title: A quantitative approach to evaluate urinary benzene and S-phenylmercapturic acid as biomarkers of low benzene exposure.
abstract: BACKGROUND
  Benzene is a ubiquitous pollutant; smoking habit, genetic polymorphisms, and analytical difficulties impact the identification of the best biomarker.
  
  
  OBJECTIVE
  To apply a systematic quantitative approach to evaluate urinary benzene (BEN-U) and S-phenylmercapturic acid (SPMA) as biomarkers of low benzene exposures.
  
  
  METHODS
  Seventy-one blue collar refinery workers, 97 white collar refinery workers and 108 general population subjects were included. Intrinsic characteristics, sampling and analytical issues were compared.
  
  
  RESULTS
  BEN-U and SPMA were detected in 99% and 78% of samples, which correlated with benzene exposure (r = 0.456 and r = 0.636, respectively) and with urinary cotinine (r = 0.630 and r = 0.570, respectively). Intrinsic characteristics were similar for the two biomarkers: specificity (0.64 and 0.69 for BEN-U and SPMA), sensitivity (0.74 and 0.83), as well as intra- and inter-individual variability (150% and >14 for both).
  
  
  CONCLUSIONS
  BEN-U and SPMA show similar intrinsic characteristics; analytical issues in detecting SPMA suggest that BEN-U is more convenient for investigating low exposure levels.
authors.affiliation: University of Milan, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Department of Occupational and Environmental Medicine, Milano, Italy. silvia.fustinoni@unimi.it
authors.forename: Silvia
authors.initials: S
authors.lastname: Fustinoni
authors.forename: Laura
authors.initials: L
authors.lastname: Campo
authors.forename: Rosa
authors.initials: R
authors.lastname: Mercadante
authors.forename: Dario
authors.initials: D
authors.lastname: Consonni
authors.forename: Danuta
authors.initials: D
authors.lastname: Mielzynska
authors.forename: Pier Alberto
authors.initials: PA
authors.lastname: Bertazzi
mesh_terms: D000111:Acetylcysteine / Q000031:analogs & derivatives / Q000652:urine; D000328:Adult; D000395:Air Pollutants, Occupational / Q000652:urine*; D001554:Benzene / Q000032:analysis*; D015415:Biomarkers / Q000652:urine; D016022:Case-Control Studies; D003367:Cotinine / Q000652:urine; D004784:Environmental Monitoring / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D008722:Methods; D008875:Middle Aged; D016273:Occupational Exposure / Q000032:analysis*; D012680:Sensitivity and Specificity
chemical_list: D000395:Air Pollutants, Occupational; D015415:Biomarkers; C053003:S-phenyl-N-acetylcysteine; D001554:Benzene; D003367:Cotinine; D000111:Acetylcysteine