Man, fish, and mercury on small islands in Japan.

This paper examines the differentiating patterns of subsistence activities, fish-eating habit, mercure level in human biological specimens, and the interrelation among these variables on several small Japanese islands. The catch and supply of fish vary according to patterns of division of labour on each island. The frequency of fish-eating is generally regulated by the availability of fish, and is well associated with the level of mercury in hair or red cells. Difference in variety of fish consumed has a modifying effect on the mercury level. The importance of understanding the total ecological setting relating to any environmental problem should be emphasized.