This volume is a compilation of 38 papers presented at the First Nagasaki Symposium of the International Consortium for Medical Care of Hibakusha and Radiation Life Science held in Japan on 21 and 22 February 2003.

The use of radiation has extended to various fields including medicine, agriculture, science and engineering, and atomic energy has come to comprise a significant portion of the electric power generated in several advanced countries. The effects of radiation on human health have been investigated in atomic bomb survivors for more than half a century, and the knowledge thus obtained has greatly enriched our understanding. The Chernobyl accident, however, indicated that exposure to low doses of radiation affects human health in a way different from that observed in atomic bomb survivors.

Recognizing the importance of research on low dose or low dose rate radiation, the above event was launched as a 21st Century COE Program with the aim to create an international base for studies on the health effects of low dose or low dose rate radiation from the viewpoint of epidemiology, molecular epidemiology and radiation biology. More than 100 scientists, including 18 scientists from seven countries overseas, participated in the symposium and satellite meetings and engaged in intensive discussions in the above field.