The project aimed to develop integrated tools for policy analysis and modeling of the air pollution challenge in Vientiane province, Laos PDR, and Chiang Rai province, Thailand. Conducted by the UNDP Bangkok Regional Hub, the Millennium Institute developed the Integrated Ambient Air Pollution (IAP) model to analyze policy interventions addressing air pollution. The model focused on key sources and drivers of air pollution, their implications for health and socio-economic development, and potential policy interventions. The project, spanning 26 months from January 2021 to March 2023, included participatory systems mapping with stakeholders, data collection, technical model development, and policy scenario simulations. It concluded with training workshops in both provinces to enable stakeholders to use the model for effective policy development and investment scenario analysis.