Public health ethics, like the field of public health it addresses, traditionally has focused more on practice and particular cases than on theory, with the result that some concepts, methods, and boundaries remain largely undefined. This paper attempts to provide a rough conceptual map of the terrain of public health ethics. We begin by briefly defining public health and identifying general features of the field that are particularly relevant for a discussion of public health ethics.

Public health is primarily concerned with the health of the entire population, rather than the health of individuals. Its features include an emphasis on the promotion of health and the prevention of disease and disability; the collection and use of epidemiological data, population surveillance, and other forms of empirical quantitative assessment; a recognition of the multidimensional nature of the determinants of health; and a focus on the complex interactions of many factors — biological, behavioral, social, and environmental in developing effective interventions. 

Richard J. Bonnie et al., Public Health Ethics: Mapping the Terrain, 30 Journal of Law, Medicine, & Ethics 170–178 (2002).