Health risk from pm2.5 and ozone in Melbourne : present and projected futures
Creators: name: Sujaritpong, Sarunya
Publisher: name: The Australian National University
Year: 2014

description: In Australia, adverse health impacts of air pollution have still been reported despite relatively low pollution levels. There is a growing concern that climate change may have a detrimental effect on future air quality and impose additional air pollution-related health burdens. This thesis aimed to assess the impacts of future climate change on the health effects of air pollution in the Melbourne Region. Firstly, the best approach was identified to estimate baseline relative risks for cardiovascular and respiratory mortality and emergency department (ED) visits associated with exposure to particulate matter with diameters of less than 2.5 micrometres (fine PM) and ozone. A Poisson regression model was fitted to estimate the baseline relative risks by using data during 1999-2008. A blending approach in which air pollution and weather data were generated by merging simulations and measurements was selected as it provided larger risk estimates, thought to indicate lower measurement error. The blending approach was used further to explore whether there was evidence of a modifying effect of temperature on the air pollution-related health risks. The Poisson model previously developed was modified to include an interaction term for temperature strata. Non-uniform relative risks for fine PM- and ozone-related respiratory ED visits across the temperature range were observed, suggesting the effect modification of temperature. Next, the baseline relative risks earlier estimated were used to predict changes in air pollution-related respiratory ED visits induced by climate change in the Port Phillip Region between 2065-2074 and 1996-2005. Two methods, with and without inclusion of the temperature modifying effect, were used. Without the temperature modifying effect, exposure to future ozone modified by the changing climate was estimated to cause an additional 60 to 110 respiratory ED visits over three summer months. An increase of 15 to 26 respiratory ED visits over the summer period was estimated due to exposure to fine PM. In winter, a reduction in fine PM-related respiratory ED visits was estimated based on three of four global circulation models. When using the method taking account of the temperature modifying effect, an increase in estimates of fine PM-related respiratory ED visits for summer and winter between the two periods was predicted, with a greater magnitude compared to the estimates predicted by the other method. A little difference in ozone-related respiratory morbidity between the two decades was predicted for summer with inclusion of the temperature modifying effect. Finally, the sensitivity of the estimated changes in respiratory morbidity to uncertainties in non-climate factors was explored. Among the factors examined, future population growth appeared to be the largest contributor to the variation in estimated changes in the future health effects of air pollution. This thesis provides a systematic investigation of the health risks of air pollution under the effects of future climate change, including a careful analysis of the sensitivity of the results to uncertainties. Assessing the health impacts of extreme air pollution episodes under climate change is an important area, not examined here, that should be the focus of future studies.