Introduction DNA methylation is regarded as a well-defined epigenetic mechanism and involved in biological processes including ageing and cancer. The purpose of this study is to find whether DNA methylation is associated with lifestyle and environmental factors in healthy population residing in an industrialised zone in Korea.

Methods A total of 758 subjects (324 males and 434 females) were included in this study. Global DNA methylation level by lifestyle factors and environmental pollutants was measured in peripheral blood leukocyte.

Results Global DNA methylation levels (expressed as PMR values) of men were varied with age, while no change was seen in women. No association between lifestyle and biochemical factors (smoking, homocysteine, leptin, albumin and BMI) with global DNA methylation was observed. The relationship between metal such as mercury, cadmium and arsenic and DNA methylation was analysed. Arsenic only had positive association with DNA methylation level in male group. Global DNA methylation pattern among family members was analysed to find familial aggregation. Significant associations of Mother with offspring, offspring with offspring were found. Correlation between sibling pairs was also increased in young age group, suggesting that DNA methylation patterns determined not only by genetic factors but environmental factors.

Conclusion DNA methylation levels of men were varied with age, while those of women were consistent throughout the age group. Positive association was shown in urinary arsenic only in adult male. DNA methylation level can be regulated by environmental stressor, but the association between each environmental factor and global DNA methylation was not strong.