Confronto tra benzene urinario e acido S-fenilmercapturico urinario come indicatori di esposizione a benzene

Biological monitoring of benzene exposure is representing a challenge for occupational and environmental health: in this study the capability of urinary S-phenylmercapturic acid (SPMA) and benzene (BEN-U) as biomarkers of benzene exposure were compared. Seventy one refinery blue collars and 97 white collars, both working in a petrochemical plant, were investigated.Blue collars had a median personal exposure to airborne benzene during a work shift of 0.19 (from 0.02 to 6.13) mg/m3. End-shift urinary BEN-U and SPMA were 550 ng/L and 0.91 μg/L in blue collars and 320 ng/L and 0.70 μg/L in white collars. Correlations between biomarkers and airborne benzene were significant, with Pearson’s r 0.27 and 0.33 among all subjects, and r 0.44 and 0.42 among non-smokers; BEN-U and SPMA were correlated with r 0.727. Cigarette smoking increased the levels of biomarkers of two- to five-fold. BEN-U and SPMA showed similar features as biomarkers of benzene exposure; even at occupational exposures as those experienced by workers in a refinery plant, smoking plays a major role in determining the internal dose of benzene.