In this paper I address conceptual associations, boundaries, and limits of definitive knowledge about pollution risk, safety, and mental health after the Fukushima Nuclear Power Plant catastrophe. My concerns are primarily two-fold: First, as uncertainty of knowledge about the extent of radiation contamination produces dangers beyond biophysical hazards, looking beyond epidemiological data on mental wellbeing, I suggest extending an ethnographic focus not only to the risks of pollution but also to the pollution of risks, including the socially polluting aspects of contamination. Second, the ‘psychologisation’ –– an extension of the problem of medicalisation –– of disaster is interrogated to access how judgements about the catastrophic potential of risk perception are formed.