47 - range 700 to 1400 rads). The fact that a part of the total dose to the thyroid (175 rads) was due to whole-body gamma exposure (including the pituitary gland) maybe of somesignificance. The fact that all three Marshallese developing the thyroid nodules weregirls is in accord with the experience of others that thyroid neoplasia and goiters predominatein females. In the report by Sheline et al.*° referred to above, 8 cases among 256 patients treated with I**' developed thyroid nodules. All 8 cases were females: the ages at the time of treatmentin 6 were <(18 (4 aged <10 and 2 between 20 and 30). In the Marshallese girls, the stress of puberty may have beena factorin the developmentof the nodules. Nore: During the 11th-year survey now in progress (March 1965) 3 newcases of thyroid nodules in the exposed group have been detected. Two were in boys 12 and 17 years of age and one in an adult woman 41 years of age. The nodules ap- peared grossly similar to those described in the teen-age girls in this report, and these cases will receive study and treatment. MALIGNANCY | Two older women who had been exposed died with a diagnosis of cancer, one at 67 years of age of ovarian malignancy at 5 years post exposure andthe otherat 60 years of age of probable cancer ofthe cervix at 8 years post exposure. The diagnosis in the latter case was not confirmed by autopsy or biopsy. One unexposed older woman died possibly of cancer of the cervix, but the diagnosis was not confirmed. No other cases of malignancy have been noted in the unexposed population. No cases of leukemia have been detected in either the exposed or unexposed Rongelapese. Peripheral blood smears were studied closely for leukemic cells, including examinationsfor alkaline phosphatase and basophil counts. Thethree cases of thyroid nodules plus the two earlier cases of cancer in older exposed women raise the question whether an increased frequency of cancer may be expected in future years. However, in evaluating the role of radiation, it must be kept in mind that one case of cancer in the ex- posed group occurred at 5 years after exposure — too soon, it is believed, to be related to radiation 7] Cc CD | oo Cc cs exposure — andin the second caseit was not possible to obtain autopsy or biopsy material for con- firmation of the diagnosis. Atomic Bomb Casualty Commission studies have conclusively demonstrated an increased incidence of leukemia in Japanese exposed to the atom bombradiation.**-*° An increased incidence hasalso been notedin patients who hadreceived radiation therapy for ankylosing spondylitis.*' There are many reports of the late developmentof neoplasia, particularly cancer of the thyroid gland,following radiation exposure of infants and children.*?-** Increased instances of cancerof the thyroid gland and adenomata have been reported in the Japanese heavily exposed to ionizing radiation from the atomic bombs.*7-* The Marshallese will be carefully observed for such a possibility in future surveys. The question of increased incidence of malignancy in the irradiated Marshallese must be left open for the present. “BETA BURNS” During the past several years, increased numbers of pigmented nevus-like lesions have been’ noted in previously irradiated areas of the skin, but these have appeared to be quite benign. Neither chronic radiation dermatitis nor cancers of the skin have been noted. INTERNALLY ABSORBED ISOTOPES Radiochemicalurine analyses and whole-body gammaspectrometric analyses revealed that the level of body burdensof radioisotopes in the exposed Rongelapesefell rapidly, so that by 2 and 3 years post exposurethe levels were far below the stated maximum permissible level.+° The return of the Rongelapese to their homeisland wasassociated with a rise in their body burdensof Cs’*’, Zn**, and Sr®*’. By 1961, the whole-body content of Cs'*" had apparently reached an equilibrium with the environment at a value of about 14.7 mpC/kg body weight or about 300 times the mean of the medical team measured at the sametime. Zn°*, which hadrisen to about 9.9 mpC in 1959, fell by 1961 to 1.5 mpC/kg body weight, or about 100 times that measured in membersof the medical team. The levels of Sr°® in 1962 and 1963 hov- ered around the 12.0-mpC level in adults and about 22 mpCin children, about 5 and 10% of the maximum permissible level (for members of the population at large). It thus appears that body