Project summary Exposure to smoke from cooking fires is among the top five causes of DALYs and death globally, and in Africa in particular. Our proposed study evaluates the impact of these exposures on lung development. To date, most large-scale research on household air pollution (HAP) has focused on childhood pneumonia. Our preliminary data shows, however, that lung function at age one month correlates with HAP exposures in utero. These results are corroborated by a substantial literature that links ambient air pollution exposures to similar outcomes. Decrements in lung function early in life increase risk of COPD and other chronic respiratory diseases. We propose to build on an existing birth cohort in Ghana – the Ghana Randomized Air Pollution and Health Study, or GRAPHS – to assess how early life exposures affect lung function ages 3 and 6. We will use well-established, validated methods to assess these outcomes, and will also measure air pollution exposures at each of these ages. To gain insight into the molecular mechanisms that link HAP exposure to health, we will also study how exposure affects RNA expression in the placenta, and how these epigenetic changes relate to lung function trajectories. In the long run, our research will help build the evidence base for cost effective interventions to improve health by reducing HAP exposure.