Dissertations / Theses on the topic 'Air pollution'

Air pollution from DEEEs is becoming an increased international concern, and whilst attention has been primarily focused on the automotive industry, concerns have also been raised about emissions from diesel rail vehicles. The research is designed to assess the hypothesis that diesel rolling stock severely impacts air quality at Birmingham New Street station due to the station’s enclosed nature. To assess this hypothesis, an extensive series of long term measurements were made at Birmingham New Street station. The monitoring campaign consisted of diffusion tube measurements, to measure NO2 at locations in and around the station, followed by measurements of NOx, PM, CO2 and BC at stationary and mobile sites at the platform level. The results illustrated that diesel trains serving the station elevated pollutant concentrations, particularly oxides of nitrogen. During the sampling campaign the average NO2 concentration in the centre of platform 10/11 was 407 μg/m3, approximately 10 times greater than the EU ambient air quality limit. NO exceed its WEL 35% of the time during the monitoring campaign for the same site. Furthermore, this research concludes that CO2 is not suitable as a surrogate for assessing DEEEs exposure. NO2 concentrations exceeded their relevant exposure limits, whilst CO2 did not exceed the ventilation system’s 50% speed threshold, as a result it is unlikely that harmful pollutants were being successfully exhausted from the station. The environmental analysis identified a potential trapped vortex in the West end of the station, which could have an impact on the ventilation system in place at Birmingham New Street station. It is clear that this research has been pivotal in driving a focus towards air quality with the railway industry and has prompted further research at other enclosed railway stations.

Aims: The project is designed to investigate the effects of exposure to airborne pollution on cardiovascular health. Many studies have identified an association between exposure to elevated levels of airborne pollution and increases in morbidity and mortality associated with acute myocardial infarction, heart failures and coronary heart disease. The project investigates the occurrence of these diseases in a low pollution scenario and investigates plausible biomedical causes of the observed increases. The study investigates the composition of airborne particles in the city, as one hypothesis is that particle composition may be as important as the total mass of respired particles. The project investigates the aetiology of myocardial infarction and heart failure in the city, associated with exposure to air pollution and variations in meteorological conditions. The study aimed to identify to what degree these diseases are affected by changes in environmental conditions. Variations in the composition of the blood were investigated as a possible mediator in the association between air pollution, meteorology and MI and HF. In one study an epidemiological approach was used to investigate changes in the concentrations of blood coagulation factors. The second study used blood obtained from healthy volunteers on high pollution days and low pollution days, accounting for meteorological changes. The samples were analysed for several non-blood coagulation factors, with the capability of adversely altering MI and HF aetiology. Primary results: The study identified that no significant association is observed between exposure to airborne pollution and morbidity and mortality associated with acute myocardial infarction of heart failure. The gaseous pollution levels in the city were identified as too low to have a significant effect on cardiovascular health, however decreases in outdoor temperature were seen to have a significant detrimental effect on myocardial infarction and heart failure. However air pollution levels were observed to be significantly associated with deaths arising from respiratory disease. The composition of the collected particulate matter was identified as the primary reason of the lack of any association between airborne particulate matter and acute myocardial infarction of heart failure. Daily variations in outdoor temperature are identified as the most significant environmental parameter affecting the occurrence of morbidity and mortality associated with acute myocardial infarction of heart failure. There was no significant association between exposure to elevated levels of air pollution or decreased temperature and variations in blood coagulation factors. There was also no significant association between changes in non-coagulation blood factors and changes in meteorological and air pollution factors. Two possible explanations exist to explain these results, either air pollution levels are too low to effect blood composition, or the association between air pollution and MI and HF is not mediated through the studied parameters. Several significant associations were identified between exposure to airborne pollution and changes in non-coagulation blood parameters. These changes, including a variety of changes in white blood cells, the haematocrit and plasma viscosity, all suggest mechanisms by which exposure to airborne pollution may exacerbate myocardial infarction and heart failures. These findings indicate that exposure to airborne pollution has more than a statistical association with MI and HF. Conclusions: In the city and county of Cardiff levels of primary airborne pollutants is at a much lower level than many other study areas. As a consequence of these differences in air pollution dynamics there is a significant difference in the disease aetiology, particularly associated with MI and FIF. However even in this low pollution environment adverse health effects are noted, including elevation in deaths associated with respiratory disease. The pollution levels identified in Cardiff were associated with changes in several blood parameters, which in other studies are associated with adverse health effects, including exacerbation of MI and HF.

Although air pollution levels are increasing, there is no knowledge of air pollution effects on agricultural crops in the Peshawar region of Pakistan. The aim of this study was to assess the impact of ozone (O3) and hydrogen fluoride (HF) on agricultural crops in Peshawar through a combination of field work and experiments. The mean monthly O3 concentration in Peshawar, measured using passive samplers, was between 25-30ppb in February and March, but increased to 35-55ppb in April and May; it fell to 15-20ppb in November/December. O3 injury was found on potato (black flecking), onion (leaf tipburn) and cotton (white stipples) in a survey in April/May, but was absent from many other crops. No O3 injury was found on any crops during a winter survey. O3 fumigation experiments on spinach (Beta vulgaris) and onion (Allium cepa) in open-top chambers in UK showed that high O3 concentrations can affect both species in terms of visible injury and growth. However, onion is at greater risk in the field as it is a summer crop and is likely to be exposed to high O3 concentrations, unlike spinach, which is grown in the winter season. An EDU experiment on spinach under field conditions in Peshawar showed no effect on growth during winter season. However, elemental contents of spinach were significantly reduced in EDU treated plants. The HF concentrations in Peshawar, measured using passive samplers were higher in summer than in winter in areas close to brick kiln fields. The mean summer concentration was 0.2μg HF m-3, with maximum of 0.3μg HF m-3 in May. HF was below detection limits of <0.1μg HF m-3 in November-December. Severe HF injuries to mango, apricot and plum leaves, in form of necrotic leaf margins and tipburn, were found near the brick kiln fields. Tomato, maize, wheat and sugarcane were found to be less sensitive, but also showed some HF injury. The fluoride content of fruit leaves, wheat grains and spinach was significantly higher in the brick kiln area than at control sites. There was no significant difference between the soil fluoride content of wheat fields in the brick kiln area and at control sites. Wheat grown at different NaF levels in alkaline soils similar to those in Peshawar, in a greenhouse experiment in the UK showed no effect of fluoride on growth. The degree of powdery mildew infestation increased with increased fluoride concentrations in the soil and ear emergence was also delayed in all treatments except the control. It was concluded that O3 and HF are significant pollutants in Peshawar, especially for summer crops. More detailed studies should be conducted to determine the magnitude of damage caused by these pollutants in the Peshawar region.

The present study deals with air pollution modelling over complex topography, both from the phenomenological and numerical point of view. The theme of air pollution modelling has been faced at first from a phenomenological point of view. Then a numerical approach for the resolution of the diffusion-advection equation has been followed. Two different methods have been explored: puff-models and lagrangian particle models. The eulero-lagrangian puff-model CALPUFF (released by Earth Tech) has been used as a reference: closures and parametrizations adopted by this software have been tested over complex terrain and some minor changes have been introduced into the original code. A further step was the development of a lagrangian particle-tracking program, suitable for not homogenous not stationary flows, and also adapted to complex terrain cases, accounting for vertical skewed turrbulence in any atmospheric stability class. Langevin equation were solved following Thomson's (1987) approach. Special attention was put on near field dispersion processes. In fact, lagrangian models turn out to be the most advanced numerical schemes for pollutant transport simulations but at now only suitable for short term simulations, at least in complex errain where high spatial resolution is needed. An extension for the lagrangian model has been then developed, using the so called "kernel method"; this feature improves considerably the calculation performance, dramatically reducing computation time, so that simulations also become praticable for longer temporal scales; nevertheless it seems the kernel method seems to lead to unreliable results for narrow valleys or very steep slopes, so results cannot be generalized. Moreover, the problem of the determination of vertical profiles of turbulent diffusivity on complex orography has been faced. Both a local approach and a global one (suitable for compact valleys) for the estimate of eddy diffusivity in valley have been investigated. The first one has been adopted in the lagrangian problem previously developed. Since atmospheric turbulence is mostly generated by solar thermal flux, a procedure for the calculation of the effective solar radiation was developed. The method, which can be introduced into meteorological models which use complex orography as input, takes into account for shadowed areas, soil coverage and the possible precense of clouds which filter and reduce the incoming solar radiation. Tests have been carried out using a modified version of model CALMET (EarthTech Inc.). Results are in agreement with turbulence data acquired by means of a sonic anemometer during a field campain performed by the Department. Finally, the analysis of near field dispersion over complex terrain has been extended to the urban context, adopting, basically, the same conceptual tools on a smaller scale. A finite volume three-dimensional numerical model has been developed and tested in simulating dispersion of traffic derived pollutants in the town of Trento. For ground level sources geometry of the domain and emission condition turn out to be very important with respect to meteorological conditions (especially atmospheric stability). The roughness, i.e. the buildings of the study area has been therefore explicitely considered, using a high resolution deigital elevation map of the urban area. This approach has turned out to be necessary for near field dispersion, when the emission source is located inside the roughness and the impact area entirely fall inside the near field. Here a comparison has been made between the predicted numerical solution and data measured by air quality stations which are present in the urban area, showing a good agreement. A further refinement of the study has lead to the development of a two-dimensional x-z lagrangian model at the "street scale", for the study of canyon effects which tends to trap pollutant inside an urban canyon with behaviours which typically depends on geometric features, atmospheric turbulence and wind speed.

Environmental injustice has received high attention in the field of environmental studies. The concept of environmental justice is well defined within different academic disciplines. It refers to the rightness, fairness, and equity that a person in his own living environment is entitled to. In contrast, environmental injustice refers to the failure for one to receive the environmental justice that he is entitled to. Environmental injustice has been well substantiated by numerous international studies and evidenced in many countries overseas. A key question thus emerges: Is environmental injustice well evidenced in Hong Kong? Air pollution presents a major environmental challenge to the socially deprived communities both internationally and locally. Whilst the relationship between air pollution and social deprivation is well established internationally, given the strong evidence supporting the hypothesis that the socially deprived are exposed to more air pollution, the validity of such claim in the local context is not as obvious. Existing local studies investigating the relationship between air pollution and social deprivation are limited by, first, the lack of fine-grained air pollution data at a smaller geographical scale, which constrains the observation and conclusion of such hypothesis at a more refined geographical scale (Stern, 2003) and second, a stronger tendency to focus on the vulnerability of air pollution on different socio-economic spectrums (C. M. Wong et al., 2008). The current study aims to close the research gap by (a) developing a sophisticated methodology to enhance the collection and analysis of air pollution data at the Territorial Planning Unit, (b) examining the relationship between air pollution exposure and social deprivation at the TPU level, and (c) examining whether environmental injustice in relation to air pollution exists in Hong Kong. Our key research questions thus include the following: (1) Are the socially deprived in Hong Kong exposed to more air pollution? (2) Can we break through the existing methodological constraint and develop a brand new sophisticated air pollution data estimation methodology to interpolate air pollution at a smaller geographical scale? (3) If (1) is positive, would the exposure to more air pollution by the socially deprived in Hong Kong constitute the case of environmental injustice? A more sophisticated and accurate air pollution estimation methodology to estimate air pollution at a smaller geographical scale with the least root mean square error (RMSE) as compared to other key traditional models is introduced. The model identifies key spatial factors that affect the dispersion of air pollution in Hong Kong. By regression analysis, it is shown that the relationship between exposure to air pollution and social deprivation is positive and statistically significant. Both NO2 and PM10, the two major road-based pollutants, are positively correlated with the social deprivation index (for NO2: coefficient=0.4404 R= 0.6937, p<0.01; for PM10: coefficient = 0.4185, R = 0.6430, p<0.01). This leads to the conclusion that the socially deprived in Hong Kong are exposed to more air pollution, thus establishing the case of environmental injustice. This study has generated a key methodological breakthrough by developing a sophisticated air pollution estimation model that generates more accurate and fine-grained air pollution data at the TPU level – which was not previously available due to the limited number of air pollution monitoring stations in Hong Kong. This methodology allows the pursuit of social-economic air pollution study at a more refined geographical scale. The study strongly points to the existence of air-pollution related environmental injustice in Hong Kong. It calls for the Hong Kong Government to immediately address this under-researched and long neglected social-environmental problem, by formulating and implementing effective policies based on the fine-grained air pollution and socio-economic data, and the evidence generated from this study.
published_or_final_version
Environmental Management
Master
Master of Science in Environmental Management

La rinitis tiene un impacto importante en la salud pública, sin embargo en los adultos no existe una estandarización de la definición en los estudios epidemiológicos. Además, apenas se conocen los factores ambientales de la rinitis y, en particular, existen muy pocos estudios sobre los efectos de la contaminación atmosférica a largo plazo sobre la rinitis en adultos. Para llenar estos vacíos, utilizamos datos de dos estudios epidemiológicos europeos multicéntricos con datos extensos sobre la salud respiratoria y con datos de exposición individual a la contaminación atmosférica a largo plazo. Nuestros resultados mostraron que para caracterizar mejor la rinitis, es necesario considerar conjuntamente todas las características de los síntomas nasales, las comorbilidades y la sensibilización alérgica, y no restringir la enfermedad a una pregunta o a una prueba de sensibilización alérgica. No encontramos asociación entre la contaminación atmosférica a largo plazo y la incidencia de rinitis, pero demostramos que la exposición a la contaminación del aire a largo plazo aumenta la severidad de la rinitis, enfatizando que es necesario controlar la contaminación atmosférica.
Whereas rhinitis has an important public health impact, in adults there is no standardized definition of rhinitis in epidemiological studies. Furthermore, environmental factors of rhinitis are barely known, and in particular, there are very few studies on the effects of long-term exposure to air pollution on rhinitis in adults. To fill these gaps, we used data from two European multicentre epidemiological studies with extensive data on respiratory health and individual estimated exposures to long-term air pollution. Our findings showed that to better characterize rhinitis, one need to consider together all the characteristics of the nasal symptoms, the comorbidities and the allergic sensitization, and not to restrict the disease to one question or one allergic sensitization test. We found no association between long-term air pollution and incidence of rhinitis, but we showed that long-term exposure to air pollution is associated to an increased severity of rhinitis, emphasising that air pollution needs to be controlled.

Urban air pollution and climate are closely connected due to shared generating processes (e.g., combustion) for emissions of the driving gases and aerosols. They are also connected because the atmospheric lifecycles of common air pollutants such as CO, NOx and VOCs, and of the climatically important methane gas (CH4) and sulfate aerosols, both involve the fast photochemistry of the hydroxyl free radical (OH). Thus policies designed to address air pollution may impact climate and vice versa. We present calculations using a model coupling economics, atmospheric chemistry, climate and ecosystems to illustrate some effects of air pollution policy alone on global warming. We consider caps on emissions of NOx, CO, volatile organic carbon, and SOx both individually and combined in two ways. These caps can lower ozone causing less warming, lower sulfate aerosols yielding more warming, lower OH and thus increase CH4 giving more warming, and finally, allow more carbon uptake by ecosystems leading to less warming. Overall, these effects significantly offset each other suggesting that air pollution policy has a relatively small net effect on the global mean surface temperature and sea level rise. However, our study does not account for the effects of air pollution policies on overall demand for fossil fuels and on the choice of fuels (coal, oil, gas), nor have we considered the effects of caps on black carbon or organic carbon aerosols on climate. These effects, if included, could lead to more substantial impacts of capping pollutant emissions on global temperature and sea level than concluded here. Caps on aerosols in general could also yield impacts on other important aspects of climate beyond those addressed here, such as the regional patterns of cloudiness and precipitation.
Abstract in HTML and technical report in PDF available on the Massachusetts Institute of Technology Joint Program on the Science and Policy of Global Change website (http://mit.edu/globalchange/www/).
This research was supported by the U.S Department of Energy, U.S. National Science Foundation, and the Industry Sponsors of the MIT Joint Program on the Science and Policy of Global Change: Alstom Power (France), American Electric Power (USA), BP p.l.c. (UK/USA), ChevronTexaco Corporation (USA), DaimlerChrysler AG (Germany), Duke Energy (USA), J-Power (Electric Power Development Co., Ltd.) (Japan), Electric Power Research Institute (USA), Electricité de France, ExxonMobil Corporation (USA), Ford Motor Company (USA), General Motors (USA), Mirant (USA), Murphy Oil Corporation (USA), Oglethorpe Power Corporation (USA), RWE/Rheinbraun (Germany), Shell International Petroleum (Netherlands/UK), Statoil (Norway), Tennessee Valley Authority (USA), Tokyo Electric Power Company (Japan), TotalFinaElf (France), Vetlesen Foundation (USA).

Increases in air pollution, especially the particulate component, are associated with increased cardiovascular mortality, possibly through increases in thrombogenic mechanisms. The research presented in this thesis addresses the hypothesis that diesel exhaust particulates (DEP) increase thrombogenicity by impairing the release of tissue plasminogen activator (t-PA) from vascular endothelial cells, thus inhibiting the endogenous fibrinolytic mechanisms that promote thrombus breakdown. The initial aims of this work were to develop an in vivo model of thrombosis, to determine whether exposure to DEP did alter clotting. Initial attempts to develop the Folts’ model (which stimulates thrombus formation via arterial stenosis and mechanical injury), first in male C57/Bl6 mice and later in male Wistar rats, were unsuccessful. An alternative approach, using ferric chloride (FeCl3) to induce chemical injury to the rat carotid artery was found to produce reliable and reproducible thrombotic occlusion: this model was used for all subsequent experiments. The effects of DEP on thrombus formation were assessed in vivo by applying the FeCl3 model. DEP were administered via intratracheal instillation or tail vein injection 2, 6 or 24 hours prior to induction of thrombosis. The effects of DEP were compared with vehicle and suitable controls: carbon black (a clean carbon nanoparticle); quartz (a large non-carbon particle that causes well-characterised pulmonary inflammation). The time to thrombotic occlusion was significantly reduced 6h after intra-pulmonary instillation of DEP (0.5ml of a 1mg/ml suspension). In contrast, instillation of carbon black or quartz had no significant effect on thrombosis, despite causing greater pulmonary (increased neutrophils and levels of interleukin-6, tumour necrosis factor-α and C-reactive protein in bronchoalveolar lavage fluid) and systemic (C-reactive protein in plasma) inflammation than DEP. Direct administration of DEP (0.5mg/kg) to the blood stream resulted in an acute (2 hours after injection) increase in time to thrombotic occlusion in the absence of pulmonary inflammation. A similar (but less pronounced) effect was observed following administration of carbon black (0.5mg/kg). These data suggest that the DEP-mediated increase in thrombosis is independent of pulmonary and systemic inflammation. The mechanisms involved were addressed by measuring platelet-monocyte interactions (flow cytometry) and markers of the endogenous fibrinolytic system (ELISA). Exposure (either instillation of injection) to DEP significantly increased platelet-monocyte aggregation. Carbon black and quartz produced no such effect (but did increase platelet-platelet aggregation). t-PA antigen and activity were reduced, whilst PAI-1 and fibrinogen were increased, following either instillation or injection of DEP. The final aim was to develop a suitable dispersant for use in cell culture to determine whether DEP alter the expression (real-time polymerase chain reaction; rtPCR) and generation (enzyme-linked immunosorbent assay; ELISA) of t-PA and plasminogen activator inhibitor (PAI-1). Cell culture medium containing bovine serum albumin (0.5mg/ml; BSA) provided the best combination for DEP dispersal and maintenance of small particle size (<200nM), without detrimental effects on human umbilical endothelial cells (HUVECs). Exposure (6 and 24 hours) of HUVECs to DEP resulted in reduced basal and thrombin stimulated t-PA and PAI-1 expression. This was mirrored by reduced detection of t-PA and PAI-1 in culture medium. In conclusion, these investigations confirm that exposure to DEP is capable of increasing the rate of thrombus formation and that this is, in part, mediated by an alteration in the endogenous fibrinolytic system. These changes did not appear to be secondary to pulmonary or systemic inflammation. Whilst cell culture experiments suggested DEP could directly alter endogenous fibrinolytic activity in endothelial cells, there was no evidence from these experiments of DEP translocation into the systemic circulation. Thus, this work suggests that DEP is capable of increasing thrombus formation in vivo via several mechanisms. Similar changes may account for the increased thrombus formation in humans exposed to diesel exhaust in air pollution.

A street canyon is a typical urban configuration with surrounding buildings along the street, where emissions from vehicles are normally released. Buildings are the artificial obstacles to the urban atmospheric flow and give rise to limited ventilation, especially for deep street canyons. This study implements a large-eddy simulation (LES) coupled with a reduced chemical scheme (the LES-chemistry model) to investigate the processing, dispersion and transport of reactive pollutants in a deep street canyon. Spatial variation of reactive pollutants are significant due to the existence of unsteady multiple vortices and pollutant concentrations exhibit significant contrasts within each vortex. In practical applications of using one-box model, the hypothesis of a well-mixed deep street canyon is shown to be inappropriate. A simplified two-box model (vertically segregated) is developed and evaluated against the LES-chemistry model to represent key photochemical processes with timescales similar to and smaller than the turbulent mixing timescale. The two-box model provides the capability of efficiently running a series of emission scenarios under a set of meteorological conditions. In addition, a box model with grid-averaged emissions of street canyons is compared with a two-box model considering each street canyon independently (horizontally segregated) to evaluate uncertainties when grid-averaged emissions are adopted in a grid-based urban air quality model. This study could potentially support traffic management, urban planning strategies and personal exposure assessment.

The valleys of northern Utah, where most of Utah’s population resides, experience episodic air pollution events well in excess of the National Ambient Air Quality Standards. Most of the events are due to an accumulation of particulate matter during persistent cold air pools in winter from both direct emissions and secondary chemical reactions in the atmosphere. High wintertime ozone concentrations are occasionally observed in the Uintah Basin, in addition to particulate matter. At other times of the year, blowing dust, wildland fires, fireworks, and summertime ozone formation contribute to local air pollution. The objective of this dissertation is to investigate one facet of the health effects of Utah’s air pollution on its residents: the acute impacts of air pollution on gastrointestinal (GI) disease.

To study the health effects of these episodic pollution events, some measure of air pollution exposure must be matched to the health data. Time and place are used to link the health data for a person with the pollution data. This dissertation describes the method of kriging data from the sparse pollution monitoring network to estimate personal air pollution history based on the zip code of residence. This dissertation then describes the application of these exposure estimates to a health study on GI disease.

The purpose of the GI study is to retrospectively look at two groups of patients during 2000-2014: those with autoimmune disease of the GI tract (inflammatory bowel disease, IBD) and those with allergic disease of the GI tract (eosinophilic esophagitis, EoE) to determine whether disease exacerbations occur more commonly during and following periods of poor air quality compared to periods of good air quality. The primary analysis method is case crossover design. In addition to using the kriged air pollution estimates, the analysis was repeated using simpler empirical estimation methods to assess whether the odds ratios are sensitive to the air pollution estimation method.

The data suggests an association between particulate matter smaller than 2.5 microns and prednisone prescriptions, gastrointestinal infections in general, clostridium difficile infections specifically, and hospitalizations among people who have at least five entries of IBD diagnosis codes in their medical records. EoE exacerbations appear to be associated with high concentrations of particulate matter as well as ozone.

Air pollution and quality is one of the major problems in Örebro. Much research has been done to understand the impact of air pollution in urban societies and much more needs to be done in order to understand the implications of air quality impact on the region. Social structures in terms of environmental based planning for good air quality should focus on economic social costs need for new technologies and attainable health costs. Society can't survive without a healthy environment therefore understanding air quality and how new structures evolve for a practical human environmental interaction, is an absolute necessity for the well being and growth of Örebro region. The paper therefore, is an investigation into air quality impact on the existing structures in Örebro with air pollution as the major subject. It is based on critical evaluation of air pollution as derivative of a symbiotic human interaction with her environment and how contemporary planning structures should be attained. The paper throws light on the strategies being undertaken in Örebro region, in order to attain good health and cheap habitable environment in terms of technological, social and economic development.

El crecimiento industrial ha acarreado grandes avances tecnológicos para nuestra sociedad. Lamentablemente, el precio a pagar por estos avances ha sido un aumento significativo de los niveles de contaminación del aire en todo el mundo, afectando tanto a zonas urbanas como a las zonas rurales. Por lo general, la monitorización de la calidad aire se realiza mediante estaciones de monitorización fijas. Sin embargo, este método es demasiado costoso, poco escalable y difícil de implementar en nuestras ciudades, las cuales están cada vez más pobladas. El uso de Mobile CrowdSensing, paradigma en el cual la monitorización la realizan los propios usuarios, permite realizar monitorización ambiental utilizando sensores móviles integrados en vehículos. Los posibles escenarios se pueden dividir en dos: entornos urbanos, donde hay un amplio conjunto de vehículos disponibles, y entornos rurales o industriales, donde el tráfico vehicular es escaso y está limitado a las principales arterias de transporte. Teniendo en cuenta estos dos escenarios, esta tesis propone una arquitectura, llamada EcoSensor, que permite monitorizar la contaminación del aire utilizando pequeños sensores de bajo coste instalados en diferentes tipos de vehículos, tales como bicicletas, automóviles o autobuses del sistema de transporte público, en el caso de entornos urbanos, y en drones o UAS en entornos rurales. La arquitectura propuesta está compuesta por tres componentes: un sensor de bajo coste para capturar datos de contaminación, un smartphone para realizar un preprocesamiento de la información y para transmitir los datos hacia un servidor central, y el servidor central, encargado de almacenar y procesar la información de contaminación ambiental. Para entornos urbanos, analizamos diferentes alternativas con respecto al diseño de una unidad de monitorización de bajo coste basada en plataformas de prototipado comerciales como RaspberryPi o Arduino, junto con sensores también de precio reducido. En la tesis realizamos un análisis, y proponemos un proceso, para llevar a cabo la monitorización ambiental utilizando la arquitectura propuesta. Este proceso abarca cuatro operaciones básicas: captura de datos, conversión de unidades, reducción de la variabilidad temporal, e interpolación espacial. Para entornos rurales, proponemos el uso de drones como unidades de sensorización móviles. Específicamente, equipamos el drone con capacidades de monitorización a través de un microordenador RaspberryPi y sensores de calidad del aire de bajo coste. Finalmente, se propone un algoritmo llamado PdUC para controlar el vuelo del UAV con el objetivo de realizar monitorización ambiental, identificando las áreas más contaminadas, y tratando de ese modo de mejorar la precisión general y la velocidad de monitorización. Además, proponemos una mejora a este algoritmo, denominada PdUC-D, basada en la discretización del área a monitorizar dividiéndola en pequeñas áreas (tiles), donde cada tile se monitoriza una sola vez, evitando así realizar muestreos redundantes. En general, verificamos que la monitorización móvil es una aproximación eficiente y fiable para monitorizar la contaminación del aire en cualquier entorno, ya sea usando vehículos o bicicletas en entornos urbanos, o UAVs en entornos rurales. Con respecto al proceso de monitorización ambiental, validamos nuestra propuesta comparando los valores obtenidos por nuestros sensores móviles de bajo coste con respecto a los valores típicos de referencia ofrecidos por las estaciones de monitorización fijas para el mismo período y ubicación, comprobando que los resultados son semejantes, y están acuerdo a lo esperado. Además, demostramos que PdUC-D, permite guiar autónomamente un UAV en tareas de monitorización del aire, ofreciendo un mejor rendimiento que los modelos de movilidad típicos, reduciendo tanto los errores de predicción como el tiempo para cubrir el área completa,
Industrial growth has brought unforeseen technological advances to our society. Unfortunately, the price to pay for these advances has been an increase of the air pollution levels worldwide, affecting both urban and countryside areas. Typically, air pollution monitoring relies on fixed monitoring stations to carry out the pollution control. However, this method is too expensive, not scalable, and hard to implement in any city. The Mobile Crowdsensing (MCS) approach, a novel paradigm whereby users are in charge of performing monitoring tasks, allows environment monitoring to be made using small sensors embedded in mobile vehicles. The possible scenarios can be divided into two: urban scenarios, where a wide set of vehicles are available, and rural and industrial areas, where vehicular traffic is scarce and limited to the main transportation arteries. Considering these two scenarios, in this thesis we propose an architecture, called EcoSensor, to monitor the air pollution using small sensors installed in vehicles, such as bicycles, private cars, or the public transportation system, applicable to urban scenarios, and the use of an Unmanned Aerial System (UAS) in rural scenarios. Three main components compose our architecture: a low-cost sensor to capture pollution data, a smartphone to preprocess the pollution information and transmit the data towards a central server, and the central server, to store and process pollution information. For urban scenarios, we analyze different alternatives regarding the design of a low-cost sensing unit based on commercial prototyping platforms such as Raspberry Pi or Arduino, and Commercial Off-the-shelf (COTS) air quality sensors. Moreover, we analyze and propose a process to perform pollution monitoring using our architecture. This process encompasses four basic operations: data reading, unit conversion, time variability reduction, and spatial interpolation. For rural scenarios, we propose the use of an Unmanned Aerial Vehicle (UAV) as a mobile sensor. Specifically, we equip the UAV with sensing capabilities through a Raspberry Pi microcomputer and low-cost air quality sensors. Finally, we propose an algorithm, called Pollution-driven UAV Control (PdUC), to control the UAV flight for monitoring tasks by focusing on the most polluted areas, and thereby attempting to improve the overall accuracy while minimizing flight time. We then propose an improvement to this algorithm, called Discretized Pollution-driven UAV Control (PdUC-D), where we discretize the target area by splitting it into small tiles, where each tile is monitored only once, thereby avoiding redundant sampling. Overall, we found that mobile sensing is a good approach for monitoring air pollution in any environment, either by using vehicles or bicycles in urban scenarios, or an UAVs in rural scenarios. We validate our proposal by comparing obtained values by our mobile sensors against typical values reported by monitoring stations at the same time and location, showing that the results are right, matching the expected values with a low error. Moreover, we proved that PdUC-D, our protocol for the autonomous guidance of UAVs performing air monitoring tasks, has better performance than typical mobility models in terms of reducing the prediction errors and reducing the time to cover the whole area.Moreover, we analyze and propose a process to perform pollution monitoring using our architecture. This process encompasses four basic operations: data reading, unit conversion, time variability reduction, and spatial interpolation.
El creixement industrial ha implicat grans avanços tecnològics per a la nostra societat. Lamentablement, el preu que cal pagar per aquests avanços ha sigut un augment significatiu dels nivells de contaminació de l'aire a tot el món, que afecta tant zones urbanes com zones rurals. En general, el monitoratge de la qualitat aire es fa mitjançant estacions de monitoratge fixes. No obstant això, aquest mètode és massa costós, poc escalable i difícil d'implementar a les nostres ciutats, les quals estan cada vegada més poblades. L'ús de Mobile CrowdSensing (MCS), paradigma en el qual el monitoratge el duen a terme els mateixos usuaris, permet realitzar monitorització ambiental tenint sensors mòbils integrats en vehicles. Els possibles escenaris es poden dividir en dos: entorns urbans, on hi ha un ampli conjunt de vehicles disponibles, i entorns rurals o industrials, on el trànsit vehicular és escàs i està limitat a les principals artèries de transport. Tenint en compte aquests dos escenaris, aquesta tesi proposa una arquitectura, anomenada EcoSensor, que permet monitorar la contaminació de l'aire utilitzant petits sensors de baix cost instal·lats en diferents tipus de vehicles, com ara bicicletes, automòbils o autobusos del sistema de transport públic, en el cas d'entorns urbans, i en UAVs (Unmanned Aerial Vehicles) en entorns rurals. L'arquitectura proposada està composta per tres components: un sensor de baix cost per a capturar dades de contaminació, un smartphone per a realitzar un preprocessament de la informació i per a transmetre les dades cap a un servidor central, i el servidor central, encarregat d'emmagatzemar i processar la informació de contaminació ambiental. Per a entorns urbans, analitzem diferents alternatives pel que fa al disseny d'una unitat de monitoratge (sensor mòbil) de baix cost basada en plataformes de prototipatge comercials com Raspberry Pi o Arduino, juntament amb sensors també de preu reduït. En la tesi fem una anàlisi, i proposem un procés, per a dur a terme el monitoratge ambiental utilitzant l'arquitectura proposada. Aquest procés abasta quatre operacions bàsiques: captura de dades, conversió d'unitats, reducció de la variabilitat temporal, i interpolació espacial. Per a entorns rurals, proposem l'ús de drons o Unmanned Aerial Vehicles (UAVs) com a unitats de sensorització mòbils. Específicament, equipem el dron amb capacitats de monitoratge a través d'un microordinador Raspberry Pi i sensors de qualitat de l'aire de baix cost. Finalment, es proposa un algorisme anomenat PdUC (Pollution-driven UAV Control) per a controlar el vol del UAV amb l'objectiu de realitzar monitoratge ambiental, que identifica les àrees més contaminades i que, d'aquesta manera, tracta de millorar la precisió general i la velocitat de monitoratge. A més, proposem una millora a aquest algorisme, denominada PdUC-D, basada en la discretització de l'àrea a monitorar dividint-la en xicotetes àrees (tiles), on cada tile es monitora una sola vegada, fet que evita dur a terme mostrejos redundants. En general, verifiquem que el monitoratge mòbil és una aproximació eficient i fiable per a monitorar la contaminació de l'aire en qualsevol entorn, ja siga usant vehicles o bicicletes en entorns urbans, o UAVs en entorns rurals. Pel que fa al procés de monitoratge ambiental, validem la nostra proposta comparant els valors obtinguts pels nostres sensors mòbils de baix cost pel que fa als valors típics de referència oferits per les estacions de monitoratge fixes per al mateix període i ubicació, i es comprova que els resultats són semblants, i estan d'acord amb el resultat esperat. A més, es demostra que PdUC-D permet guiar autònomament un UAV en tasques de monitoratge de l'aire, oferint un millor rendiment que els models de mobilitat típics, reduint tant els errors de predicció com el temps per a cobrir l'àrea completa, i aconseguint una major precisió dins de les àrees més
Alvear Alvear, ÓP. (2018). Mobile Sensing Architecture for Air Pollution Monitoring [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/107928
TESIS

Mestrado em Tradução Especializada
No âmbito da Tradução Especializada, o presente projeto aborda os desafios de uma tradução técnica, tendo como texto de partida três capítulos de um livro científico relativo à poluição atmosférica e respetivos efeitos na saúde do ser humano. Este projeto é constituído pela análise e caracterização do texto de partida, metodologia de tradução, problemas terminológicos e elaboração de um glossário terminológico.
This project approaches the challenges of a technical translation having as a source text three chapters from a scientific book about air pollution and health effects on human beings. The project comprises the analysis and characterization of the source text, methodology of translation, terminology problems and elaboration of a terminological glossary.

The study quantified air quality in three indoor microenvironments (homes, public places, and transportation environments) in urban areas of Vietnam. The overall findings highlighted significant indoor and outdoor air quality problems in all three studied microenvironments. The research demonstrated the great potential of low-cost sensors to monitor air quality and the feasibility of car air filters to screen for chemicals in cars. Incense burning and smoking were found to be the leading factors correlated with negative indoor air quality in urban areas. These outcomes are significant for supporting policy formulation and public health interventions in Vietnam and similar developing countries.

Beginning in March 1999 at Georgia Institute of Technology, the ASACA (Assessment of Spatial Aerosol Composition in Atlanta) program has provided PM₂. ₅ concentration and speciation using particle concentration monitoring in and around metropolitan Atlanta. Since 1999, three of the ASACA sites have collected PM₂. ₅ in an urban setting: Fort McPherson (FT, SW), South Dekalb (SD, SE), and Tucker (TU, NE). In January 2007, TU was retired and Fire Station 8 (FS8, NE) was employed as the new urban site. Starting in 2002, PM₂. ₅ concentrations have also been characterized at a rural site, Fort Yargo (YG). Water-soluble ionic species and carbonaceous species concentrations are collected daily on filters using a three-channel particulate composition monitor (PCM). From 1999 to 2008, average PM₂. ₅ concentrations range from 12.9 µg/m3 at YG to 15.4 µg/m3 at TU. Sulfate and organic matter are the main components of Atlanta PM, contributing around 26% and 31% respectively to PM mass. Overall ASACA data quality increased from around 5 in 1999 to a value of 9 in 2005. Seasonal PM data quality appears to be significantly affected by volatility of secondary aerosol species during warm months because ionic data quality regularly decreases in the summer. PM is more sensitive to total sulfate concentration than nitrate and ammonia year-round.

Air quality in urban areas of Chiang Mai Province, Thailand has seriously deteriorated as a consequence of population growth and urbanization and due to a lack of effective air quality management (AQM). As a result, respiratory diseases among Chiang Mai residents have increased in these affected areas. The health status and experiences of air pollution of both children and adults in Chiang Mai was assessed and improvements recommended to the developing AQM scheme. Air quality modelling, using ADMS-Urban was used to identify probable air polluted and control sites for further study. The polluted sites were found to be located along major roads in the city. However, ADMS-Urban was unable to predict air pollutant concentrations accurately because it could not cope with the very low wind speeds and complex topography of Chiang Mai. As a result, the utility of other air pollution modelling programmes should be investigated. The results of a questionnaire survey conducted with adults showed that urban respondents had a higher percentage of respiratory diseases than suburban respondents. However, later investigations were unable to establish a statistical linkage between air pollution concentrations and respiratory diseases. An ISAAC study was conducted among children attending schools located in the selected sites to assess the potential impacts of air pollution on health. The results showed that the prevalence of asthma was similar in all of the schools (approximately 5%) but that the prevalence of rhinitis (24.3% vs. 15.7%) and atopic dermatitis (12.5% vs. 7.2%) was higher in the urban schools which were considered to be more polluted. Logistic regression analysis identified other factors which may be involved in addition to pollution, including some components of the diet and contact with animals. In order to investigate the adequacy of the AQM system in Thailand, a comparative study was conducted between Hong Kong and Thailand. Both countries were investigated with respect to conformance to Good Urban Governance. The comparison showed that there are significant differences between the two countries and the AQM system in Hong Kong was more highly developed. For example, in contrast to the system in Hong Kong, it was found that there was insufficient involvement of the population in the development and implementation of AQM systems in Thailand. In order to better understand the reasons why the AQM system in Thailand is poor at both the provincial and local levels in Chiang Mai, prioritisation of AQM was assessed for major national environmental policies and plans; at the provincial level, fund allocations to development projects were reviewed; and at the sub-district level; a questionnaire survey was conducted among local government officials. It was concluded that AQM was not given sufficiently high priority in national plans and was generally ineffective and that, due to the non-specific nature of guidelines and frameworks in these plans, it was difficult for government organizations at the lower levels to establish AQM action plans for effective implementation. A range of appropriate measures to improve air quality in Chiang Mai were recommended. These included a more effective management of air pollution, an identified need for training and major changes in the transport system in the city.

The research presented in this thesis provides a quantitative analysis of atmospheric influences on particulate matter pollution in Christchurch across a wide range of spatial and temporal scales. A complex interaction of low level flow characteristics that form in response to local and regional features of complex terrain, together with an urban setting that is characterised by low density housing, mostly comprised of single storey dwellings that are poorly insulated, regularly leads to nocturnal smog events during winter in Christchurch. Provided synoptic flow is weak, the above mentioned flow interaction promotes flow stagnation over the city, when nocturnal katabatic drainage flows and day-time north-easterly on-shore winds converge over the city. Additionally, undercutting of the density currents promotes highly stable atmospheric stratification close to the surface, so that, in combination, both horizontal and vertical air movement is suppressed. As particulate emission release from solid fuel burning for home heating coincides with this poor atmospheric dispersion potential, particle concentrations can increase substantially so that national air quality guidelines are regularly exceeded during winter in Christchurch. At the core of this thesis is a classification based approach that examines the day-to-day probabilities of breaches of the national air quality guideline for PM over the last decade at a single location in Christchurch as a result of variations in meteorological conditions alone. It is shown that, based on variations in temperature and wind speed, up to 85% of exceedence occurrence can be explained. From this, concentration trends over time, when meteorological variability is kept to a minimum, are assessed and evidence is found that recent regulatory measures to enhance air quality are beginning to show positive effects. Atmospheric processes that control pollution dispersion on the mesoscale are investigated through means of atmospheric numerical modelling in a novel approach that assimilates observational climatic wind field averages to drive low level flow for two idealised case studies. It is shown that this approach is able to reproduce the observed diurnal concentration patterns very well and that much of these patterns can be attributed to mesoscale circulation characteristics and associated atmospheric dispersion potential, namely flow stagnation and recirculation of contaminants. When timing of stagnation and subsequent recirculation is such that it occurs within a few hours after peak emission release, concentration increase is enhanced and dilution is delayed, thus severely exacerbating the problem. Links between exceedence probabilities and synoptic situations that favour the degradation of air quality are established and various synoptic transition scenarios are examined with regard to local air quality. The progression of anticyclones across the country is identified to be the dominant synoptic control mechanism and it is shown that latitudinal variation in the progression path determines the extent of expected exceedence probability. On interdecadal hemispheric scales, it is found that a particular combination of local and synoptic atmospheric conditions that favours air quality degradation, shows a re-occurring pattern of frequency maxima (and minima) with a periodicity of approximately 14 - 16 years. For the synoptic part of this interdecadal variability, a close relationship to Southern Hemispheric pressure anomalies in high latitudes is revealed. Finally, for verification of the combined findings and to assess their prediction capability, a validation case study is given which shows that the applied methodology is able to capture day-to-day variations in pollution levels with acceptable (statistically significant) accuracy.

Although sexual reproductive development is a critical phase in the life cycle of plants, the effects of air pollutants on the processes involved have not been investigated extensively. This thesis describes experiments undertaken to determine the direct effects of short-term exposures to ozone on the reproductive biology of species with contrasting reproductive growth habits, Brassica campestris L., an indeterminate species, and Plantago major L., a more determinate species. Two purpose-designed exposure chambers were constructed, each of which permitted the reproductive structures of up to twelve plants to be isolated from the vegetative parts and exposed simultaneously to ozone-enriched or charcoal-filtered air. The design of these chambers also permitted whole plant exposures. The occurrence of significant decreases in stomatal conductance and the net rate of photosynthesis following exposure to 70 ppb ozone established that the vegetative structures of both B. campestris and P. major were sensitive to ozone. Visible leaf injury also developed in B. campestris, the extent of which varied with the stomatal conductance of plants prior to fumigation and therefore ozone uptake. The growth of B. campestris and P. major was also reduced following 10 and 14 days of exposure respectively to 70 ppb ozone for 7 h d-1. The effects of ozone on growth differed between the four populations of P. major examined in this study. While a single 6 h exposure of the terminal inflorescence of B. campestris to 100 ppb ozone had no significant effect on reproductive development, repeated exposures over four consecutive days increased the abortion of seeds in apical pods and the precocious germination of seeds in older pods. However, the impact on final seed yield was dependent upon the timing of exposure; thus seed yield was significantly reduced following exposure during the early flowering phase, but was unaffected following exposure during the later stages of reproductive development. The compensation for seed losses in more mature plants resulted from their ability to retain naturally aborting seeds in older pods. Nonetheless, single and multiple exposures to ozone both reduced the rate of germination of harvested seeds and multiple exposures affected seed colour. In P. major, exposure of the fIrst spike to 120 ppb ozone for 7 h d-1 during flowering primarily affected seed number per capsule. Both significant increases and decreases in seed number were observed in the four populations examined, and seed number was also affected in spikes which had not been exposed to ozone, indicating the existence of possible compensation mechanisms. Pollen from both species was also shown to be sensitive to a 6 h in vivo exposure to ozone. The complex responses of B. campestris and P. major following direct exposure of the reproductive structures to ozone suggest that factors other than the type of reproductive growth habit are important in determining the extent of ozone damage and the ability of plants to compensate for reproductive site losses.