cont'd.
II.
Fruits.
Analyses of the following number of samples of
different fruits, about half of each of which were produced before 19h5,
revealed that the post-'lS samples showed no significant increase in
total radioactivity: pears, 8; cherries, 61; peaches, 89; apricots, 28;
plums, 61; tomatoes and tomato products, 13h; berries, 73; fruit Juices,
78 and miscellaneous, 57.
III. Sea Food. 51 samples of miscellaneous fish varieties and
32 samples of oysters and clams, half of each of which were canned after
1945, exhibited a trend toward higher radioactivity.
However, individual
shellfish values showed a significant rate of increase when plotted by
years since 19h.
Other types of sea food such as shrimp, lobster and
crabs showed no trend whatsoever.
IV.
A number of unrelated items were also examined for total radilo~
activity. Analyses of the following numbers of samples revealed no increase
in total radioactivity: meat products, 26; wheat, 7; sugar and jams, 38.
In the case of bread where there were unfortunately no pre-'45 samples
available there was no evidence of total radioactivity that could not be
accounted for by the potassium content. On the other hand in cocoa and
‘cocoa beans there was a radioactive content greater than could be accounted
for by potassium.
Without comparison with pre-'lS samples it could of
course not be determined whether this excess radioactivity had been caused
by fallout contamination,
V.
In consonance with the findings of other investigators, the
analyses of dairy products consisting: chiefly of fresh fluid milk,
evaporated milk, milk powder and cheese, show a statistically significant
increase in total radioactivity in those products produced since 1945.
VI.
The largest increase noted was in tea.
While the examination
of 36 pre-"h5S samples showed no radioactivity on the average in excess of
that accountable by potassium, 78 post-'h5 samples chiefly from 1956 and
1957 harvests showec radioactivity that averaged about 30 times greater,
with 6 individual samples ranging as high as 109 to 135 times greater,
In terms of micro micro curies per kilogram of tea leaves the average
value for the 78 samples was 13,500. While no specific isotopes have been
identified we may assume that at least 1% of this activity could potentially
be Sr 90.
It could therefore be possible that many of the tea samples
examined contain Sr 90 in excess of the present tolerance of 80 micro micro
curies per kg., but analyses of strong tea brews revealed that only about
17% of the radioactivity was extracted.
It can be concluded therefore that
the beverage as commonly consumed would not contain over-tolerance amounts
of Sr 9.
Conclusion
Compared to food samples produced prior to 1945 this survey shows
that the great majority of post-'hS samples do not carry significant
burdens of radioactivity.
products and tea,
Notable exceptions are certain sea foods, dairy
~ 95 -