Oxidative DNA damage estimated by plasma 8-hydroxydeoxyguanosine (8-OHdG): influence of 4, 4'-methylenebis (2-chloroaniline) exposure and smoking

J Occup Health. 2007 Sep;49(5):389-98. doi: 10.1539/joh.49.389.


Oxidative DNA damage may play an important role in the human carcinogenic process. Recently, we reported a case of bladder cancer among 4, 4'-methylenebis (2-chloroaniline) (MBOCA)-exposed workers. By measuring the plasma level of 8-hydroxydeoxyguanosine (8-OHdG), we investigated the association between oxidative DNA damage and MBOCA exposure. In addition, we examined the effects of different confounders on the plasma level of 8-OHdG. We undertook a cross-sectional survey at four MBOCA-producing factories in Taiwan (158 subjects). Plasma 8-OHdG levels and urinary MBOCA concentrations were measured by liquid chromatography coupled with tandem mass spectrometry (LC/MS/MS). Personal characteristics were collected by questionnaire. The workers were classified according to their job titles as exposed (n=57) or unexposed (n=101) groups as well as classified according to urinary MBOCA levels as high urinary MBOCA (>20 microg/g creatinine) (n=45) or low urinary MBOCA (n=108) groups. Neither the MBOCA-exposed workers nor the high urinary MBOCA workers had a significant increase in the mean plasma 8-OHdG level, even after adjustment for potential confounders. Age and gender were significantly positively correlated with plasma 8-OHdG levels. Smokers among high urinary MBOCA workers also had significantly higher 8-OHdG levels than non-smokers among high urinary MBOCA workers. Our study provides evidence that smoking rather than MBOCA exposure induces elevation of plasma 8-OHdG levels among workers exposed to MBOCA, indicating that oxidative DNA damage does not play an important role in the carcinogenic processes of MBOCA.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 8-Hydroxy-2'-Deoxyguanosine
  • Adult
  • Age Distribution
  • Air Pollutants, Occupational / analysis
  • Air Pollutants, Occupational / toxicity
  • Alcohol Drinking / epidemiology
  • Biomarkers / blood
  • Biomarkers / urine
  • Body Mass Index
  • Chromatography, Liquid
  • Confounding Factors, Epidemiologic
  • Cross-Sectional Studies
  • DNA Damage / drug effects
  • DNA Damage / physiology*
  • Deoxyguanosine / analogs & derivatives*
  • Deoxyguanosine / blood
  • Dose-Response Relationship, Drug
  • Humans
  • Linear Models
  • Male
  • Methylenebis(chloroaniline) / analysis
  • Methylenebis(chloroaniline) / toxicity*
  • Middle Aged
  • Occupational Exposure / adverse effects*
  • Occupational Exposure / analysis
  • Oxidative Stress / drug effects
  • Oxidative Stress / physiology*
  • Sex Distribution
  • Smoking / adverse effects*
  • Smoking / epidemiology
  • Surveys and Questionnaires
  • Taiwan / epidemiology


  • Air Pollutants, Occupational
  • Biomarkers
  • Methylenebis(chloroaniline)
  • 8-Hydroxy-2'-Deoxyguanosine
  • Deoxyguanosine