Association of long-term radon exposure with peripheral blood DNA methylation levels and expression of regulatory genes in underground miners
10.13491/j.issn.1004-714X.2026.03.010
- VernacularTitle:井下矿工长期氡暴露与外周血DNA甲基化水平及调控基因表达的关联
- Author:
Pinhua ZHANG
1
;
Jia ZHANG
1
;
Chunnan PIAO
1
;
Yunyun WU
1
;
Quanfu SUN
1
;
Jianxiang LIU
1
Author Information
1. Key Laboratory of Radiological Protection and Nuclear Emergency, China CDC, National Institute for Radiological Protection, Chinese Center for Disease Control and Protection, Beijing 100088, China.
- Publication Type:OriginalArticles
- Keywords:
Underground miner;
Radon exposure;
DNA methylation
- From:
Chinese Journal of Radiological Health
2026;35(3):370-378
- CountryChina
- Language:Chinese
-
Abstract:
Objective This study aimed to investigate the association between long-term radon exposure and changes in peripheral blood DNA methylation levels, as well as alterations in the expression of methylation-related regulatory genes (DNMT1, DNMT3A, and MBD2) among underground non-uranium metal miners. Methods Five non-uranium metal mines with varying levels of radon exposure were enrolled in this study. From each mine, 30 underground miners and 30 aboveground workers were randomly recruited. Basic demographic information was collected via a standardized questionnaire, and peripheral venous blood samples were obtained from all participants. An enzyme-linked immunosorbent assay (ELISA) colorimetric method was used to detect peripheral blood DNA methylation levels. Real-time quantitative PCR was used to measure mRNA expression levels of DNMT1, DNMT3A, and MBD2. These indicators were compared between underground and aboveground groups and among underground miners with different radon exposure levels. Multiple linear regression analysis was conducted to examine the associations between cumulative radon dose and two outcomes: peripheral blood DNA methylation levels, and the expression levels of methylation-related regulatory genes in underground miners. Results The average radon concentration in the underground workplaces of the five mines was 4,088 Bq/m3 (range: 116-18,188 Bq/m3), corresponding to an estimated annual effective dose of approximately 25.67 mSv for miners. The average radon concentration in aboveground workplaces was 58 Bq/m3 (range: 28-1796 Bq/m3), equivalent to an annual effective dose of approximately 0.51 mSv for aboveground workers. The average cumulative radon dose of underground miners was approximately 26.56 times that of aboveground workers (Z=−12.469, P<0.001). Compared with the aboveground workers, the peripheral blood DNA methylation level of underground miners was significantly decreased, approximately 0.77 times that of the aboveground group (Z=−2.313，P<0.05), accompanied by decreased expression of DNA methyltransferase genes DNMT1 and DNMT3A, which were 0.83 and 0.68 times those of the aboveground group, respectively (Z=−3.002、−4.190，P<0.01). After adjusting for age, working years, body mass index, smoking status, and alcohol consumption, multiple linear regression analysis revealed two key findings: cumulative radon dose was significantly and inversely correlated with peripheral blood DNA methylation levels (β=−0.752, P<0.001); and cumulative radon dose was significantly negatively associated with the expression of DNMT1 and DNMT3A (β=−0.319, −0.369, P<0.01). Conclusion The reduced DNA methylation levels and downregulated expression of DNA methyltransferase genes in underground miners are closely associated with long-term radon exposure.
