Abstract
The selenium content and its chemical form were studied in water collected from nine main rivers in Japan. It was confirmed that there are two different chemical forms of selenium in river water, i.e., the tetra- and hexa-valent inorganic ions, but no organic form is found. The total selenium content of river water ranged from 33 to 94 ng l-1 with a weighted average of 57 ng l-1. The fraction of selenium contained in suspended matters was below 10% of the total.
