10409 Windsor View Drive 
Potomac, Maryland 20854 
November 5, 1979 
Donald S. Fredrickson, M.D. 
Director, National Institutes of Health 
Bethesda, Maryland 20014 
Dear Doctor Fredrickson: 
This letter is written as an individual who has practiced and taught the 
laboratory, clinical and epidemiologic aspects of infectious diseases, 
rather than as an officer or member of one or more related organizations. 
The letter concerns the recommendation regarding the level of safety 
(containment) required for laboratory/identical work involving recombinant 
DNA and related research employing strains of E. col i K-12. I have 
reviewed much of the data relating to potential perceived hazards. 
While I appreciate the concerns expressed, especially by individuals who 
are less familiar with pathogenesis and the normal microbial flora of 
man, animals and the environment, it appears to me that the potential 
benefits to man from downgrading the level of containment to P-1 far 
outweigh the theoretical risks. This is not to imply that the risk of 
such a decision is zero since any microorganism may become a pathogen 
given the appropriate circumstances of host susceptibility and environ- 
mental factors. The potential for acquiring hazardous microorganisms 
are far greater from touching the refrigerator in a laboratory, ward or 
at home since these are regularly contaminated with pseudomonads or in 
many areas from city tap water which is often contaminated with species 
of mycobacteria designated as "rapid growers". Recognizing that you are 
being deluged with unsolicited letters such as this, thank you for 
taking the time to read yet another individual's view. 
Sincerely, 
Ja,, anford, M.D. 
[3681 
