OFFICIAL USE ONLY

IT.

A.

GROSS ACTIVITY

Land Plants

Graph Two indicates the general levels of activity of edible

plants (pandanus, papaya, breadfruit, arrowroot), and coconut meat and
milk at Rongelap Atoll together with their decline of activity with

time ee
Tables One and Two show

3

first survey in February 1955.

the analyses made by NRDL for the
Table Three is based on the February

1956 survey.
Tables Four, Five and Six show the analyses by HASL.”? 6

The high initial activity of the "edible plants” (Graph Two)
was probably due to surface contamination caused by the direct fallout.
The rise in activity after a year after the fallout occurred may be due
in part to sampling and counting variances but probably results from
the ability of some plants to concentrate cet3T (See Section Radiochemical
Analysis), or may represent a condition of increased availability of the

radioactive fallout material to the plants.

Initially the activity

in the coconut milk and meat was less than other edible plants but
the rate of decline of activity has been less than for other edible
land plants probably due to the higher percentage uptake of this

longer~lived cst3T,

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