USE OF MOLECULAR EPIDEMIOLOGIC TECHNIQUES IN A PILOT-STUDY ON WORKERSEXPOSED TO CHROMIUM

Objectives-Molecular epidemiological techniques, capable of detecting damage to DNA, were used to see if such damage occurred in the lymphoc ytes of a group of workers exposed to chromium. The two aims of this p ilot study were to see if these new techniques might make useful biolo gical monitoring tools for workers exposed to chromium and also, to he lp assess whether the current occupational exposure limit for chromium (VI) was sufficiently protective in this:specific working situation. Methods-Volunteer groups of 10 workers exposed to chromium and 10 none xposed workers provided urine and blood samples towards the end of the working week. Chromium concentrations were measured in whole blood, p lasma, lymphocytes, and urine. Lymphocytes were used to examine two fo rms of DNA damage in the two groups; these were the level of DNA stran d breakage and, the production of 8-hydroxydeoxyguanosine. Results-Chr omium concentration in whole blood, plasma, and urine of workers expos ed to chromium was significantly raised (P<0.01) compared with non-exp osed controls, but in isolated lymphocytes, there was only a modest bu t significant (P<0.05) increase in chromium in the group exposed to ch romium. There was no difference in the levels of DNA strand breaks of 8-hydroxydeoxyguanosine between the groups. Air monitoring for chromiu m was not undertaken but current levels for the group exposed to chrom ium were reported to be around 0.01 mg/m(3), which is 20% of the curre nt United Kingdom occupational exposure limit. Conclusions-We were una ble to detect any damage in lymphocytic DNA due to exposure to chromiu m; This may have been due to the low chromium exposure (<20% of the Un ited Kingdom occupational exposure limit) the ability of plasma to det oxify chromium (VI) to chromium (III) before it reached the lymphocyte s, or perhaps the insensitivity of the molecular techniques used. It i s now important to test these and other such techniques on groups expo sed to levels closer to the United Kingdom occupational exposure limit .