MEDICAL EFFECTS OF EXPOSURE OF HUMAN-BEINGS TO FALLOUT RADIATION FROMA THERMONUCLEAR EXPLOSION

On March 1, 1954, after detonation of a thermonuclear device on Bikini atoll, an unexpected mind shift resulted in the deposition of radioac tive fallout on inhabited atolls. The fallout radiation caused fleetin g systemic effects, dose-dependent depression of hematopoiesis and ski n burns primarily due to the beta ray component of the fission radionu clides. Within a few weeks, hematopoietic recovery was substantial but slight depression of blood counts was maintained for several years. O ne ease of fatal acute myeloblastic leukemia developed in a boy receiv ing 1.9 Gy as an infant. Cretinism developed in two boys exposed as in fants with estimated thyroidal dose in excess of 50 Gy. Chemical hypot hyroidism was detected in several persons. Thyroid adenomas and cancer commenced appearance ten years after exposure and became a major long -term medical problem. There have been no late effects attributable to the beta burns 40 years after exposure. Internal contamination from i ngestion and inhalation of radionuclides is detectable. The doses are comparable to background levels in the U.S. There is no detectible dec rease in longevity of the exposed Marshallese compared to an unexposed Marshallese population.