70
EFFECTS OF IONIZING RADIATION
Table 5.2.—Summary of Human Urine Analysis, Gross Beta Activity
pinePost
144 Montes
No
246 MontHs
VOLUME
{24 HRS)
D/M
24 HRS
165
439
581
404
758
1208
ML
No
VOLUME
(24 HRS)
ML
3 MontTHs
D/M
24 HRS
No.
VOLUME
(24 HRS)
ML
6 Moxtas
D/M
24 HRS
No
VOLUME
(24RS)
D/M
24 nRS
8
12
33
360
510
625
12
5
0
3
12
400
655
0
0
ML
Rongelap
Age in vears
A (<5)
B (5-16)
CC 16)
7
il
31
10
824
705
10
379
339
Ailinginae
Age in years
A (<5)
B (5-16)
C (> 16)
American
2
10
l
275
722
150
217
25
1158
309
126
553
All values corrected for decay.
highest activity was in the Rongelap group
(Table 5.2). The Ailinginae group had less
than half that of the Rongelap group, and the
Americans had about one-quarter the activity
of the Rongelap group.
The mean gross beta activity of the urine of
the three groups above was roughly proportional to the external dose each group received.
However, a comparison of the mean beta activity of the urine of Ailinginae and American
groups indicated that the latter had a somewhat
lower amount of internal contamination, even
though both groups received about the same external dose. This may be accounted for by the
fact that the Ailinginae group drank contaminated water from open containers and ate contaminated food up to the time of evacuation,
whereas the Americans ingested much less contaminated food and water, since both were
largely stored in closed containers. Indoctrination of the Americans concerning radiation
hazards probably was also a factor in reducing
the amount of contamination which they received,
The variation of gross activity among the
individuals in any of the three groups is quite
large (Tables 5.8 and 5.4). This is chiefly the
result of variations in the quantity of water
and both the kind and quantity of food ingested. The degree of exposure of the individual to air-borne activity is also a factor in
determining the individual degree of contamination. While there were large variations
among individuals, the day-to-day levels of activity for each individual were fairly consistent.
Further information on the source of individual variations was obtained by grouping
the individuals from the Rongelap and Ailinginae groups according to age (Tables 5.3 and
5.4). While the activity excreted per unit volume of urine is about the same for both children
and adults, the mean activity of the urine excreted in 24 hours by children under 15 years
was significantly lower than that excreted by’
adults. The data available do not indicate
definitely whether the lower total excretion
indicates a smaller total body burden in the
children resulting from lower inhalation and
ingestion, or whether it represents a higher deeree of fixation of the radio-elements by growing bone.