a
3)
The reason for the serious discrepancy between AEC
conclusions and our own conclusions regarding the safety of the
Nevada test program is the following:
Nearly all monitoring data reported by the AEC represent
radioactivity measurements of either the gamma-ray intensity
emanating from the ground, the total beta-radioactivity deposited on a gummed film placed on or near the ground, or of total
beta activity in the eir.
There are established safety stan-
Gards regarding exposure to the body fron a given level of
radioactivity which has its source outside the body.
These
standards for externa] exposure have been used, by the AE,
to evaluate environmental radioactivity measurements during
nuclear tests.
a
In most cases, the measurements in the regions
neighboring the test site did not exceed this safety linit,
The AEC therefore concluded that there was no hazard to the
nearby populations.
In the few instances where the gamma and
beta measurements indicated that this safety level for exter-
mal exposure would be exceeded, protective measures (remaining
indoors, or evacuation) were recommended.
The foregoing AEC interpretation of gamma and beta rediae
tion measurements is, however, valid onlyifthefalloutwhiod
gives rise to this redioactivity does not enter into the food
ghein.
If fallout radioisotopes do enter the food chain and
find their way into the body, certain isotopes become highly
eoncentrated in a particular part of the body and expose it
to very intense rediation.
Safety standards for externa)
exposure are then no longer applicable.
Iodine 131 is a par-