POSSIBLE GENOTOXICITY IN LOW-LEVEL BENZENE EXPOSURE

Structural chromosome aberrations and sister chromatid exchanges (SCEs ) in peripheral blood were studied in female workers employed in the s hoe-making industry in two periods: 1987 (group I; N = 38) and 1992 (g roup II; N = 45). Only 11 of the workers were present in both groups a nd their results are presented both together and separately. Occupatio nal exposure to benzene and toluene was confirmed through their determ ination in the working area, blood, and phenol in pre- and post-shift urine. The results were compared with those from the control group (N = 35). Benzene in the working atmosphere was significantly higher in 1 987 compared to 1992, but was always lower than the current Croatian p ermissible concentration of 50 mg m(-3) (in the near future this value will be changed to 15 mg m(-3)). A statistically significant differen ce was also found in biological markers of benzene exposure between th e two periods of the investigation. Increased absorption in the first period occurred because of intensified production in 1987, and this de creased significantly in 1992 because of the war in Croatia. The cytog enetic study showed a significant increase in dicentric chromosomes in exposed groups I and II when compared to the control group. Statistic ally significant higher SCE frequencies were found in group I compared to the control group and also compared to group II. Between exposed g roup II and the controls no statistically significant difference in SC Es was found. Comparing the same 11 workers present in both periods th e results showed no difference in chromosome aberrations between the t wo periods of examination. SCE frequencies were significantly higher i n 1987 when greater benzene absorption occurred, confirmed by biomarke rs of benzene exposure. The presented results indicate that genotoxici ty may occur in workers exposed to low levels of benzene in the shoe i ndustry. (C) 1995 Wiley-Liss, Inc.