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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
211

Study of Linkage between Indoor Air Quality along with Indoor Activities and the Severity of Asthma Symptoms in Asthma Patients

John, Reena January 2023 (has links)
Asthma, a chronic respiratory disease affecting millions of people worldwide, can vary in severity depending on individual triggers such as Carbon Dioxide, Particulate Matter, dust mites, tobacco smoke, and indoor household activities such as cooking, cleaning, use of heating, and window opening, which can have a negative impact on indoor air quality (IAQ) and exacerbate asthma symptoms. Investigating the relationship between IAQ and asthma severity, a case study was conducted on five asthmatic participants from Bradford, UK. IAQ was measured using IoT indoor air quality monitoring devices. Indoor activities were recorded using a daily household activities questionnaire, and asthma severity was assessed using the Asthma Control Questionnaire (ACQ). Machine learning prediction models were used to analyse various IAQ parameters, such as particulate matter, carbon dioxide, and humidity levels, to identify the most significant predictors of asthma severity with IAQ. The study aimed to develop targeted interventions to improve IAQ and reduce the burden of asthma. Results showed that higher asthma severity scores were associated with increased indoor activity and higher levels of indoor air pollution. Some interventions were implemented to improve ventilation hours, significantly improving IAQ and reducing asthma symptoms, particularly those with more severe asthma. The findings indicate that interventions targeting IAQ, and indoor activities can effectively reduce asthma severity, with up to a 60% reduction in symptoms for asthma patients.
212

An Analysis Of Indoor Air Quality At Cal Poly For Sensor Design

Santi, Isabella M 01 June 2024 (has links) (PDF)
Prior research has shown that indoor air quality (IAQ) impacts cognitive performance. At Cal Poly, many older buildings are unable to maintain appropriate IAQ because of their outdated ventilation systems and the increasing number of students in the rooms. This work analyzes the IAQ of different buildings at Cal Poly, with a focus on Building 20. Carbon dioxide, temperature, and relative humidity inside classrooms are collected using an integrated circuit sensor and a microcontroller. A total of 38 hours of data was collected, with 22 of those hours in Building 20 specifically. We find that unlike temperature and relative humidity, CO2 levels routinely exceed 1,000 ppm—a concentration that hinders cognitive function. A questionnaire distributed to Cal Poly students suggests that while students can recognize poor IAQ in classrooms, they erroneously attribute these poor conditions to temperature and humidity instead of CO2. This data is then used to propose a system which can collect long-term data based on optimal placement, storage, and power requirements.
213

DOMESTIC WEATHER : Researching the potential of convective ventilation strategies in the setting ofa northern climate.

Adler, Henric January 2024 (has links)
The primary objective of ventilation in a building is to ensure that the Indoor Air Quality (IAQ), together with the heating system, keep the thermal climate at an acceptable level. Meaning the deployment of ventilation air at the appropriate temperature rate supplied to meet the thermal climate into the parts of the building where residents reside. In Sweden, the two most commonly used ventilation strategies are stack ventilation and forced extract ventilation. Both methods utilize exhaust openings in kitchens and sanitary areas, while fresh air is drawn from either permeable external walls or through inlets located near windows and as distant as possible from the exhaust openings (Manz & Huber, 2000). Stack-effect ventilation, also known as buoyancy ventilation, utilizes convective forces. Thus, vertical interior openings such as stairways or atriums play an essential role in the distribution of air and its suitability. Utilizing additional building elements such as a chimney enhances the stack-effect ventilation by elevating the height of the “vertical core” of warm air within the structure. The disparity in density (the difference in temperature between hot and cold) increases as a result of the amplification of pressure disparities (Liu et al., 2010). Hence, larger differences in pressure between the inside and outside will result in an increased driving force for the stack effect by enhancing the convective currents. The principle operates by drawing cooler air from the exterior,generally from the bottom or sides of the building, into the building. The air is then gradually heated and ascends through the vertical core due to convective forces, before being ultimately discharged through the chimney (Savin & Jardinier, 2009). The architectural proposal seeks to adhere to sustainable building development by employing deliberate steps that incorporate a combination of principles and strategies based on the theory of convection. In order to acquire knowledge and validation, an extensive investigation of case studies was carried out, with the works of Philippe Rahm serving as the fundamental basis for further development. Furthermore, a laboratory environment was established to conduct physical tests as well as virtual simulations (CFD) in order to gain deeper understanding and accuracy regarding the relationship between convective forces and geometry. The thesis set out to place a bet based on the notion of consciousness, in terms of implementation of chosen principles, using materials with low embodied carbon, and employing a strategic geometric relationship. This approach enabled the design of an architectural proposal that is both responsive and educative, while also addressing the existing knowledge gap between different professions.
214

Modifiable Risk in a Changing Climate: Linking household-level temperature, humidity, and air pollution to population health

Quinn, Ashlinn Ko January 2016 (has links)
Background: This dissertation comprises research conducted on two distinct projects. Project I focuses on the connection between household air pollution (HAP) from cooking with biomass fuels and blood pressure (BP); this research is situated in the context of a large randomized trial of a cookstove intervention in Ghana, West Africa. The setting of Project II, meanwhile, is the residential environment of New York City, where we explore temperature and humidity conditions in homes and relate these conditions to summertime heat wave risk and to the survival and transmission of respiratory viruses in the winter. Although these projects are quite distinct, each relates to the complex relationship between climate change and health. Reducing HAP to improve health (the focus of Project I) will simultaneously reduce climate change through a reduction in emissions of short-lived climate pollutants into the atmosphere. Meanwhile, furthering our understanding of heat and humidity levels inside urban residences (the focus of Project II) is crucial to our ability to protect health in light of projections for a changing climate. Domestic activities associated with heating, cooling, and cooking are thus very relevant both to human health and to climate change mitigation and adaptation. Objectives and Methods: Our overall objective for Project I was to investigate exposure- response relationships between HAP and BP in a cohort of pregnant women taking part in the Ghana Randomized Air Pollution and Health Study (GRAPHS). We first explored this association in a cross-sectional study (Chapter 1), in which we used 72-hour personal monitoring to ascertain levels of exposure among the GRAPHS women to carbon monoxide (CO), one of the pollutants emitted by traditional wood-fed cooking fires. These exposure data were collected at enrollment into the GRAPHS study, prior to the initiation of cooking with improved cookstoves. We investigated the association between these “baseline” CO exposure levels and the women’s blood pressure at enrollment into GRAPHS. A limitation of this study was that BP was only measured once. We followed this with a second study of 44 women drawn from the same cohort (Chapter 2), for whom we designed BP protocols using 24-hour ambulatory blood pressure monitoring (ABPM), the current gold standard for clinical diagnosis of hypertension. As we were not aware of any prior research in Africa that had employed ABPM, we also designed a parallel BP protocol using home blood pressure monitoring (HBPM) equipment for comparison with ABPM. The use of ABPM with concurrent personal CO monitoring enabled us to investigate hourly associations between CO exposure and changes in BP. We also evaluated BP in these women both before and after the cookstove intervention; this allowed us to investigate whether any changes in BP were associated with switching to an improved cookstove. Our objectives for Project II were to understand the distribution of temperature and humidity conditions in a range of New York City homes during the summer and winter seasons, to evaluate the impact of structural and behavioral factors (e.g. building size, use of air conditioning, and use of humidifiers) on these conditions, and to build models that could help predict indoor conditions from more readily available outdoor measurements. We conducted this research in two ways. We first analyzed a set of indoor temperature and humidity measurements that were collected in 285 New York City apartments during portions of summers 2003-2011 and used these data to simulate indoor conditions during two heat wave scenarios, one of which was more moderate and the other of which was more extreme (Chapter 3). Second, we designed and conducted a new study in which temperature and humidity were monitored in a set of 40 NYC apartments between 2013 and 2015 (Chapters 4-6). This second study enabled us extend our research into the winter season, and also to explore how factors such as air conditioning and humidifier use impacted indoor temperature and humidity. We also investigated relationships between the monitored conditions, self-reported perceptions of the indoor environment, and symptoms that were experienced among household members. Results: In the cross-sectional analysis of CO and BP in the GRAPHS cohort (Chapter 1), we found a significant positive association between CO exposure and diastolic blood pressure (DBP): on average, each 1 ppm increase in exposure to CO was associated with 0.43 mmHg higher DBP [0.01, 0.86]. A non-significant positive trend was also observed for systolic blood pressure (SBP). In our study of the acute relationship between CO exposure and BP (Chapter 2), we determined that peak CO exposure (defined as above the 90th percentile of the exposure distribution, or an average of 4.1ppm) in the two hours prior to BP measurement was associated with elevations in hourly systolic BP (4.3 mmHg [95% CI: 1.1, 7.4]) and diastolic BP (4.5 mmHg [95% CI: 1.9, 7.2]), as compared to BP following lower CO exposures. We also observed a non-significant trend toward lower BP following initiation of cooking with an improved cookstove. Lastly, we demonstrated that ABPM was a feasible and well-tolerated tool for BP assessment in a rural West African setting. For Project II in New York City, we first determined that there was a great deal of variability in indoor summer heat index (HI) between homes in association with similar outdoor conditions, and that this variability increased with increasing outdoor heat (Chapter 3). Our simulation of a moderate heat wave led us to conclude that the hottest 5% of the homes would reach peak indoor heat index (HI) values of 39°C. In a more extreme heat wave simulation, HI in the hottest 5% of homes reached a peak of 41oC and did not drop below 34oC for the entire nine- day simulated heat wave period. Our second indoor monitoring study yielded the following findings: in the summer season (Chapter 4), we found significant differences in indoor temperature and heat index according to the type of air conditioning (AC) in the home. Homes with central AC were the coolest, followed by homes with ductless AC, window AC, and no AC. Apartments on the top floor of a building were significantly hotter than other apartments regardless of the presence of AC. During the winter season (Chapter 5), median vapor pressure in our sample of apartments was 6.5mb. Comparing humidity levels in the apartments to a threshold of 10mb vapor pressure that has been proposed as protective against influenza virus transmission, levels of absolute humidity in the homes remained below this threshold for 86% of the winter: a total of over three months. Residential use of humidifiers was not associated with higher indoor humidity levels. Larger building size (above 100 units) was significantly associated with lower humidity, while the presence of a radiator heating system was non-significantly associated with higher humidity. Lastly, perceptions of indoor temperature and measured temperature were significantly associated in both the summer and the winter (Chapter 6), while sleep quality was inversely related to measured indoor temperature in the summer season only. Reports of heat- stress symptoms were associated with perceived, but not measured, temperature in the summer season. Conclusions: The work presented in this dissertation adds to a growing body of evidence on the importance of exposures in the domestic environment to health and well-being. The research reported here on household air pollution in Ghana documents an exposure-response relationship between air pollution from cookstoves and elevations in blood pressure, on both a chronic and an acute basis. As elevated BP is a known risk factor for cardiovascular disease (CVD), our research provides support for a plausible factor linking HAP exposure to CVD. Meanwhile, our research on temperature and humidity in New York City residences provides concrete data to supplement the very slim literature to date documenting these conditions in the home environment, where Americans spend over half their time. We conclude, first, that AC may not be fully protective against summertime heat risk, and second, that the levels of humidity we observed in residential environments are consistent with levels that have been shown to promote enhanced survival and transmission of respiratory viruses in experimental settings. We suggest that interventions that can reduce exposure to household air pollution and excess indoor heat can also mitigate climate change, and that with thoughtful planning we can improve health at the same time as we foster resiliency in the face of a changing climate.
215

Indoor air pathogens and HVAC systems in office buildings

Lee, Kai-Yip, 李繼業 January 2004 (has links)
published_or_final_version / Environmental Management / Master / Master of Science in Environmental Management
216

Indoor air quality management: a case study in Hong Kong office buildings

Lam, Pui-fong, Kat., 林珮芳. January 2004 (has links)
published_or_final_version / Environmental Management / Master / Master of Science in Environmental Management
217

Trace organic pollution in the indoor environment

Poon, Tim-leung., 潘添良. January 1993 (has links)
published_or_final_version / Environmental Management / Master / Master of Science in Environmental Management
218

An Evaluation of Mold in Public Schools in the City of Richmond, VA

Asante-Ansong, Stephen 01 January 2007 (has links)
Forty-three (43) schools in the City of Richmond were used for this study. The rooms in these schools that were selected for testing were those rooms in which complaints about air quality were made by school staff. Tests were done to find out the counts of the different mold species present in these schools. Air-O-Cell (AOC) samples were taken in all schools, swab samples were taken in a few and in the rest biotapes were used. Samples that were taken were analyzed and interpreted at AmeriSci Laboratories, an accredited industrial hygiene laboratory. Documentation was done for the sampling methods. Statistical analysis was run on the data received. Tables of results were made, discussions done and conclusions drawn from the laboratory results.The null hypothesis for this study is that "Total inside mold counts are not elevated above the total outside mold counts in Richmond Public Schools" and the alternative hypothesis is that "Total inside mold counts are elevated above the total outside mold counts in Richmond Public Schools". Biodiversity of molds in the indoor environment should be equal to biodiversity of molds in the outdoor environment for each of the classrooms sampled. Also, Total indoor mold counts exceeding 1000 counts/m3 means that particular school could be faced with a mold problem. In conclusion, it was found out that 58% of the schools sampled could be faced with mold problems, thereby rejecting the null hypothesis, and 42% had no mold problems at all, supporting the null hypothesis. Cladosporium was the most dominant mold genus in the schools and the school with the highest total count of molds in the rooms sampled was Maggie Walker School. Recommendations were then made to reduce the abundance of molds in Richmond Public Schools.
219

Charakteristika ovzduší vnitřních prostor zdravotnických zařízení / Characterization of indoor air in health care buildings

Hladíková, Dita January 2013 (has links)
Hospitals and healthcare facilities are very specific times of microenvironments, which requiring monitoring air quality. People who use healthcare facilities are due to a weakened immune system very sensitive to air quality. Acceptable indoor air quality in healthcare facilities may have adverse effects on job performance at the personnel and their errors may have very serious consequences. The aim of this paper is to evaluate the main components of the inner microclimate (temperature and relative air humidity) and concentrations of carbon dioxide in the environment of selected healthcare facilities in the Czech Republic and to compare the results with the related legislation. The measurements were carried out in two hospitals and nine private medical offices from December 2011 to March 2013. The results showed that the values of microclimate factors and the concentration of carbon dioxide in the environment of patient rooms were different in cold and warm part of the year. In the patient rooms the levels of relative humidity diverged from the legal requirements mostly in winter - while those of temperature in summer. The concentration of carbon dioxide was affected by the occupancy rate and the size of the rooms. Air quality in the operating theater was primarily characterized by very low relative...
220

Développement d'un dispositif expérimental pour la mesure des émissions induites par la combustion des parfums d'ambiance

Manoukian, Audrey 13 June 2012 (has links)
La composition de l'air intérieur est complexe et fortement influencée par les activités humaines. Celles-ci engendrent notamment l'émission de composés organiques et de particules. Les inquiétudes grandissantes quant à la qualité de l'air intérieur et à son impact sanitaire ont contraint les pouvoirs publics à prendre des mesures pour mieux assurer son suivi. Parmi les activités humaines fréquemment soupçonnées de contribuer à la contamination de l'air intérieur, on retrouve l'utilisation de parfums d'ambiance de types encens et bougies. De récentes études ont montré que cette pratique pouvait entraîner l'émission de composés organiques volatils (COV) et de particules. Une des carences liées à ces études résulte dans le fait qu'il n'existe pas de protocole de prélèvement et de mesures normalisés pour ce type de pratique, rendant l'exploitation et l'inter comparaison des résultats sujette à beaucoup de controverses. Les industriels français ont dès lors souhaité réagir, par la mise en place d'une méthodologie commune de mesure des émissions induites par la combustion des parfums d'ambiance. Le but de ce travail est de développer et de valider un dispositif expérimental permettant de mieux contrôler la combustion et les paramètres environnementaux qui l'influencent, afin de disposer d'un protocole expérimental calibré et reproductible. Ainsi, après avoir étudié les types de polluants et les possibilités de prélèvements et d'analyses associées, l'étude a été conduite en trois étapes. La première a été réalisée dans une pièce laboratoire simulant en taille réelle la pièce d'un logement. Elle a permis de déterminer le type de composés émis (COV et particules) par la combustion de parfums d'ambiance et les niveaux de concentrations associés. La seconde étape consistait en la réalisation d'un plan d'expériences complet dans une enceinte d'essais d'émissions pour déterminer l'influence de la température, de l'humidité relative et du taux de renouvellement d'air sur les niveaux émissions. Enfin, dans le cadre de la dernière étape, la méthode et les connaissances acquises précédemment ont été transférées à une enceinte d'essai climatique de faible volume, afin de permettre la réalisation d'analyse en routine. / The indoor air composition is complex and widely influenced by human activities. These practices generate organic compound and particles. Growing concerns about indoor air quality and its impact on health have forced the government to make more studies. Among the human practices, recent studies shown that incense and candle combustion could result in the emission of volatile organic compounds (VOC) and particles. However, there is no standard sample protocol for measuring these emissions. The results comparison is then largely controversy. French manufacturers want to develop a methodology for emissions controlling due to the combustion of incense and candle processes. Through this experimental system, they want to learn much more about these processes and emissions control to anticipate the new law. Thus, after studying about the types of pollutants and sampling/analysis protocol associated, three types of studies were conducted. The first study was carried in a room of a house, to determine which kind of compounds were emitted (VOCs and particulate matter) and their concentration levels. The second study was to apply a full factorial design in a chamber emission test, to determine temperature, relative humidity and air exchange rates emissions influences. Finally, in a last study, the method and the knowledge acquired previously were transferred to a climate test chamber of small volume, allowing manufacturers to make routine analysis.

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