Association of low-dose exposure to persistent organic pollutants with global DNA hypomethylation in healthy Koreans

Environ Health Perspect. 2010 Mar;118(3):370-4. doi: 10.1289/ehp.0901131. Epub 2009 Nov 6.


Background: Global DNA methylation levels have been reported to be inversely associated with blood levels of persistent organic pollutants (POPs), xenobiotics that accumulate in adipose tissue. Whether these associations extend to a population with much lower concentrations of POPs is not known.

Objectives: This study was performed to examine whether low-dose exposure to POPs was associated with global DNA hypomethylation in Koreans.

Methods: The amount of global DNA hypomethylation was estimated by the percent 5-methyl-cytosine (%5-mC) in Alu and LINE-1 assays in 86 apparently healthy Koreans. Among various POPs, organochlorine (OC) pesticides, polychlorinated biphenyls (PCBs), and polybrominated diphenylethers (PBDEs) were measured.

Results: Most OC pesticides were inversely and significantly associated with %5-mC in the Alu assay, with correlation coefficients in the range 0.2 to 0.3 after adjusting for age, sex, body mass index, smoking, and alcohol. The strongest OC pesticide associations with %5-mC in the Alu assay were observed with oxychlordane, trans-nonachlor, and p,p -dichlorodiphenyldichloroethylene. The correlation coefficient of age with %5-mC in the Alu assay was 0.24, similar to correlations of OC pesticides with %5-mC in the Alu assay. Most PCBs and PBDEs showed nonsignificant inverse trends with %5-mC in the Alu assay, but for some PCBs the U-shaped association was significant. On the other hand, POPs were not associated with %5-mC in the LINE-1 assay.

Conclusions: We found that low-dose exposure to POPs, in particular OC pesticides, was associated with global DNA hypomethylation in apparently healthy Koreans.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Age Factors
  • Aged
  • Asians
  • DNA Methylation / drug effects*
  • Demography
  • Environmental Exposure / adverse effects
  • Environmental Exposure / analysis*
  • Environmental Pollutants / blood
  • Environmental Pollutants / toxicity*
  • Female
  • Halogenated Diphenyl Ethers
  • Health*
  • Humans
  • Hydrocarbons, Chlorinated
  • Korea / ethnology
  • Male
  • Middle Aged
  • Organic Chemicals / blood
  • Organic Chemicals / toxicity*
  • Pesticides
  • Polychlorinated Biphenyls
  • Reference Values
  • Time Factors


  • Environmental Pollutants
  • Halogenated Diphenyl Ethers
  • Hydrocarbons, Chlorinated
  • Organic Chemicals
  • Pesticides
  • Polychlorinated Biphenyls