African air quality standard during the sampling campaign. Enrichment factors for each element of the particles sampled with an aerodynamic diameter of less than 10 μm (PM10) samples have been calculated in order to identify their possible sources. The analysis yielded five potential sources of PM10 : soil dust, sea salt, gasoline emissions, domestic wood and coal combustion. Interestingly, enrichment factor values for the Khayelitsha samples show that sea salt constitutes a major source of emissions, while Ferrobank samples, the source apportionment by unique ratios (SPUR) indicate soil dust and coal emission are the major sources of pollution. The source apportionment at Khayelitsha shows that sea salt and biomass burning are major source of air pollution.

Le charbon est l’une des ressources fossiles les plus économiques pour la production d’énergie. Cependant, il présente des inconvénients liés à l’impact environnemental lors de sa combustion qui produit CO2, principal gaz à effet de serre, ainsi que d’autres gaz et particules polluants et nocifs pour la santé. Afin de lutter contre ces effets, plusieurs procédés sont envisagés dont l’oxycombustion (possibilité de séquestrer CO2 en sortie du système de combustion) et la co-combustion charbon/biomasse sachant que le bilan carbone est neutre pour la biomasse. Pour caractériser ces procédés, un dispositif expérimental a été développé. Il s’agit d’un four à chute qui permet de reproduire en laboratoire les conditions expérimentales prévalant dans les chaudières industrielles dont une vitesse de chauffe des particules de l’ordre de 104 K s-1. Ce dispositif a permis d’étudier la réaction de dévolatilisation de différents solides pulvérisés (charbons, biomasse) à différentes températures (de 600 à 1400 °C). Pour comparer les procédés de combustion et d’oxycombustion, la dévolatilisation sous N2 (étape préliminaire à la combustion sous air) et sous CO2 (étape préliminaire à l’oxycombustion) a été étudiée pour différents charbons à différentes températures. Les résultats obtenus montrent que l’influence de l’atmosphère gazeuse sur la dévolatilisation du charbon n’est significative que pour des températures supérieures à 1200 °C. L’influence des différentes conditions opératoires sur les émissions de particules (PM2.5) issues de la combustion du charbon et de la biomasse a été évaluée et des corrélations sont mises en évidence entre l’intensité d’émission des particules et la nature du combustible, la température et l’atmosphère gazeuse. Une étude cinétique de la pyrolyse a été effectuée et les paramètres cinétiques correspondants déterminés par modélisation à partir de plusieurs schémas cinétiques réactionnels. / Coal is the most economically attractive fossil fuel and the main resource used for electricity production. However, the main issue with coal combustion is the greenhouse gas as well as other gases and particulates matter leading to environmental and human concerns. In order to reduce the environmental impact of coal utilization, researches are conducted to improve the combustion process and to use other carbon-based fuels. The first approach includes the oxy-fuel combustion that can be coupled with Carbon Capture and Storage process (CCS). The second approach promotes the partial substitution of coal by carbon-neutral fuels, such as biomasses, which are promising fuels.For the evaluation of the application of these technologies, an experimental device was developed. This device is a drop tube furnace (DTF) in which high particle heating rate (approximately 104–105 K s−1) has to be achieved in order to characterize solid fuels under conditions similar to those taking place in power plant furnaces. DTF allowed to investigate pyrolysis reaction involving coal and/or biomass particles at different temperatures (600-1400 °C). The comparison between the oxy-combustion and the conventional air combustion process starts with the investigation of the pyrolysis step. The impact of N2 (for conventional air combustion) and CO2 (for oxy-fuel combustion) atmospheres during pyrolysis of different coals at different temperatures was investigated. Results showed that the coal devolatilization is influenced by the gas under which the fuel devolatilization is carried out (N2 or CO2) only at high temperatures (>1200 °C). The influence of different operating conditions on PM2.5 emission were experimented for coals or biomass, including combustion atmosphere (air or oxy-fuel conditions), particle residence time and temperature. A kinetic study of the pyrolysis was carried out and the corresponding kinetic parameters were determined by modeling from several kinetic reaction schemes.