12, No. 2, 1959)
LAUG AND WALLACE: RADIOACTIVE RESIDUES IN FOODS
.
uffs
|
is
.
Sfaten
8
from it, 5% of the original radioactive eoncentration. From these results it appears
that a relatively small transfer of radioactivity from the leaves to the infusion
occurs.
a
0.087
0.005
0.125
0.119
0.234
0.196
0.874
RaDOachyvity
8.8.4)
Conclusion
§
z
5
o 1957 inel.
435
40
‘48
YEAR
Fig. 1—Change in radioactivity of shelifish.
The results presented in this report comprise approximately 2000 samples, half of
which originated before 1945. Of those
sampled after 1945 until the end of 1957,
strontium (89 and 90) and cesium 137. In
the other sample the percentages were, re-
tive regression.
hown in Fig. 1.
vo samples of
rked elevation
that the prinwo samples of
i the presence
jum 95. These
monly consumed, (assume normal brew 1
g/100 ml) 100 grams of infusion was made:
{a) Sample 13 contained 154 d/m/g tea
leaves; the extract from it, 10% of the original radioactive concentration, (6) Sample 21
contained 34 d/m/g tea leaves; the extract
Table 5. Resume of total beta radioactivity
of tea for August, September, October,
November, and December, 1958
| spectrometry
Total Beta
Radioactivity per
Gram Tea Leaves
relatively high
‘ted to radiohe total beta
7% and 4.5%
ely, by total
ave shown
ity when
samples
From 1945 to
1957incl.
No.
d/m/g
26
32
46
88
0.324
0.364
0.557
31.4
Country
d/m
curies
Far East
Japan
Formosa
India
Malaya
Ceylon
Sumatra
Indonesia
Java
Viet Nam
Brazil
Peru
Kenya
Portuguese
East Africa
| tung fish,
No. of
Samples
Micromicro-
Belgian viene?
anganyika
Tran
66
104
59
8
30
22
20
39
4
South America
37
79
36
28
13
13
6
30
28
11
10
7
6
12
14
13
5
5
3
3
5
4
Africa
10
5
8
11
5
4
8
4
Middle East
14
9
4
4
8
3
3
RADIOACTIVITY
d/mAgmn
=
&
mately 10 times the strength of that com-
fo
&
conveyed to the beverage. Under conditions
designed to produce an infusion approxi-
ia post 45
2.5)
o
+ a
tucts described
activity in the tea, it became of interest to
determine how much radioactivity would be
s
ears, the indi-
BEE ore 45
Because of the surprisingly high radio-
a
oT
own significant
at least well
Table 4. Of
vy a highly sigactivity in the
an outstanding
a inka
spectively, 8.4 and 4.9.
Froite
Fig.
x
Vegttabina
2—~Increase
foods since 1948.
aa
Frah
in
ans
Shaltish
radioactivity
eaARCAs
Oty Products
v7
of certain
(the cutoff date for all samples except tea)
it can be seen that fish, sheilfish, dairy products, and tea showed significant increase of
radioactivity above the 1945 base line. These
results are graphically summarized in Fig. 2.
It can be seen that fruits and vegetables
showed no noteworthy increases in radioactivity. Since nearly all of the latter had
been processed by canning or freezing, there
is some question whethersignificant removal
of surface contamination may have occurred.
Addendum
At the time this report was made to the
A.O.A.C. in October 1958, a total of 88
samples of tea from various parts of the
world had been analyzed; they gave an aver-
age total beta value of 31 d/m/g (see Table
4). As of January 1, 1959, nearly 400 additional samples of tea have been examined;
the results are given in Table 5. Listed by
country of origin, it can be seen that Japanese, Formosan, Malayan, and Indian tea