Removable surface contamination at a biomedical research institution

A rigorous, unannounced, campus-wide survey for removable surface contamination was performed at our institution. Wipe samples (n = 1,090) were collected from a variety of standardized locations in 45 large biomedical research laboratories that routinely use kBq-MBq (microCi-mCi) amounts of 3H, 14C, 32P, 35S, 51Cr, and 125I. The results showed a log-normal distribution for contamination, with about 90% of all samples below ten times background. Although working surfaces and equipment used in these laboratories can become contaminated with radioactive materials, especially by transfer from soiled gloves, the magnitude of the contamination is very small and typically restricted to surfaces, instruments, and equipment that are directly handled in the course of experimental work and which can be reasonably anticipated to be contaminated. These data suggest that contamination is not a significant problem in biomedical research laboratories at this institution and that the best protection from workplace contamination appears to continue to be the use of well-reviewed standard operating procedures and good work practices.