Let Chromosomes Speak: The Cytogenetics Project at the Atomic Bomb Casualty Commission (ABCC).

Hibakusha (atomic bomb survivors) are "witnesses" of the atomic bombings, not just in a standard sense but also in the instrumental sense. For medical and scientific experts, hibakusha are biological resources of unparalleled scientific value. Over the past seventy years, the hibakusha bodies have narrated what it means to be exposed to radiation. In this paper, I explore studies at the Atomic Bomb Casualty Commission (ABCC) that examined hibakusha bodies as sites where risk could be read. I focus on a period from the mid-1950s to 1975, during which new methods, practices, and technologies allowed ABCC scientists to investigate chromosomes as a way to study radiation exposure and human risk. By focusing on chromosomal aberrations, ABCC scientists connected their work directly to the emerging infrastructure for radiobiology at the time. ABCC administrators actively sought out such prestige, especially given their relationship with the Atomic Energy Commission (AEC). The shift in approach would also alleviate some public relations problems with which the institution was struggling. Launching a cytogenetics program required some older practices that had assumed American privilege and dominance to be abandoned. Eventually, the decision to let chromosomes speak of radiation exposure brought about fundamental changes in ABCC, which came to symbolize the model for future studies at the organization, especially as ABCC was transitioning to a US-Japan binational organization. More broadly, this case highlights the intricate scientific negotiation of radiation risk where uncertainties necessarily prevail.

Healing a Sick World: Psychiatric Medicine and the Atomic Age.

The onset of nuclear warfare in Hiroshima and Nagasaki had far-reaching implications for the world of medicine. The study of the A-bomb and its implications led to the launching of new fields and avenues of research, most notably in genetics and radiation studies. Far less understood and under-studied was the impact of nuclear research on psychiatric medicine. Psychological research, however, was a major focus of post-war military and civilian research into the bomb. This research and the perceived revolutionary impact of atomic energy and warfare on society, this paper argues, played an important role in the global development of post-war psychiatry. Focusing on psychiatrists in North America, Japan and the United Nations, this paper examines the reaction of the profession to the nuclear age from the early post-war period to the mid 1960s. The way psychiatric medicine related to atomic issues, I argue, shifted significantly between the immediate post-war period and the 1960s. While the early post-war psychiatrists sought to help society deal with and adjust to the new nuclear reality, later psychiatrists moved towards a more radical position that sought to resist the establishment's efforts to normalise the bomb and nuclear energy. This shift had important consequences for research into the psychological trauma suffered by victims of nuclear warfare, which, ultimately, together with other research into the impact of war and systematic violence, led to our current understanding of Post-Traumatic Stress Disorder (PTSD).

Rediscovery of an old article reporting that the area around the epicenter in Hiroshima was heavily contaminated with residual radiation, indicating that exposure doses of A-bomb survivors were largely underestimated.

The A-bomb blast released a huge amount of energy: thermal radiation (35%), blast energy (50%), and nuclear radiation (15%). Of the 15%, 5% was initial radiation released within 30 s and 10% was residual radiation, the majority of which was fallout. Exposure doses of hibakusha (A-bomb survivors) were estimated solely on the basis of the initial radiation. The effects of the residual radiation on hibakusha have been considered controversial; some groups assert that the residual radiation was negligible, but others refute that assertion. I recently discovered a six-decade-old article written in Japanese by a medical doctor, Gensaku Obo, from Hiroshima City. This article clearly indicates that the area around the epicenter in Hiroshima was heavily contaminated with residual radiation. It reports that non-hibakusha who entered Hiroshima soon after the blast suffered from severe acute radiation sickness, including burns, external injuries, fever, diarrhea, skin bleeding, sore throat and loss of hair-as if they were real hibakusha. This means that (i) some of those who entered Hiroshima in the early days after the blast could be regarded as indirect hibakusha; (ii) 'in-the-city-control' people in the Life Span Study (LSS) must have been irradiated more or less from residual radiation and could not function properly as the negative control; (iii) exposure doses of hibakusha were largely underestimated; and (iv) cancer risk in the LSS was largely overestimated. Obo's article is very important to understand the health effects of A-bombs so that the essence of it is translated from Japanese to English with the permission of the publisher.