Environmental and biological monitoring of benzene exposure in a cohort of Italian taxi drivers

• Published in: Toxicology letters Vol. 167; no. 2; pp. 142 - 151
• Main Authors: Manini, Paola, De Palma, Giuseppe, Andreoli, Roberta, Poli, Diana, Mozzoni, Paola, Folesani, Giuseppina, Mutti, Antonio, Apostoli, Pietro
• Format: Journal Article
• Language: English
• Published: Shannon Elsevier Ireland Ltd 01.12.2006; Amsterdam Elsevier Science
• Subjects: Acetylcysteine - analogs & derivatives; Acetylcysteine - urine; Adult; Air Pollutants, Occupational - analysis; Air Pollutants, Occupational - urine; Benzene; Benzene - analysis; Benzene - metabolism; Benzene Derivatives - analysis; Benzene Derivatives - urine; Biological and medical sciences; Cotinine - urine; Environmental Monitoring; Epoxide Hydrolases - genetics; Glutathione Transferase - genetics; GSTM1 polymorphism; Humans; Italy; Male; Medical sciences; Middle Aged; Motor Vehicles; NAD(P)H Dehydrogenase (Quinone) - genetics; Occupational Exposure - analysis; Polymorphism, Genetic; S-Phenylmercapturic acid; Smoking - metabolism; Sorbic Acid - analogs & derivatives; Sorbic Acid - metabolism; t, t-Muconic acid; Taxi drivers; Toxicology; Urinary benzene; Italy; Europe; S-Phenylmercapturic acid; t, t-Muconic acid; Taxi drivers; GSTM1 polymorphism; Urinary benzene; Benzene; Urine; Genetic variability; Enzyme; Isozyme; Transferases; Genotype; Exposure; Biological monitoring; Glutathione transferase; Cohort study; t,t-Muconic acid; Environment; Polymorphism
• ISSN: 0378-4274; 1879-3169
• DOI: 10.1016/j.toxlet.2006.08.016

An integrated approach based on ambient and biological monitoring, the latter including both biomarkers of exposure and susceptibility, was applied to characterize benzene exposure in a group of 37 taxi drivers of the city of Parma (Italy). Airborne benzene concentrations were assessed by 24 h personal sampling and work-shift sampling inside the taxicab using passive samplers (Radiello ®). Benzene metabolites, trans, trans-muconic acid ( t, t-MA) and S-phenylmercapturic acid ( S-PMA), and urinary cotinine as biomarker of smoking habits were measured by isotopic dilution liquid chromatography tandem mass spectrometry in both pre-shift (PS) and end-of-shift (EOS) samples. Urinary benzene (U-B) levels were determined by solid-phase microextraction gas chromatography–mass spectrometry in EOS samples. Relevant polymorphisms of microsomal epoxide hydrolase, NAD(P)H:quinone oxidoreductase, glutathione S-transferases M1-1 ( GSTM1), T1-1, and A1 were characterized by PCR-based methods. Mean airborne benzene concentration was 5.85 ± 1.65 μg/m 3, as assessed by 24 h personal sampling integrating for work-shift, indoor or general environment activities. Significantly, higher benzene concentrations were detected in the taxicab during the work-shift (7.71 ± 1.95 μg/m 3, p < 0.005). Smokers eliminated significantly higher concentrations of U-B and S-PMA than non-smokers in EOS samples [geometric mean (geometric S.D.): 2.58 (4.23) versus 0.44 (1.79) μg/l for U-B; 3.79 (1.50) versus 2.14 (1.87) μg/g creat. for S-PMA, p < 0.002]. Within smokers, S-PMA concentrations significantly increased at the end of the work-shift compared to pre-shift values ( p < 0.05). t, t-MA showed a similar behaviour, although differences were not significant. In the narrow range examined, no correlation was observed between air benzene concentration and urinary biomarkers. All benzene biomarkers but EOS t, t-MA were correlated with U-cotinine ( p < 0.05). GSTM1 polymorphism significantly modulated S-PMA excretion, as subjects bearing the GSTM1pos genotype [3.61 (1.15) μg/g creat.] excreted significantly higher S-PMA concentrations than GSTM1null subjects [2.19 (1.18) μg/g creat., p < 0.05].