1. Hiroshima City Asa Hospital, Hiroshima, Japan;
2. Radiation Effects Research Foundation, Hiroshima and Nagasaki, Japan;
3. Hirosoft International, Eureka, California;
4. Welfare Association Onomichi General Hospital, Japan;
5. Nagasaki Health Promotion Corporation, Nagasaki, Japan; and
6. Division of Cancer Epidemiology and Genetics, National Cancer Institute, Bethesda, Maryland