title: Biological monitoring of low benzene exposure in Italian traffic policemen.
abstract: A comparative evaluation of urinary biomarkers was carried out to characterize benzene exposure in a group of 100 traffic policemen of the city of Parma (Italy). All subjects were monitored once, in two consecutive days characterized by similar climatic conditions but preceded by two windy days. Benzene ambient concentration measured by municipal air monitoring stations was 1 microg/m(3) (Day 1) and 2 microg/m3 (Day 2). Personal exposure to ambient concentrations of benzene, toluene, ethylbenzene and xylene (BTEX) was assessed by using Radiello((R)) passive-diffusive samplers in a subgroup of 24 workers. Benzene metabolites, t,t-muconic acid (t,t-MA) and S-phenylmercapturic acid (S-PMA) were determined by isotopic dilution liquid chromatography-tandem mass spectrometry on spot urine samples collected at the end of the shift. Urinary benzene (U-B) was determined by solid-phase microextraction gas chromatography-mass spectrometry. Airborne benzene concentration expressed as median [and interquartile range] was 6.07 [0.28-9.53] microg/m(3), as assessed by personal sampling. Urinary concentrations of biomarkers in the whole group were 41.8 [34.1-89.8] microg/g creatinine for t,t-MA, 0.67 [0.23-1.32] microg/g creatinine for S-PMA, and 0.16 [0.13-0.26] microg/l for U-B. Smokers eliminated significantly higher concentrations of unchanged BTEX and benzene metabolites than non-smokers (p < 0.05). When traffic policemen were distinguished into indoor (n=31) and outdoor workers, no significant differences were observed for either airborne benzene or urinary biomarkers. Significantly lower concentrations of S-PMA and U-B were determined in samples collected at Day 1 as compared to Day 2 (p < 0.0001 and p = 0.003, respectively) suggesting that these biomarkers are enough sensitive and specific to detect changes in airborne benzene concentration even at few microg/m(3).
authors.affiliation: Laboratory of Industrial Toxicology, Department of Clinical Medicine, Nephrology and Health Sciences, University of Parma, Via Gramsci 14, 43100 Parma, Italy. paola.manini@unipr.it
authors.forename: Paola
authors.initials: P
authors.lastname: Manini
authors.forename: Giuseppe
authors.initials: G
authors.lastname: De Palma
authors.forename: Roberta
authors.initials: R
authors.lastname: Andreoli
authors.forename: Diana
authors.initials: D
authors.lastname: Poli
authors.forename: Marta
authors.initials: M
authors.lastname: Petyx
authors.forename: Massimo
authors.initials: M
authors.lastname: Corradi
authors.forename: Antonio
authors.initials: A
authors.lastname: Mutti
authors.forename: Pietro
authors.initials: P
authors.lastname: Apostoli
mesh_terms: D000111:Acetylcysteine / Q000031:analogs & derivatives / Q000652:urine; D000328:Adult; D001554:Benzene / Q000378:metabolism*; D004784:Environmental Monitoring; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D016273:Occupational Exposure; D016495:Police; D012044:Regression Analysis; D013011:Sorbic Acid / Q000031:analogs & derivatives / Q000032:analysis
chemical_list: C005939:muconic acid; C053003:S-phenyl-N-acetylcysteine; D001554:Benzene; D000111:Acetylcysteine; D013011:Sorbic Acid