Sister chromatid exchanges in rotogravure printing plant workers

Objective: The individual burden of inhaled ambient-air toluene and its link to genotoxic phenomena in exposed printing workers. Method: The influence of toluene on sister chromatid exchange (SCE) was investigated by monitoring of the individual toluene burden of 42 exposed printing workers. Therefore, the urinary hippuric acid (HA) excretion was measured directly after the work shift. The results were compared with those recorded for a control group consisting of 45 blood donors. SCE frequencies were determined from peripheral lymphocytes for both groups. Results: The median HA excretion of the exposed and nonexposed groups amounted to 1.94 and 0.45 g/g creatinine, respectively. For both groups, different SCE rates were detected: 10.13 and 6.84 counts/lymphocyte for exposed and nonexposed persons, respectively. The independence of the measured values proved to be significant at a high confidence level (P = 0.000) for both groups. The influences of smoking and alcohol consumption on SCE as well as on HA values could be clearly separated from those induced by toluene. Conclusions: The results of our study indicate a strong relationship between the individual toluene burden and the genotoxic risk of the exposed persons. Since toluene was used for dilution of the letter-press ink, the influence of ink mist on the genotoxic effects could not be completely excluded.