of the American Cancer Society. The program now includes: a. A review of systems and a complete medical examination. b. Advice on decreasing risk factors and on self-detection of lesions. c. Pelvic examinations with Papanicolaou smears. d. Stool testing for occult blood. e. Amammographyunit anda flexible 65cm sigmoidoscope have been recently acquired. 2. Pursuant to the intent of PL 95-134, the examinations and procedures listed under (1) are performed more frequently than proposed by the American Cancer Society for populations not at increased risk for cancer. Therefore, the physical examinations are annual and include a pelvic examination and Pap smearforall exposed women. Annual mammograms, using a new low-dose mammography unit, will begin at age 35. Routine mammography was not begun earlier because older machines produced doses of x rays which were judged unacceptable for routine annual screening of a population already at increased risk for radiogenic breast cancer. Rectal examinations andstool testing for occult blood are done annually, starting at least by age 40. Routineflexible sigmoidoscopy will be offered before age 50 and will be repeated every other year, or more frequently if clinically indicated. 3. The delayed effects of radiation exposure are generally considered to be limited to malignant disease. The exposed Marshallese, however, receive additional attention for two reasons.First, their radiation exposure was ofa unique type, and a tabulation of risks derived from the statistics of other irradiated pop- ulations may not cover the range of late con- eal sequences that could befall them. Second, data now collected by the Brookhaven medical program suggest previously undocumented late effects of radiation exposure in man. These include an increased incidence of pituitary neoplasms and a trend toward lowerblood cell counts (Adams etal. 1984a, 1984b). Another late effect, hypothyroidism, was documented in some of the exposed Rongelap during earlier years of the program (Larson et al. 1982), Therefore, nonmalignant endocrine neoplasms, endocrine dysfunction, and hematologic abnor- malities are actively sought. To this end, the medical program providesthe following: a. Annual’thyroid examinations by an endocrinologist or surgeon. b. Thyroid functiontesting for all exposed persons, annually for the people of Rongelap and biennially for those of Utirik. c. Thyroid suppression (Synthroid) for all the Rongelap exposed. The intent is to decrease the likelihood of thyroid malignancy. d. Serum prolactin levels on all exposed persons every three years. The most commonly encountered pituitary tumorin the United States is the prolactinoma. e. Annual complete blood counts, including a platelet count. f. Evaluation for ‘‘paraneoplastic’” evidence of neoplasia, such as monoclonal spikes on serum protein electrophoresis (myeloma, lymphoma) and abnormal serum calcium levels (parathyroid adenoma, hypoparathyroidism, metastatic tumor). 4. There is ongoing evaluation for clinical evidence of depression in immunocompetence. The more recent medical surveys of serum immunoglobulins, toxoplasma antibodies, serologic markers of hepatitis B, and tuberculin sensitivity reveal no good evidence that the exposed Marshallese have a significant impairment of their immune mechanisms (Adams et al. 1984b). However, the matter should not be considered settled, and continued surveillance for evidence of increased risk for unusual manifestationsof infectious diseaseis a part of the medical program. 5. The treatment of any neoplastic process which could conceivably be radiation related is done in referral facilities, generally in Hono- lulu, Hawaii. The exceptionsare thyroid nodule surgery, which continues to be performed by Dr. Brown Dobyns, Professor of Surgery at Case Western Reserve University, and therapy for pituitary neoplasia, which has been done at the NationalInstitutes of Health, Bethesda, Maryland. Few such lesions can be adequately treated in the health facilities of the Republic of the Marshall Islands. The medical program also refers almost all diagnostic workups for malignancy to Honolulu. For example, if the cause of persistent occult blood in the stool is not