Dr.Miyao from Nagoya university published a report about low dose symptom.
He researched the victims of Hiroshima atomic bomb. Accoring to his study,even the low dose exposure(~5mSv~100mSv in total life span) causes cancer risk.
Solid Tumors;120~130%
Liver cancer;170~270%
Uterus cancer;180~200%
http://www.47news.jp/CN/200808/CN2008080401001105.html