OCCUPATIONAL EXPOSURE TO CR(VI) - COMPARISON BETWEEN CHROMIUM LEVELS IN LYMPHOCYTES, ERYTHROCYTES, AND URINE

The relationships between chromium (Cr) levels in lymphocytes, erythro cytes, urine, and ambient air were compared among 14 chrome-platers fr om a metallurgic plant in Bulgaria and two groups of local controls, o ne from the same heavily polluted industrial town as the chrome-plater s (n = 11) and one from a seaside resort town 100 km away (n = 6). Amo ng the chrome-platers, the Cr concentration in peripheral lymphocytes was positively correlated with total Cr and Cr(VI) levels in ambient a ir and with Cr excretion in urine. As compared to the controls, the ch rome-platers had mean Cr levels in lymphocytes twice as high, in eryth rocytes ninefold higher, and in urine fourfold to eightfold higher. Al though Cr levels in urine and lymphocytes were similar between the two control groups, levels in erythrocytes were 3 times higher among subj ects from the industrial area than among those from the seaside town. The study suggests that lymphocyte Cr could be a good indicator of the Cr body burden caused by high exposures to Cr(VI), such as in electro plating operations. In these conditions, erythrocyte Cr may be less us eful, possibly owing to increased toxicity due to the high affinity of erythrocytes for Cr. However, when exposure is lower, such as in most environmental situations, erythrocyte Cr should provide a better and more situations, erythrocyte Cr should provide a better and more sensi tive index that lymphocyte Cr. By contrast, urinary Cr, which provides information on total Cr exposure, including Cr(III) from dietary and environmental sources, does not seem to be of value for studying occup ational exposure to Cr(VI).