title: Urinary 8-hydroxy-2'-deoxyguanosine as a biomarker of oxidative DNA damage induced by ambient pollution in the Normative Aging Study.
abstract: BACKGROUND
  Studies show that exposure to air pollution damages human health, but the mechanisms are not fully understood. One suggested pathway is via oxidative stress.
  
  
  OBJECTIVE
  This study examines associations between exposure to air pollution and oxidative DNA damage, as indicated by urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG) concentrations in ageing participants during 2006-2008.
  
  
  METHODS
  We fit linear regression models to examine associations between air pollutants and 8-OHdG adjusting for potential confounders.
  
  
  RESULTS
  8-OHdG was significantly associated with ambient particulate matter ≤2.5 μm in aerodynamic diameter (PM(2.5)), nitrogen dioxide (NO(2)), maximal 1 h ozone (O(3)), sulphate (SO(4)(2-)) and organic carbon (OC), but not with black carbon (BC), carbon monoxide (CO), the number of particles (PN) or elemental carbon (EC). Effects were more apparent with multi-week averages of exposures. Per IQR increases in 21-day averages of PM(2.5), PN, BC, EC, OC, CO, SO(4)(2-), NO(2) and maximal 1 h O(3) were associated with 30.8% (95% CI 9.3% to 52.2%), -13.1% (95% CI -41.7% to 15.5%), 3.0% (95% CI -19.8% to 25.8%), 5.3% (95% CI -23.6% to 34.2%), 24.4% (95% CI 1.8% to 47.1%), -2.0% (95% CI -12.4% to 8.3%), 29.8% (95% CI 6.3% to 53.3%), 32.2% (95% CI 7.4% to 56.9%) and 47.7% (95% CI 3.6% to 91.7%) changes in 8-OHdG, respectively.
  
  
  CONCLUSIONS
  This study suggests that ageing participants experienced an increased risk of developing oxidative DNA injury after exposure to secondary, but not primary, ambient pollutants.
authors.affiliation: Department of Environmental Health, Exposure, Epidemiology and Risk Program, Harvard School of Public Health, Boston, MA 02215, USA. rencizao@yahoo.com
authors.forename: Cizao
authors.initials: C
authors.lastname: Ren
authors.forename: Shona
authors.initials: S
authors.lastname: Fang
authors.forename: Robert O
authors.initials: RO
authors.lastname: Wright
authors.forename: Helen
authors.initials: H
authors.lastname: Suh
authors.forename: Joel
authors.initials: J
authors.lastname: Schwartz
mesh_terms: D000080242:8-Hydroxy-2'-Deoxyguanosine; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000235:genetics / Q000652:urine; D000393:Air Pollutants / Q000032:analysis / Q000633:toxicity; D000397:Air Pollution / Q000009:adverse effects* / Q000032:analysis; D015415:Biomarkers / Q000652:urine; D004249:DNA Damage / Q000502:physiology*; D003849:Deoxyguanosine / Q000031:analogs & derivatives* / Q000652:urine; D004784:Environmental Monitoring / Q000379:methods; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D018384:Oxidative Stress / Q000235:genetics; D052638:Particulate Matter / Q000032:analysis / Q000633:toxicity
chemical_list: D000393:Air Pollutants; D015415:Biomarkers; D052638:Particulate Matter; D000080242:8-Hydroxy-2'-Deoxyguanosine; D003849:Deoxyguanosine