Comments on Ortwin Renn's article 'Hormesis and risk communication': considerations about uncertainity, ignorance and...

After acknowledging Renn's careful investigation and valuable insights, this paper expands on some issues that have been somewhat neglected in his account. It addresses the relationship between risk, uncertainity and ignorance in risk assessment, focusing in particular on the need to recognize that framing assumptions condition all subsequent steps. Subsequently, it discusses the implications for risk communication in the case of hormesis. The author maintains that problems of risk are strictly and irremediably intertwined with problems of governance. Therefore, she is doubtful that regulatory agencies would promote, and the public would welcome, modifications in current regimes on the basis of still limited and debated evidence of good.