Sister chromatid exchange (SCE) and micronucleus (MN) frequencies in lymphocytes of gasoline station attendants.

Peripheral blood lymphocytes from 22 men with low average exposure (229 micrograms/m3 = 0.72 ppm) to benzene and 19 control men were investigated for Sister Chromatid Exchange (SCE) frequency. The majority of the men (21 exposed, 19 controls) were also investigated using the micronucleus assay (MN). The exposed subjects were employed at 10 different gas stations in or near the city (Bari/South Italy). SCE frequencies were significantly related with age and smoking habits, on the contrary no relation was observed between SCE and length of employment (SCE = 7.41 + 0.03.age () + 0.0001.length of employment (n.s.) + 0.03.cigarette consumption (); F = 4.87; p < 0.01; () significant; (n.s.) non-significant). MN frequencies were significantly increased in relation with length of employment; but no relation was observed when age and smoking habits were taken into consideration (regression model: MN = 18.03 + 0.006.age (n.s.) + 0.32.length of employment () - 0.1.cigarette consumption (n.s.); F = 4.138; p < 0.05).