Understanding the human health impacts of extreme events in a changing climate using an environmental health translational research approach
Creators: name: Campbell, SL
Publisher: name: University Of Tasmania
Year: 2023

description: Anthropogenic climate change is influencing healthcare outcomes, policy and service delivery around the world, from the direct impact of extreme events, to the consequences of water and food insecurity and the management of poor mental health arising from trauma and displacement associated with these events. Understanding how extreme events impact health outcomes allows the healthcare system to prepare for, manage and support an appropriate emergency response and recovery effort when these events occur. This thesis uses an existing environmental health translational research framework (Kaufman &amp; Curl 2019) to contextualise a series of studies related to climate change and health. The five stages of this framework: i) discovery; ii) health implications; iii) policy implications; iv) policy and practice implementation and v) outcome evaluation, are applied to the studies. Each study relates to climate-related extreme events, such as heatwaves, severe storms, and bushfires across international, national and local settings, all with direct relevance to the state of Tasmania, Australia. This thesis uses a mix of methods, including a literature review, a descriptive survey, and quantitative epidemiological analyses of health services utilisation data using case-crossover and case-control study designs. Datasets from a number of existing sources were integrated, including meteorological (temperature, wind and lightning strike), air quality (particulate matter and pollen), and health outcomes (hospital emergency department presentations and ambulance dispatches), as well as online data collection and surveys to generate and analyse unique datasets. Through a literature review (Chapter 2), I found that research on heatwaves and human health is not evenly distributed across the globe, but concentrated on those regions with the greatest capacity to respond to and recover from these types of events. I found that regions at greatest risk of adverse human health outcomes, due to the likelihood of non-survivable temperatures in the near future and/or high rates of poverty and disadvantage, are substantially underrepresented in the research. This process enabled the identification of research gaps, thereby supporting the progression of research in subsequent chapters, and fitting to Stage 1 (the discovery stage) of the identified research translation framework. In Chapters 3 and 4, I used a case-crossover study design to evaluate the association between heatwaves and hospital emergency department presentations (Chapter 3) and heatwaves and ambulance dispatches (Chapter 4) in the temperate island state of Tasmania, Australia. I found that severe and extreme heatwave events were associated with a 5% increase in emergency department presentations (OR 1.05, 95% CI 1.01-1.09) across the whole population, with a 13% increase for children 15 years and under (OR 1.13, 95% CI 1.03-1.24), and a 19% increase for children 5 years and under (OR 1.19, 95% CI 1.04-1.36). My results for ambulance dispatch data were similar. I found that severe heatwaves were associated with a 10% increase in ambulance dispatches overall (OR 1.10, 95% CI 1.05-1.15), and extreme heatwaves were associated with an increase of 34% (OR 1.34, 95% CI 1.18-1.52). In both studies I found an increased magnitude of association between heatwaves and health service use in younger and older age groups, and for ambulance dispatches, an increase in utilisation for areas of greater socio-economic disadvantage. These findings critically inform public health responses and health promotion efforts. Both chapters are placed in Stages 2 and 3 of the framework, where the health implications and policy and practice implications are identified. In Chapter 5, I analysed 14.5 years of meteorological and asthma emergency department data and found no documented instance of an epidemic of asthma coinciding with thunderstorm activity, despite recurrent serious and life-threatening epidemic thunderstorm asthma events repeatedly experienced in mainland Australia over a similar time period. I concluded that that the risk of epidemic thunderstorm asthma events in Tasmania is minimal, due to its island biogeography and climate leading to different seasonal patterns of thunderstorms unlikely to coincide with peak pollen seasons. This risk assessment informs the policy and practice implementation of asthma management in Tasmania, thereby providing a robust example of Stage 4 of the Kaufman and Curl framework. In Chapter 6, I distributed an online survey to users of the AirRater smartphone app and asked about their experience of the Australian 2019-20 bushfire season. Respondents documented a wide range of self-reported symptoms attributed to smoke exposure with one-third of respondents visiting a medical professional for assistance with health issues associated with smoke exposure. Furthermore, the responses informed how digital technology is used in extreme and prolonged smoke events. These findings helped to inform policy and practice in a third climate-related extreme event, thereby supplying a second example of Stage 4 in the research translation framework. These findings have broad policy implications, with a clear research to policy translation pathway. Within Tasmania, these findings can be used to target public health campaigns to reduce heat illness during periods of extreme heat, while also enabling emergency responders such as paramedics and emergency physicians to understand and manage surge capacity during these events. Public health policymakers in Tasmania can also use this research to realistically manage the threat of a local thunderstorm asthma event. More broadly, public health policymakers seeking to understand the impact of adverse air quality on human health have been provided with an insight into the needs and concerns of those experiencing prolonged and extreme poor air quality events. The inclusion of a research translational framework, and placing these studies into the framework, describes the range of outcomes translational research can provide.