o
B.
Nannattan Lrotect workers
Another study of human respiratory exposure to plutonium
relates to 22 young men exposed to plutcnium during tne
Manhattan Project.
found them te be
states,
66
.
.
The latest examination of this qroup
free of lung cancer altnouagn
the
report
"The bronchial cells of several subjects showed
moderate to marked metaplastic changes, but the significance
of these changes is not clear."
Such metaplastic changes are
a possible indicator for detecting incipient or actual
cancer.
lung
In one case the report indicates that the subject
was a heavy smoker
(3 packs/day)
tributed to the cnances.
suggest that
and undoubtedly this con-
Nevertheless,
these findings
lung cancer may become manit est in some of
these subjects in the future.
Indeed, one would not be
Surprised to find one lung cancer even in such a group of
non-exposed suojects.
During the latest examination of these
a
workers, in vivo measurement of the plutonium lung burdens
f
were
conducted with
these
results:
An average MDA for a 2000-sec counting time is
about 7 nCi if one uses the 95% confidence level.®?
For the 68%
,
confidence level and a Similar counting
time, the comparable value is about 3.5 nci.
66/
Hemplemann, L.H., et al, “Manhattan Project Plutonium
Workers;
67/
A Twenty-Seven “Year Follow- Up Study of Selected Cases."
MDA refers
to the minimum detectable amount.
Mca ht
al
e
ace