ATTACHMENT 6



August 16, 1944

L. H. Hempelmann

J. R. Oppenheimer

Your memorandum of August 16, 1944

In answer to your memorandum on the health hazards of plutonium, 
and in confirmation of our conversation, I should like herewith to 
authorize you to undertake two programs: (a) the development of
methods of detection of plutonium in the excreta; (b) the 
development of methods of detection of plutonium in the lung.

We both agree that if this program is to be effective it must be 
prosecuted with rather high priority. We both agree that in view of 
the many urgent problems facing the laboratory, it should be carried 
out with as small an investment of personnel as possible. We think 
that there are good chances that the work can be carried out with 
fewer than ten people. If the program should threaten to grow beyond 
this point, I should like to have you clear with me before carrying 
out such an expansion.

As for the biological sides of the work, which may involve animal 
or even human experimentation, I feel that it is desirable if these 
can in any way be handled elsewhere not to undertake them here. In 
any case, problems (a) and (b) above must be solved before the 
biological findings can be applied, and the methods developed for 
them may have a real if limited usefulness even in the absence of 
further biological research. I suggest that you and I discuss the 
biological questions with Colonel Warren at a very early date.


cc: Dr. Bacher
Dr. Kennedy