The average measured adult body

burdens on Rangel ap were 0.17 uli
)
At Utirik Atoll the average
predicted '37¢5 adult body burdens were 0.043 uCi when imported foods are

available and 0.098 uCi when only local foods are qygt lable.

The average

measured body burdens for the adults was 0.053uCil 0),
Imported foods are almost always available at Rongelap and Utirik and it
is hard to say what fraction of the year the people might be only on a local
food diet.
It can only be said that it is not very often.
The relatively good agreement between model predictions and measured body

burdens indicates that the observed body burdens are predicted better by the

MLSC qieta qgjuming imported foods are available, than by other diet

models.‘
7.

'¥»

Dose Calculation Methodology

7.1

The !37cs and 6%po Methodology

Ingestion

For 137c¢s and 6%%o, the methods of the 1crp( 14,15) and the National

Counci] on Radiation Protection and Meqsyrements (NCRP )
) as developed by
Killough and Rohwer in the INDOS code
are used for the dose
calculations. This code is used as published; however, the output is modified
to show the body burdens for each year.
The amount of
Cs ingested that is transferred to the wholebody is

ceterred to as the gut transfer coefficient.

The gut transfer coefficient for

Cs is Faken to be 1.
The
Cs dose model for adults consists of two compartments with
removal half-times of 2 and 110 d, with 10% of the intake going to the 2-d
compartment and 90% to the 110-d compartment. These data are consistent with
preliminary data obF a ined by BNL on the half-time of the long-term compartment

in the Marshallese
. The average results for ten Marshallese males
showed a mean of 114 d (range: 76 to 178 d).

Childrens doses from
Cs are always less than those for the adults.
The half-time in days of 137¢s in children is determined using the
relationship, Ty/2 = 1.63M, where M is the body mass in kilograms (19) |
The M as
Funct4én of age is determined using equations given by
Spiers 20), When the snyder gnd Spiers equations are combined, the
physiological half-time of 3’/cs as a function of age can be determined.

The average half-time using the above approach for ages 5 through 10 is about
42d. Data from BNL whole-body counting for 14 Marshallese children in this
age bracket is 43 d. For ages 11 to 15, the Snyder-Spiers method gives an
average half-time of about 70 d, while the BNL data for nine adolescents in
this age bracket is 69 d
Combining a constant dietary intake with radionuclide reduction only by
radiological decay, a gut transfer factor of 1 for the intake of 37Cs, a
distribution of 90% of the intake in the 110d compartment and 10% in the 2d
compartment, an exponential decay from these compartments and an effective
energy of 0.59 Mev, leads to the 30-y integral dose conversion constant of
0.00045 listed in Table 6.

200011 1

D-6

+ a-eetandindpeesiea

imported foods are available and 0.42 wCi if imported foods are unavailable

and the total diet consists of lora} foods.

Select target paragraph3