163
Acute and chronic intakes of fallout radionuclides @ S. L. SIMoNn ET AL.
Table 1. (Continued)
Population group
Nectar
Zuni
Flathead
Tewa
Cactus
Fir
Koa
Maple
Redwood
Cedar
Ailinginae*
Ailinglaplap
—
168
—
—
71
—
—
—
—
—
179
—
—
—
—
—
—
—
—
Bikini community”
182
—
—
—
183
—
101
—
Enewetak community*
112
31
59
Ailuk
Arno
Aur
Ebon
Jaluit
—
—
—
98
—
—
—
91
84
182
—
—
—
126
126
—
84
—
126
154
Majuro
Maloelap
Meyjit Island
—
—
—
Mili
70
182
Kwajalein
Lae
Lib Island
Likiep
—
76
—
—
—
—
—
—
—
—
25
84
161
158
189
60
63
—
—
—
—
—
—
174
197
192
—
—
—
—
104
91
98
—
—
—
98
67
104°
—
—
—
—
—
—
188
185
76
—
101
—
—
—
—
—
—
101
101
101
—
—
—
160
157
84
—
—
—
101
101
102
—
—
17
102
17
—
—
—
—
104°
—
—
76
—
—
—
—
—
—
—
—
—
—
154
126
140
—
—
76
—
—
—
—
—
98
—
Utrik community
Wotho
Wotje
112
70
92
energy expenditure, and body surface area (ICRP 2002).
For the ages younger than adult, we found that the age
dependence of body surface area to be most similar to the
age dependenceof the reported bioassay data.
Ourinterpretation of body surface area as a surrogate
index for scaling adult intakes to younger age groups is
related to the concept that particulate contamination of the
face and hands (whose area can be considered to be a
constant fraction of the body surface at each age) was a
major contributor to internal contamination. This would be
particularly true for children, for whom hand to mouth
contact is frequent. The age-dependent acute intakes, relative to adults, selected in this study are presented in Table 2.
For the youngest age group (<1 y), we assumedthat
there are two sources of intake: the consumption of mother’s breast milk and the ingestion of fallout particles. The
intake of a given radionuclide via mother’s breast milk is
the product of the mother’s radionuclide intake, the fraction
of the activity of each nuclide ingested by the motherthatis
transferred to breast milk (F,,,,), and the consumption rate of
breast milk by the infant. We discuss the derivation of these
—
—
—
—
—
—
92
—
—
—
—
—
—
42
—
—
—
—
60
101
—
101
101
101
Rongelap Island
community*
Rongerik®
84
91
—
—
—
—
—
—
—
119
165
—
—
—
—
—
,
—
—
63
182
154
—
Ujae
—
101
—
Namorik
Namu
Rongelap control
group*
126
—
—
—
—
—
176
—
—
—
—
189
—
—
—
101
101
105
—
—
—
—
—
76
84
70
—
—
—
—
—
—
—
101
—
101
—
—
—
101
—
—
17
—
factors in a later section. In addition to the intake of
radionuclides via breast milk, we assumed infants (O-1 y of
age) had direct ingestion of fallout equal to 10% of the adult
intake (Table 2), since the body surface area of the infant is
about 10% of that of the adult (CRP 2002).
Chronic intakes
Chronic intakes of radionuclides that persisted in the
environment for years after fallout deposition were also
assessed. The environmental pathways resulting in chronic
intake are substantially different from those of the acute
Table 2. Assumed age dependence of acute radionuclide intake
relative to adult intake.
Age category (y)
Acute intake relative to adult
<1
1 to <3
3 to <8
8 to <13
13 to <18
=18
0.1 + breastfeeding
0.3
0.4
0.6
0.9
1