Background: Air pollution is a serious concern all over the world, and there have been numerous studies showing its adverse effects on health outcomes including disease-specific hospitalization and mortality. Most of these studies were conducted in Western settings and focused on NO2, SO2, PM10 and black smoke; limited results on PM2.5 in Asia have been published. Objectives: This study attempted to identify association between PM2.5 concentration and daily mortality due to all-natural causes, cardiovascular diseases, and respiratory diseases in Hong Kong, a tropical city in Asia from 2008 to 2011. Methods: The study used a case-crossover study design with time-stratified referent selection strategy. The referents were selected on the same day of the week of the same month and year as the event day. In this way, biases due to autocorrelation, time trend, and seasonal pattern were controlled for by study design. Covariates including temperature, humidity, and gaseous pollutants (NO2, SO2, O3 and CO) were adjusted for by statistical modelling. The statistical method applied was Conditional Logistic Regression. Sensitive analyses using matched by month strategy were also conducted to check the robustness of the main analyses. The health outcome variables included were mortality due to all natural causes, cardiovascular disease, and respiratory disease. Each model was examined for effects of PM2.5 at each lag 0 through lag 5 day and, for the current and lag 1 day moving average (lag 0-1). Effects were measured in Excess Risks (ER) associated with 10 μg/m^3 increase in PM2.5. Results: Significant associations with PM2.5 were observed for mortality from all natural causes and cardiovascular disease at lag 0, lag 1, and lag 0-1; and from respiratory disease only at lag 1. At lag 0-1, PM2.5 was associated with mortality from all natural causes, cardiovascular disease, and respiratory disease with the ER (95% confidence interval) of 0.74% (95% CI: 0.29, 1.19), 1.4% (95% CI: 0.52, 2.27), and 0.67% (95% CI: -0.30, 1.64), respectively. After adjusting for each of the co-pollutants in two-pollutant model, the effect magnitude dropped except that one adjusting for CO. The ERs of mortality in co-pollutant models from all natural causes ranged from 0.23% to 1.72%, from cardiovascular disease ranged from 1.00% to 2.93%, and from respiratory disease ranged from -0.10% to 1.83%. The results were robust in sensitivity analyses. Conclusion: My study provides some information to support formulation of air quality control strategies and policies, and for updating air quality standards. Such information includes the overall and seasonal patterns of air pollutants and mortality in Hong Kong, as well as the excess risks of mortality associated with increase in PM2.5. Studies with individual data stratified for subgroups can be conducted in the future to investigate effect modification of lifestyle factors for the individuals and population. / published_or_final_version / Public Health / Master / Master of Public Health

abstract / Public Health / Master / Master of Philosophy

published_or_final_version / Urban Studies / Master / Master of Social Sciences

published_or_final_version / Medical Sciences / Master / Master of Medical Sciences

published_or_final_version / Statistics / Master / Master of Social Sciences

published_or_final_version / Community Medicine / Master / Master of Philosophy

published_or_final_version / Community Medicine / Doctoral / Doctor of Philosophy

by Siu-Fai Leung. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1998. / Includes bibliographical references (leaves 80-81). / Abstract also in Chinese. / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Mortality and Socioeconomic Status --- p.1 / Chapter 1.2 --- Research Plan and Difficulties Encountered in the Study --- p.4 / Chapter 2 --- Imputation and File Merging --- p.8 / Chapter 2.1 --- Structure and Contents of Data Sets --- p.8 / Chapter 2.2 --- Imputation of Missing Values --- p.14 / Chapter 2.3 --- Merging Data Sets --- p.22 / Chapter 2.3.1 --- Merging Death Data and Census Data --- p.22 / Chapter 2.3.2 --- Merging Two Census Data Sets --- p.29 / Chapter 2.3.3 --- Final Data Set Used in Modeling --- p.31 / Chapter 3 --- Modeling and Estimation --- p.33 / Chapter 3.1 --- Discrete-Time Hazard Function Analysis --- p.33 / Chapter 3.1.1 --- The Hazard Function --- p.34 / Chapter 3.1.2 --- Logistic Regression --- p.36 / Chapter 3.2 --- Application of Discrete-Time Hazard Model on the Death Data Set --- p.37 / Chapter 3.2.1 --- Preparing the Person-Period Data Set --- p.38 / Chapter 3.2.2 --- Modeling the Person-Period Data Set --- p.41 / Chapter 3.3 --- Combining Results from different imputed data sets --- p.47 / Chapter 3.4 --- Estimation of Cell Probabilities --- p.51 / Chapter 4 --- Model Adequacy Checking --- p.52 / Chapter 4.1 --- The Definition of Residuals in Multiple Imputation --- p.52 / Chapter 4.2 --- Residual Analysis of The Cancer Mortality Model --- p.59 / Chapter 5 --- Conclusion --- p.63 / Chapter 5.1 --- The Cancer Mortality --- p.63 / Chapter 5.2 --- Competing Risk --- p.68 / Chapter 5.3 --- Discussion --- p.72 / Appendix A: Coding Description of District --- p.75 / Appendix B: Results of the Heart Diseases Mortality Model --- p.76 / Bibliography --- p.80

by Chiu Yuk Lan. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1998. / Includes bibliographical references (leaves 127-133). / Abstract also in Chinese. / TABLE OF CONTENTS / ABSTRACT (ENGLISH) --- p.a / ABSTRACT (CHINESE) --- p.b / ACKNOWLEDGEMENTS --- p.iv / Chapter CHAPTER 1 --- INTRODUCTION --- p.1 / Chapter 1.1 --- Cancer in Food-service Workers --- p.1 / Chapter 1.2 --- Carcinogenicity of Cooking Fumes --- p.1 / Chapter 1.3 --- High Risk of Lung Cancer in Chinese Women --- p.2 / Chapter 1.4 --- Why do We Conduct This Study? --- p.3 / Chapter 1.5 --- Implication of This Study --- p.4 / Chapter 1.6 --- What Types of Cancer were Included in This Study? --- p.4 / Chapter 1.7 --- Aims and Hypothesis of This Study --- p.5 / Chapter 1.8. --- Outline of the Thesis --- p.5 / Chapter CHAPTER 2 --- LITERATURE REVIEW --- p.8 / Chapter 2.1. --- Occupational Epidemiological Studies --- p.8 / Chapter 2.1.1 --- Studies of occupation and cancer occurrence based on routine records --- p.8 / Chapter 2.1.2 --- Retrospective cohort studies among food service workers --- p.21 / Chapter 2.1.3 --- Case-control studies --- p.27 / Chapter 2.1.4 --- Case reports --- p.29 / Chapter 2.1.5 --- Summary --- p.29 / Chapter 2.2. --- Mutagens and Carcinogens in Cooking Fumes --- p.39 / Chapter 2.2.1 --- Mutagens and carcinogens in cooking fumes --- p.40 / Chapter 2.2.2 --- Summary --- p.42 / Chapter CHAPTER 3 --- METHODS --- p.44 / Chapter 3.1 --- Study Design --- p.44 / Chapter 3.2 --- Study Population and Subjects --- p.46 / Chapter 3.3 --- Reference Population --- p.48 / Chapter 3.4 --- Sample Size Estimation --- p.48 / Chapter 3.5 --- Data Sources and Data Collection --- p.49 / Chapter 3.6 --- Data Processing --- p.53 / Chapter 3.7 --- Data Analyses --- p.54 / Chapter 3.7.1 --- Standardised proportional mortality ratio (SPMR) --- p.54 / Chapter 3.7.2 --- Adjusted' SPMRs --- p.56 / Chapter 3.7.3 --- Mortality odds ratio (MOR) --- p.58 / Chapter 3.8. --- Exploring if Smoking could be a Confounding Factor --- p.62 / Chapter CHAPTER 4 --- RESULTS --- p.64 / Chapter 4.1 --- Characteristics of the Food-service Workers --- p.64 / Chapter 4.2 --- Cancer Mortality Patterns of Food-service Workers --- p.69 / Chapter 4.3 --- Adjusted SPMRs --- p.72 / Chapter 4.4 --- Mortality Odds Ratios (MORs) --- p.76 / Chapter 4.5 --- Mortality Odds Ratios Using Multiply Reference Diseases --- p.77 / Chapter 4.6. --- Comparing SPMRs with MORs --- p.82 / Chapter 4.7. --- Internal Comparison --- p.83 / Chapter 4.8 --- Summary of Results --- p.90 / Chapter 4.9. --- Survey on Smoking and Drinking Prevalence among Current Food-service Workers --- p.92 / Chapter 4.9.1 --- Smoking habit --- p.92 / Chapter 4.9.2 --- Drinking habit --- p.94 / Chapter CHAPTER 5 --- DISCUSSION OF FINDINGS --- p.95 / Chapter 5.1 --- Outcomes for This Study --- p.95 / Chapter 5.1.2 --- Cancer risks for the kitchen workers --- p.96 / Chapter 5.1.3 --- Cancer risks for the outside kitchen workers --- p.102 / Chapter 5.2 --- Limitations of the Methods Adopted in the Present study --- p.107 / Chapter 5.2.1 --- Standardised proportional mortality ratio (SPMR) --- p.107 / Chapter 5.2.2 --- Morality odds ratio (MOR) --- p.109 / Chapter 5.3 --- Bias and Control --- p.111 / Chapter 5.3.1 --- Selection bias --- p.111 / Chapter 5.3.2 --- Information bias --- p.113 / Chapter 5.3.3 --- Confounding --- p.116 / Chapter 5.4 --- Implications from the Results of the Present Study --- p.117 / Chapter 5.5 --- Conclusion --- p.119 / APPENDIX --- p.121 / Appendix 1 --- p.121 / Appendix 2 --- p.123 / Appendix 3 --- p.124 / Appendix 4 --- p.125 / REFERENCES --- p.127