SHORT-TIME EXPOSURE TO BENZENE AND GASOLINE AT GARAGES

This study was carried out to evaluate car mechanics' short time expos ure to benzene and gasoline vapours. The measurements were performed d uring adjustment of direct fuel injection systems, carburettor adjustm ent and fuel system repairings. The vapour concentrations from unleade d and leaded gasoline were compared during different workphases. Biolo gical monitoring were used to evaluate total exposure to benzene. The mean short time exposure level of car mechanics exposed to unleaded ga soline vapours was 8+/-6 cm3/m3 and 26+/-19 cm3/m3 to leaded gasoline. The concentrations of benzene in breathing zone varied from the detec tion limit (0.2 cm3/m3) to 1.3 cm3/m3 from unleaded gasoline and from the detection limit to 3.7 cm3/m3 from leaded gasoline. The average ba ckground concentration of gasoline vapours in the garages were 6+/-7 ( SD.) cm3/m3 and concentration of benzene was under the detection limit . The samples of benzene in blood were collected 2-9 hours after the e xposure and concentrations ranged from 3 to 16 nmol/l. When approximat ed to the time point of 16 hours after exposure according to the elimi nation rate constant the benzene levels in blood ranged from 1.6 - 11. 1 nmol/l. Biological monitoring of benzene showed exposure levels high er than expected according to the corresponding air measurements (TWA8 h). Comparison of expected benzene levels in blood if no dermal exposu re were present to the calculated levels 16 hours after the exposure s howed that dermal exposure in the motor repairing work may be the most significant route (80%) of exposure. Leaded gasoline caused higher ex posure than unleaded gasoline.