title: Alterations in leukocyte telomere length in workers occupationally exposed to benzene.
abstract: Exposure to benzene, a known leukemogen and probable lymphomagen, has been demonstrated to result in oxidative stress, which has previously been associated with altered telomere length (TL). TL specifically has been associated with several health outcomes in epidemiologic studies, including cancer risk, and has been demonstrated to be altered following exposure to a variety of chemical agents. To evaluate the association between benzene exposure and TL, we measured TL by monochrome multiplex quantitative PCR in 43 workers exposed to high levels of benzene and 43 age and sex-matched unexposed workers in Shanghai, China. Benzene exposure levels were monitored using organic vapor passive dosimetry badges before phlebotomy. The median benzene exposure level in exposed workers was 31 ppm. The mean TL in controls, workers exposed to levels of benzene below the median (≤31 ppm), and above the median (>31 ppm) was 1.26 ± 0.17, 1.25 ± 0.16, and 1.37 ± 0.23, respectively. Mean TL was significantly elevated in workers exposed to >31 ppm of benzene compared with controls (P = 0.03). Our findings provide evidence that high levels of occupational benzene exposure are associated with TL. Environ.
authors.affiliation: Occupational and Environmental Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, NIH, DHHS, Bethesda, Maryland.
authors.forename: Bryan A
authors.initials: BA
authors.lastname: Bassig
authors.forename: Luoping
authors.initials: L
authors.lastname: Zhang
authors.forename: Richard M
authors.initials: RM
authors.lastname: Cawthon
authors.forename: Martyn T
authors.initials: MT
authors.lastname: Smith
authors.forename: Songnian
authors.initials: S
authors.lastname: Yin
authors.forename: Guilan
authors.initials: G
authors.lastname: Li
authors.forename: Wei
authors.initials: W
authors.lastname: Hu
authors.forename: Min
authors.initials: M
authors.lastname: Shen
authors.forename: Stephen
authors.initials: S
authors.lastname: Rappaport
authors.forename: Francesco
authors.initials: F
authors.lastname: Barone-Adesi
authors.forename: Nathaniel
authors.initials: N
authors.lastname: Rothman
authors.forename: Roel
authors.initials: R
authors.lastname: Vermeulen
authors.forename: Qing
authors.initials: Q
authors.lastname: Lan
mesh_terms: D000328:Adult; D000367:Age Factors; D001554:Benzene / Q000633:toxicity*; D016022:Case-Control Studies; D002681:China; D005260:Female; D006801:Humans; D007962:Leukocytes / Q000187:drug effects*; D008297:Male; D016273:Occupational Exposure / Q000009:adverse effects*; D016133:Polymerase Chain Reaction / Q000379:methods; D016615:Telomere / Q000187:drug effects*
chemical_list: D001554:Benzene
keywords: benzene; occupational exposure; telomere length; telomeres