title: DNA damage and repair capacity in workers exposed to low concentrations of benzene.
abstract: DNA damage and cellular repair capacity were studied in 18 male fuel tanker drivers and 13 male filling-station attendants exposed to low and very low concentrations of benzene, respectively, and compared to 20 males with no occupational exposure (controls). Exposure to airborne benzene was measured using passive personal samplers, and internal doses were assayed through the biomarkers t,t-muconic acid, S-phenylmercapturic acid and urinary benzene. DNA damage was evaluated using tail intensity (TI) determined by the comet assay in peripheral lymphocytes. Urinary 7-hydro-8-oxo-2'-deoxyguanosine (8-oxodG) was measured as a biomarker of oxidative damage. DNA repair kinetics were assessed using the comet assay in lymphocytes sampled 20 and 60 min post H2O2 exposure. Benzene exposure differed significantly between the drivers (median 246.3 µg/m(3)), attendants (median 13.8 µg/m(3)), and controls (median 4.1 µg/m(3)). There were no differences in TI and 8-oxodG among the three groups, or between smokers and non-smokers. DNA repair kinetics were similar among the drivers, attendants and controls, although the comet assay on H2 O2 -damaged lymphocytes after 60 min revealed significantly lower levels of TI only in drivers. The DNA repair process in smokers was similar to that observed in drivers. In conclusion, this study found no relationship between low levels of benzene exposure and DNA damage, although there was evidence that exposure interferes with DNA repair kinetics. The biological impact of this finding on the onset of genotoxic effects in exposed workers has still to be ascertained.
authors.affiliation: Interdisciplinary Department of Medicine, Section of Occupational Medicine "E.C. Vigliani," University of Bari, Bari, Italy.
authors.forename: Piero
authors.initials: P
authors.lastname: Lovreglio
authors.affiliation: Department of Public Health and Community Medicine, Section of Pharmacology, University of Verona, Verona, Italy.
authors.forename: Denise
authors.initials: D
authors.lastname: Doria
authors.affiliation: Department of Public Health and Community Medicine, Section of Pharmacology, University of Verona, Verona, Italy.
authors.forename: Maria Enrica
authors.initials: ME
authors.lastname: Fracasso
authors.affiliation: Department of Medical and Surgical Science, Section of Occupational Medicine, University of Bologna, Bologna, Italy.
authors.forename: Anna
authors.initials: A
authors.lastname: Barbieri
authors.affiliation: Department of Medical and Surgical Science, Section of Occupational Medicine, University of Bologna, Bologna, Italy.
authors.forename: Laura
authors.initials: L
authors.lastname: Sabatini
authors.affiliation: Interdisciplinary Department of Medicine, Section of Occupational Medicine "E.C. Vigliani," University of Bari, Bari, Italy.
authors.forename: Ignazio
authors.initials: I
authors.lastname: Drago
authors.affiliation: Department of Medical and Surgical Science, Section of Occupational Medicine, University of Bologna, Bologna, Italy.
authors.forename: Francesco S
authors.initials: FS
authors.lastname: Violante
authors.affiliation: Interdisciplinary Department of Medicine, Section of Occupational Medicine "E.C. Vigliani," University of Bari, Bari, Italy.
authors.forename: Leonardo
authors.initials: L
authors.lastname: Soleo
mesh_terms: D000080242:8-Hydroxy-2'-Deoxyguanosine; D000111:Acetylcysteine / Q000031:analogs & derivatives / Q000097:blood; D000328:Adult; D001554:Benzene / Q000008:administration & dosage / Q000633:toxicity*; D015415:Biomarkers; D016022:Case-Control Studies; D020552:Comet Assay; D004249:DNA Damage / Q000187:drug effects*; D004260:DNA Repair / Q000187:drug effects* / Q000502:physiology; D003849:Deoxyguanosine / Q000031:analogs & derivatives / Q000652:urine; D006801:Humans; D008214:Lymphocytes / Q000187:drug effects / Q000502:physiology; D008297:Male; D008875:Middle Aged; D016273:Occupational Exposure / Q000009:adverse effects* / Q000032:analysis; D012907:Smoking / Q000009:adverse effects; D013011:Sorbic Acid / Q000031:analogs & derivatives / Q000032:analysis
chemical_list: D015415:Biomarkers; C005939:muconic acid; C053003:S-phenyl-N-acetylcysteine; D000080242:8-Hydroxy-2'-Deoxyguanosine; D003849:Deoxyguanosine; D001554:Benzene; D000111:Acetylcysteine; D013011:Sorbic Acid
keywords: Comet assay; DNA repair kinetics; benzene exposure; genotoxic effects