title: Comparison between urinary o-cresol and toluene as biomarkers of toluene exposure.
abstract: The characteristics of urinary o-cresol (o-C) and urinary toluene (TOL-U) as biomarkers of occupational exposure to toluene were comparatively evaluated. One hundred healthy male rotogravure printing workers and 161 male and female control subjects were studied. Personal exposure to airborne toluene (TOL-A) during the shift was determined as a time-weighted average. Simple analytical procedures based on solid phase microextraction followed by gas chromatography/mass spectometry analysis were applied to the determination of end-shift o-C and TOL-U. Median TOL-A was 48 (6.0-162.0) mg/m3 in printers and 0.021 (<0.003-0.137) mg/m3 in controls. o-C was 0.185 (0.032-0.948) mg/g creatinine in printers and 0.027 (<0.006-0.330) mg/g creatinine in the controls. TOL-U was 7.6 (1.8-23.9) microg/L in printers and 0.140 (0.094-0.593) microg/L in the controls. According to all indices, exposure to toluene was higher in printers than in the controls. Nevertheless, the distribution of o-C in the two groups partially overlapped, whereas such behavior was not found in TOL-U. Both o-C and TOL-U in printers were correlated with TOL-A (Pearson's on log10-transformed variables r = 0.704 and 0.844, respectively) and with each other (r = 0.683). Smoking habits significantly increased the excretion of o-C but not of TOL-U. From the point of view of sampling conditions and analytical requirements, TOL-U and o-C showed similar properties, but comparison of their intrinsic characteristics showed that TOL-U had higher specificity and sensitivity, lower background values, was better correlated with airborne exposure, and was not influenced by cigarette smoking. Therefore TOL-U may be considered superior to o-C as a biomarker of occupational exposure to toluene.
authors.affiliation: Department of Occupational and Environmental Medicine, University of Milano and Fondazione IRCCS Ospedale Maggiore Policlinico, Milan, Italy. silvia.fustinoni@unimi.it
authors.forename: Silvia
authors.initials: S
authors.lastname: Fustinoni
authors.forename: Rosa
authors.initials: R
authors.lastname: Mercadante
authors.forename: Laura
authors.initials: L
authors.lastname: Campo
authors.forename: Licia
authors.initials: L
authors.lastname: Scibetta
authors.forename: Carla
authors.initials: C
authors.lastname: Valla
authors.forename: Dario
authors.initials: D
authors.lastname: Consonni
authors.forename: Vito
authors.initials: V
authors.lastname: Foà
mesh_terms: D000328:Adult; D000395:Air Pollutants, Occupational / Q000652:urine*; D015415:Biomarkers / Q000032:analysis; D016022:Case-Control Studies; D003408:Cresols / Q000652:urine*; D004784:Environmental Monitoring; D008401:Gas Chromatography-Mass Spectrometry; D006801:Humans; D008297:Male; D016273:Occupational Exposure / Q000032:analysis*; D011327:Printing; D012680:Sensitivity and Specificity; D014050:Toluene / Q000652:urine*
chemical_list: D000395:Air Pollutants, Occupational; D015415:Biomarkers; D003408:Cresols; D014050:Toluene; C034047:2-cresol