title: Short-term markers of DNA damage among roofers who work with hot asphalt.
abstract: Roofers are at increased risk for various malignancies and their occupational exposures to polycyclic aromatic hydrocarbons (PAHs) have been considered as important risk factors. The overall goal of this project was to investigate the usefulness of phosphorylated histone H2AX (γH2AX) as a short-term biomarker of DNA damage among roofers.
  
  
  
  Blood, urine, and dermal wipe samples were collected from 20 roofers who work with hot asphalt before and after 6 h of work on Monday and Thursday of the same week (4 sampling periods). Particle-bound and gas-phase PAHs were collected using personal monitors during work hours. γH2AX was quantified in peripheral lymphocytes using flow cytometry and 8-hydroxy-2-deoxyguanosine (8-OHdG) was assessed in urine using ELISA. General linear mixed models were used to evaluate associations between DNA damage and possible predictors (such as sampling period, exposure levels, work- and life-style factors). Differences in mean biomarker and DNA damage levels were tested via ANOVA contrasts.
  
  
  
  Exposure measurements did not show an association with any of the urinary biomarkers or the measures of DNA damage. Naphthalene was the most abundant PAH in gas-phase, while benzo(e)pyrene was the most abundant particle-bound PAH. Post-shift levels of γH2AX and 8-OHdG were higher on both study days, when compared to pre-shift levels. Cigarette smoking was a predictor of γH2AX and urinary creatinine was a predictor of urinary 8-OHdG. Between-subject variance to total variance ratio was 35.3 % for γH2ax and 4.8 % for 8-OHdG.
  
  
  
  γH2AX is a promising biomarker of DNA damage in occupational epidemiology studies. It has a lower within-subject variation than urinary 8-OHdG and can easily be detected in large scale groups. Future studies that explore the kinetics of H2AX phosphorylation in relation to chemical exposures may reveal the transient and persistent nature of this sensitive biomarker of early DNA damage.
authors.affiliation: Department of Environmental and Occupational Health, Colorado School of Public Health, University of Colorado Denver, Denver, USA. Berrin.Serdar@ucdenver.edu.|Department of Epidemiology, Colorado School of Public Health, University of Colorado Denver, Denver, USA. Berrin.Serdar@ucdenver.edu.|Colorado School of Public Health, University of Colorado Anschutz Medical Campus, Mail Stop B119-V20, 12850 East Montview Boulevard, Rm. V20-3126, Aurora, CO, 80045, USA. Berrin.Serdar@ucdenver.edu.
authors.forename: Berrin
authors.initials: B
authors.lastname: Serdar
authors.affiliation: Department of Environmental and Occupational Health, Colorado School of Public Health, University of Colorado Denver, Denver, USA.
authors.forename: Stephen
authors.initials: S
authors.lastname: Brindley
authors.affiliation: Analytical Toxicology Laboratory, Center for Environmental Medicine, Colorado State University, Fort Collins, USA.
authors.forename: Greg
authors.initials: G
authors.lastname: Dooley
authors.affiliation: Department of Mechanical Engineering, Colorado State University, Fort Collins, USA.
authors.forename: John
authors.initials: J
authors.lastname: Volckens
authors.affiliation: Department of Biostatistics and Informatics, Colorado School of Public Health, University of Colorado Denver, Denver, USA.
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Juarez-Colunga
authors.affiliation: Department of Epidemiology, Colorado School of Public Health, University of Colorado Denver, Denver, USA.
authors.forename: Ryan
authors.initials: R
authors.lastname: Gan
mesh_terms: D000080242:8-Hydroxy-2'-Deoxyguanosine; D000395:Air Pollutants, Occupational / Q000032:analysis* / Q000652:urine; D003120:Colorado; D060389:Construction Industry; D004249:DNA Damage; D003849:Deoxyguanosine / Q000031:analogs & derivatives / Q000652:urine; D004784:Environmental Monitoring; D006657:Histones / Q000378:metabolism*; D006801:Humans; D006838:Hydrocarbons; D008214:Lymphocytes / Q000378:metabolism; D016273:Occupational Exposure / Q000009:adverse effects / Q000032:analysis*; D011084:Polycyclic Aromatic Hydrocarbons / Q000032:analysis* / Q000652:urine
chemical_list: D000395:Air Pollutants, Occupational; C468783:H2AX protein, human; D006657:Histones; D006838:Hydrocarbons; D011084:Polycyclic Aromatic Hydrocarbons; C006647:asphalt; D000080242:8-Hydroxy-2'-Deoxyguanosine; D003849:Deoxyguanosine
keywords: DNA double strand breaks; Polycyclic aromatic hydrocarbons, PAHs, Biomarkers, 8-hydroxy-deoxyguanosine, γH2AX