Dissertations / Theses on the topic 'Pollution de l'air – effets indésirables'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 31 dissertations / theses for your research on the topic 'Pollution de l'air – effets indésirables.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
Barbier, Emeline. "Étude des mécanismes physiopathologiques impliqués dans la toxicité des particules ultrafines chez un modèle murin : une approche multi-organes." Electronic Thesis or Diss., Université de Lille (2022-....), 2023. http://www.theses.fr/2023ULILS063.
Full textAlthough there has been a significant reduction in air pollution since the 1990s, it remains a major public health problem, responsible for over 4.2 million premature deaths worldwide every year. At present, experts' attention is focused on ultrafine particles (PM0.1 or UFP) because of their ability to translocate into the systemic circulation and reach peripheral organs, where they are likely to have a harmful impact. Nevertheless, the knowledge of the cellular and molecular mechanisms involved in the toxicity of these particles is still very patchy, and most often remains focused on their main target, the lung. Thus, the main objectives of this thesis project were to provide innovative insights into the toxicokinetics (i.e., distribution/persistence) and toxicodynamics (i.e., pathophysiological mechanisms, associated cell signaling pathways) of UFP collected in urban environments, on the one hand, and the organospecific effects of UFP and the use of circulating miRNA as indicators of chronic and/or cumulative exposure to UFP in a mouse model, on the other hand. To answer these questions, Balb/cJRj mice were exposed for 3 months to various doses of UFP collected in the urban area of Lille, then analyzed in various target organs richly vascularized, and therefore directly exposed to UFP during their translocation and systemic distribution phase. The results showed that, in all target organs, the intrinsic oxidative potential of UFP undeniably induced the production of oxidative oxygen species and the activation of antioxidant defenses in sufficient quantities to restore a state of redox homeostasis, but were unable to prevent the onset of an inflammatory response in the lungs, heart and brain. Transcriptomic approaches carried out in the lungs, the target organ with the most marked deleterious effects, have suggested the deregulation of numerous signaling pathways in relation to oxidative and inflammatory responses, which constitute the central mechanisms of UFP toxicity, but also with more original toxicity mechanisms such as mitochondrial dysfunction, epithelial-mesenchymal transition and tissue remodeling, whose modulation has also been validated from a functional point of view. These promising data could ultimately contribute to better decision-making on the reduction of UFP emissions, as well as to the updating of current regulatory standards
Ben, Romdhane Safa. "Effets du climat et de la pollution de l'air sur la santé respiratoire à Tunis." Thesis, Sorbonne Paris Cité, 2017. http://www.theses.fr/2017USPCC027/document.
Full textThe Greater metropolitan area of Tunis, often referred to as Grand Tunis or Tunis, presents a vulnerability to air pollution due to the high concentrations of population and the infrastructures characterizing its territory. Ozone (O3) and particles (PM10) often exceed the Tunisian thresholds for these pollutants. As for the international standards set by the WHO (world health organization), they have not been met infrequently.The respiratory tract is a preferred route of exposure to aggressions related to the environment. Many lung diseases are directly linked to inhalation of pollutants in the atmosphere. The influences of climate mechanisms on respiratory health are also very extensive, including extreme weather events, also called weather paroxysms.The main objective of this thesis was to characterize the impact of environmental factors, climate and atmospheric pollutants on respiratory health in Grand Tunis. We have chosen to quantify this relationship from the biometeorological indicators and absolute thresholds of meteorological stress, specific Tunisian climate, and air quality to predict episodes at risk for respiratory health and thresholds of weather variables and air quality resulting in excess hospital admissions for respiratory causes. And this from the climate extremes of the parameters affecting the respiratory health : temperature, relative humidity and maximum wind speed. We, too, set realistic standards for air quality, relative to O3 and PM10, identifying critical thresholds excess hospitalizations in Grand Tunis and can be applied throughout the country. Given the effect of some climatic parameters on the dispersion of pollutants in the atmosphere, we also studied the relationship between climatic parameters and pollutants of O3 and PM10. The results of this study reveal that, throughout the year, Tunisians are confronted with at least an environmental risk : photochemical pollution and heat waves, which are very responsive during the hot season ; during the cold season, it is the risk of cold and particulate pollution; and during the off-season, biological pollution, together with pollen, is more at risk. However, short-term exposure to these risks, the worsening of the respiratory illness or irritation of the respiratory system is real. This study showed that the development and worsening of respiratory diseases appear to result from a complex interplay of individual and environmental factors. They are mainly in relation to time, air quality and atopy. The importance of these factors varies the respective disease. Moreover, the low socioeconomic status of the family increases the likelihood of being exposed to more of these risk factors. Added to this are behavioral factors such as alcohol, active and passive smoking
Ndong, Awa. "Pollution de l'air extérieur et intérieur à Dakar (Sénégal) : caractérisation de la pollution, impact toxicologique et évaluation épidémiologique des effets sanitaires." Thesis, Littoral, 2019. http://www.theses.fr/2019DUNK0510/document.
Full textAir pollution is nowadays a major societal challenge, as much for its harmful consequences on human health as on the environment. The general objective of this work was to determine the level of Dakar air pollution, outdoor and indoor, and to assess its health impact in the urban population. Fine particles (PM₂.₅) and a coarser fraction (PM>₂.₅) sampled at an urban site in Dakar (HLM), characterized by high road traffic emissions, were compared with particles sampled at a rural area, Toubab Dialaw located about 40 km from Dakar. The physicochemical characteristics of samples revealed that PMs differ for their physical (surface area) and chemical properties (in terms of CHN, metals, ions, paraffins, VOCs and PAHs) that were 65 to 75 % higher in urban samples. In accordance with the different sources and different physical and chemical properties, the inflammatory response (TNF-α, IL-1β, IL-6, IL-8) and the oxidative damage (total carbonylated proteins and 8-OHdG) were found higher in bronchial BEAS-2B cells exposed to urban PMs. The air quality measurement campaign showed that the bus interior was more polluted with PM₁₀, CO, CO₂ and NO than the market and the urban and rural indoor sites. The comparison of air quality between indoor and outdoor sites revealed that, particularly in urban areas, indoor air quality may be worse than the corresponding outdoor one. Monitoring individual exposure to pollutants showed that housewives in urban and rural sites were more exposed than professionals to air pollution, confirming previous observations of potential higher individual exposure level to pollutants in indoor environment. However, exposure level of traders and bus drivers that would result from the exhaust of traffic with often old, poorly maintained and uncontrolled vehicles has to be taken into consideration due the higher levels of gaseous pollutants here reported
Reyes, Perez Eneida. "Chimie multiphasique des pesticides dans l'air : distribution et photoréactivité." Strasbourg, 2009. http://www.theses.fr/2009STRA6048.
Full textThis thesis focuses on the environmental fate of pesticides, particularly in the atmosphere. We are interested on their partitioning between the different phases of the atmosphere and their photolysis in the environment. The partitioning between aqueous and gaseous phases in the atmosphere depends on the Henry’s law constant (H) while the partitioning between atmospheric particulate and gaseous phases is related to their vapor pressure. Henry’s law constants of two widely used herbicides, namely EPTC and trifluralin, were determined as a function of temperature (278 – 293 K) using a device based on a dynamic air/water equilibrium. The obtained results are the first experimental temperature dependence of H for trifluralin and the second one for EPTC. The measurements performed between 278 and 293 K have been used to determine the Van't Hoff expressions of H for both compounds and the corresponding enthalpies of solvation. Our data obtained at 283 K have also helped to calculate that only 0. 3% of gaseous EPTC and 0. 8% of gaseous trifluralin could be scavenged by clouds droplets, which can be considered as negligible. Thus, EPTC and trifluralin are almost exclusively present in the gas phase where degradation takes place through photochemical reactions [. . . ]
Morelli, Xavier. "Pollution de l'air, santé et défaveur sociale en zone urbaine." Thesis, Université Grenoble Alpes (ComUE), 2016. http://www.theses.fr/2016GREAS015/document.
Full textIn urban areas, atmospheric pollution represents a major threat to human health. The accurate characterization of this threat relies centrally on the quality of exposure assessment. It also requires assessment of other factors sharing the same sources and also possibly impacting health, such as noise. Fine-scale exposure assessment of air pollution levels may allow identifying spatial contrasts. Such spatial variations may lead to social differences in the distribution of the health impact of these pollutants.The general aims of the PhD were: 1. To study the possibility to model ultrafine particles distribution in urban areas and assess the correlation of ultrafine particles levels with road traffic noise; 2. To assess the risk incurred by air pollution exposure with a fine-scale modelling approach and investigate the potential socio-economic disparities in health burden induced by particulate matter; 3. To investigate the health benefits expected from hypothetical scenarios of reduction of air pollution levels at the urban scale.The first aim relies on Tri-tabs project, conducted in three European cities (Basel, Girona, Grenoble). Measurements during 20 minutes of outdoor noise and traffic, but not of UFP, were strongly reproducible over durations of a couple of days or months. In these areas, on the short-term, noise levels and UFP concentrations exhibited relatively moderate correlations, which may allow adjustment for mutual confounding in epidemiological studies, thus allowing to disentangle their possible short-term health effects.The second aim introduces health effects, and focuses on the longer term. Risk assessment studies often ignore within-city spatial variations of air pollutants. In Grenoble and Lyon areas (0.4 and 1.2 million inhabitants, respectively) in 2012, PM2.5 exposure was estimated on a 10×10 m grid by coupling a dispersion model to fine-scale data on population density. Outcomes were mortality, lung cancer and term low birth weight incidences. The numbers of cases attributable to air pollution were estimated overall and stratifying areas according to the European Deprivation Index, a measure of social deprivation. Estimations were repeated assuming spatial homogeneity of air pollutants within city. The proportion of cases attributable to air pollution was in the 3-8% range for mortality and 9–43% range for term low birth weight. In Grenoble, 6.8% (95% CI: 3.1–10.1%) of incident lung cancer cases were attributable to air pollution. The impact was underestimated by 8 to 20% when background monitoring stations were used to assess exposure, compared to fine-scale dispersion modeling. Health impact was highest in neighborhoods with intermediate to higher social deprivation.Several countries across Europe have implemented air pollution regulation policies, or low emission zones, France being an exception. We estimated the health impact of air pollution under different scenarios of reduction of fine particulate matter concentrations. Scenarios targeting a reduction in the PM2.5 annual averages by 5% led to a 10% decrease of the health burden, while actions aiming at only reducing the exposure of the population exposed above the 90th percentile did not yield a significant reduction of the health burden (around 1%).In conclusion, we have shown that short-term measurements cannot be used to model ultrafine particles levels in urban areas; we were among the first to rely on a fine-scale exposure model for estimating the health impact of air pollution, and quantify its impact on term low birth weight. Our estimations showed that background air quality monitoring stations used classically in France for health impact assessment studies tend to underestimate exposure, compared to a spatially-resolved dispersion model. We have provided an estimate of the air pollution decrease required to obtain a significant reduction of the health impact of air pollutants in urban areas
Dappe, Vincent. "Impact de la pollution de l'air en milieu industriel sur l'accumulation et le transfert foliaire des métaux dans les végétaux." Thesis, Lille 1, 2015. http://www.theses.fr/2015LIL10174/document.
Full textIndustrial activities such as production and recycling of ferrous and non-ferrous metals can emit in the atmosphere large quantities of metal(loid)s-rich particles (As, Cd, Fe, Pb, Sb, Zn …) which may have an impact on the environment and human health. Especially when these industries are located near urban areas, particles can contaminate soils and plants when they fallout, thus inducing a health risk for the population. Contamination of vegetables by metals is a topic of concern for public authorities and the scientific community. Studying the accumulation and transfer of metal(loid)s in food webs is therefore of major importance to assess health risks. The plant contamination by the soil-plant transfer has led to numerous studies and the contamination of vegetables by foliar pathway can't be ignored, as shown by recent work. The study of accumulation and transfer of metals (metalloids) has been carried out in situ and under controlled conditions for various consumable plants with different morphological characteristics (lettuce, ryegrass and cabbage). The accumulation and transfer of metals and their phytotoxicity, characterized by microscopy and spectrometric techniques (SEM-EDX, Raman, EXAFS/XANES, LA-ICP-MS, EPR…) and biological tests (photosynthetic activity, genotoxicity, gene expression), have been discussed in terms of metals concentration, metals location and speciation on/into leaves and exposure time
Duché, Sarah. "La pollution de l'air en région parisienne : exposition et perception sur les sites touristiques." Phd thesis, Université Paris-Diderot - Paris VII, 2013. http://tel.archives-ouvertes.fr/tel-00840818.
Full textJacob, Florence. "Génération contrôlée et détermination de l'impact toxicologique des aérosols organiques secondaires." Electronic Thesis or Diss., Université de Lille (2022-....), 2023. http://www.theses.fr/2023ULILS078.
Full textChronic exposure to atmospheric particles with a diameter less than 2.5 μm (PM2.5) at concentrations exceeding the levels recommended by the World Health Organization is responsible for the onset and/or exacerbation of respiratory, cardiovascular, neurological, and even cancer-related diseases. Regulatory threshold values have been defined regarding the ambient mass concentration of PM2.5, but these values do not take into account the impact of variations in the chemical composition of particles on induced biological effects. Special attention has been given in the literature to certain recognized harmful compounds such as metals and polycyclic aromatic hydrocarbons, some of which have been regulated. Nevertheless, other compounds are still poorly studied to date, even though they could also play an important role in particulate toxicity. This includes secondary organic aerosols (SOA), which constitute a major chemical fraction of PM2.5 and can represent up to 90% of their organic matter mass. They are formed through the reaction/oxidation/condensation of volatile organic compounds (VOCs) in the atmosphere. A rise in ambient SOA concentration is expected in the future due to the simultaneous increase in VOC precursor emissions and the oxidizing capacity of the atmosphere related to climate change. In this context, the present project first consisted in generating model SOA resulting from the oxidation of two VOCs that are widely present in the atmosphere, one of biogenic origin, limonene, and the other of anthropogenic origin, m-xylene. Limonene ozonolysis and m-xylene photooxidation were respectively carried out in a flow reactor and a simulation chamber. Two types of oxidations were tested for biogenic SOA synthesis: one with low ozone concentration and the other with high ozone concentration. The particulate phases were then characterized in terms of size (few hundred nm), mass, and chemical composition (hydroxyl, carbonyl, carboxylic acid functions, oligomers for limonene; nitrophenols, dimers for xylene). In a second step, the intrinsic oxidative potential (OP) of the generated biogenic and anthropogenic SOA was evaluated, as well as their toxicological impact in terms of oxidative stress and inflammatory effects on a model of immortalized human bronchial epithelial cells (BEAS-2B). The results obtained showed that among the biogenic SOA, those produced with low ozone concentration exhibit a more pronounced OP and antioxidant response. Furthermore, our results also indicate that, compared to these biogenic SOA, SOA resulting from m-xylene photooxidation have a higher OP and display greater cytotoxicity and activation of antioxidant defenses. In addition, oxidative damage to proteins and DNA was also detected in cells exposed to these SOA. Overall, the results from this project contribute to improving our knowledge on the chemical composition of SOA particulate phase and provide new insights into the mechanisms involved in their pulmonary toxicity
Borgie, Mireille. "Étude des particules fines et ultrafines en suspension dans l'air au Liban : caractérisation physicochimique et évaluation des effets toxicologiques sur des cellules pulmonaires humaines BEAS-2B." Thesis, Littoral, 2014. http://www.theses.fr/2014DUNK0366/document.
Full textThe objectives of this study, one of the first conducted in Lebanon, were to acquire a better knowledge on the physico-chemical characteristics of atmospheric fine particles (FP or PM₂.₅₋₀.₃) and ultrafine ones (UFP or PM₀.₃), and to assess their potential toxicity. Particles were collected at two coastal sites between may and sept. 2011 at Sin El-Fil (urban site in Greater Beirut), and between sept. and oct. 2011 at Bejje (rural site). After sampling, FP and UFP were subjected to a physico-chemical characterization by quantifying their inorganic ions and elements, total carbon and organic compounds contents. Then, composite samples of FP and UFP were prepared in order to expose bronchial epithelial cells (BEAS-2B) in culture, and therefore to assess the underlying toxic mechanisms. Our results showed an influence of combustion sources especially for urban particles that are richer in total carbon, organic compounds, metals and secondary inorganic ions than rural ones. On the other hand, a more pronounced cytotoxicity was caused by UFP when compared to FP. In addition, epigenetic modifications and genotoxicity mechanisms, such as metabolic activation of organic compounds, changes in three microRNAs expression, telomerase activation and DNA breaks induction, which are potentially involved in the initiation and promotion of carcinogenesis, were induced by the two samples of FP, with a more pronounced effect of urban particles. Exposure of BEAS-2B cells to collected FP, especially urban ones, may therefore induce the transformation of lung cells to immortal cells, and consequently the initiation or the promotion of broncho-pulmonary carcinogenesis
Almarj, Elie. "Effets de la pollution atmosphérique sur la santé : développement de protocoles innovants de simulation d'atmosphères urbaines et d'exposition de modèles précliniques." Electronic Thesis or Diss., Université Paris Cité, 2023. https://wo.app.u-paris.fr/cgi-bin/WebObjects/TheseWeb.woa/wa/show?t=6223&f=54454.
Full textThe World Health Organization estimates that exposure to atmospheric pollution causes more than 4 million premature deaths annually worldwide. Atmospheric pollution is therefore a major health risk. However, the assessment of the health effects of atmospheric pollution has shortcomings. Indeed, epidemiological and experimental studies only take into account regulated atmospheric pollutants without considering the synergy that may exist between them, whereas atmospheric pollution is a multiphasic mixture of gaseous and particulate compounds interacting with each other and with environmental parameters. Moreover, the concentrations studied are rarely within realistic ranges. The objective of this work is to implement an innovative platform to study the effects of atmospheric pollution on health. To do this, mice were exposed to atmospheric situations representative of real atmospheres and episodes of urban air pollution, simulated in the laboratory. These simulated atmospheres were then qualified. We have thus succeeded in reproducing multiphasic urban atmospheres, by simulating their gaseous and particulate phases in the laboratory. The formation of secondary organic aerosols and functionalized volatile organic compounds confirm the quality of our simulations (proxy of real urban atmospheres), by highlighting the oxidation of organic matter. The results of the biological analyses on the exposed mice have highlighted the relevance of the platform for studying the effects of atmospheric pollution on health
Signoret, Jonathan. "Etude de la qualité de l'air en Lorraine-Nord par les lichens : contribution en tant que bioindicateurs écologiques, bioaccumulateurs d'éléments chimiques et biomarqueurs du stress oxydant." Metz, 2002. http://docnum.univ-lorraine.fr/public/UPV-M/Theses/2002/Signoret.Jonathan.SMZ0213.pdf.
Full textFaburé, Juliette. "Etude de l'accumulation et des effets des composés organiques volatils (BTEX) chez les bryophytes." Lille 2, 2009. http://www.theses.fr/2009LIL2S050.
Full textGoger, Thierry. "Unindicateur d'impact environnemental global des polluants atmosphériques émis par les transports." Lyon, INSA, 2006. http://theses.insa-lyon.fr/publication/2006ISAL0099/these.pdf.
Full textWe intend to build a global environmental impact indicator of air pollution to assess transport infrastructures, technologies or flows. This indicator tries to be simple and transparent to facilitate its use in decision-making. The intention is for the indicator to be like the Global Warming Potential (GWP), which establishes a relationship between the emission of six greenhouse gases and the average temperature increase of the Earth. The indicator therefore allows estimating the global environmental impact of transport-generated air pollution, while simultaneously conserving the value of the environmental impact of each type of air pollution and the emission assessment. This work is based on an environmental impact typology, a set of indicators, and aggregation architecture of atmospheric pollution. The typology is established as a function of the specific and homogenous characteristics of each type of pollution in terms of pollutants, impact mechanisms, targets and environmental impacts. To ensure exhaustiveness and non-redundancy, 10 types of air pollution impact are proposed: greenhouse effect, ozone depletion, direct ecotoxicity (this type of pollution excludes greenhouse effects on nature, ozone depletion, eutrophication, acidification and photochemical pollution), eutrophication, acidification, photochemical pollution, restricted direct health effects (not taking into account welfare, and excluding the effects on health of the greenhouse effect, ozone depletion, acidification and photochemical pollution), sensitive pollution (annoyance caused by odours and fumes), and degradation of common and historical man-made heritage. Indicators similar to GWP can be identified in the literature for each type of atmospheric pollution, except for the degradation of common and historical man-made heritage, for which none indicator have been suggested. However, these indicators do not seem to have achieved wide scientific consensus, except for GWP, which may make it necessary to continue research in this field. Aggregating the different indicators is proposed by using an architecture composed of two structures that aggregate types of air pollution. One is based on the target affected, whereas the second has three dimensions, i. E. Targets, space and time. This architecture allows also the indicator’s users to establish a hierarchy of concerns for each type of atmospheric pollution. The indicator makes thus it possible to give a global value to impact of air pollutants, taking into account scientific assessment and social perception
Michelot, Nicolas. "L'influence des topoclimats sur la pollution de l'air aux particules dans le sud-ouest des Alpes-Maritimes." Phd thesis, Université Nice Sophia Antipolis, 2014. http://tel.archives-ouvertes.fr/tel-00959704.
Full textIsmert, Muriel. "Les enzymes de biotransformation des xénobiotiques chez Helix aspersa (escargot) et Pleurozium schreberi (mousse) : biomarqueurs potentiels de la pollution atmosphérique par des hydrocarbures aromatiques polycycliques." Metz, 2000. http://docnum.univ-lorraine.fr/public/UPV-M/Theses/2000/Ismert.Muriel.SMZ0049.pdf.
Full textDendene, Marie-Aude. "Exposition au monoxyde de carbone et aux hydrocarbures aromatiques monocycliques : étude comparative des divers modes de déplacement urbain et recherche de biomarqueurs de l'air expiré." Paris 5, 1995. http://www.theses.fr/1995PA05P016.
Full textRinaldo, Mickaël. "Particules ultra-fines et santé : caractérisation des particules ultra-fines dans l'air et dans les tissus humains." Thesis, Bordeaux, 2015. http://www.theses.fr/2015BORD0449/document.
Full textEpidemiologic studies on the health effects of ultrafine particles from atmospheric pollution and in vitro or in vivo studies on manufactured nanoparticles toxicity suggest that potential hazards may result from new physico-chemical properties of materials at nanometric scale. To assess human health risk after occupational or environmental exposure or to demonstrate a causal relationship between such exposures and diseases may be hindered by the lack of reference method to characterize and quantify nanometric particles in biological tissues and fluids. This work allowed us to develop such a method based on samples preparation by alkaline digestion and microfiltration followed by analytical electron microscopy analysis. This method applied in two studies allowed us to confirm that pleural translocation of nanometric particles and accumulation in black spots were possible in human and that they also may pass through the placental barrier with potential fetal exposure. This work also allowed us to characterize some sources of occupational and environmental exposures. After time-cost optimization of this method, it could be used to define reference values on larger population-representative samples or used for the medical follow-up of exposed workers
Zabrocki, Léo. "Improving the Design of Studies on the Acute Health Effects of Air Pollution." Thesis, Paris, EHESS, 2022. http://www.theses.fr/2022EHES0041.
Full textThe goal of this thesis is to improve the design of observational studies on the acute health effects of air pollution.In the first chapter jointly written with Anna Alari and Tarik Benmarhnia, we advocate using matching procedures to enhance the design stage of studies exploiting changes in wind directions as instrumental variables. We show that observed confounders are imbalanced across wind directions and that the common support of the data is small. An outcome regression analysis might therefore suffer from interpolation and extrapolation biases. Using a sensitivity analysis, we also provide quantitative evidence that the estimated effects of wind directions on air pollutant concentrations seem robust to the presence of hidden bias. Our approach could be relevant for similar strategies based on binary instruments such as thermal inversions or public transport strikes.In the second chapter co-authored with Marion Leroutier and Marie-Abèle Bind, we study the impact of cruise traffic on air pollution in Marseille. With a pair-matching algorithm designed for time series data, we create hypothetical randomized experiments and estimate the change in air pollution caused by a short-term increase in cruise traffic. We also rely on randomization-inference—a mode of inference which is not based on large-sample approximation and is distribution-free—to compute confidence intervals. We find that cruise vessels’ arrivals increase city-level concentrations of nitrogen dioxide and particulate matter. Our results suggest that well-designed hypothetical randomized experiments provide a principled approach to better understand the negative externalities of maritime traffic.In the third chapter, Vincent Bagilet and I explain that the combination of publication bias for statistically significant results and low statistical power could lead to inflated estimates on the short-term health effects of air pollution. We first gather a unique corpus of estimates and standard errors of all available articles found in the standard epidemiology and economics literatures. Using statistical power calculations, we show that at least half of the literature could have a power below 80% and produce estimates that are two times too large. We then run simulations based on real data to identify which parameters of research designs affect statistical power. We find that the number of exogenous shocks and cases of a health outcome are key drivers of power. These results matter since many studies exploit rare exogenous shocks and focus on subgroups such as children and the elderly. At the end of the paper, we provide several recommendations to take into account this highly important but overlooked issue.The fourth chapter is an extension and generalization of the third chapter. To avoid confounding, quasi-experimental studies focus on specific sources of treatment variation. This could lead to a reduction in statistical power. Yet, published estimates can overestimate true effects sizes when power is low. Using fake data simulations, Vincent Bagilet and I show that for all causal inference methods, there could be a trade-off between confounding and exaggerating true effect sizes due to a loss in power. We discuss how power calculations and sensitivity analysis could help take this trade-off into account
Giovannelli, Jonathan. "Description et déterminants de la santé respiratoire et cardiovasculaire dans deux communautés urbaines du Nord-Pas-de-Calais : l’enquête ELISABET 2011-2013." Thesis, Lille 2, 2015. http://www.theses.fr/2015LIL2S053/document.
Full textIntroduction. The general goal of the ELISABET (Enquête Littoral Souffle Air Biologie Environnement) survey is to study the respiratory and cardiovascular health in two urban areas in northern France (Lille and Dunkirk). The specific objectives of this thesis are to study: (i) the prevalence and underdiagnosis of airway obstruction (AO), (ii) long-term time trends in the prevalence of cardiovascular risk factors between 1986 and 2013 in the Lille urban area, (iii) the relationships between both the fractional exhaled nitric oxide (FENO) and the blood eosinophil count (B-eos) on one hand and asthma and atopy on the other, according to smoking status, (iv) whether low-grade systemic inflammation (as measured by the level of high sensitivity-C-reactive protein, hs-CRP) mediated the relationship between diabetes and lung function, and (v) the short-term impact of atmospheric pollution on lung function.Methods. The 3276 participants (aged from 40 to 64) in the 2011-2013 ELISABET cross-sectional survey were selected from electoral rolls by random sampling, and recruited between January 2011 and November 2013. A detailed questionnaire, lung function tests, and a blood sample collection were performed. (i) AO was defined by a forced expiratory volume in the first second (FEV1) to forced vital capacity (FVC) ratio below 0.70 or below the lower limit of normal calculated by the most recent reference equations of the Global Lung Initiative. (ii) The prevalence of the main cardiovascular risk factors was estimated from representative samples inhabitants of Lille urban area from MONICA1986-88, MONICA1995-96, MONALISA2005-07 and ELISABET2011-13 surveys. (iii) Allergic asthma was defined as asthma (a self-report of physician-diagnosed asthma, and wheezing in the previous 12 months or the use of asthma medications) with atopy. (iv) Diabetes mellitus was defined as ongoing diabetes treatment or a fasting blood glucose level ≥1.26 g/L or a hemoglobin A1c value ≥6.5%. A mediation analysis was performed to assess and quantify the hs-CRP level as a mediator of the relationship between diabetes and lung function from a sample of participants without self-reported pulmonary and atherosclerotic disease. (v) Measurements of particles less than 10 mm in diameter (PM10) and nitrogen dioxide (NO2) were provided by measuring stations ATMO in the two urban areas.Main results. (i) The prevalence of AO in northern France ranged from 9.5 to 16.0%, depending on the centre and definition used; the underdiagnosis rate was high (around 75%). (ii) A steady decline in the prevalence of cardiovascular risk factors over a 25-year period was observed, with the exception of tobacco use in women, prevalence of diabetes in men (both of which remained stable) and prevalence of overweight in men (which increased). (iii) A positive interaction between smoking status and allergic asthma was observed in multivariate models explaining FENO (p=0.003) and B-eos (p=0.001). Thus, compared to those without allergic asthma, participants with allergic asthma had higher FENO values (+63.4%, 95%CI=[39; 92]) and higher B-eos (+63.2% [38.2; 92.7]) in never and former smokers, but not in current smokers. (iv) Diabetes was associated with FEV1 (-3.5% [-5.8; -1.3]) and FVC (-3.6% [-5.9; -1.3]). Strength of both latter associations fell to -3.1% [-5.4; -0.9] after adjustment for hs-CRP. Hence, the proportion of the effect that is mediated by hs-CRP was 12% [2.4; 37] and 13% [3.7; 39.4] for FEV1 and FVC, respectively. (v) Measurements of PM10 and NO2 seemed to be associated with lower values of the expiratory flow at 25% of the FVC (preliminary result).Conclusion. Data from the ELISABET survey have allowed the study of the prevalence of AO and the main cardiovascular risk factors in our population. They also allowed obtaining original results from clinical and pathophysiological studies
Awan, Faraz Malik. "Towards synthetic sensing for smart cities : a machine/deep learning-based approach." Electronic Thesis or Diss., Institut polytechnique de Paris, 2022. http://www.theses.fr/2022IPPAS006.
Full textWe worked on one of the most significant research directions in Smart City, i.e., Intelligent Transportation System (ITS). ITS encapsulates several domains, such as electronic vehicles notification systems, traffic information, smart parking, and environment. However, in this thesis, we target two of its important domains; i) Smart Parking, and ii) Road Traffic. We started our research with Smart Parking use case. Performing literature review, we realized that different Machine Learning (ML) and Deep Learning (DL) approaches have been used for smart parking solutions. In most of these proposed approaches, enclosed parking areas were targeted with different feature sets to predict the "occupancy rate" in parking areas. It inspired us to conduct a comparative analysis to answer following questions; Given the parking prediction use case, how do the traditional ML models perform as compared to complex DL models? Provided big data, can less complex, traditional ML models outperform complex DL models? How well these models can perform to predict the availability of the individual on-street parking spots rather than predicting the overall occupancy rate of an enclosed parking area. To answer these questions, we choose five well-known classical ML algorithms (K-Nearest Neighbours, Random Forest, Decision Tree) and DL algorithm (Multilayer Perceptron). To take our investigation into depth, we train Ensemble Learning Model, in which we combine all the above-mentioned ML and DL models. A huge parking dataset of city of Santander, Spain, has been used which consists of around 25 million records. We also propose to recommend available parking spots based on the current location of the driver. Moving forward with our research goals, we performed literature review on road traffic and found road traffic associated with air pollution and noise pollution often. However, to the best of our knowledge, air pollution & noise pollution have never been use d in traffic prediction problem. In this part of our research, firstly we used air pollution (CO, NO, NO2, NOx, and O3) along with the atmospheric variables, such as wind speed, wind direction, temperature, and pressure to improve the traffic forecasting in the city of Madrid. This successful experiment motivated us to extend our investigation to another factor, which is also strongly correlated with road traffic i.e., noise pollution. Hence, as an extension of our previous work, in this part of our research, we use noise pollution to improve the traffic prediction in the city of Madrid
Mariet, Anne-Sophie. "Influence de l’exposition au bruit et à la pollution de l’air en milieu urbain sur la survenue de complications et d’issues défavorables de la grossesse." Thesis, Bourgogne Franche-Comté, 2020. https://nuxeo.u-bourgogne.fr/nuxeo/site/esupversions/b8bd098d-4e78-4f44-b87c-01a65906c7a1.
Full textPregnancy is a period of vulnerability where the occurrence of adverse pregnancy outcomes (APO) can have major consequences on the future of the mother and/or the newborn. Multiple factors are responsible for this. However, there is still an unexplained part of APO, for which the environment is suspected to play a role.This PhD thesis is included in the PreCEE (Pregnancy Combined Environmental Exposure) program and aimed to study the influence of environmental exposures to noise and air pollution on the occurrence of APO, more particularly on fetal growth disorders and hypertensive disorders of pregnancy (HDP). All pregnancies of adult women living in Besançon or in the urban unit of Dijon and who gave birth to the Besançon University Hospital or the Dijon-Burgundy University Hospital between 2005 and 2009 were included, i.e. more than 10,000 pregnancies. The socio-demographic, medical and medico-obstetrical characteristics were collected from computerized and paper obstetric records. The levels of exposure to noise and air pollution (nitrogen dioxide (NO2) and fine particles (PM10)) were modeled at the mother's home according to several spatial and temporal windows.Results show that noise exposure is not associated with the occurrence of HDP or fetal growth disorders in single pregnancies. Exposure to PM10 is associated with fetal growth disorders. This association is not changed by taking noise exposure into account. Finally, in multiple pregnancies, exposure to NO2 is associated with fetal growth disorders
Lemaire, Vincent. "Hiérarchisation des déterminants de la composition atmosphérique future en Europe." Thesis, Université Paris-Saclay (ComUE), 2017. http://www.theses.fr/2017SACLX091/document.
Full textThe atmospheric composition is mainly driven by the emission of primary pollutants and precursors and meteorology. Because of its sensitivity to unfavorable weather patterns, air pollution is expected to be sensitive to climate change. That is why the aim of this work is to estimate the effect of climate change over air pollution in Europe at the end of the century. To achieve this we rely on modeling which allow to cover such timescales. To reduce uncertainties and quantify the effect of climate change on air quality, ensemble approaches should be applied. However, the computing cost of such methods is substantial. To overcome this issue we developed a statistical method which does not require forcing a chemistry and transport model with a large ensemble of climate projections. The results obtained with this statistical method are in good agreement with full chemistry-transport models when considering long time periods. But we point out the limits of the method when focusing on extreme pollution events. The statistical model can be used to assess the uncertainty of using a comprehensive ensemble of climate forcing in terms of air quality impacts. The statistical approach can also help identifying a subset of climate forcing that should be explored in priority to drive chemistry-transport models.Such a subset of climate models is however only available at a degraded vertical resolution on existing databases such as EuroCordex. To quantify the error induced when using a meteorological variables only saved for a few vertical levels, a sensitivity study focused on the impact of the vertical resolution of the meteorological data has been perfomed. We emphasized that a minimum of 10 vertical levels and some specific variables were required to study the impact of climate change on air quality to keep the error lower than the climate change signal.Finally, we use the statistical method to compare the climate change effect and the future emissions reduction impact estimated also with a surrogate model. We exhibit that the magnitude of climate benefit for PM2.5 will be comparable to the emissions reductions of the dominant sector in each country studied. These emissions decreases will therefore be reinforced the climate change. On the opposite, for SOMO35, the climate penalty will jeopardize the emission reductions between 2010 and 2050. We also evaluate that climate change will become more important than the expected reduction emissions signal
Abraham, Émilie. "Associations entre les expositions environnementales et les issues de grossesse d’une part et la méthylation de l’ADN placentaire d’autre part." Thesis, Université Grenoble Alpes (ComUE), 2016. http://www.theses.fr/2016GREAS018/document.
Full textNowadays, air pollution and weather conditions represent a major public health issue. It is recognized that they may have serious consequences for health especially in the most sensitive populations such as pregnant women. More recent studies have suggested an effect of exposure to these environmental factors during the fetal period. Fetal life is a critical period for the healthy development of the child. Maternal exposure to environmental exposures during pregnancy could have serious consequences on pregnancy outcomes and short- and long- term health. Furthermore, the biological mechanisms that could explain the effect of environmental exposures on adverse pregnancy outcomes are largely unknown up to now. The objectives of the thesis were: 1) to study the association between maternal exposure to temperature and relative humidity during pregnancy and birth weight, gestational duration and preterm birth; 2) to study the association between maternal exposure to air pollutants and meteorological conditions during pregnancy and placental DNA methylation using A) an agnostic approach and B) a priori approach based on integration of biological knowledge. The first part of this work relied on data from two mother-child cohorts EDEN (Poitiers and Nancy, 2003-2006) and PELAGIE (Britain, 2002-2006) corresponding to 5185 mother-infant pairs analyzed; and the second part relied on a sample of the EDEN cohort for which methylation data were available (n = 668). Daily data of temperature and humidity were obtained from Météo-France and pollution data were obtained using a dispersion model. Their exposure was averaged over different periods during pregnancy. Central placenta samples were collected at delivery and DNA methylation was analyzed using Illumina 450K chip. For the first objective, linear regression models and Cox models were used. For the second objective, robust linear regression models, especially across the genome-wide, were used and correction methods for multiple testing such as Bonferroni and Benjamini-Hochberg were applied. Our results suggest a deleterious effect of temperature and relative humidity on birth weight and did not show an association between air pollution and pregnancy outcomes. Exposure to air pollutants (NO2 and PM10) during pregnancy was associated with a decrease in placental DNA methylation for ADORA2B and ADARB2 genes; the first gene is known to be potentially involved in preeclampsia and hypoxia of the pregnant woman and the second being potentially involved in metabolic disorders in adults such as abdominal circumference and BMI. The results of agnostic and a priori approaches were consistent for ADORA2B gene. We did not found association between weather conditions and placental DNA methylation. To our knowledge, we are the first to study the association between DNA methylation in the placental tissue and prenatal exposure to air pollutants and weather conditions using data from the entire epigenome. This work opens up new possible pathways regarding mechanisms of action of environmental pollutants and provides pointers as to the possible long-term effects of these exposures
Havard, Sabrina. "Contribution de la pollution atmosphérique aux inégalités socio-spatiales de santé : analyse écologique du risque d'infarctus du myocarde dans l'agglomération de Strasbourg." Phd thesis, Rennes 1, 2008. http://www.theses.fr/2008REN1B120.
Full textPfister, Hugo. "Caractérisation des expositions professionnelles des éleveurs laitiers bretons : déterminants professionnels de l’exposition à la fraction thoracique des bioaérosols, à l’ammoniac et à l’acétaldéhyde, et effets inflammatoires des poussières organiques." Thesis, Rennes 1, 2017. http://www.theses.fr/2017REN1B046/document.
Full textDairy farmers have an increased risk of lower airway diseases that is likely related to occupational exposures to airborne contaminants. Nevertheless, occupational determinants of dairy farmers’ exposures remain poorly documented and the biological effects of the contaminants chronically inhaled by farmers need to be fully characterized. In this context, the objectives of this PhD thesis were i) to identify the occupational determinants of exposure to thoracic bio-aerosols (organic dusts, endotoxins, bacteria and moulds), ammonia and acetaldehyde, and ii) to characterize the pro-inflammatory effects of thoracic dusts emitted during the mechanical spreading of straw bedding, a task well-known to generate inhalable dusts. To achieve these goals, we carried out a 112-repeated exposure measurement campaign on 29 dairy farms located in Britany. Using multivariate mixed-effect regression models, we have demonstrated that farmers’ exposures to bio-aerosols were mainly induced by tasks related to bedding material distribution and cow feeding (straw, hay, silage). Exposure levels to ammonia were highly dependent on cow numbers and times spent by the farmers in stable and milking parlour. Acetaldehyde exposure was modulated according to the farm size and times spent to distribute silage. Our work also highlighted that an increase of the area of wall opening significantly reduced exposure to mould, acetaldehyde and ammonia. Finally, our study showed that dusts emitted during mechanical straw spreading have (1) a size small enough to allow them to deposit in the tracheobronchial regions, (2) a complex bacterial and fungal composition, and (3) strong in vitro pro-inflammatory effects that induced TNF-α, IL-1β, IL-6 and IL-8 expression in human macrophages. In conclusion, these results have identified different dairy farm characteristics and occupational tasks that significantly increased the exposure levels to chemical contaminants and thoracic organic dusts. Statistical models built during this research project already allow reconstitution of dairy farmers’ exposure that may of use in future epidemiological studies and to develop new preventive measures
Havard, Sabrina. "Contribution de la Pollution Atmosphérique aux Inégalités Socio-Spatiales de Santé :Analyse Écologique du Risque d'Infarctus du Myocarde dans l'Agglomération de Strasbourg." Phd thesis, Université Rennes 1, 2008. http://tel.archives-ouvertes.fr/tel-00362785.
Full textCette étude a été conduite dans la Communauté Urbaine de Strasbourg (CUS, Bas-Rhin) à l'échelle du quartier de résidence (IRIS). Les infarctus du myocarde survenus parmi la population âgée de 35 à 74 ans entre le 1er janvier 2000 et le 31 décembre 2003 (n = 1193) ont été recueillis auprès du registre bas-rhinois des cardiopathies ischémiques. Les concentrations horaires de pollution atmosphérique (NO2, PM10, O3 et CO) ont été modélisées par IRIS à l'aide du modèle ADMS Urban. Le niveau socio-économique des IRIS a été estimé à l'aide d'un indice de défaveur construit par analyse en composantes principales à partir des données du recensement.
Nous avons tout d'abord cherché à évaluer le degré d'injustice environnementale qui prévalait sur notre zone d'étude afin de vérifier l'hypothèse d'un différentiel d'exposition à la pollution atmosphérique selon le niveau socio-économique des IRIS. Notre analyse de régression spatiale a démontré l'existence d'inégalités socio-économiques dans l'exposition à la pollution atmosphérique ; les quartiers de défaveur moyenne, localisés aux abords des principales infrastructures routières entourant le centre urbain, étaient les plus exposés à la pollution liée au trafic.
Nous nous sommes ensuite intéressés à examiner l'association entre le niveau socio-économique des IRIS et la survenue de l'infarctus du myocarde afin de vérifier l'hypothèse d'inégalités sociales de santé sur notre zone d'étude. Notre analyse bayésienne a montré l'existence de forts gradients socio-économiques du risque d'infarctus du myocarde chez les hommes et les femmes et mis en exergue une vulnérabilité particulière des femmes vivant dans les quartiers les plus défavorisés.
Nous avons finalement exploré la contribution de la pollution atmosphérique aux inégalités sociales de santé en examinant si le niveau socio-économique des IRIS modifiait les effets de la pollution atmosphérique sur le risque d'infarctus du myocarde. Notre analyse cas-croisés a révélé un effet plus élevé de la pollution particulaire chez les individus vivant dans les quartiers défavorisés, en particulier les femmes âgées de 55 à 74 ans. Ces résultats, au vu de ceux précédemment rapportés, semblent s'expliquer davantage par un différentiel de sensibilité que par un différentiel d'exposition. La recherche des mécanismes responsables de cette sensibilité exacerbée nécessite d'être poursuivie dans de futurs travaux afin que des actions de santé publique efficaces puissent être mises en œuvre pour protéger ces populations vulnérables.
Jeanjean, Maxime. "Pollution atmosphérique et déclenchement de poussées de sclérose en plaques, investigation au niveau individuel." Thesis, Rennes 1, 2018. http://www.theses.fr/2018REN1B003.
Full textMultiple sclerosis (MS) is a neuro-inflammatory disease of the central nervous system (CNS). Causes are multifactorial enrolling both genetic predisposition and influence of environmental factors. In 85% of cases, patients experience relapse corresponding to the occurrence of neurologic signs, followed by a phase of partial or total remission. Several studies put forth the hypothesis that relapses rate varies across season, mainly occurring during spring and summer. This temporal fluctuation raised the question of season-dependent parameters influence such as sunlight exposure and vitamin D, melatonin level or ambient air pollution. Considering this variation of air pollution, we explored the short-term impact of fine particles (PM10), benzene (C6H6), nitrogen dioxide (NO2), carbon monoxide (CO) and ground-level ozone (O3), on the risk of relapse triggering, separately for "cold" (i.e., October-March) and "hot" (April-September) season. This work has drawn from data of patients provided by the alSacEP network. We included 424 patients affected with remitting MS onset who experienced 1,783 relapses over the 2000-2009 period. Daily level of air pollution was modeled through ADMS-Urban software at the census block scale of the Strasbourg metropolitan area (AASQA ATMO Grand Est). Furthermore, an individual survey was conducted among all the patients (PT) in order to collect individual socioeconomic (SES) and lifestyle features. Finally, the census block SES position was estimated using a composite deprivation index - created from the INSEE census data. A short-term (3 days preceding the relapse) seasonal adverse effect was observed in PT, in particular during exposure to O3 in "hot" season and PM10 and NO2 in "cold" season. Results also suggest that the SES context might exacerbate these associations, in particular among patients who were living in deprived neighborhood with exposure to PM10, NO2, C6H6 and CO ("cold) and those who were living in most well-of and deprived places with exposure to O3 ("hot"). Finally, we observed among Ps that low education level, average family income, smoking and lack of physical activity are more associated with the risk of relapse triggering when patients were exposed to air pollution. This work shows the need to investigate environmental exposure such as air pollution along the SEP course using a holistic approach integrating individual and contextual factors
Dessimond, Boris. "Exposition individuelle à la pollution de l’air : mesure par capteurs miniatures, modélisation et évaluation des risques sanitaires associés." Electronic Thesis or Diss., Sorbonne université, 2021. http://www.theses.fr/2021SORUS297.
Full textAir pollution contributes to the degradation of the quality of life and the reduction of life expectancy of the populations. The World Health Organization estimates that air pollution is responsible for 7 million deaths per year worldwide. It contributes to the aggravation of respiratory diseases, causes lung cancer and heart attacks. Air pollution has therefore significant health consequences on human life and biodiversity. Over the last few years, considerable progress has been made in the field of microcontrollers and telecommunications modules. These are more energy efficient, powerful, affordable, accessible, and are responsible for the growth of connected objects. In the meantime, the recent development of microelectromechanical systems and electrochemical sensors has allowed the miniaturization of technologies measuring many environmental parameters including air quality. These technological breakthroughs have enabled the design and production in an academic environment, of portable, connected, autonomous air quality sensors capable of performing acquisitions at a high temporal frequency. Until recently, one of the major obstacles to understanding the impact of air pollution on human health was the inability to track the real exposure of individuals during their daily lives; air pollution is complex, and varies according to the habits, activities and environments in which individuals spend their lives. Portable air quality sensors completely remove this obstacle as well as a number of other important constraints. These are designed to be used in mobility, over long periods of time, and produce immediately available granular data, which describes the exposure to air pollution of the person wearing it. Although the measurement modules embedded in these sensors are not currently as reliable as reference tools or remote sensing, when it comes to assessing individual exposure to air pollution, because they are as close as possible to the wearer, they provide the most accurate information, and are therefore an indispensable tool for the future of epidemiological research. In this context, we have been involved in the development and improvement of two air quality sensors; the CANARIN II and the CANARIN nano. The CANARIN II is a connected sensor communicating via Wi-Fi, which reports the concentration of 10, 2.5 and 1 micrometer diameter particles, as well as the environmental parameters of temperature, humidity, and pressure, every minute, making them available in real time. The CANARIN nano is a smaller sensor with the same capabilities of the CANARIN II, while additionally sensing volatile organic compounds levels. The CANARIN nano is able to operate autonomously, as it communicates through the cellular network. Two types of results have been obtained with the CANARIN sensors; on one hand, results produced from their use in real life conditions, and on the other hand, results related to the interpretation and understanding of the measurements produced by the particle sensors. These two sensors were both used in two research projects, in which we have helped deploy several heterogeneous sensor fleets and analyzed the acquired data. Firstly, in the POLLUSCOPE project funded by the French National Research Agency, where 86 volunteers from the general population wore a set of air pollution sensors for a total of 101 weeks, 35 of which the volunteers were also equipped with health sensors. Secondly, in the POLLAR project, where 43 subjects underwent polysomnography and then wore one CANARIN sensor for 10 days, thus allowing for the first time to explore the link between sleep apnea and particulate matter exposure. [...]
Kammer, Julien. "LANDEX : étude des aérosols organiques secondaires (AOS) générés par la forêt des Landes." Thesis, Bordeaux, 2016. http://www.theses.fr/2016BORD0402/document.
Full textForest ecosystems affect air quality and climate, especially through the emissions and the reactions of biogenic volatile organic compounds (BVOCs) with the atmospheric oxidants, known to generate Secondary Organic Aerosols (SOAs). This work aims to improve our knowledge on the processes involved in biogenic SOA formation and fate. Two field campaigns have been conducted in the Landes forest. In a first step, the measurement site was characterized by a statistical study of local meteorological conditions. During these campaigns, complementary physical and chemical measurements have been carried out, implying measurements of fluxes and concentrations of particles, BVOCs and oxidants. The results evidenced nocturnal new particle formation, which is an original result as this process was usually only reported during daytime. The strong contribution of BVOCs (dominated by α- and β-pinene) ozonolysis to nocturnal new particle formation has been demonstated. Particle flux measurements suggested that particles are transfered from the canopy to the higher atmospheric surface layer. The comparison between ozone fluxes and a physical ozone deposition model also highlighted an ozone production source. This ozone production might be related to BVOC photooxidation
Marin, Ospina Yohan Manuel. "Etude de l'influence de la dilution du combustible et de l'oxydant dans le processus de décrochage de flammes-jet non-prémélangées et l'émission de polluants." Thesis, Rouen, INSA, 2016. http://www.theses.fr/2016ISAM0025/document.
Full textUnderstanding the main mechanisms piloting non-premixed jet flame stability is an important point in characterizing the operation modes of industrials burners in which dilution is involved. This work puts special emphasis on the experimental study of the influence of air-side and methane-side dilution in the lifting process of attached non-premixed jet flames. The study is based on numerous experiments combining the following conditions : i) carbon dioxide (CO2), nitrogen (N2), argon (Ar) or water vapor (H20v,) used as diluents d ; ii) two diluted configurations : air-side or methane-side dilution ; iii) two air and fuel velocities covering the entire flame hysteresis domain, from the laminar to the turbulent regime. This allows the influence of the intrinsic diluent nature effects to be discriminated from those of the aerodynamics of the reactants (fuel and oxidant), in attached flame stability. In particular, the behavioral differences of the flame response to air-side or to fuel-side dilution are analyzed. These two configurations differ by two mixing effects which are independent of the combustion reaction, and which are significant when the fuel is diluted, but negligible when air is diluted : i) an effect due to the changes in the stoichiometric mixture fraction ; ii) a mechanical impact induced by the addition of matter (diluents) producing an increase in the bulk velocity of the reactants. The study is composed of three parts. First, the global flame response to dilution is analyzed on the basis of the lifting limits defined as the critical molar fractions of the diluents in the fuel or in the oxidant measured at liftoff. The fuel Peclet number, Pef, appears as the dimensionless number which puts these limits in a homothetic order. This homothetic behavior allows the introduction of two affinity parameters, Kd,ox for air-side dilution and Kd,f for fuel-side dilution. They are defined by the ratio of the flame lifting limits calculated with a diluent d and with CO2, at Pef=const. Kd,ox and Kd, allow two generic polynomial laws to be established describing the flame lifting limits for all the diluents and in the whole range of aerodynamic conditions of this study. Indeed, Kd,ox and Kd,f encompass all the diluent effects affecting flame stability (pure dilution, thermal, transport, chemical), to which mechanical impacts are added. These coefficients make it possible to obtain the self-similarity laws of the lifting limits for any chemically-weak diluent, by using the results obtained in this work. Then, a local and detailed study of the flame lifting process induced by dilution is presented. This is based on the flame-leading-edge approach describing flame stability as a result of the balance between the incoming gas velocity of the reactants and the flame propagation velocity at the flame base. In order to show the link between this approach and flame stability, an extensive analysis of the flame-base characteristics (location, CH* emission intensity and velocity field) is carried out. The results attest to the pertinence of the propagative flame-leading-edge, as the mechanism describing the attached flame stability under dilution. Finally, a study concerning the influence of both the diluent nature and the diluted configuration (air or fuel) on pollutant emissions (soot, NOx and CO) is presented
Batisse, Emmanuelle. "Inégalités socioéconomiques et effets cardiovasculaires des expositions aux émissions industrielles au Québec, Canada." Thèse, 2017. http://hdl.handle.net/1866/19463.
Full textOn a daily basis, populations are exposed to a complex mixture of air pollutants such as fine particulate matters, sulphur dioxide and nitrogen dioxide that have been associated with a range of health effects namely respiratory and cardiovascular effects. Emitting sources’ distribution, landscape characteristics (i.e. infrastructure, topography) and thus the complex mixture of air pollutants and populations’ exposure vary greatly in space and time. This thesis aimed to document social inequalities in exposure to industrial air emissions of pollutants and associations between daily exposure to these pollutants and cardiovascular mortality in vulnerable populations living near these sources. Thus, using an ecological design, we analyzed Pearson’s correlations between deprivation level (using four indicators) of 2,189 primary and secondary Quebec schools and their exposure to industrial emissions in a radius of 2.5 to 7.5 km. Our results suggest inequalities in exposure to industrial air emissions at school in children. These associations were not consistent among all four indicators of deprivation. Besides, using a case-crossover design, we evaluated the associations between exposure to industrial air pollutants using both emission exposure estimates and sensor levels and deaths from cardiovascular diseases in the elderly living near industrial sources (<7.5 km). We found no convincing evidence of association. Our results varied greatly which could be caused by the limits of our study related to estimating exposure. Further studies using improved exposure estimates are necessary to support our findings.