46 
what you haven't heard is the question of all the people who had expertise 
who weren't there, and whose arena might not normally be considered appro- 
priate expertise such as the identification of the inadvertent infections, 
which is intensely studied in hospital surgical units, where it is a real 
problem, and not intensely studied in microbiology or by people who study 
traveler's diarrhea. This is quite a question. 
DR. STETTEN: I am advised that time is running on. We go on to the 
next public witness. 
DR. LIBERMAN: Can I just make one quick statement? Professor King 
just referred to me. I am Dan Liberman from MIT, and I would like to make 
it clear initially that we are reviewing various methods of making that 
distinction. We have some approaches. We have some methods we feel may 
help in this area, but we are testing them. We don't have anything that we 
are willing to say works. So I don't want anyone to have the wrong impres- 
sion here as to what the level of technology will allow. 
DR. STETTEN: Dr. Fredrickson, we are up to the next public witness. 
DR. FREDRICKSON: Thank you, Dr. Stetten. 
Mr. Helms. 
MR. HELMS: One point here. We were on risk-assessment while you 
stepped away. I have some thoughts on that, but is that going to come up 
at a later point? Is it better to address it — 
DR. FREDRICKSON: I think it will, Mr. Helms, under Permissible Experi- 
ments. There will be a reiteration of much of this. 
MR. HELMS: Because there have been a lot of things said here that 
need further clarification. 
DR. FREDRICKSON: I think that we would be best advised to go ahead 
with the public witnesses who have been added to this particular section. 
I call on Dr. Mary Chilton. She is an invited witness who wants to 
be added to this section. She works with plants, but I don't remember where. 
DR. CHILTON: University of Washington. 
DR. FREDRICKSON: I apologize. Thank you, Dr. Chilton. 
DR. CHILTON: I would just like to address two points at which I feel 
the introductory section is vague. I feel that in a quasi-legal document 
of the kind that the Guidelines are, that vagueness is to be avoided at all 
costs. I favor the idea of excluding certain kinds of recombinant DNA experi- 
ments from regulation by the Guidelines. By excluding from consideration 
a large number of experiments which everyone agrees are innocuous, we 
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