—2V4 KECOROS: COLLECTION (VARS HALL ISLANDS acpositony BOX No MEDICAL DEFT FELDER —12432 y+ tay Sau rele Brookhaven National Laboratory ISIN Upton, L. L, New York #9o of Human Beings to Fallout \iedical Effects of Exposure Radiation from a Thermonuclear Explosion ae 1 af) Meg The Medien) Besesrcy Contos PVBLILATIONS PRAM MESSION OLANNIAE wove Mues, ney. ALBA? Euvene P. Cronkite, Victor P. Bond, Robert A. Conard Medical Department. Brookhaven National Laboratory, Upton. New York, USA Abstract. On March 1, 1954, after detonation of a thermonuclear device on Bikini atoll, an unexpected wind shift resulted in the deposition of radioactive fallout on inhabited atolls. The fallout radiation caused fleeting systemic effects, dose-dependent depression of hematopoiesis and skin burns pri-. marily due to the beta ray componentofthefission rudionuclides. Within a few weeks, hematopoietic recovery was substantial but slight depression of hluod counts was maintained for several years. One case of fatal acute myeloblastic leukemia developed ina boy receiving 1.9 Gy as an infant. Cretinism developed in two boys exposed as infants with estimated thyroidal dose in excess of 50 Gy. Chemical hy pothyroidism was detected in several persons. Thyroid adenomas and cancer commenced appearunce ten years after exposure and became a major long-term medical problem. There have been no late cifects attributable to the beta burns 40 years after exposure. Internal contamination from ingestion and inhalation of radionuclides is detectable. The doses are comparable to backgroundlevels in the | .S. There is no detectible decrease in longevity of the exposed Marshallese compared to an unexposed Marshallese population. introduction The Marshall Islands are located in the castern part of Micronesia a few degrees north ot the equator. The atolls consist of a ring of ‘ow-TNing coral islands surrounding a lagoon. The islands are formed on the rims of extinct ‘olcanic craters. The coral sand consists primarily of calcium carbonate and lesser amounts Correspondence: Dr. Eugene P. Cronkite. Medical Department, Brookhaven National Laboratory. P.O. Box 5000, Upton. New York 11973-5000 USA. Received November 14, 1994; accepted for publation November 14, 1994, ©AlphaMed Press 1066*099/95/$5 00/0 < + of other minerals. From 1946 until the termination of atmospheric testing in 1958, the Marshall Islands were used fortesting of nuclear devices. Testing was done on Bikini atoll and Enewetak atoll. In addition, the United States developed the Pacific Missile Range at Kwajaiein. thus the area was under the control of the Department of Defense and the Atomic Energy Commission. Until Operation Castle in 1954, Marshallese populations were removed from the atolls near the test site during testing. During Operation Greenhouse 1951, fallout was detected but not considered a serious health problem. The Marshallese people were not evacuated from inhabited atolls for Operation Castle. On March 1, 1954, at 6:30 a.m., a nuclear device was detonated on Bikini. An unexpected change in the windstructure distributed fallout over inhabited areas exposing Marshallese. American military personnel and Japanese fisherman on board the Lucky Dragon. Details of the accident and its effect on the Marshallese were published by Cronkite er ai. [1.2]. The data are summarized herein. The intense heat of the detonation incinerated the coral producing calcium oxide in which fission products were deposited. The Marshallese lived in buildings appropriate for the tropics with thatched roofof palm fronds and open sides for ventilation. Fallout material collected on the palmfronds, the ground, trees and on individuals that were in the open. From the wind velocity, arrival time and decay patterns. isodose lines were constructed in the downwind region. The fallout occurred in a cigar shaped pattern. In the westerly direction the 8.00 Gy isodose curve extended about 140 miles. 5.00 Gy about 160 miles. 3.00 Gy about 190 miles and 2.00 Gy about 220 miles. The north-south distance for 2 Gy was roughly STEM CELLS 19953;13(suppl 1):49-57 9012471 eo Sogt nah Pr a a Key Words. Thermonuclear explosion * Fallout * Humanradiation exposure * Short-term and long-term radiation effects