Chromosome Stories: How Scientists Tracked Radiation Risk after Hiroshima and Nagasaki

This dissertation is about the scientists who strived to track radiation risk after Hiroshima and Nagasaki. It focuses on cytogeneticists and epidemiologists at the Atomic Bomb Casualty Commission (ABCC)—later re-institutionalized as the Radiation Effects Research Foundation (RERF)—who devoted their careers to investigating chromosomes drawn from the hibakusha, atomic-bomb survivors, as biological entities. It considers the experiences of these scientists who studied chromosomes, the technologies and infrastructure that facilitated the studies, the complex relationship between the hibakusha and the scientists, as well as the broader community in which the research outcomes shaped the policy and practice of radiation protection. By doing so, it asks how acts of extreme violence that wrought unique biological effects became an opportunity and resource for scientific advancement, and the implications of such a story for our understanding of science, ethics, and social justice. Chromosomes reveal much more than the internal working of the ABCC and RERF, or the development of cytogenetics as a field of scientific inquiry. This dissertation uses the hibakusha chromosomes to contextualize the cytogenetic labor at ABCC/RERF and the aspirations of scientists in the larger history of the atomic age; to highlight the complex relationship between diplomacy and science; to shed light on the extensive global infrastructure of radiobiology as a response to emerging geopolitical risks; and to consider the forms of power and violence that are inextricably linked to the work of science. The dissertation argues that as long as the RERF remains as an institution that primarily serves regulatory bodies, whose ultimate aim is risk estimates at a population level, it does not reconcile with hibakusha who ask the science to serve their individual health. Ultimately, this dissertation shows how studies of chromosome mutations were in themselves mutated forms of scientific violence. The RERF was undoubtedly a critical node in post-WWII global biomedicine—connected to intimate experiences of pain and illness, and to international debates on nuclear weapons and nuclear energy. The contradictions and vexations of this institution reflect its almost impossible agenda—to transform Hiroshima and Nagasaki from sites of violence into sites of knowledge.