title: Urinary 2,5 hexanedione as a biomarker of n-hexane exposure.
abstract: n-Hexane is a saturated aliphatic hydrocarbon widely used in industry. In most cases it is used as a mixture with hexane isomers and various others solvents in the form of commercial hexane. n-Hexane is metabolized oxidatively to a number of compounds, including 2,5-hexanedione (2,5-HD), which is eliminated through the urine and is implicated in the neurotoxic effect of this solvent. The main objective of this study was to evaluate urinary 2,5-HD as a biomarker of n-hexane exposure. The study was carried out in seven industrial units. Post-shift urine samples from 111 workers who handled commercial hexane were collected and analysed for 2,5-HD by capillary gas chromatography. Air sampling was performed in the breathing zones of the workers, and the air samples were analysed using validated methods. Monitoring individual exposures showed that n-hexane exposure varied from 5 to 70 p.p.m. (mean +/- SD = 15.24 +/- 2.98 p.p.m.). Significant correlation was observed between exposure to n-hexane and urinary 2,5-HD levels, with high correlation coefficients (rho = 0.81, p = 0.000), suggesting that urinary 2,5-HD is a good biomarker of occupational exposure to n-hexane. Urinary 2,5-HD is recommended as a better tool than air monitoring in the assessment of health risk, namely the early detection of n-hexane neurotoxicity.
authors.affiliation: Center of Environmental and Occupational Health, Instituto Nacional de Saúde Dr. Ricardo Jorge, Porto, Portugal. olgamayan@mail.telepac.pt
authors.forename: Olga
authors.initials: O
authors.lastname: Mayan
authors.forename: Joao Paulo
authors.initials: JP
authors.lastname: Teixeira
authors.forename: Sandra
authors.initials: S
authors.lastname: Alves
authors.forename: Conceição
authors.initials: C
authors.lastname: Azevedo
mesh_terms: D000328:Adult; D000395:Air Pollutants, Occupational / Q000493:pharmacokinetics* / Q000633:toxicity; D015415:Biomarkers / Q000652:urine; D001711:Biotransformation; D005260:Female; D006586:Hexanes / Q000008:administration & dosage* / Q000493:pharmacokinetics* / Q000633:toxicity; D006588:Hexanones / Q000652:urine*; D006801:Humans; D008297:Male; D008875:Middle Aged; D016273:Occupational Exposure
chemical_list: D000395:Air Pollutants, Occupational; D015415:Biomarkers; D006586:Hexanes; D006588:Hexanones; C026385:n-hexane; C011269:2,5-hexanedione