rate constant (K,=0) was used for Zn, the dose equivalent rate for the average
adult was in excess of Federal Radiation Council Guidelines for the first 2
years following the return to Utirik.
=»
*
he.
Internal Dose Equivalents
Disintegrations occurring in the total body of an individual during residence following repatriation were determined by several methods.
Equation (3),
together with personal body-burden histories and atoll-specific dietary rate con-
stants from Table 3, provided an initial estimate of disintegrations between consécutive body-burden measurements.
The *gcond method used was a log-log plot of
the subject's body-burden history and an algebraic determination of area between
two consecutive measured points.
subject's body-burden history.
The third method used a linear plot of the
The area under the curve was cut and weighed and
compared to a standard weight of known area.
Quality control procedures
required that all three methods agree within 10% before a subject was assigned
his or her total body disintegrations during residence post-return.
In general,
the methods compared to within +5%.,
After the total number of disintegrations occurring in a subject's body
were assigned, they were apportioned among the body organs according to the following equation
.
. £52 5A,B. (ARE. D. + In2/A)
ECD. (2 A.B, + In2A)
©
(5
where
F
= the fraction of total body disintegrations occurring in the organ of
interest,
A.
= organ compartment deposition fraction for the element,
36