Table 9. The integral 30-, 50-, and 70-y dose equivalents for bone marrow and bonesurfaces for intake of
90Sr beginning atvarious ages.
Age intake begins
Birth
4 months
9 months
1Sy
4y
12 y
18
||
|
!
|
Bone marrow
30 y
50 y
70 y
414
41.7
43.1
438
43.2
493
485
620
625
63.7
643
640
704
698
Integral dose equivalent, mrem
Bonesurface
30 y
50 y
70 y
30 y
750
756
766
771
770
835
82.9
122
123
127
129
126
137
116
182
184
187
189
187
199
175
223
224
227
229
228
241
217
Effective
50 y
70 y
8.6
8.7
90
9.1
90
10.0
9.3
12.9
15.7
130
158
°13.3 + 16.0
13.4
16.1
133
161
144
173
13.6
165
Table 10. The integral 30-, 50-, and 70-y effective dose equivalent for continuous intake of 137Cs and
90Sr beginning at various ages.
Integral effective dose equivalent,
mrem?
Age intake begins
|
50 y
70 y
702
0.02
0.02
0.02
9 months
367
560
683
0.03
0.02
0.02
663
786
L5y
4y
'
30 y
580
:
|
|
70 y
386
4 months -
|
~ Oy
Birth
}
|
30 y
Fraction due to 70Sr
12y
398
370
391
469
18 y
513
592
714
564
585
687
708
705
829
0.02
0.02
0.03
0.02:
0.02
0.02
0.02
0.02
0.02
0.02
0.02
0.02
0.02
0.02
0.02
4 The effective dose equivalent is a unit defined by the ICRP (1984) which allows for the different
mortality risks associated with irradiation of different organs, together with a proportion of the
hereditary effects.
Discussion
reason is the consistently higher intake of local
The result of our analysis is that the
integral
30-, 50-, and
foods, and thus !3’Cs , for adults found in the
70-y effective dose
diet surveys from the Marshall Islands. Also,
equivalent estimated for intake beginning as
adults at a contaminated atoll is greater than
that for intake beginning at any other age.
Consequently, the estimated integral dose
equivalent for adults is a conservative estimate
for infants and children. There are two basic
reasons for this result. The first, and major,
S000 TS
the higher intake of food in general by adultsis
supported by diet surveys of other societies; the
intake for adults is greater than for infants and
children.
The second reason is that even for continuous
137Cs intake that declines at a rate equal to the
21