Attachnent ftige 3 
SU>»1ARY 
Planned Industrial applications of recombinant DNA (rONA) technologies will 
increase potential exposures of skilled and unskilled workers to 
microorganisms containing rDNA and to the products of those organisms. The 
health hazard of occupational exposure to recombinant organisms appears 
minimal, given current use of highly attenuated microbial species in rDNA 
applications; the hazards of microbial colonization, or infection may, 
however, increase with any introduction to industry of more robust 
microorganisms. The hazards of occupational exposure to the biologically 
active products of microorganisms containing rONA appear to be more 
substantial; product exposures in the pharmaceutical industry have caused 
occupational diseases such as gynecomastia, Cushing's syndrome, and toxic 
hepatitis. Sensitization to peptides may produce occupational asthma. 
Strict physical containment of microorganisms and their products constitutes 
the primary defense against occupational exposures in rDNA applications. 
"Biological containment", achieved through the use of attenuated species, is a 
second defense. Medical surveillance of workers, although inherently limited 
in its ability to detect disease, can provide a third level of protection. 
Medical surveillance programs should be highly specific; they must evaluate 
the particular hazards which confront an occupational group. At a minimum, 
medical surveillance of rDNA workers should include: (1) p re -employment 
examination with collection of baseline serun; (2) periodic follow-up; (3) 
evaluation of all illnesses; (4) epidemiologic and other longer term studies; 
(5) periodic evaluation of data; and (6) regular communication of results to 
management and workers. Establishment of medical surveillance programs for 
rDNA workers constitutes prudent medical practice. 
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