Esposizione a vapori di benzina : MTBE urinario quale nuovo indicatore per il monitoraggio biologico

Gasoline, labelled as carcinogenic to human, is added with a mixture of aromatic hydrocarbons and oxygenated compounds to increase antiknock power. Among these chemicals benzene and methyl tert-butyl ether (MTBE) are of particularly interest due to their toxicological properties. Exposure to benzene and MTBE was evaluated in 89 gasoline station attendants and in a matched group of 90 controls working in the area surrounding Milan, Italy. Median personal exposure to airborne benzene and MTBE were 59(from 3-3246) and 408 (2-57616) μg/m3 in gasoline station attendants,and 4 (1-48) and 4 (1-528) μg/m3 in controls. In end shift samples median urinary benzene and MTBE were 339 and 780 ng/L in gasoline attendants and 157 and 78 ng/L in controls. A relevant influence of cigarette smoking was found on urinary benzene, but not on MTBE. Significant correlations between environmental and biological markers were found. The highest correlations were those between urinary MTBE and airborne MTBE or benzene (r=0.871 or 0.816), whereas urinary benzene correlated with airborne benzene with much lower correlation coefficient(r=0.439). Gasoline station attendants are exposed to significant concentration of benzene; for biomonitoring their exposure to gasoline vapours the use of urinary MTBE is suggested.