Thesis (M. Phil.)--University of Hong Kong, 2000. / Includes bibliographical references (leaves 110-120).

Thesis (M. Sc.)--University of Hong Kong, 2000. / Includes bibliographical references (leaves 85-90).

Thesis (Ph. D.)--University of Texas at Austin, 1998. / Vita. Includes bibliographical references (leaves 346-351). Available also in a digital version from Dissertation Abstracts.

Thesis (M.S.)--Rochester Institute of Technology, 2006. / Typescript. Includes bibliographical references (leaves i-xvi).

Thesis (M.Phil.)--Hong Kong University of Science and Technology, 2007. / Includes bibliographical references (leaves 85-92). Also available in electronic version.

No description available.

This thesis presents the results of a research project that involved laboratory experimentation for gathering data on how the concentration of a dense gas disperses in indoor air. A box was built and designed as a model of a typical indoor environment and a dense contaminant, carbon dioxide, was injected into the box at a known flow rate through either a high or a low injection port. The gases left the box through either a high or a low exit port. The concentration of the contaminant inside the box was measured with an indoor air quality monitor at sampling ports at different locations and at different times during the experiments. The time and place dependent data were organized to observe the pattern of dispersion of a dense indoor air contaminant. It was determined that CO2 tended to sink down and move away from the point of injection at lower elevations, while gradually diffusing upwards. It was concluded that the dispersion of carbon dioxide in the box was driven mainly by the density gradient and to a less extent by diffusivity.

BACKGROUND: Dampness and mould exposure have been repeatedly associated with respiratory health. However, less is known about the specific agents provoking or arresting health effects in adult populations. We aimed to assess predictors of microbial agents in mattress dust throughout Europe and to investigate associations between microbial exposures, home characteristics and respiratory health. METHODS: Seven different fungal and bacterial parameters were assessed in mattress dust from 956 adult ECRHS II participants in addition to interview based home characteristics. Associations between microbial parameters and the asthma score and lung function were examined using mixed negative binomial regression and linear mixed models, respectively. RESULTS: Indoor dampness and pet keeping were significant predictors for higher microbial agent concentrations in mattress dust. Current mould and condensation in the bedroom were significantly associated with lung function decline and current mould at home was positively associated with the asthma score. Higher concentrations of muramic acid were associated with higher mean ratios of the asthma score (aMR 1.37, 95%CI 1.17-1.61). There was no evidence for any association between fungal and bacterial components and lung function. CONCLUSION: Indoor dampness was associated with microbial levels in mattress dust which in turn was positively associated with asthma symptoms.

No description available.

Background: Exposure to indoor air pollutants has been associated with poorer respiratory health in children. This study investigates the respiratory health of Malaysian schoolchildren in relation to indoor air pollution. Methods: This cross-sectional study was conducted among 2,164 schoolchildren aged 10-11 years in urban and semi-rural schools. Parents completed a questionnaire and concentrations of air pollutants were measured in schools. SHS exposure was assessed using salivary cotinine. Results: The WHO Air Quality Guideline for PM2.5 was exceeded for most of the semi-rural schools while almost all of the urban schools exceeded the annual exposure limit for NO2. The Geometric Mean salivary cotinine concentrations for non-smoking schoolchildren were 0.47 ng/ml. The 3 main predictors of nocturnal cough were the presence of a current smoker at home (OR 1.97; 95% CI: 1.31-2.96), the absence of exhaust system in the kitchen (OR 1.67; 95% CI: 1.03-2.68) and the use of air conditioning (OR 3.10; 95% CI: 1.37-5.71). Exposure to SHS of ≥4 hours per day (OR 2.53; 95% CI: 1.55-4.14) explained approximately 6.0% of the likelihood of reporting doctor-diagnosed asthma. For the measure of asthma severity, NO2 and log average family size were the 2 predictors of limited speech during wheeze; NO2 concentrations of >50 μg/m3 contributes an OR of 5.98 (95% CI: 1.02-34.9) and log average family size with an OR of 14.6 (95% CI: 1.70-126). Conclusion: This study has identified that many Malaysian schoolchildren experience exposure to air pollution indoors that exceeds WHO guidance limits for several pollutants. There was no clear relationship between traffic-generated air pollutants and children’s respiratory health but there was a strong relationship between the number of hours children were exposed to SHS and asthma. There is a need for increased enforcement of existing smoke-free legislation and policies to reduce children’s exposure to SHS.