THE UNIVERSITY OF NORTH CAROLINA 
AT 
CHAPEL HILL 
Division of Health Affairs 
The School of Medicine 
Department of Bacteriology and Immunology 
The University of North Carolina at Chapel Hill 
804 Faculty Laboratory Office Building 231 H 
Chapel Hill. N.C. 27514 
20 December 1979 
Director 
National Institutes of Health 
Bethesda, Maryland 20205 
Dear Dr. Fredrickson: 
I would like to comment on the "E. coli K-12/P1 recommendation" 
presented in the November 30th, 1979 Federal register p 69235. This 
recommendation seems like an overdue step in the right direction. In 
the absence of a documented hazard the current guidelines seem ex- 
cessively conservative. I certainly hope that this proposal will be 
extended to the Ff bacteriophages in the near future. 
Yours , 
Marshall Hall Edgell, Ph.D 
Professor 
MHE/jab 
[ 562 ] 
