Abstract
An ecological perspective places emphasis on features of the environment, social as well as physical and biological, as a system of resources and constraints within which people act in obtaining, distributing, and consuming resources. Emphases of public health activities also have been placed on the same areas: the interactions of environmental conditions, and health conditions of people. Different emphasis between the two directions may be placed depending on the decision of health planners, the severity of the health problems, the technology and the resources available. But, in a closed and traditional rural community, or the national level, the two focuses have been generally well integrated. These two em-phases are what I would like to interpret as site-specific and population-specific focuses. With a rapid urbanization and industrialization, there is a wide recognition of an increased permeability of population boundaries due to a growing flux of migration. People maintain their relation to the areas of origin, and their health conditions are subject to the environmental conditions of both the areas of origin and of destination. In this situation, traditional community-based health activities do not necessarily cover the health problems of migrants. Thus there is a need for conceptual integration of site- and population-specific research focuses so that the two focuses appropriately include people moving from one area to the other.
