B.
.
Manhattan Project Workers
Another study of human respiratory exposure to plutonium
relates to 25 young men exposed to plutonium during the
Manhattan Project. °°
The latest examination of this group
' found them to be free of lung cancer although the report
states,
"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 lung
cancer.
In one case the report indicates that the subject
“was a heavy smoker (3 packs/day) and undoubtedly this contributed to the changes.
Nevertheless, these findings
suggest that lung cancer may become manifest 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 subjects.
During the latest examination of these
workers, in vivo measurement of the plutonium lung burdens
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 comparabie value is about 3.5 nCi.
*.
66/
Hemplemann, L.H., et al, “Manhattan Project Plutonium
67/
MDA refers
Workers; A Twenty-Seven Year Tollow-Up Study of Selected Cases.
to the minimum detectable
amount.