This chapter has a tripartite structure, each step corresponding to a section and sub-sections. This tripartite structure mirrors the three key elements of the problem that this book aims to tackle: public and environmental health; risk and environmental health risk; governance and risk governance. These key notions shape the problem of (perceived) legitimacylegitimacy and accountability gaps in the governance of environmental risks to public health. In the chapter, these notions are described as isolated concepts as well as in their interplay. These concepts are problematized through the juxtaposition of definitions formulated from different standpoints, i.e., the institutional and the academic. Arguably ‘reference notions’, such as that of environmental health and public health, are criticized through the voices of diverging opinions expressing criticisms (i.e., over-simplification, biases). The discussion of these notions sets the scene for the research that follows and unveils inherent conflicts in notions presented as the reference.