title: Urinary biomarkers of exposure and of oxidative damage in children exposed to low airborne concentrations of benzene.
abstract: The aim of this work was to evaluate the oxidative damage to nucleic acids in children (5-11 years) associated with exposure to environmental pollutants and tobacco smoke (ETS). For each subject, urinary sampling was done twice (evening and next morning) to measure by tandem LC-MS-MS such oxidated products of nucleic acids as 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodGuo), 8-oxo-7,8-dihydroguanosine (8-oxoGuo), and 8-oxo-7,8-dihydroguanine (8-oxoGua). Methyl tert-butyl ether (U-MTBE), benzene (U-Benz), and its metabolites (t,t-muconic and S-phenylmercapturic acids, t,t-MA and S-PMA, respectively) were determined as biomarkers of exposure to air pollution, and cotinine as a biomarker of exposure to ETS. Biomarkers of exposure (S-PMA and U-MTBE) and of DNA oxidation (8-oxodGuo) were dependent on the urbanization and industrialization levels and increased in the evening sample as compared to next morning (p<0.05). In both evening and next morning samples, 8-oxodGuo and 8-oxoGuo correlated with each other (r=0.596 and r=0.537, respectively, p<0.01) and with biomarkers of benzene exposure, particularly S-PMA (r=0.59 and r=0.45 for 8-oxodGuo and r=0.411 and r=0.383 for 8-oxoGuo, p<0.01). No such correlations were observed for U-MTBE and cotinine. Multiple linear regression analyses showed that 8-oxodGuo was positively associated with S-PMA at both sampling times (β=0.18 and β=0.14 for evening and next morning sampling, respectively; p<0.02) and weakly with U-MTBE (β=0.07, p=0.020) only in the evening urines. These results suggest that the selected biomarkers of exposure to benzene, particularly S-PMA, are good tracers of exposure to complex mixtures of oxidative pollutants and that the associated oxidative damage to nucleic acids is detectable even at very low levels of exposure.
authors.affiliation: Department of Clinical and Experimental Medicine, University of Parma, Parma, Italy. Electronic address: roberta.andreoli@unipr.it.
authors.forename: R
authors.initials: R
authors.lastname: Andreoli
authors.affiliation: Department of Environmental Science, Security, Territory, Food and Health, University of Messina, Messina, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Spatari
authors.affiliation: CERT, INAIL Research Center at the University of Parma, Parma, Italy.
authors.forename: D
authors.initials: D
authors.lastname: Pigini
authors.affiliation: CERT, INAIL Research Center at the University of Parma, Parma, Italy.
authors.forename: D
authors.initials: D
authors.lastname: Poli
authors.affiliation: Department of Clinical and Experimental Medicine, University of Parma, Parma, Italy.
authors.forename: I
authors.initials: I
authors.lastname: Banda
authors.affiliation: Department of Clinical and Experimental Medicine, University of Parma, Parma, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Goldoni
authors.affiliation: Department of Clinical and Experimental Medicine, University of Parma, Parma, Italy.
authors.forename: M G
authors.initials: MG
authors.lastname: Riccelli
authors.affiliation: INAIL, DMLEL, Monteporzio Catone, Rome, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Petyx
authors.affiliation: Department of Public Health and Infectious Diseases, La Sapienza University, Rome, Italy.
authors.forename: C
authors.initials: C
authors.lastname: Protano
authors.affiliation: Department of Public Health and Infectious Diseases, La Sapienza University, Rome, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Vitali
authors.affiliation: Department of Environmental Science, Security, Territory, Food and Health, University of Messina, Messina, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Barbaro
authors.affiliation: Department of Clinical and Experimental Medicine, University of Parma, Parma, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Mutti
mesh_terms: D000080242:8-Hydroxy-2'-Deoxyguanosine; D000111:Acetylcysteine / Q000031:analogs & derivatives / Q000652:urine; D000393:Air Pollutants / Q000633:toxicity* / Q000652:urine; D001554:Benzene / Q000633:toxicity*; D015415:Biomarkers / Q000652:urine; D002648:Child; D002675:Child, Preschool; D003367:Cotinine / Q000652:urine; D004247:DNA / Q000378:metabolism; D004249:DNA Damage; D003849:Deoxyguanosine / Q000031:analogs & derivatives / Q000652:urine; D004784:Environmental Monitoring; D005260:Female; D006147:Guanine / Q000031:analogs & derivatives / Q000652:urine; D006151:Guanosine / Q000031:analogs & derivatives / Q000652:urine; D006801:Humans; D008297:Male; D008738:Methyl Ethers / Q000652:urine; D010084:Oxidation-Reduction; D012802:Sicily
chemical_list: D000393:Air Pollutants; D015415:Biomarkers; D008738:Methyl Ethers; D006151:Guanosine; C043243:methyl tert-butyl ether; C046215:8-hydroxyguanosine; C053003:S-phenyl-N-acetylcysteine; C024829:8-hydroxyguanine; D006147:Guanine; D000080242:8-Hydroxy-2'-Deoxyguanosine; D004247:DNA; D003849:Deoxyguanosine; D001554:Benzene; D003367:Cotinine; D000111:Acetylcysteine
keywords: Benzene exposure; Children; Nucleic acid oxidation; Oil refinery; S-phenylmercapturic acid