year period.
The standard deviation was in general 30% of the mean value for all age
and sex subgroup distributions.
the fact that
65
This less pronounced variation may be due tu
“Zn measurements took place over a 3 year interval while
90
Sr
and 1376, occurred over a 23 year interval and thus was contained in a more
homogeneous population than were the longer lived nuclides.
,
ys
”
90
Figures 22 and 23a and 23b summarize the
Sr dose equivalent results for
individuals at Rongelap.
In this analysis, only the ingestion pathway was considered important.
Some radioactivity would enter the body via the resuspension and direct inhilia-
tion pathways.
It is known that for a given soil concentration of ‘the stab!
naturally occurring analogs to the radiopuclides considered here, the ratios
fe
Lf
Co > 3000
Zn > 130
Fe > 550
Sr > 10,000
Cs > 400
Thus, dietary intake of radioactive material is the principal pathway leadiiz to
This applies to most nuclides in the environment, how ver,
there are notable exceptiona including I, U, and Pu,
one meter above the surface, was used to convert exposure in air to absorbe! Jose
in tissue.
The source was assumed to be an exponential distribution of a7, acu
tivity with depth in soil, typical of aged fallout (Be70).
Because of the
multidirectional nature of the source, variation of absorbed dose with depth of
organ was minimal.
Additionally, external doses were adjusted for living pit -
43
“oe
A value of .73 rads in tissue of interest per rontgen, measured in aii 11
ahaa
ae
bees
External Exposure
Pie Lede ow,
internal deposition,
Vee eeuS osaf tte
follows:
ne
as
Se Se ee ney
of food and fluid intake to blood relative to airborne intake to blood, are