it was likely that another 75 rads of laboratory, or X-radiation, would have
caused some deaths.

The report concluded that the minimum lethal dose for man

was probably 225 rads in a fallout field.

The "best estimate’ figure was used

consistently, with acknowledgments, for a period covering ten years.

In 1964,

undoubtedly as a result of the first findings of thyroid nodules, a recalculation was carried out.

This recalculation,

Lawrence Radiation Laboratory of

by one Ralph A.

James of the

the University of California,

was

interesting

for two reasons.
First,

in earlier calculations of the fallout,

the dose of the cloud

passing over the island could not be calculated (1956 report).
later,

in 1964,

Ten years

because of evidence from tests conducted after 1958,

calculation was made,

including the dose from the cloud.

a re-

This review took

into account the dose delivered as the radioactive particles passed over the
‘slands.

James,

in his exposition,

noted that the exact method of arriving

at the original 175 rad estimate for the people of Rongelap was ''not given’
and that it apparently did not include "the dose from the cloud, but only
from fallout"
(based on 12 hours)

(36, p.

79).

James' recalculation included dose received

from time of beginning to time of end of fallout,

lls

rads; cloud passage, 47 rads; and from the fallout during cloud passage, 4?
rads, a total of 208 rads.

James, then, in allowing for factors which might

change or alter this amount for individuals who might have remained indoors,
noted that the probable dose was 175 rads, plus or minus 25 rads.
The second reason this recalculation was so important was because it dealt
with and partially explained the reasons for the late development of thyroid

nodules.

This second aspect of the recalculation involved the amount of

[o14105

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