Dans cette thèse, nous avons caractérisé chimiquement (métaux, EC, OC) les particules atmosphériques (PM10, PM2,5, PM1), étudié leurs sources et leur devenir puis modélisé leur comportement dynamique dans l’air intérieur de classes d’écoles du Nord Pas de Calais. Les teneurs en PM10 dépassent largement et presque systématiquement (moyenne de huit écoles : 97±28µg/m3) la valeur de gestion journalière (50µg/m3) pour l’air intérieur (recommandations OMS et ANSES). Les seuls éléments métalliques (Al, Ba, Ca, Fe) nettement associés à une source intérieure sont liés à l’utilisation de craie. Bien que l’on retrouve une quantité importante de particules d’origine extérieure dans les classes (trafic automobile, sources industrielles ou naturelles, …), les activités physiques des élèves sont à l’origine de la majeure partie des teneurs en PM10 en suspension dans l’air intérieur. Ce phénomène de remise en suspension n’influence pas significativement la répartition des métaux, majeurs et traces dans les PM10. La modélisation de l’évolution des teneurs en PM10 intérieures est clairement influencée par la présence d’activité dans les classes, nécessitant de prendre en compte les phénomènes de remises en suspension. De même, le comportement des particules est lié à la distribution granulométrique ainsi qu’aux caractéristiques intrinsèques du bâtiment qui contrôlent les échanges d’air avec l’extérieur. Le modèle déterministe développé dans ce travail permet une prédiction simple de l’évolution des concentrations en particules en fonction de leur distribution granulométrique dans les classes d’écoles. / During this thesis, we chemically characterized (metals, EC, OC) then studied the sources and the fate of airborne particles (PM10, PM2,5, PM1) in indoor air. Another part of this work concerns the modelization of their behavior in class-rooms of primary schools in the Nord Pas de Calais region. These PM10 values largely and almost systematically exceed (average value for eight schools: 97 ± 28μg/m3) the daily limit values (50μg/m3) for indoor air (WHO and ANSES recommendations). The only elements Al, Ba, Ca and Fe clearly associated to an indoor source are linked to the use of chalk. Although there is a significant amount of particles of outdoor origins found in class-rooms (such as traffic, industrial or natural sources), pupils’ physical activities represent the major source of airborne PM10 in indoor air. The resuspension phenomenon doesn’t influence significantly the elemental (major and traces elements) distribution of the indoor PM10.The modelization of the evolution of indoor PM10 is clearly influenced by the activities of the pupils in class-rooms, requiring taking into account the resuspension phenomena. In addition, the behavior of particles is associated to their size distribution as well as the intrinsic characteristics of the building envelope which control the indoor-outdoor air exchange.The deterministic model developed in this work will allow easily simulating the evolution of particle concentrations according to their size distribution in class-rooms.

The literature and data describing the environmental effects of air pollution in South Africa were examined, with a focus on the effects that are produced by the use of energy. This examination consisted of three parts: The emissions resulting from the use of the different fuels were calculated, with a complete sectorial and regional breakdown for pollution sources. A review of the data obtained from pollution monitoring programmes conducted in South Africa was completed. It was found that while monitoring is conducted in various regions and urban districts, there are areas with recognised pollution problems, such as townships, where little or no monitoring has been conducted. Often the resulfs of monitoring programmes were not published, or only available in unprocessed form. The literature describing environmental effects related to air pollution was reviewed. The number of studies pertaining to South African environments was found to be limited and tended to focus on certain areas, while neglecting others. Areas requiring further study and research were identified.

No description available.

Thesis advisor: Yasmin Zaerpoor / The Coronavirus pandemic has cast a new light on the intersection of environmental justice and public health, as communities of color and low-income communities have experienced greater rates of infection and mortality due to the Covid-19 pandemic. These inequalities can be attributed to a multitude of injustices. I investigate the impact that air pollution has had on COVID-19 incidence within Massachusetts, while also investigating other possible correlating factors. I use a regression model to consider the impact of air pollution, population density, race, income, age, and education on COVID-19 positivity rates in Massachusetts. In this study, I found that air pollution, population density, and the percentage of Hispanic population in a given community were all statistically significant in a linear regression model. Further research would be needed to investigate whether the coefficient on Hispanic population is conclusive. It is possible that the significant coefficient is picking up variables that are not included in this regression, namely the percentage of essential workers or access to healthcare. / Thesis (BA) — Boston College, 2021. / Submitted to: Boston College. College of Arts and Sciences. / Discipline: Departmental Honors. / Discipline: Environmental Studies.

Indiana University-Purdue University Indianapolis (IUPUI) / Alzheimer’s disease (AD) is a devastating neurodegenerative disease that is expected to affect approximately 6.2 million Americans. Despite its high prevalence, the mechanisms underlying AD remain poorly understood. In recent years, increasing reports indicate that exposure to urban air pollution is a risk factor for the development of AD. However, the mechanistic underpinnings of this association are not well studied. Rats exposed to diesel exhaust (DE) showed neuroinflammation and impaired expression of TREM2 and disease-associated microglia (DAM), a cell subtype hypothesized to play beneficial roles during neurodegeneration, markers. Microglia in the cortex of rats exposed to DE, also showed decreased association with the vasculature, providing a novel link between the microglia and the brain vasculature. Examining the functional role of TREM2 during DE exposures, Trem2-/- mice showed an altered pro-inflammatory profile in both the brain and lungs in response to DE particles as well as altered phagocytic oxidase related gene expression. Examining another prominent component of air pollution, ozone (O3), in a mouse model of AD, it was discovered that subchronic O3 exposure exacerbates amyloid pathology through impaired microglial-plaque association in 5xFAD mice. 5xFAD mice exposed to O3 also showed increased expression of pro-inflammatory cytokines, increased markers of dystrophic neurites, and decreased expression of key acetylcholinergic pathway components. Examining the peri-plaque microenvironment, it was discovered that O3 dysregulates key DAM proteins and amyloid processing proteins. In the lung, it was found that O3 exacerbated immune cell infiltration in 5xFAD mice compared to WT controls, suggesting that ongoing amyloid pathology regulates pulmonary immune response to air pollution. To examine how O3-induced pulmonary immune responses may be signaling to the CNS, we examined the serum of 5xFAD mice, where HMGB1, VEGF, and IL-9 were upregulated. Injection of rHMGB1 into mice showed similar gene changes to 5xFAD mice exposed to O3, along with impaired Trem2 expression. Using a peripheral myeloid specific knock-out model of HMGB1, we also show that HMGB1 regulates O3-induced Trem2 expression impairment. Taken together, these data support that air pollution exposure impairs TREM2, DAM cells, and the microglial plaque response through a bidirectional lung-brain axis to exacerbate AD-like pathology.

Due to rapid urbanisation, people in metropolises spend the majority of their time indoors. Indoor mould contamination, as one of the most pungent biohazards in built environments, can ubiquitously present in humid areas and potentially compromise the health of occupants. Governmental institutions like the World Health Organisation and United States Environmental Protection Agency have put forward guidelines for indoor mould prevention. However, these guidelines normally require occupants to maintain a low indoor humidity (<75% or even 40%), and thus, in tropical and subtropical areas, one of the most widely used approaches to prevent indoor mould contamination is to continuously operate air-conditioners or dehumidifiers (AC/D). The 24 h operation of AC/D, however, conflicts with the requirement of energy sustainability, and hence posits a trade-off between sustainability and indoor mould hygiene. The aim of this study was to facilitate the development of sustainable and effective mould prevention strategies for indoor environments. The literature on currently adopted mould prevention strategies including that target moisture (24 h AC/D), temperature (air-conditioning system and cool wall paint) and nutrient (dust removal) elements as well as new nanoparticles technology (Ag, TiO 2 and MgO nanoparticles), was reviewed and the main limitations of these strategies were discussed. It was found that none of these current mould prevention measures has addressed both sustainability and mould hygiene on balance, urging further investigations. Therefore, the objective of the first phase investigation was to develop sustainable cause-specific mould control measures in built environments. A case study of a mould contaminated site was conducted to illustrate the micro-environments that contribute to mould contamination in buildings. The currently used 24-h AC/D approach was compared with and ranked against other sustainable alternatives. The results of this case study suggest that determining an effective non-24 h AC/D management regime tends to be a sustainable and user-friendly solution. To develop such a regime, understanding the critical mechanisms regulating indoor mould responses to water dynamics is essential. Thus, the objective of the second phase was to characterise the critical mechanism regulating the growth of common indoor moulds under water dynamics. It was hypothesised that oxidative stress is associated with the growth of indoor moulds under water dynamics. Using Cladosporium cladosporioides as a model, both its pre-germination and germinated spores were exposed to daily wet-dry cycles. Afterwards, the growth was assessed and cellular H 2 O 2 concentration and catalase activity were measured. It was found that under water dynamics, the longer growth delay in C. cladosporioides was associated with a higher encountered oxidative stress, with 12-12 wet-dry cycle (12 h wet, 12 h dry) showing the longest delay and highest oxidative stress. Pearson correlation and linear regression analysis suggest a positive correlation between growth delay and oxidative stress under water dynamics (R 2 =0.85, P<0.0001). Moreover, pre- germination spores generally exhibited shorter growth delay, lower cellular H 2 O 2 concentration and higher catalase activity. Collectively, these results suggest that the growth of C. cladosporioides is associated with oxidative stress under water dynamics. After revealing the association between the growth of C. cladosporioides and oxidative stress under water dynamics, at the third phase, this finding was extrapolated to different mould species (C. cladosporioides, Aspergillus niger and Aspergillus penicillioides), water activity (a w ) (0.4 a w , 0.6 a w and 0.8 a w ) and temperature levels (19 °C and 28 °C). In addition, the antioxidant responses of treated moulds, including antioxidant enzymes (superoxide dismutase, catalase, glutathione reductase and glutathione peroxidase) were monitored. The results showed that lower water activity levels imposed higher oxidative stress to moulds, and A. penicillioides exhibited the highest tolerance which displayed the highest antioxidant activities and encountered lowest oxidative damage under water dynamics. Moreover, no significant difference was measured in terms of the survival, oxidative stress and antioxidant responses between these two temperature levels. The third phase of the study, for the first time discovered the reason contributing to the different resistance towards water dynamics among common indoor moulds, and further confirmed the important role of oxidative stress adaptation in withstanding transient water supply. In conclusion, this study reveals the critical role of oxidative stress adaptation in helping moulds to cope with changing water conditions, which may shed light on a new perspective for the future development of indoor mould prevention strategies. It also indicates that longer operation time of AC/D each day may not necessarily lead to better prevention of mould contamination, suggesting that in order to sustainably prevent mould contamination, one should operate reasonable non-24 h AC/D each day (12 h/day according to the examined species in this study) to yield a more stressful wet-dry cycle to moulds. The outcomes of this study foster the development of novel and sustainable indoor mould prevention strategies

Due to rapid urbanisation, people in metropolises spend the majority of their time indoors. Indoor mould contamination, as one of the most pungent biohazards in built environments, can ubiquitously present in humid areas and potentially compromise the health of occupants. Governmental institutions like the World Health Organisation and United States Environmental Protection Agency have put forward guidelines for indoor mould prevention. However, these guidelines normally require occupants to maintain a low indoor humidity (<75% or even 40%), and thus, in tropical and subtropical areas, one of the most widely used approaches to prevent indoor mould contamination is to continuously operate air-conditioners or dehumidifiers (AC/D). The 24 h operation of AC/D, however, conflicts with the requirement of energy sustainability, and hence posits a trade-off between sustainability and indoor mould hygiene. The aim of this study was to facilitate the development of sustainable and effective mould prevention strategies for indoor environments. The literature on currently adopted mould prevention strategies including that target moisture (24 h AC/D), temperature (air-conditioning system and cool wall paint) and nutrient (dust removal) elements as well as new nanoparticles technology (Ag, TiO 2 and MgO nanoparticles), was reviewed and the main limitations of these strategies were discussed. It was found that none of these current mould prevention measures has addressed both sustainability and mould hygiene on balance, urging further investigations. Therefore, the objective of the first phase investigation was to develop sustainable cause-specific mould control measures in built environments. A case study of a mould contaminated site was conducted to illustrate the micro-environments that contribute to mould contamination in buildings. The currently used 24-h AC/D approach was compared with and ranked against other sustainable alternatives. The results of this case study suggest that determining an effective non-24 h AC/D management regime tends to be a sustainable and user-friendly solution. To develop such a regime, understanding the critical mechanisms regulating indoor mould responses to water dynamics is essential. Thus, the objective of the second phase was to characterise the critical mechanism regulating the growth of common indoor moulds under water dynamics. It was hypothesised that oxidative stress is associated with the growth of indoor moulds under water dynamics. Using Cladosporium cladosporioides as a model, both its pre-germination and germinated spores were exposed to daily wet-dry cycles. Afterwards, the growth was assessed and cellular H 2 O 2 concentration and catalase activity were measured. It was found that under water dynamics, the longer growth delay in C. cladosporioides was associated with a higher encountered oxidative stress, with 12-12 wet-dry cycle (12 h wet, 12 h dry) showing the longest delay and highest oxidative stress. Pearson correlation and linear regression analysis suggest a positive correlation between growth delay and oxidative stress under water dynamics (R 2 =0.85, P<0.0001). Moreover, pre- germination spores generally exhibited shorter growth delay, lower cellular H 2 O 2 concentration and higher catalase activity. Collectively, these results suggest that the growth of C. cladosporioides is associated with oxidative stress under water dynamics. After revealing the association between the growth of C. cladosporioides and oxidative stress under water dynamics, at the third phase, this finding was extrapolated to different mould species (C. cladosporioides, Aspergillus niger and Aspergillus penicillioides), water activity (a w ) (0.4 a w , 0.6 a w and 0.8 a w ) and temperature levels (19 °C and 28 °C). In addition, the antioxidant responses of treated moulds, including antioxidant enzymes (superoxide dismutase, catalase, glutathione reductase and glutathione peroxidase) were monitored. The results showed that lower water activity levels imposed higher oxidative stress to moulds, and A. penicillioides exhibited the highest tolerance which displayed the highest antioxidant activities and encountered lowest oxidative damage under water dynamics. Moreover, no significant difference was measured in terms of the survival, oxidative stress and antioxidant responses between these two temperature levels. The third phase of the study, for the first time discovered the reason contributing to the different resistance towards water dynamics among common indoor moulds, and further confirmed the important role of oxidative stress adaptation in withstanding transient water supply. In conclusion, this study reveals the critical role of oxidative stress adaptation in helping moulds to cope with changing water conditions, which may shed light on a new perspective for the future development of indoor mould prevention strategies. It also indicates that longer operation time of AC/D each day may not necessarily lead to better prevention of mould contamination, suggesting that in order to sustainably prevent mould contamination, one should operate reasonable non-24 h AC/D each day (12 h/day according to the examined species in this study) to yield a more stressful wet-dry cycle to moulds. The outcomes of this study foster the development of novel and sustainable indoor mould prevention strategies

It is believed that the analysis of air traffic impacts on air quality will benefit from attention to the three-dimensional nature of the air traffic network as well as the actions of individual aircraft during the study period. With the existence of air traffic simulation models, the actions of individual aircraft may already be defined in a simulated environment. SIMMOD, the Federal Aviation Administration's airport and airspace modeling software, performs such models of scheduled air traffic. The results of such models may be used to determine the impacts of scheduled air traffic on air quality as well as other parameters. This report addresses the interpretation of output from SIMMOD models for use in air quality analysis and visualization of the air traffic network, and the application of these techniques in a stand-alone computer program. This program, named AQM for its purpose in assisting development of Air Quality Models, provides a working framework for future development of software for detailed air quality analysis and visualization. / Master of Science

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No description available.