population approached 300 in number but since appears to have
stabilized at 230.
Several radiological and biological surveys,
a monitoring nature,
were conducted
contamination until 1958
(Dunning,
from the
1957).
primarily of
time
of the
first
During this time the
gamma dose rates over land areas declined at approximately the
rate predicted for mixed fission products by Miller and Loeb
(1958).
and 1958,
However,
Slight rises in gamma dose rate were observed in 1956
resulting from tests conducted during these years.
the total contribution of radioisotopes from these
subsequent fallouts amounted to a fraction of one per cent of
the amount from the 1954 fallout.
Rongelap Atoll is located in the Marshall Islands,
Central Pacific Ocean,
at about 11° North.
in the
It is a typical
atoll with a lagoon area of 388 square miles and about 180-foot
average depth.
The emergent land area is about 3 square miles
and is made up of 61 small islets ranging in size from a fraction
of an acre to the largest island,
Rongelap, which is about 4
miles long and 1/2 mile across at its widest point.
There is one small islet on the western reef and the remainder are strung along the northern,
eastern and southern reefs.
The islets on the northern reef are not as well developed as
those to the east and south.
The waters of the lagoon
are