401655 Brief Summary of Medical Findings in the Marshallese Accidentally Exposed to Radioactive Fallout in 1954 (May, 1977) The accidental exposure occurred on March 1, 1954, following detonation of a thermonuclear device on Bikini in the Pacific’ Proving Grounds. resulted in fallout on the following inhabited islands: Island Distance from Bikini Rongelap | Ailingnae” Rongerik Utirik 105 miles 110 miles © 135 miles 275 miles No. of People 64 18 28°" 158 K A shift in wind Estimated Gamna Dose 175 rads 69 rads 70 rads 14 rads a» Ronge lap people visiting Ailingnae atoll American servicemen There were no deaths but certain acute effects were noted, particularly in the Rongelap people. Transient depression of blood cells was followed by recovery to near normal levels by one year. Fallout deposited on the body resulted in skin burns and spotty loss of hair in the Rongelap, Ailingnae and Rongerik groups. The burns healed and the hair regrew without complications in several months. Urine analyses revealed that internal absorption of radioactive material had occurred from inhalation and ingestion of contaminated food and water, but no acute effects were observed from this source. (As will be seen below late effects did occur.) Follow-up examinations during the first decade showed few findings that could be related to radiation exposure.* About twice the number of miscarriages and stillbirths occurred in the exposed compared with unexposed Rongelap women, but this finding cannot definitely be related to radiation exposure. This difference was not seen after 5G years. During the second decade, some Rongelap children showed growth retardation which was later realized to be associated with a hypothyroid condition due to radiation injury to the thyroid gland, largely from radioactive iodine absorbed at the time of the fallout. The thyroid dose was estimated to be 335 rads for Rongelap adults and 700-1400 rads for children, the higher dose in children being due to the small size of their thyroid glands. The dose calculated for the Utirik group varied between about 30 rads to adults to 60-90 rads for young children, In 1963 tumors of the thyroid began to appear in Rongelap children and to a lesser extent in adults. As of April 1977 33 of the original population of 86 on Rongelap and Ailingnae (38%) have developed abnormalities of the thyroid pland, including 18 of the 22 persons (70%) who were less than 10 years of age at the time of exposure in 1954, A lesser number of Cumors have developed in the Utirik population (fable LL). A small number of thyroid tumors have also been seen in the unexposed populations examined, “k The American servicemen exposed on Rongerik have not been followed by the Brookhaven medical team. MS 54 30