Phosphorus (P) is an essential, finite resource whose geological, economic, and geopolitical accessibility may become critical in the future. Because P losses from agriculture, sewage and waste have serious environmental impacts such as eutrophication, it would be desirable to close P cycles. However, there may arise
dilemmas due to trade-offs with other issues. For instance, recycling of animal bones – containing relatively high amounts of P – was prohibited in Switzerland after the BSE crisis (1989 to 2000) due to perceived health risks. Our analysis indicates that the greatest potentials for closing the P cycle in Switzerland are to reduce P losses in agriculture and to increase P recovery from sewage and
waste. Whereas in agriculture significant improve ments have been made, the disposal dilemma of animal bones led to diminishing amounts of P being recycled from waste. Based on their risk percep tion, the involved stakeholders prioritized preventing poten tial harm to (human) health over maximiz ing P recycling.