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Title Statistical analysis of acute health effects of air pollution
Author Iskandar, Amne
Johansen, Tine
Supervisor Andersen, Klaus Kaae (Mathematical Statistics, Department of Informatics and Mathematical Modeling, Technical University of Denmark, DTU, DK-2800 Kgs. Lyngby, Denmark)
Institution Technical University of Denmark, DTU, DK-2800 Kgs. Lyngby, Denmark
Thesis level Master's thesis
Year 2010
Abstract This thesis deals with statistical methods and the application of these on the association between ambient air pollution in Copenhagen during the years 2003-2009 and stroke incidents occurring in the city. The purpose of the study is to investigate whether the exposure to air pollution is a risk factor for experiencing a stroke. Air pollutants treated are particulate matter measured as PM10, PM2.5, and PM7−800nm, and the traffic pollutant NO2. Air pollution data is given as an average of measurements from three monitors located in downtown Copenhagen, and the measurements are daily averages. Stroke admission data considered is information about 8808 patients with ischemic stroke and without atrial fibrillation (the most common type of arrhythmia. An arrhythmia is a problem with the rate or rhythm of the heartbeat). In order to explore the association between ambient air pollution and the number of acute hospitalised stroke patients, a systematically working process is needed. Therefore, the performing process is divided in several steps. First, descriptive introductions of the stroke and air pollution data are given. Second, an exploratory data analysis is performed and a theoretical introduction to the statistical approach is given. Two methods have been applied for comparison. Both a time series analysis and a casecrossover analysis have been considered using generalised additive models and conditional logistic regression respectively. Furthermore two techniques have been applied to the pollutants in each case, namely moving average and unconstrained distributed lag. Third, the results from both the time series analysis and case-crossover analysis are presented in two separate chapters. Each chapter includes discussions of the results and a conclusion. Last, an overall discussion and a conclusion is given together with thoughts and considerations about future work. The results from the analysis using both generalised additive models and conditional logistic regression showed somewhat the same results. Particulate matter was found not to be significant associated with stroke incidents, although the ultrafine particles, PM7−800nm, showed associations for certain subgroups of the stroke population. NO2 was found significantly associated with stroke incidents for all patients as well as for subgroups without certain co-morbidity or unhealthy habits. It appears from these finding that traffic is the main contributor for the relation between stroke incidents and ambient air pollution in Copenhagen.
Imprint Technical University of Denmark (DTU) : Kgs. Lyngby, Denmark
Series IMM-M.Sc.-2010-35
Original PDF ep10_35_net.pdf (2.83 MB)
Admin Creation date: 2010-06-18    Update date: 2010-06-18    Source: dtu    ID: 263866    Original MXD