title: Influence of glutathione S-transferases polymorphisms on biological monitoring of exposure to low doses of benzene.
abstract: The environmental and biological monitoring of benzene exposure is crucial to prevent the toxic effects of this solvent in workers. The degree of correlation, however, between the two and of different biomarkers among them varies, particularly at low levels of exposure, depending on various factors, including variability in metabolizing enzymes and smoking habits. To investigate these further, a cohort of 28 petrochemical workers (6 smokers and 22 non smokers) was monitored throughout ten consecutive days, on two occasions, two years apart, by collecting in total 173 environmental and biological samples. The airborne benzene levels, the urinary t,t-muconic acid (t,t-MA) and S-phenylmercapturic acid (S-PMA) concentrations, and the glutathione S-transferases (GST) M1 and T1 genotypes were measured. S-PMA was the only metabolite statistically correlated with airborne benzene levels (r=0.447, P<0.0001), particularly in non smokers (r=0.667, P<0.0001), the smoking habit being the only variable influencing metabolite excretion. Finally, a reduced S-PMA excretion was found to be associated with the GSTT1, but not the GSTM1, null genotype. In conclusion, the results show that S-PMA, but not t,t-MA, is able to monitor exposure to low benzene concentrations and confirm that the GSTT1 null genotype has a significant influence on metabolite excretion. The influence of the GSTT1 null genotype, however, was low, even when studying each subject with several urine samples.
authors.affiliation: Department of Environmental Medicine and Public Health, University of Padova, Italy.
authors.forename: Mariella
authors.initials: M
authors.lastname: Carrieri
authors.forename: Giovanni Battista
authors.initials: GB
authors.lastname: Bartolucci
authors.forename: Maria Luisa
authors.initials: ML
authors.lastname: Scapellato
authors.forename: Giovanna
authors.initials: G
authors.lastname: Spatari
authors.forename: Daniela
authors.initials: D
authors.lastname: Sapienza
authors.forename: Leonardo
authors.initials: L
authors.lastname: Soleo
authors.forename: Piero
authors.initials: P
authors.lastname: Lovreglio
authors.forename: Giovanna
authors.initials: G
authors.lastname: Tranfo
authors.forename: Maurizio
authors.initials: M
authors.lastname: Manno
authors.forename: Andrea
authors.initials: A
authors.lastname: Trevisan
mesh_terms: D000111:Acetylcysteine / Q000031:analogs & derivatives / Q000652:urine; D000328:Adult; D000388:Air / Q000032:analysis; D001554:Benzene / Q000009:adverse effects* / Q000032:analysis / Q000493:pharmacokinetics; D004784:Environmental Monitoring; D005838:Genotype; D005982:Glutathione Transferase / Q000235:genetics*; D006801:Humans; D008297:Male; D016273:Occupational Exposure / Q000032:analysis*; D011110:Polymorphism, Genetic / Q000235:genetics*; D012907:Smoking / Q000009:adverse effects; D013011:Sorbic Acid / Q000031:analogs & derivatives / Q000032:analysis
chemical_list: C005939:muconic acid; C053003:S-phenyl-N-acetylcysteine; D005982:Glutathione Transferase; D001554:Benzene; D000111:Acetylcysteine; D013011:Sorbic Acid