Sister chromatid exchange frequency in workers exposed to high levels of ethylene oxide, in a hospital sterilization service.

Blood samples were taken from a group of 25 subjects professionally exposed to high levels of ethylene oxide (EO) during the past two years; the samples were compared to those from 22 control subjects, using sister chromatid exchange (SCE) methodology. The quantity of ethylene oxide inhaled during the two previous years was subsequently evaluated to fall between 500 and 5800 mg. When compared with the control group, the exposed group demonstrated a significant increase in the SCE rate. For certain individuals, the rate of increase rose 100% beyond the control mean. Smoking habits significantly influenced the data observed for the control group, but no significant differences in the SCE rate were found for the exposed group, regardless of smoking habits. Senior workers had the highest SCE mean levels. This observation indicated that the effect of exposure to EO was sufficient to produce a genetic reaction, was cumulative and in some cases persistent.