Informing effective public health interventions to reduce exposure to household air pollution in urban Rwanda

Cooking with solid biomass fuel is a global public health concern, presenting significant morbidity and mortality due to exposure to household air pollution (HAP). The HAP burden in urban Rwanda is high because of ongoing reliance upon solid biomass usage and rapid population growth. This thesis aims to inform the future development of effective public health interventions to address HAP in urban Rwanda, using a convergent mixed-methods approach. A systematic review, secondary data analyses of a population-based dataset and primary quantitative (semi-structured survey) and qualitative (in-depth interviews) data collection and analysis have been undertaken. Results of these activities have been interpreted and integrated using the development phase of the Medical Research Council's (MRC) complex intervention framework. Health risk assessments showed reduced risks of acute respiratory infections for children under five years associated with outdoor compared to indoor biomass fuel cooking, which may inform development of a health behaviour focussed intervention. In addition, biomass fuel use was not protective against risk of malaria infection, of relevance for a health educational intervention. Transition from charcoal to wood fuel (as observed during the COVID-19 pandemic) may be associated with increased risks of acute respiratory infection; of importance for future unintended consequences arising from fuel restriction policies, including a proposed charcoal ban in Rwanda. Qualitative investigation identified that cleaner fuels were the desired cooking fuel of choice, but structural and cultural barriers remain to access, uptake and concerns persist regarding outdoor cooking practices. The evidence from this thesis has enabled identification of potential health behavioural change interventions to mitigate HAP harms in urban Rwanda. Findings highlight the importance of early user involvement and co-production to ensure cultural suitability and sustained uptake. Interventions may be supported by appropriate policy initiatives, which must identify and mitigate potential unintended consequences at a policy formulation stage.