@
The lack of the necessary data to conduct valid analytic epidemiologic studies (see
Sections 4 and 5).
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Medical Surveillance
7.3.1
_End-points of Interest
7.3.1.1 Neoplastic disease
Additional neoplasms are expected to occur as this population ages, therefore a major focus of
follow up should be on their detection. However, because of the lack of data to conduct valid
analytic epidemiological studies it will not be possible to estimate the magnitude oftherisk of
neoplasms thatis attributable to the radiation exposure relative to the baseline intake of
neoplasms in this population unknown. For certain malignancies, such as leukemia, should they
occur, someindication ofthe relationship may be possible through the use of the NIH
Radioepidemiological Tables (National Institutes of Health; 1985). Unfortunately these tables are
based on observed health effects and mortality rates in other exposed populations and so may not
be applicable to the Marshail Islanders.
Follow-up of this and other radiation-exposed populations suggests that thyroid tumors have been
and will remain the major risk of radiogenic neoplasms among the MarshallIslanders.
7.3.1.2 Non-neoplastic and Non-specific Aging Conditions
Cardiovascular and other non-specific aging conditions are also expected in this aging population,
but they are likely to be related to factors other than radiation exposure.
7.3.1.3
Late Deterministic Effects
Because of the long interval (39 years) since the exposure, and because the estimated radiation
doses were below accepted threshold levels for such deterministic effects, radiogenic cataracts and
fibroatrophy of tissues other than skin and permanentinfertility were and are unlikely to occur.
Radiation-induced thyroid hypofunction has been observed in the population and warrants
continued surveillance. Individuals who experienced beta-burns should continue to be monitored
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