Human ecology in understanding environmental health problems.

The role of human ecology in understanding of environmental health problems is discussed, and the importance of study on "regional" ecosystems is emphasized in consideration of recent arguments on theoretical frame work of human ecology. After brief conceptual discussion on "regional" ecosystems, the environmental health on hunter-gatherer populations, and then, the influence of agricultural development is discussed in relation to the "closedness" of regional ecosystems. Finally, by an example, e.g. islanders on small islands of southern Japan, the differentiation of economic activities by island is shown as the most important regulating factor for the accumulation of mercury in islanders.