oma Se remem pe EL Re aes eenrentnsneer RSANEDA Table 2. Expected malignancies in Marshallese* in 25 years based on risk estimates (cases/106/rad/yr) (99) for exposed Japanese.** Expected Type Observed M F M F Leukemia (20-yr risk period) Thyroid 0.5 1.4 0.3 3.7 1 0 0 7 Stomach 0.3 1 0 Breast Lung 0 0.7 All cancers 2.4 1.1 0.7 0.3 4.5 0 0 2 0 0 7 *The combined exposed populations of Rongelap and Utirik (244 people), with an average whole-body dose of 62 rads and thyroid dose of 202 rads per person. kkRisks are estimated to have the following male/female ratio: leukemia 3/2; thyroid 2.2/5.8; breast 0/5.8; lung 3-6/3.93 stomach 1.5/1.7; all cancers 12.8/23.1. These risks are age-weighted averages with certain stipulations noted in Table V-14 of ref. 99. Skin. Because of the extensive radiation exposure of the skin of the Rongelap people and the development of acute lesions and epilation, careful ex- aminations of the skin for possible late changes have been continued. Residual scarring and pigment changes as well as histopathological changes have been described previously (2). A notable finding was the development of a num- ber of benign nevi in former areas of beta burns of the neck in several women, also described previously (11); there has been no further development of such lesions in recent years. The absence of chronic radiation dermatitis and of developing skin cancers is notable in view of the extensive radiation lesions of the skin that had occurred in the majority of the exposed Rongelap people. As has been pointed out, the low mean energy of the beta radiation may not have caused sufficient injury to the germinal layer of the skin to result in late effects, or skin cancer may have a longer Latent period and may yet appear. C. Pituitary Tumor* A Rongelap woman who had been exposed to fallout radiation at age 20 underwent a thyroidectomy in 1969 (at age 36) with a finding of an invasive %Drs. J. Robbins (NIH, Bethesda, MD) and R.A. Conard (BNL). - 49 -