This lecture delves into the widespread dioxin pollution uncovered in Lausanne, Switzerland, raising concerns about health consequences, clean-up costs, and the extent of the problem. It explores the historical pollution carried out over several decades, the surprising findings in the city's drinking water, and the need for precautionary measures. The instructor discusses the challenges posed by legacy contamination, the industrial history of Switzerland, and the remediation technologies available. The lecture also covers the importance of investigating and cleaning up public sites, the potential for similar dioxin problems in other Swiss regions, and the government's draft revision of environmental protection laws.