- 3 - 
it would be only after a substantial amount of the population is 
infected that the trouble could be traced to these organisms , and 
by this time the infection can have spread far and wide. This is 
due in part to the fact that the organisms may evoke symptoms that 
are new, may take 20 to 30 years to cause cancer symptoms , or 
may imitate other diseases. Also unknown are the methods of 
treatment of any illnesses caused by the new organisms . 
5 . The greatest danger of these experiments is that the 
hazard is alive, self-perpetuating, and reproduces rapidly. Once 
out, it can not be recalled. If released into polluted waters , such 
as the Potomac River, even relatively small quantities of organisms 
can rapidly multiply to the point where large populations are 
threatened. Conduct of such experiments in laboratories contiguous 
to a large populated area, upstream from a water supply source 
already reputed to be polluted, unnecessarily exposes the population 
to many unpredictable health hazards. 
6. The E_. coli to oe utilized in the experiments is a 
"weakened" strain, as opposed to the natural, "wild type" strain. 
It is not known whether the weakened strain, when combined with 
the mouse cancer genes can exchange genetic information with 
other, wild type strains , but such exchanges occur commonly among 
different E_. coli strains and among E_. coli and other microorganisms . 
The wild type strains of ^E. coli inhabit the whole environment, 
living in soil, water and all warm blooded animals , and are carried 
by insects and fish. If such genetic interchange did occur, there is 
[Appendix C — 73] 
