ABSTRACT
The shift to a more ecological focus for understanding health and disease has been accelerated by social and political realities that currently affect opportunities for scientific inquiry. A larger picture is unfolding of how humans interact with their macro and micro environments. Collective human activity helps shape larger environmental conditions. The biological and social environments have been changing in ways that affect health. Since World War II, the global physical and atmospheric environment has changed in ways that have important implications for the health of humans in various parts of the world, including persons living in the United States. As ecological perspectives came into wider use, however, they began to restructure the medical community's understanding of the germ theory of disease, and the relation of biological processes to other levels of causation. Research on cardiovascular disease, a health problem that only occasionally can be traced to the work of infectious agents, helped move medical understanding in a more 'ecological' direction.
