788
GUSTAFSON, BRAR, AND MUNIAK
body measurements® made in September 1964 indicate that the body
burden has reached its maximum level, some fivefold greater than the
minimal levels during late 1961. If it is assumed that a human weighs
70 kg and contains 135 g of potassium, the whole-body burden is equiv-
alent to a 70-day intake of food at a given ‘*’Cs level or to 130 kg of
food according to the standard diet considered. The relative contribution of various foodstuffs to the total *’Cs level has changed somewhat
during the period of observation in that milk assumes greater impor-
tance during and for some time after nuclear testing. The partition of
37Cs among the various foodstuffs shown in Fig. 5 for the November
1963 sampling is fairly representative.
MILK
MEAT
GRAIN PRODUCTS
FRUIT
VEGETABLES
OTHER
0
3
10
15
20
25
30
35
40
PERCENT OF TOTAL INTAKE
Fig..5—Distribution of 19’Cs in the diets of Chicago residents in November 1963.
Although cesium, being chemically similar to potassium, is primarily distributed in soft tissues, there is evidence that some of this
element does become incorporated in bone. A number of samples of
human rib bone were collected in 1961 prior to the resumption of testing.” These were selected from various age groups ranging from in-
fants to persons over 60 years. A second collection was made from
mid-1962 to late 1963. The results of both samplings are shown in
Fig. 6. The specimens have had the marrow removed by cracking the
bone, scraping the marrow cavity, and washing with distilled water.
The marrow and the wash water were saved, and the '*’Cs was mea-
sured. The intact bone was then ashed at 400°C, and the ash from various subjects within a specified age group were grouped and counted by