La combustion de bois, ou plus largement de la biomasse, est une source de pollution très importante en particules atmosphériques en hiver, particulièrement en France. Si les émissions primaires ont été étudiées depuis de nombreuses années, il existe de grandes incertitudes sur le devenir de ces émissions dans l’atmosphère. Le travail de thèse a donc porté sur l’étude du vieillissement en chambre de simulation atmosphérique de l’aérosol émis par 3 appareillages pour le chauffage au bois (conçus entre 2000 et 2010 et représentatifs de la politique de renouvellement mis en place par l’ADEME), avec un intérêt particulier pour le potentiel de formation d’aérosol organique secondaire (SOA) et la modification de l’empreinte chimique à l’échelle moléculaire au cours du transport atmosphérique. Les expériences ont montré un potentiel de formation de SOA très important. La concentration en OA peut ainsi être multipliée par 7 (1.5 – 7.1) entre l’émission et après un temps de résidence atmosphérique équivalent à 5 h. Cette étude met également en évidence l’impact de l’efficacité de combustion sur les facteurs d’émission et par conséquent le rôle crucial de l’opérateur. L’étude à l’échelle moléculaire a mis en évidence la formation de composés susceptibles de servir de marqueurs de combustion de biomasse âgée, principalement des nitrocatéchols. Enfin, cette étude démontre le rôle clé de la volatilisation du lévoglucosan, principal marqueur organique de la combustion de biomasse, au cours du processus de dilution dans l’atmosphère, et pose clairement la question de la pertinence des constantes cinétiques de dégradation préalablement calculées en chambre de simulation atmosphérique. / Biomass burning is in winter a main source of air pollution by particulate matter, especially in France. While primary emissions have been characterized extensively before, few studies have addressed the aging of these emissions in the atmosphere and large uncertainties remain. Therefore, the objectives of this thesis was to study in a smog chamber the aging of the aerosol emitted by 3 different woodstoves used for residential heating (fabricated from between 2000 and 2010, and representative of the policy engaged by the French environmental agency to renew the appliances across the country), with a specific focus on the Secondary Organic Aerosol (SOA) production potential and the modification of the chemical fingerprint of the emissions at the molecular level during their transport in the atmosphere. The experiments showed the SOA production potential can be significant. The OA concentration can be increased by up to a factor of 7 (1.5 – 7.1) after being aged in the smog chamber with a time equivalent to 5 hours in the atmosphere. The study also further demonstrated the influence of the combustion efficiency on the emissions and implicitly the role of the operator. The study of the composition of the aerosol at the molecular level showed the formation of compounds, likely to serve as markers for aged biomass burning, mainly nitrocatechols. Finally, the work also illustrates the influence of the volatilization of levoglucosan, main marker of biomass burning, during the dilution process occurring in the atmosphere, and challenge the pertinence of the degradation rate constant determined previously in smog chamber.

O material particulado nas frações fina e inalável (MP2,5 e MP10) para três cidades da América Latina (São Paulo Brasil, Lima Peru e Medellín Colômbia) foi analisado quimicamente para a avaliação de fontes de poluição atmosférica e dos riscos à saúde. Em São Paulo, uma campanha extensiva foi realizada ao longo de 2014 no campus da Universidade de São Paulo, com coletas de MP2,5 e MP10. Campanhas intensivas (no inverno) foram realizadas em São Paulo nos anos de 2010, 2013 e 2014, e em Lima e Medellín no ano de 2010. As espécies hidrocarbonetos policíclicos aromáticos (HPA), íons orgânicos e inorgânicos, e monossacarídeos foram determinadas por técnicas cromatográficas; as espécies carbonáceas (carbono orgânico e elementar) foram determinadas por análise termo-óptica. Os elementos foram determinados por espectrometria de massas com plasma indutivamente acoplado. Os riscos associados à exposição ao material particulado com base nas concentrações de HPA foram avaliados com os índices benzo(a)pireno equivalente (BaPE) e de risco de câncer de pulmão (RCPV). Nas campanhas intensivas de 2010, a concentração média do MP10 foi mais elevada em São Paulo do que nos outros dois sítios, 75% das amostras apresentaram concentrações acima do recomendado pela Organização Mundial da Saúde. A razão levoglucosano/manosano para São Paulo sugeriu a grande contribuição da queima da cana-de-açúcar, que em 2010 ocorreu em 70 % dos municípios do estado. Elementos relacionados às emissões veiculares (Fe, Cu) apresentaram maiores concentrações também em São Paulo. As e Pb tiveram concentrações mais elevadas em Medellín, atribuídos às emissões industriais. A concentração de Ni foi mais elevada em Lima, a espécie é associada às emissões de instalações de fundição de metal e à combustão de óleo em navios. Altos índices de BaPE e RCPV foram observados na maioria das amostras em São Paulo no ano de 2014, alcançando valores críticos no inverno (acima de 1 ng m-3 e 10-4, respectivamente). Além disso, as concentrações de HPA e traçadores de queima de biomassa foram mais elevadas no inverno. As espécies traçadoras de fontes veiculares também foram mais abundantes na campanha intensiva (inverno) devido à menor dispersão de poluentes, menos chuvas e maior frequência de inversões térmicas. A fatoração de matriz positiva permitiu uma melhor compreensão das contribuições de fontes de emissão que afetam o sítio (ressuspensão do solo, emissões industriais, emissão veicular, queima de biomassa e formação secundária). Os resultados enfatizaram a contribuição das emissões veiculares e uma contribuição significativa da queima de biomassa na estação seca (30,9 e 18,3 %, respectivamente). A maior parte do material particulado foi relacionada às fontes locais (veiculares), além da influência da queima de biomassa (cana-de-açúcar e queimas urbanas). Assim, os resultados destacaram a importância e a contribuição das atividades humanas na qualidade do ar nos três sítios latino-americanos. / The particulate matter in the fine and inhalable fractions (PM2.5 and PM10) collected in three Latin American cities (São Paulo, Brazil; Lima, Peru; and Medellín, Colombia) was chemically analysed in order to investigate the sources of atmospheric pollution and related health risks. In São Paulo, a year-round extensive campaign (2014) was conducted at the University of São Paulo campus (PM2.5 and PM10). Intensive campaigns were performed in São Paulo (2010, 2013 and 2014) and in Lima and Medellín (2010). The species such as polycyclic aromatic hydrocarbons (PAHs), organic and inorganic ions and the monosaccharides were determined by chromatographic techniques. The carbonaceous species (organic and elemental carbon) were determined by thermal-optical analysis. Trace elements were determined by inductively coupled plasma mass spectrometry. The associated risks to particulate matter exposure based on PAH concentrations were assessed with the indexes benzo[a]pyrene equivalent (BaPE) and lung cancer risk (LCR). In 2010, PM10 average concentration was higher in São Paulo than in the other two sites; 75 % of the samples presented concentrations above that recommended by World Health Organization. Levoglucosan/mannosan ratios for São Paulo samples suggested sugarcane burning; in 2010 it occurred in 70 % of São Paulo state municipalities. Vehicular related elements (Fe and Cu) also presented higher concentrations in São Paulo. As and Pb concentrations were higher in Medellín, attributed to industrial emissions. Ni was abundant in Lima atmosphere and associated to emissions from metal smelting facilities and ship heavy oil combustion. High BaPE and LCR were observed in most of the samples in São Paulo in the year of 2014, reaching critical values in the wintertime (above 1 ng m-3 and 10-4, respectively). Also, PAHs and biomass burning tracers concentrations were higher in this season. The vehicular tracer species were also more abundant in the intensive campaign (wintertime) suggesting the lower dispersion conditions, less rainfall and higher frequency of thermal inversions in that period. Positive matrix factorization provided a better comprehension over the contribution sources affecting the site; five different factors were identified: road dust, industrial emissions, vehicular exhaust, biomass burning and secondary formation. The results emphasized the contribution of vehicular emissions and the significant input from biomass combustion in the dry season (30,9 and 18,3 %, respectively). Most of the particulate matter was due to local sources (vehicular), besides the influence of pre-harvest sugarcane and urban biomass burning. Thus, the results emphasize the importance and contribution of the anthropogenic activities in the air quality for the three latin american cities.

O material particulado nas frações fina e inalável (MP2,5 e MP10) para três cidades da América Latina (São Paulo Brasil, Lima Peru e Medellín Colômbia) foi analisado quimicamente para a avaliação de fontes de poluição atmosférica e dos riscos à saúde. Em São Paulo, uma campanha extensiva foi realizada ao longo de 2014 no campus da Universidade de São Paulo, com coletas de MP2,5 e MP10. Campanhas intensivas (no inverno) foram realizadas em São Paulo nos anos de 2010, 2013 e 2014, e em Lima e Medellín no ano de 2010. As espécies hidrocarbonetos policíclicos aromáticos (HPA), íons orgânicos e inorgânicos, e monossacarídeos foram determinadas por técnicas cromatográficas; as espécies carbonáceas (carbono orgânico e elementar) foram determinadas por análise termo-óptica. Os elementos foram determinados por espectrometria de massas com plasma indutivamente acoplado. Os riscos associados à exposição ao material particulado com base nas concentrações de HPA foram avaliados com os índices benzo(a)pireno equivalente (BaPE) e de risco de câncer de pulmão (RCPV). Nas campanhas intensivas de 2010, a concentração média do MP10 foi mais elevada em São Paulo do que nos outros dois sítios, 75% das amostras apresentaram concentrações acima do recomendado pela Organização Mundial da Saúde. A razão levoglucosano/manosano para São Paulo sugeriu a grande contribuição da queima da cana-de-açúcar, que em 2010 ocorreu em 70 % dos municípios do estado. Elementos relacionados às emissões veiculares (Fe, Cu) apresentaram maiores concentrações também em São Paulo. As e Pb tiveram concentrações mais elevadas em Medellín, atribuídos às emissões industriais. A concentração de Ni foi mais elevada em Lima, a espécie é associada às emissões de instalações de fundição de metal e à combustão de óleo em navios. Altos índices de BaPE e RCPV foram observados na maioria das amostras em São Paulo no ano de 2014, alcançando valores críticos no inverno (acima de 1 ng m-3 e 10-4, respectivamente). Além disso, as concentrações de HPA e traçadores de queima de biomassa foram mais elevadas no inverno. As espécies traçadoras de fontes veiculares também foram mais abundantes na campanha intensiva (inverno) devido à menor dispersão de poluentes, menos chuvas e maior frequência de inversões térmicas. A fatoração de matriz positiva permitiu uma melhor compreensão das contribuições de fontes de emissão que afetam o sítio (ressuspensão do solo, emissões industriais, emissão veicular, queima de biomassa e formação secundária). Os resultados enfatizaram a contribuição das emissões veiculares e uma contribuição significativa da queima de biomassa na estação seca (30,9 e 18,3 %, respectivamente). A maior parte do material particulado foi relacionada às fontes locais (veiculares), além da influência da queima de biomassa (cana-de-açúcar e queimas urbanas). Assim, os resultados destacaram a importância e a contribuição das atividades humanas na qualidade do ar nos três sítios latino-americanos. / The particulate matter in the fine and inhalable fractions (PM2.5 and PM10) collected in three Latin American cities (São Paulo, Brazil; Lima, Peru; and Medellín, Colombia) was chemically analysed in order to investigate the sources of atmospheric pollution and related health risks. In São Paulo, a year-round extensive campaign (2014) was conducted at the University of São Paulo campus (PM2.5 and PM10). Intensive campaigns were performed in São Paulo (2010, 2013 and 2014) and in Lima and Medellín (2010). The species such as polycyclic aromatic hydrocarbons (PAHs), organic and inorganic ions and the monosaccharides were determined by chromatographic techniques. The carbonaceous species (organic and elemental carbon) were determined by thermal-optical analysis. Trace elements were determined by inductively coupled plasma mass spectrometry. The associated risks to particulate matter exposure based on PAH concentrations were assessed with the indexes benzo[a]pyrene equivalent (BaPE) and lung cancer risk (LCR). In 2010, PM10 average concentration was higher in São Paulo than in the other two sites; 75 % of the samples presented concentrations above that recommended by World Health Organization. Levoglucosan/mannosan ratios for São Paulo samples suggested sugarcane burning; in 2010 it occurred in 70 % of São Paulo state municipalities. Vehicular related elements (Fe and Cu) also presented higher concentrations in São Paulo. As and Pb concentrations were higher in Medellín, attributed to industrial emissions. Ni was abundant in Lima atmosphere and associated to emissions from metal smelting facilities and ship heavy oil combustion. High BaPE and LCR were observed in most of the samples in São Paulo in the year of 2014, reaching critical values in the wintertime (above 1 ng m-3 and 10-4, respectively). Also, PAHs and biomass burning tracers concentrations were higher in this season. The vehicular tracer species were also more abundant in the intensive campaign (wintertime) suggesting the lower dispersion conditions, less rainfall and higher frequency of thermal inversions in that period. Positive matrix factorization provided a better comprehension over the contribution sources affecting the site; five different factors were identified: road dust, industrial emissions, vehicular exhaust, biomass burning and secondary formation. The results emphasized the contribution of vehicular emissions and the significant input from biomass combustion in the dry season (30,9 and 18,3 %, respectively). Most of the particulate matter was due to local sources (vehicular), besides the influence of pre-harvest sugarcane and urban biomass burning. Thus, the results emphasize the importance and contribution of the anthropogenic activities in the air quality for the three latin american cities.

A colheita não-mecanizada da cana-de-açúcar, precedida por sua queima, expõe os trabalhadores e pessoas de cidades vizinhas a altas concentrações de poluentes. Este estudo foi desenvolvido para avaliar os impactos cardiopulmonares e os biomarcadores de estresse oxidativo e atividade inflamatória sistêmica desencadeados pela exposição à poluição proveniente da queima da cana. Cortadores de cana (safristas, n = 113) e voluntários saudáveis da cidade de Mendonça - São Paulo, Brasil - (população de referência, n = 109) foram avaliados com espirometria, variabilidade da frequência cardíaca (VFC), enzimas antioxidantes, dosage do nível plasmático do malonaldeído e de interleucinas pró-inflamatórias durante a pré-safra e a safra. A concentração de PM2.5 aumentou de 8g/m3 durante a pré-safra para 23.5g/m3 na área urbana e 61g/m3 nas plantações de cana, durante a safra. Na safra, evidenciou-se uma diminuição mais acentuada na VFC, função pulmonar e da atividade das enzimas antioxidantes entre os cortadores de cana, em comparação com os voluntários da população de referência. Houve elevação do Malonaldeído em ambos os grupos durante a safra, com um maior aumento entre os safristas. Além disso, encontramos um aumento na pressão diastólica apenas nos cortadores de cana. Tanto os cortadores de cana quanto os voluntários da população local exibiram impactos cardiopulmonares e metabólicos da exposição à poluição durante a safra, com maior magnitude dessas alterações entre os safristas, o que destaca o impacto deletério da poluição atmosférica na população exposta. Esses achados pré-clínicos podem sinalizar processos fisiopatológicos desencadeados pela poluição advinda da queima de biomassa nas populações estudadas / Non-mechanized sugarcane harvesting preceded by burning exposes workers and people of neighboring towns to high concentrations of pollutants. This study was designed to assess cardiopulmonary impacts and biomarkers of oxidative stress triggered by exposure to pollution from sugarcane burning. Sugarcane workers (n=113) and healthy volunteers of a reference population (n=109) from the city of Mendonça (São Paulo, Brazil) were evaluated with spirometry, heart rate variability (HRV), antioxidant enzymes, plasma malonaldehyde and proinflammatory interleukins during non-harvest and harvest periods. Concentration of PM2.5 increased from 8g/m3 during nonharvest to 23.5g/m3 in the urban area and to 61g/m3 in sugarcane fields, during harvest. It was evidenced a more remarkable decrease in lung function, HRV and in activity of antioxidant enzymes among sugarcane workers, compared to individuals from the reference population. Malonaldehyde had elevated in both groups during harvest, with a higher increase among sugarcane workers. Furthermore, we found an increase in diastolic pressure only in sugarcane workers. Both sugarcane workers and volunteers from the local population exhibited significant cardiopulmonary and metabolic impacts of exposure to outdoor air pollution during harvest, with a higher magnitude of these alterations among sugarcane workers, which highlights the deleterious impact of air pollution. These preclinical findings may signal pathophysiological processes triggered by biomassburning outdoor pollution in the populations studied

A colheita não-mecanizada da cana-de-açúcar, precedida por sua queima, expõe os trabalhadores e pessoas de cidades vizinhas a altas concentrações de poluentes. Este estudo foi desenvolvido para avaliar os impactos cardiopulmonares e os biomarcadores de estresse oxidativo e atividade inflamatória sistêmica desencadeados pela exposição à poluição proveniente da queima da cana. Cortadores de cana (safristas, n = 113) e voluntários saudáveis da cidade de Mendonça - São Paulo, Brasil - (população de referência, n = 109) foram avaliados com espirometria, variabilidade da frequência cardíaca (VFC), enzimas antioxidantes, dosage do nível plasmático do malonaldeído e de interleucinas pró-inflamatórias durante a pré-safra e a safra. A concentração de PM2.5 aumentou de 8g/m3 durante a pré-safra para 23.5g/m3 na área urbana e 61g/m3 nas plantações de cana, durante a safra. Na safra, evidenciou-se uma diminuição mais acentuada na VFC, função pulmonar e da atividade das enzimas antioxidantes entre os cortadores de cana, em comparação com os voluntários da população de referência. Houve elevação do Malonaldeído em ambos os grupos durante a safra, com um maior aumento entre os safristas. Além disso, encontramos um aumento na pressão diastólica apenas nos cortadores de cana. Tanto os cortadores de cana quanto os voluntários da população local exibiram impactos cardiopulmonares e metabólicos da exposição à poluição durante a safra, com maior magnitude dessas alterações entre os safristas, o que destaca o impacto deletério da poluição atmosférica na população exposta. Esses achados pré-clínicos podem sinalizar processos fisiopatológicos desencadeados pela poluição advinda da queima de biomassa nas populações estudadas / Non-mechanized sugarcane harvesting preceded by burning exposes workers and people of neighboring towns to high concentrations of pollutants. This study was designed to assess cardiopulmonary impacts and biomarkers of oxidative stress triggered by exposure to pollution from sugarcane burning. Sugarcane workers (n=113) and healthy volunteers of a reference population (n=109) from the city of Mendonça (São Paulo, Brazil) were evaluated with spirometry, heart rate variability (HRV), antioxidant enzymes, plasma malonaldehyde and proinflammatory interleukins during non-harvest and harvest periods. Concentration of PM2.5 increased from 8g/m3 during nonharvest to 23.5g/m3 in the urban area and to 61g/m3 in sugarcane fields, during harvest. It was evidenced a more remarkable decrease in lung function, HRV and in activity of antioxidant enzymes among sugarcane workers, compared to individuals from the reference population. Malonaldehyde had elevated in both groups during harvest, with a higher increase among sugarcane workers. Furthermore, we found an increase in diastolic pressure only in sugarcane workers. Both sugarcane workers and volunteers from the local population exhibited significant cardiopulmonary and metabolic impacts of exposure to outdoor air pollution during harvest, with a higher magnitude of these alterations among sugarcane workers, which highlights the deleterious impact of air pollution. These preclinical findings may signal pathophysiological processes triggered by biomassburning outdoor pollution in the populations studied

No description available.

Biomass burning started to attract attention since the last decade because of its impacts on the atmosphere and the environmental air quality, as well as significant potential effects on human health and global climate change. Knowledge of particle emission characteristics from biomass burning is crucially important for the quantitative assessment of the potential impacts. This thesis presents the results of study aimed towards comprehensive characterization of particle emissions from biomass burning. The study was conducted both under controlled laboratory conditions, to quantify the particle size distribution and emission factors by taking into account various factors which may affect the particle characteristics, and in the field, to investigate biomass burning processes in the real life situations and to examine vertical profile of particles in the atmosphere. To simulate different environmental conditions, a new technique has been developed for investigating particle emissions from biomass burning in the laboratory. As biomass burning may occur in a field at various wind speeds and burning rates, the technique was designed to allow adjustment of the flow rates of the air introduced into the chamber, in order to control burning under different conditions. In addition, the technique design has enabled alteration of the high particle concentrations, allowing conducting measurements with the instrumentations that had the upper concentration limits exciding the concentrations characteristic to the biomass burning. The technique was applied to characterize particle emissions from burning of several tree species common to Australian forests. The aerosol particles were characterized in terms of size distribution and emission factors, such as PM2.5 particle mass emission factor and particle number emission factor, under various burning conditions. The characteristics of particles over a range of burning phases (e.g., ignition, flaming, and smoldering) were also investigated. The results showed that particle characteristics depend on the type of tree, part of tree, and the burning rate. In particular, fast burning of the wood samples produced particles with the CMD of 60 nm during the ignition phase and 30 nm for the rest of the burning process. Slow burning of the wood samples produced large particles with the CMD of 120 nm, 60 nm and 40 nm for the ignition, flaming and smoldering phases, respectively. The CMD of particles emitted by burning the leaves and branches was found to be 50 nm for the flaming phase and 30 nm for the smoldering phase, under fast burning conditions. Under slow burning conditions, the CMD of particles was found to be between 100 to 200 nm for the ignition and flaming phase, and 50 nm for the smoldering phase. For fast burning, the average particle number emission factors were between 3.3 to 5.7 x 1015 particles/kg for wood and 0.5 to 6.9 x 1015 particles/kg for leaves and branches. The PM2.5 emission factors were between 140 to 210 mg/kg for wood and 450 to 4700 mg/kg for leaves and branches. For slow burning conditions, the average particle number emission factors were between 2.8 to 44.8 x 1013 particles/kg for wood and 0.5 to 9.3 x 1013 particles/kg for leaves and branches, and the PM2.5 emissions factors were between 120 to 480 mg/kg for wood and 3300 to 4900 mg/kg for leaves and branches. The field measurements were conducted to investigate particle emissions from biomass burning in the Northern Territory of Australia over dry seasons. The results of field studies revealed that diameters of particles in ambient air emissions were within the size range observed during laboratory investigations. The laboratory measurements found that the particles released during the controlled burning were of a diameter between 30 and 210 nm, depending on the burning conditions. Under fast burning conditions, smaller particles were produced with a diameter in the range of 30 to 60 nm, whilst larger particles, with a diameter between 60 nm and 210 nm, were produced during slow burning. The airborne field measurements of biomass particles found that most of the particles measured under the boundary layer had a CMD of (83 ± 13) nm during the early dry season (EDS), and (127 ± 6) nm during the late dry season (LDS). The characteristics of ambient particles were found to be significantly different at the EDS and the LDS due to several factors including moisture content of vegetation, location of fires related to the flight paths, intensity of fires, and burned areas. Specifically, the investigations of the vertical profiles of particles in the atmosphere have revealed significant differences in the particle properties during early dry season and late dry season. The characteristics of particle size distribution played a significant role in these differences.

La combustion de la biomasse est l’une des sources majoritaires de particules atmosphériques en périodes hivernales dans les vallées alpines, et particulièrement en vallée de l’Arve où des dépassements des seuils européens sont très régulièrement observés. Ceci a conduit à la mise en place d’un large programme de remplacement des dispositifs de chauffage au bois les moins performants dans le cadre d’une des actions du Plan de Protection de l’Atmosphère, le Fond Air Bois. Le projet DECOMBIO (DÉconvolution de la contribution de la COMbustion de la BIOmasse aux PM10 dans la vallée de l’Arve) a ainsi été mis en place en octobre 2013 afin de mesurer l’impact de cette politique de rénovation des appareils de chauffage au bois sur la qualité de l’air. C’est dans ce programme que s’inscrivent ces travaux de thèse dont l’objectif principal est de valider les méthodologies mises en place en routine pour permettre une déconvolution rapide de la combustion de la biomasse et mettre en relation les éventuels changements observés avec les avancées des remplacements de dispositifs de chauffage au bois domestiques.Pour mener à bien ce travail, trois sites, représentant les différentes situations de la vallée de l’Arve, ont été instrumentés (Marnaz, Passy et Chamonix) afin de suivre en continu, et tout au long du projet DECOMBIO, l’évolution des concentrations atmosphériques du Black Carbon (BC) et des traceurs moléculaires permettant de distinguer la contribution de la combustion de la biomasse des autres types de combustion. Un important jeu de données a été acquis entre novembre 2013 et octobre 2014 grâce à des prélèvements réguliers sur filtre permettant une caractérisation très fine de la composition chimique des particules atmosphériques. L’utilisation de l’approche statistique « Positive Matrix Factorization » (PMF) a permis de mieux appréhender les différentes sources entrant en jeu dans les émissions de particules au sein de cette vallée avec notamment un intérêt particulier pour les émissions de la combustion de la biomasse. Le développement de cette méthodologie d’attribution et de quantification des sources de particules basé sur l’utilisation de traceurs organiques spécifiques, de contraintes particulières appliquées à ce modèle et de données de déconvolution de la matière carbonée constitue une avancée importante dans la définition des facteurs sources issus de ce modèle.Les méthodologies développées au cours de ce travail, permettant une amélioration des connaissances et des contributions des sources, constituent donc des outils directement utilisables par les Associations Agréées de Surveillance de la Qualité de l’Air (AASQA), notamment pour l’évaluation quantitative des mesures prises pour améliorer la qualité de l’air dans le cadre de Plans de Protection de l’Atmosphère, entre autres celui de la vallée de l’Arve. / Biomass burning is one of the major sources of atmospheric particles during wintertime in Alpine valleys, and more especially in the Arve valley where exceedances of the European regulated limit value are regularly observed. This situation led to the establishment of an important program of replacement of old wood stoves with new ones as part of an action of an Atmospheric Protection Plan (APP), the “Fonds Air Bois”. The research program DECOMBIO (“DÉconvolution de la contribution de la COMbustion de la BIOmasse aux PM10 dans la vallée de l’Arve”) has been set up in October 2013 to estimate the impact of this wood stoves renewal policy on air quality. This thesis works be incorporated within this program and have for main objective to validate methodologies used in routine to enable a fast deconvolution of the biomass burning source and to compare any observed changes with progress of wood stove changeout.To complete this work, three sites, representing the different situations of the Arve valley, were instrumented (Marnaz, Passy and Chamonix) to monitor the continuing evolution of atmospheric concentrations of Black Carbon (BC) and molecular markers enabling to distinguish between the biomass burning contribution and that of other types of combustion. A large dataset was acquired between November 2013 and October 2014 thanks to regular filter samples enabling a vast chemical characterization of PM10. The use of statistical analysis “Positive Matrix Factorization” (PMF) has led to an enhanced appreciation of particle emission sources within this valley with a focus on biomass burning emissions. The development of this methodology of identification and source apportionment based on the use of specific organic markers, specific constraints and data from carbonaceous matter deconvolution is an important progress in definition of factors from this model.The developed methodologies during this work, enabling an improvement of knowledges and source apportionment, are tools directly usable by French Accredited Associations for Air Quality Monitoring, especially for the quantitative assessment of actions introduced to improve air quality as part of Atmospheric Protection Plans, for example the one in the Arve valley.

Im Rahmen der vorliegenden Arbeit wurden die Eigenschaften von atmosphärischen Aerosolpartikeln im tropischen Regenwald des Amazonasgebietes bestimmt. Dazu wurden die Daten einer fast einjährigen Lidarmesskampagne ausgewertet und diskutiert. Die Messungen wurden mit einem automatischen Mehrwellenlängen-Polarisations-Raman-Lidar im zentralen Amazonasbecken nahe Manaus, Brasilien, im Zeitraum von Januar bis November 2008 durchgeführt. Somit konnten erstmalig optische und mikrophysikalische Aerosoleigenschaften im Amazonasgebiet während der Regenzeit (ca. Dezember-Mai) und Trockenzeit (ca. Juni-November) höhenaufgelöst charakterisiert werden. Einleitend werden die meteorologischen Bedingungen im Amazonasgebiet erläutert und eine Literaturübersicht über Aerosolforschung in dieser Region gegeben. Das Messgerät sowie verschiedene Kalibrier- und Korrekturschemen, die zur Datenauswertung notwendig sind, werden vorgestellt. Auch Vergleiche mit anderen Messgeräten werden diskutiert. Diese zeigen, dass die aus den Lidarmessungen abgeleiteten Parameter von hoher Qualität sind. Anhand von Fallstudien werden mit Hilfe von Rückwärtstrajektorien und Satellitenmessungen typische Aerosolbedingungen am Messstandort diskutiert. Um die generellen Unterschiede zwischen Regen- und Trockenzeit zu quantifizieren, wird eine statistische Auswertung aller analysierten Lidarmessungen präsentiert. Die Analyse der Lidardaten zeigt, dass während der Regenzeit im Amazonasgebiet in ca. der Hälfte aller Fälle sehr saubere Bedingungen mit einer Aerosol Optischen Dicke (AOD) von weniger als 0.05 (bei 532 nm) vorherrschen können. Allerdings wurde in ca. 30% aller analysierten Fälle im Zeitraum von Januar bis Mai auch afrikanisches Aerosol, vornehmlich Saharastaub und Biomasseverbrennungsaerosol (BBA), am Messstandort detektiert. Dabei dominierte meist BBA die Aerosolpopulation, wie die Depolarisationsmessungen zeigten. In der Trockenzeit ist die Atmosphäre im Amazonasbecken hauptsächlich mit BBA aus Südamerika belastet. Daher ist die AOD im Durchschnitt um einen Faktor drei größ er als in der Regenzeit. BBA wurde zu dieser Jahreszeit regelmäßig bis zu einer Höhe von 4-6 km detektiert. Basierend auf den vorgestellten Langzeitmessungen werden erstmalig die optischen Eigenschaften von südamerikanischem BBA statistisch analysiert und diskutiert. / Continuous lidar measurements were performed in the Amazon rain forest for almost one year in 2008. The results of the automated multiwavelength-Raman-polarization lidar observations were presented in this dissertation. These measurements are the first long-term observations of the vertical aerosol structure ever made in the Amazon Basin. The advanced lidar observations were conducted 60 km north of Manaus in the central northern part of Amazonia. The area is widely covered with pristine rain forest. A HYSPLIT backward-trajectory analysis showed that the observations were representative on a regional scale for the central northern part of the Amazon rain forest. The general weather conditions in this region are characterized by a wet (December-June) and a dry season (July-November). During the dry season, a high fire activity occurs in Amazonia, which heavily influences the atmospheric conditions. With the lidar instrument, vertical profiles of the particle backscatter coefficient at 355, 532, and 1064 nm, of the particle extinction coefficient at 355 and 532 nm, and of the particle linear depolarization ratio at 355 nm can be determined. The results from the long-term lidar observations performed in Brazil contain a lot of new information about the aerosol conditions in the central northern Amazon Basin and corroborate certain findings from former aerosol measurements in Amazonia. It was shown for the first time that advection of Saharan dust together with biomass burning aerosol (BBA) from Africa occurred regularly throughout the wet season. In about one third (32%) of all lidar observations during the wet season, African aerosol was dominating the optical aerosol properties in Amazonia. The analysis of the vertical aerosol structure during such events revealed that the African aerosol arriving in the central northern Amazon Basin was usually trapped in the lowermost 3-3.5 km of the troposphere. To quantify the amount of Saharan dust and African smoke transported towards the lidar site, the dust contribution to the measured optical aerosol properties was separated by means of the measured particle depolarization ratio. This study led to the result that in about one half of the cases with African aerosol advection, smoke particles contributed to more than 50% to the total Aerosol Optical Depth (AOD). The smoke transport from Africa towards Amazonia occurred predominantly between January and April when the fire activity in Central Africa was highest. BBA is thus a major constituent of the aerosol plumes that are regularly transported from Africa towards Amazonia. This is a key finding of the presented study. During clean conditions, an AOD (532 nm) of less than 0.05 was observed and the aerosol was trapped in the lowermost 2 km of the troposphere. However, the analysis of the long-term data set revealed that these clean atmospheric conditions occurred in only 48% of all wet-season cases. One example for such background conditions was intensively discussed and it was shown that a major meso-scale rain event occurred in the Amazon region at the same time. This precipitation event was possibly partly responsible for the very low aerosol load. Two case studies from the dry season were presented for which BBA dominated the optical properties. In the first case, a comparable high aerosol load (AOD of 0.41) prevailed while in the second one, a medium aerosol load (AOD of 0.15) was observed. Aged BBA advected from regions south of the lidar site were identified to be the dominant aerosol species for both cases. However, very different geometrical, optical and microphysical properties of BBA (e.g., vertical layering, lidar ratio, Ångström exponent, effective radius, SSA) were observed on both days. In the first case, aerosol was present up to about 4.5 km. Extinction-related Ångström exponent s of about 1 and lidar ratios between 70 and 90 sr were found at different heights for the smoke aerosol. The BBA was highly absorbing (SSA of 0.81) at heights of the highest RH (85%), whereas above under dry conditions (RH=50%) only moderate absorption (SSA of 0.93) was detected. In the second case, smoke was detected up to 4.5 km, and Ångström exponent of about 2 and lidar ratios of 45-55 sr were measured in the aerosol layers. The BBA was only moderately absorbing indicated by SSA values between 0.92 and 0.94. The reason for the differences in the smoke properties could be the shorter travel time to the lidar site (<24 h), different aging processes (e.g., cloud/rain processing), or different burning conditions. In both cases, no depolarizing effects of the BBA could be observed. The strong contrast between the aerosol conditions in the dry season and the wet season were confirmed by the statistical analysis of all lidar observations in 2008. Due to the high BBA concentration in the atmosphere, the mean AOD of the dry season was found to be a factor of 3 higher than the mean AOD of the wet season (0.26 compared to 0.08 at 532 nm). Maximum AOD values were less than 0.55 (at 532 nm) and hence show that the lidar location was not in the direct vicinity of fire events. In only 7% of all cases in the dry season 2008, an AOD below 0.1 was observed. Also the maximum extinction and backscatter coefficient values in the dry season 2008 were 2-3 times higher than during the wet season of this year. The vertical aerosol distributions differ also significantly between the two seasons. In the wet season, the aerosol was mostly trapped in the lowermost 2.5 km, while in the dry season aerosol typically reached up to 4.5 km. Aerosol was occasionally detected up to 6.14 km in the dry season. The majority of the aerosol (95% of the AOD), however, was found to be on average below 2.3 km in the wet season and below 3 km in the dry season. During the wet season, lofted aerosol layers and multiple aerosol stratification was less frequent than in the dry season. The extent of BBA plumes during the dry season showed no correlation to the ML top height. Virtually uniform smoke haze layers were observed up to the AL top. Thus, pyro-convection and/or cloud-related mixing seem to be the major processes for the vertical distribution of BBA.

<p dir="ltr">Atmospheric organic aerosols (OA) have diverse compositions and undergo complex reactions and transformations within the atmosphere, leading to profound impacts on air quality, climate, and atmospheric chemistry. In particular, these aerosols play an important role in Earth's effective radiative forcing (ERF) through interactions with solar radiation, absorbing and scattering sunlight and terrestrial radiation. These interactions result in a warming and cooling effect on the climate, respectively. This dissertation seeks to unravel the intricate molecular characteristics of atmospheric OA, focusing specifically on its light-absorbing components, known as ‘Brown Carbon’ (BrC), and aims to comprehend its dynamic interplay within the atmosphere. The research employs state-of-the-art multi-modal mass spectrometry techniques to investigate atmospheric OA derived from the combustion of fossil fuels and biomass burning. Through a combination of controlled laboratory experiments and real-world sample analyses, these works provide molecular-level insights crucial for source apportionment and predictive modeling of OA fate. Chapter 2 details the instrumentation and data analysis methods, laying a robust foundation for subsequent chapters.</p><p dir="ltr">Chapter 3 delves into the investigation of smoldering-phase biomass burning organic aerosols (BBOA) and introduces an innovative fractionation method for high-level molecular characterization, targeted to streamline source apportionment of BBOA. This chapter also presents an extensive assessment of particle-to-gas partitioning of BBOA, providing valuable information for modeling atmospheric lifetimes and fate. In Chapter 4, a comparative analysis of BBOA from wild and agricultural fires is conducted, employing advanced molecular characterization techniques. Chapter 5 showcases the synergistic use of multi-modal mass spectrometry techniques to probe the chemical evolution of individual BBOA components. Finally, Chapter 6 examines the molecular analysis of secondary OA (SOA) generated from the photooxidation of a fossil-fuel proxy.</p><p dir="ltr">The comprehensive molecular-level studies presented contribute essential insights for climate modeling, aiding in resolving uncertainties associated with OA's impact on global ERF. The research not only challenges existing analytical methods but also introduces novel approaches for obtaining relevant information about atmospheric OA components. Overall, this work advances our understanding of the intricate dynamics of atmospheric aerosols, facilitating more accurate climate predictions and addressing uncertainties surrounding their net radiative impact.</p>