of extreme caution has served the useful function of permitting a 
thourough evaluation of potential risks of such experiments, despite 
efforts by scientists, environmentalists, lay people, etc., to conjure 
up worst case scenarios of potential hazards, there is no evidence to 
support the contention that recombinant DNA research poses a biohazard 
to humans or their environment. Arguments that biohazardous organisms 
may be produced by recombinant DNA research appear to us to be simply 
speculation with no basis in fact and no foundation in our understanding 
of biological processes. 
In view of the lack of evidence for creation of significant 
biohazards through recombinant DNA research, the lowering of physical 
containment requirements in the proposed revised Guidelines is entirely 
appropriate. In addition^ the revised Guidelines can be expected to 
have considerable positive impact on recombinant DNA research in this 
country. This is an isssue to which we can speak to from our own 
research experience. The current Guidelines have imposed stringent 
physical containment requirements, P3 or PU, for studies involving higher 
organsisms. The requirement for these extreme levels of physical 
containment have made it difficult and in many cases impossible to use this 
important technique for studies involving genetic material from higher 
organisms. P3 facilities are costly to construct and to maintain. And many 
institutions such as our own have not had the resources to establish 
such facilities. In ray own case I have undertaken some recombinant 
DNA experiments at a P3 facility located at another institution a 
considerable distance from Virginia. As a result of the enormous 
complications and inconvenience of this_, arrangement, ray research program 
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