SLIDE 29
Activity intake by inhalation.
Airborne activity intakes were dependent upon
the breathing rate of individuals during fallout cloud passage.
Breathing
rate was assumed proportional to body mass.
We arrived at this conclusion
based on reference data given by ICRP for persons less than 58 kg (ICRP74).
Adult reference values for breathing rates (ICRP74) were assumed for all
Marshallese adults regardless of body mass. At Rongelap Island, BRAVO debris
passed during the afternoon, a period of light physical activity for the
population. At Utirik Island, the debris passed during the night, a period of
resting. At Sifo Island a period of light physical activity was assumed in
order to estimate breathing rate during the morning they were exposed. On the
basis of urine results and breathing rate, it was determ{ ged that inhalation
could not account for the estimated activity intake for
I.
Less than 1% of
the intake could be attributed to inhalation. In fact lethal external
exposure rates would have to accompany significant radioiodine intakes if
inhalation was assumed to be the dominant intake pathway leading to the urine
activity excreted on day 17.
_ ESTIMATE OF INHALED ACTIVITY?
KBa
Body
Weight
kg
135)
1347
1337
1327
Rongelap Adult Male
Rongelap Child
70
30
890
520
370
220
410
240
97
55
18
10
110
59
20
12
Utirik Adult Male
Utirik Child
70
30
70
41
_
-
1200
700
410
230
78
44
410
230
59
35
Sifo Adult Male
Sifo Child
70
30
81
48
85
48
85
48
4.4
2.5
131)
0.85
0.48
Ours é;
.
ft
oy 2
ia
* Air concentrations normalized to exposure rate measurements andfallout composition.
31
132
5.5
3.2
:
131m,
1.1
0.59