The Radiation Effects Research Foundation was established in 1975 after reorganization of its predecessor organization, the Atomic Bomb Casualty Commission (ABCC), with this year marking RERF’s 50^th anniversary. To commemorate this milestone, a 50^th anniversary ceremony was held in Hiroshima on June 17, 2025, and in Nagasaki on June 20.

At both venues, RERF was pleased to welcome survivors and their families, scientists who have consistently supported our work, distinguished guests, and members of the general public who had registered in advance to attend the event. Everyone’s participation was key to the ceremonies’ success.

The Hiroshima ceremony was held at the Hiroshima Prefectural Medical Association Hall, with around 330 attendees. During the commemorative lecture, Mr. Tomoyuki Mimaki, Chair of the Hiroshima Prefectural Confederation of A-bomb Sufferers Organizations (Hiroshima Hidankyo) and Co-chair of the Japan Confederation of A- and H-Bomb Sufferers Organizations (Nihon Hidankyo), spoke about his long-standing peace activities, including about the organization being awarded last year’s Nobel Peace Prize. Dr. Jonathan Samet, Professor and former Dean of the Colorado School of Public Health in the United States, then introduced the history and achievements of RERF’s research, highlighting the scientific organization’s considerable contributions to the health and welfare of A-bomb survivors as well as to the protection from radiation for all of humanity. Dr. Samet also expressed his expectation for further progress in future research using new analysis technologies. At the close of his remarks, he acknowledged the significance of the contributions made by the survivors themselves to such important research.

The Nagasaki ceremony was held at the venue Dejima Messe Nagasaki, with around 150 attendees. Dr. Masao Tomonaga, Professor Emeritus at Nagasaki University and President of the Nagasaki Prefectural A-bomb Victim’s Handbook Association, spoke about the history and results of research into the health effects of A-bomb radiation, particularly the longstanding research on leukemia and myelodysplastic syndromes. He also touched on the difficulties A-bomb survivors have faced in their lives. Following his talk at Hiroshima, Dr. Samet delivered another commemorative lecture at the Nagasaki event.

RERF would like to take this opportunity to express our sincere gratitude to everyone who participated in the ceremonies, including those who spoke and those who sent congratulatory messages or telegrams.

RERF has been able to continue its research and studies over the past 50 years due to the understanding and cooperation of the survivors, their descendants, members of the public, and related organizations. RERF is deeply grateful for their support. In the future, RERF will continue to conduct its research on the medical effects and diseases caused by radiation exposure, with the aim of contributing to the health and welfare of A-bomb survivors. RERF also remains committed to advancing human health globally with a focus on peaceful purposes.

Ceremony venue in Hiroshima (July 17)

Scene at Hiroshima ceremony

Jonathan Samet speaks at Hiroshima event

Lecture provided by Tomoyuki Mimaki

Congratulatory messages received from all over

Reunion among former RERF members

Ceremony venue in Nagasaki (June 20)

Scene at Nagasaki ceremony

RERF Chair Kenji Kamiya gives opening greetings

Talk provided by Jonathan Samet

Lecture by Masao Tomonaga

Scene of displays at venue