A rich literature in public health has demonstrated that health is strongly influenced by a host of environmental factors that can vary according to social, economic, geographic, cultural or physical contexts. Bioethicists should, we argue, recognize this and – where appropriate – work to integrate environmental concerns into their field of study and their ethical deliberations. In this article, we present an argument grounded in scientific research at the molecular level that will be familiar to – and so hopefully more persuasive for – the biomedically-inclined in the bioethics community. Specifically, we argue that the relatively new field of molecular epigenetics provides novel information that should serve as additional justification for expanding the scope of bioethics to include environmental and public health concerns. We begin by presenting two distinct visions of bioethics: the individualistic and rights-oriented and the communitarian and responsibility-oriented. We follow with a description of biochemical characteristics distinguishing epigenetics from genetics, in order to emphasize the very close relationship that exists between the environment and gene expression. This then leads to a discussion of the importance of the environment in determining individual and population health, which, we argue, should shift bioethics towards a Potterian view that promotes a communitarian-based sense of responsibility for the environment, in order to fully account for justice considerations and improve public health.