title: Protein adducts of 1,4-benzoquinone and benzene oxide among smokers and nonsmokers exposed to benzene in China.
abstract: Hemoglobin (Hb) and albumin (Alb) adducts of the benzene metabolites benzene oxide (BO) and 1,4-benzoquinone (1,4-BQ) were analyzed by gas chromatography-mass spectrometry in 43 exposed workers and 44 unexposed controls from Shanghai, China, as part of a larger cross-sectional study of benzene biomarkers. When subjects were divided into controls (n = 44) and workers exposed to </=31 ppm (n = 21) and >31 ppm (n = 22) of benzene, median 1,4-BQ-Alb adducts were 2110, 5850, and 13,800 pmol/g Alb, respectively (correlation with exposure: Spearman r = 0.762; P < 0.0001); median BO-Alb adducts were 106, 417, and 2400 pmol/g Alb, respectively (Spearman r = 0.877; P < 0.0001); and median BO-Hb adducts were 37.1, 50.5, and 136 pmol/g Hb, respectively (Spearman r = 0.757; P < 0.0001). To our knowledge, this is the first observation that adducts of 1,4-BQ are significantly correlated with benzene exposure. When compared on an individual basis, Alb adducts of 1,4-BQ and BO and Hb adducts of BO were highly correlated with each other and with urinary phenol and hydroquinone (P < 0.0001 for all of the comparisons). Although detectable in the assays, Hb adducts of 1,4-BQ and both Hb and Alb adducts of 1,2-BQ produced erratic results and are not reported. Interestingly, cigarette smoking increased Alb adducts of 1,4-BQ but not of BO, suggesting that benzene from cigarette smoke was not the primary contributor to the 1,4-BQ adducts.
authors.affiliation: Department of Environmental Sciences and Engineering, School of Public Health, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-7400, USA.
authors.forename: K
authors.initials: K
authors.lastname: Yeowell-O'Connell
authors.forename: N
authors.initials: N
authors.lastname: Rothman
authors.forename: S
authors.initials: S
authors.lastname: Waidyanatha
authors.forename: M T
authors.initials: MT
authors.lastname: Smith
authors.forename: R B
authors.initials: RB
authors.lastname: Hayes
authors.forename: G
authors.initials: G
authors.lastname: Li
authors.forename: W E
authors.initials: WE
authors.lastname: Bechtold
authors.forename: M
authors.initials: M
authors.lastname: Dosemeci
authors.forename: L
authors.initials: L
authors.lastname: Zhang
authors.forename: S
authors.initials: S
authors.lastname: Yin
authors.forename: S M
authors.initials: SM
authors.lastname: Rappaport
mesh_terms: D001554:Benzene / Q000009:adverse effects* / Q000032:analysis; D016227:Benzoquinones / Q000032:analysis*; D003430:Cross-Sectional Studies; D003510:Cyclohexanes / Q000032:analysis*; D004781:Environmental Exposure; D008401:Gas Chromatography-Mass Spectrometry; D006454:Hemoglobins / Q000737:chemistry*; D006801:Humans; D012907:Smoking / Q000009:adverse effects*
chemical_list: D016227:Benzoquinones; D003510:Cyclohexanes; D006454:Hemoglobins; C004532:quinone; D001554:Benzene; C023372:benzene oxide