title: [The effect of inhalable titanium dioxide on the oxidative stress among occupational population].
abstract: OBJECTIVE
  To investigate the inhalable titanium dioxide exposure level and make an assessment of its oxidative effect on occupational exposed population.
  
  
  METHODS
  A total of 7 workers occupationally exposing to inhalable titanium dioxide were recruited into the study. The basic information and occupational history were collected by interview, while their blood sample (10 ml for each subject) were collected before and after the investigation, respectively. Pre- and post-work shift urine samples (60 ml for each subject) were collected for 29 days consecutively. The daily personal titanium dioxide exposure level, temperature and relative humidity were detected too. Urinary 8-hydroxy-deoxyguanosine (8-OHdG) and serum high-sensitivity C-reactive protein (hs-CRP) were detected by ELISA and latex immunoturbidimetric assay, respectively.
  
  
  RESULTS
  The mean concentration of air inhalable titanium dioxide was (1.194 ± 1.015) mg/m(3). Serum hs-CRP level before and after the investigation was (1.13 ± 1.08), (1.33 ± 1.01) mg/L, respectively. No statistical significance was observed between hs-CRP level before and after the investigation (t = -0.848, P = 0.425). Pre- and post-work shift urinary 8-OHdG was (3.51 ± 1.39), (3.65 ± 1.06) µmol/mol Cr, respectively. A positive correlation was found between the concentration of inhalable titanium dioxide and the changes of 8-OHdG level (r = 0.192, t = 2.09, P = 0.039). Linear mixed-effect models, adjusted by work shift, years of employment, age, body mass index, smoking status, temperature and relative humidity, showed no significant exposure-respond trend between the inhalable titanium dioxide concentration and 8-OHdG level (β = 0.288, t = 1.940, P = 0.055).
  
  
  CONCLUSIONS
  Our findings do not support the potential link between occupationally exposure to inhalable titanium dioxide and high induction of DNA oxidative stress.
authors.affiliation: Department of Occupational and Environmental Health Sciences, School of Public Health, Peking University, Beijing 100191, China.
authors.forename: Sen
authors.initials: S
authors.lastname: Zhen
authors.forename: Ji
authors.initials: J
authors.lastname: Zhang
authors.forename: Yan-hui
authors.initials: YH
authors.lastname: Ma
authors.forename: Ning
authors.initials: N
authors.lastname: Zhang
authors.forename: Lan-zheng
authors.initials: LZ
authors.lastname: Liu
authors.forename: Tian-cheng
authors.initials: TC
authors.lastname: Wang
authors.forename: Chun-ying
authors.initials: CY
authors.lastname: Chen
authors.forename: Jing-wen
authors.initials: JW
authors.lastname: Zhou
authors.forename: Xin-wei
authors.initials: XW
authors.lastname: Li
authors.forename: Qin
authors.initials: Q
authors.lastname: Qian
authors.forename: Yan-peng
authors.initials: YP
authors.lastname: Lü
authors.forename: Shao-qian
authors.initials: SQ
authors.lastname: Lin
authors.forename: Guang
authors.initials: G
authors.lastname: Jia
mesh_terms: D000080242:8-Hydroxy-2'-Deoxyguanosine; D000395:Air Pollutants, Occupational / Q000009:adverse effects*; D002097:C-Reactive Protein / Q000032:analysis; D003849:Deoxyguanosine / Q000031:analogs & derivatives / Q000652:urine; D006801:Humans; D008297:Male; D008875:Middle Aged; D016273:Occupational Exposure / Q000032:analysis*; D018384:Oxidative Stress; D014025:Titanium / Q000009:adverse effects* / Q000097:blood / Q000652:urine
chemical_list: D000395:Air Pollutants, Occupational; C009495:titanium dioxide; D000080242:8-Hydroxy-2'-Deoxyguanosine; D002097:C-Reactive Protein; D014025:Titanium; D003849:Deoxyguanosine