There is a wicked paradox between the fact that metal production is essential to the global sustainable energy transition and the fact that metal production often leads to a degraded quality of life for people living near the production sites due to contaminant emissions. Involving citizens in implementing mitigation measures around metal processing (MP) sites is a key objective of the United Nations. However, establishing community engagement around MP sites has posed challenges so far because the discrepancy between the global interests of metal operators and the local concerns of residents hinders dialogues and concertation. We hypothesize that combining the perspectives of citizens and metal operators will enable us to collectively design solutions for a better quality of life near MP sites and therefore, empower citizens to implement mitigation measures. To explore this hypothesis, we will focus on 2 major MP operations: primary mining of lithium in Ghana and recycling of lead in Senegal. COMBINE will co-build knowledge and solutions to transform the quality of life near metal processing sites, by 1. evaluating the impact of MP activities on their living environment from the citizen perspective, 2. describing the metals processing and their emissions from the MP sites perspective, 3. implementing solutions to both promote sustainable policies and empower citizens around/for MP sites. We will rely on the combination of participative biomonitoring methods implementing passive vegetal sensors and MP site description that we have developed. By linking, for the first time, our 3 disciplines -geosciences, process engineering, anthropology- with participatory sciences, our consortium makes it possible to study simultaneously the processes inside MP sites and contamination outside thanks to a source-to-sink approach, bringing a global understanding of impacts of metal production and proposing associated win-win solutions that will pave the way to design new policies.