[1] Hirosaki Univ, Fac Sci & Technol, Dept Earth & Environm Sci, Hirosaki, Aomori 0368561, Japan
[2] Univ Tokyo, Res Ctr Nucl Sci & Technol, Tokyo 1130032, Japan
[3] Russian Acad Sci, Limnol Inst, Irkutsk 664033, Russia
[4] Fujii Inst Environm Geol, Toyama 9398075, Japan