people compared with four in the Rongelap people is de:
expected based on the estimated dose.
itely higher than
However, we have reviewed the data
and have found no reason to change the estimates of the dose to the thyroids
of the Utirik people.
The number of cases observed
may vary above or below
the average number expected — the variation being larger as the population
n
ize decreases.
In a small population such as Utirik the difference between
the predicted and observed number of cases may be substsntial.
Of course,
thyroid cancer occurs in populations not exposed to rediation above the
natural background.
population groups.
The incidences of thyroid cancer varies with different
For exauple, in children the risk vate (in number of
cases per million people per rad per year) varies from 0.5 to 1.5 reported
by the United Nations to 5.5 for a group of Americans in New York.
It is
‘essential to know the natural incidence in the Marshallese and larger studies
of such incidence have been initiated,
Even though it was known that the dose to the thyroid glends was higher
than to the rest of the body, what wes not known during the earlier years
was the degree of sensitivity of the thyroid gland to radiation.
Even today,
there are many facts about radiation that are not known, despite the large
number of scientists that have studied this subject for the past twenty or
thixty years.
Even less wes known about radiation in 1954 at the time of
the exposure to the people on Rongelap and Utirik.
Only relativély recently
has the degree of sensitivity of the thyroid for developing tumors from
vadiation exposure been appreciated.
Therefore,
the physicians exenining
you in past years, based on the best possible medical information available
at that time, were being truthful when they said that they did not expect
radiation effects to develop in the Utirik people.