title: Impact of coexposure on toluene biomarkers in rats.
abstract: 1. Toluene (TOL) is widely used in industry. Occupational exposure to TOL is commonly assessed using TOL in blood, hippuric acid and ortho-cresol. Levels of these biomarkers may depend on factors potentially interfering with TOL biotransformation, such as the presence of other solvents in the workplace. Mercapturic acids (MAs) could be an alternative to the "traditional" TOL biomarkers. 2. This study aims (1) to investigate in rat the effects of an exposure to vapours mixtures on the TOL metabolism, and (2) to assess how well MAs performed in these contexts compared to the traditional TOL biomarkers. 3. Rats were exposed by inhalation to binary mixtures of TOL with n-butanol (BuOH), ethyl acetate (EtAc), methyl ethyl ketone (MEK) or xylenes (XYLs); biological exposure indicators were then measured. 4. Depending on the compounds in the mixture and their concentrations, TOL metabolism was accelerated (with BuOH), unchanged (with EtAc) or inhibited (with XYLs and MEK). Inhibition leads to an increase in blood TOL concentrations, even at authorized atmospheric concentrations, which may potentiate the effect of TOL. 5. MAs excretions are little affected by coexposure scenarios, their levels correlating well with atmospheric TOL levels. They could thus be suitable bioindicators of atmospheric TOL exposure.
authors.affiliation: Pollutants and Health, Institut National de Recherche et de Sécurité (INRS) , Vandoeuvre , France.
authors.forename: Frédéric
authors.initials: F
authors.lastname: Cosnier
authors.forename: Hervé
authors.initials: H
authors.lastname: Nunge
authors.forename: Céline
authors.initials: C
authors.lastname: Brochard
authors.forename: Manuella
authors.initials: M
authors.lastname: Burgart
authors.forename: Aurélie
authors.initials: A
authors.lastname: Rémy
authors.forename: Marie-Josèphe
authors.initials: MJ
authors.lastname: Décret
authors.forename: Benoît
authors.initials: B
authors.lastname: Cossec
authors.forename: Pierre
authors.initials: P
authors.lastname: Campo
mesh_terms: D020001:1-Butanol; D000085:Acetates; D000111:Acetylcysteine / Q000097:blood; D000704:Analysis of Variance; D000818:Animals; D015415:Biomarkers / Q000097:blood*; D002074:Butanones; D003408:Cresols / Q000097:blood; D004305:Dose-Response Relationship, Drug; D006626:Hippurates / Q000097:blood; D008297:Male; D015394:Molecular Structure; D016273:Occupational Exposure / Q000032:analysis*; D051381:Rats; D017207:Rats, Sprague-Dawley; D014050:Toluene / Q000097:blood / Q000737:chemistry / Q000378:metabolism*; D014992:Xylenes
chemical_list: D000085:Acetates; D015415:Biomarkers; D002074:Butanones; D003408:Cresols; D006626:Hippurates; D014992:Xylenes; D014050:Toluene; C005222:methylethyl ketone; C007650:ethyl acetate; D020001:1-Butanol; C030514:hippuric acid; D000111:Acetylcysteine; C034047:2-cresol