} ESTIMATED BODY BURDEN OF RONGELAP PEOPLE AT TIME OF FALLOUT Isotope ese Ba Rare Earths 3ti cin thyroid gland) Ru 4Sca Fissile Material Activity (uci) 1.6-2.2 0.34-2.7 0.12 6.4-11.2 0-0.013 0-0.019 0.0.16(ugm) in 1957 a slight residual radioactive contaminacion of the island resulted in the accumulation of detectable but low body burdens of "“Sr. No effects from these isotopes have been observed. Cs, zn and LATER FINDINGS ee veny Several later findings, prior to the development of thyroid abnormalities, have been noted, some of which may have been related to their radiation exposure. During the 15 years since the accident the exposed people have remained generally in good health (excepc for etapa thyroid related abnormalities) with no greater incidence of illness or degenerative diseases than that seen in the unexposed populations examined. Though the death rate has been somewhat higher in the exposed peopie there has been no definite correlation of cause of death with radiation exposure. A somewhat greater percentage of older people in che exposed group partly accounts for this discrepancy. Quantification of a number of recognized aging parameters in order to arrive at "biological age score" have failed to reveal any evidence for premature aging in the exposed as compared with the unexposed people of the same age. No teukemia has been seen, The occurrence of 3 cases of cancer in the exposed group (1 of the thyroid gland and 2 of che female yvenital tract) presents a higher incidence tn the exposed group, but due to the small numbers of people involved, final decision on this point must await the results of future observations, Based on birth rates, fereility has been about the same in the exposed as compared with the unexposed population. However about twice the number of miscarriages and seillbirths occurred in the exposed women during the first 4 years after exposure. Fetal abnormalities did not appear more numerous in the expased proup, though na specific senetie ‘studies have been cartied out. A porsisciny Low level of chromuscomal aberrations of the type induced by radiation have been noted £10 years post exposure. Frequent slit iamp observations reveal no increase in opacities of the lens characteristic of radiation exposure. DEVELOPMENT OF THYROID ABNORMALITIES Before discussing development of thyroid abnormalities a few words should be said concerning the calculations of the dose to the thyroid, Table IL shows the estimaces of the various isotopes that were present foo eM Ser roof TABLE II pee, CONARDet al. eo oe meee ee ee mee me ee a ne me ON 328