Table 17 represents the exposure rate at each pattern of activity as listed
in Table 16 calculated assuming 100% occupancy for Rongelap Atoll.

Table 18

presents an estimate of the expesure rate for each age group, weighted by the
percent of time spenc in each area for inhabitants of Rongelap Atoll based on
the Lawrence Livermore lifestyle Model (3,4).

Summation of the exposure rates in

each area provides the average exposure rates to the Rongelapese.
Using the average hourly exposure rates, the long term external dose was calculated.

These data, presented in Table 9 for Rongelap Atoll, have been cor-

rected for background (terrestrial and cosmic) radiation by using the average
exposure rate of Wocje and Ailuk Atolls as a representative sample of che normal
(unexposed)

Marshall Island environmenc.

We feel that this is a very conservative estimate for Rengelap Atoll since
the people racely visit the more heavily contaminated islands in the north, and
tend to restrice their “other islands" visits to the southern sector where exposure
rates are similar to that on Rongelap [sland itself.

This observation was supported

by an independent Living pattern assessment from which data became available in
the fall of 1977 (5).
Specific living pactern information for Rongelap was obtained on a field crip
in October 1977 (5).

This information is presented in Table 20.

It should be

noted that as previously mentioned, the Rongelap "Lifestyle" involves very little
time away from Rongelap Island where a constant exposure rate of 7.3 .R/hr is
assumed.

Revised external dose predictions based on the observed Rongelap Living
These doses include corrections for

pattern are given in Tables 21, 22 and 23.

phvsical decay for 137¢, and 99¢5 which are responsible for 799% of the coral
external exposure rate above >ackground.

The cesium and cobalt ratios were obtained

using the averages of soil sample activities

University of Washington (LRE)

(7).

from analyses bv 3NL

(6)

and che

It was assumed for this assessment chat a0

radionuclide loss mechanisms are operacive other than physical decay.

-a-

Select target paragraph3