Prenatal exposure to drinking water disinfection by-products and DNA methylation in cord blood.
Maternal exposure to drinking water disinfection by-products (DBPs) during pregnancy has been related to adverse birth outcomes. While experimental studies have shown that exposure to DBPs induce DNA hypomethylation, evidence from humans is limited. This study aimed to examine whether prenatal exposure to drinking water DBPs was associated with DNA methylation in cord blood. Maternal biomarkers of exposure to drinking water DBPs including blood trihalomethanes [THMs, including chloroform (TCM), bromodichloromethane (BDCM), dibromochloromethane (DBCM), and bromoform (TBM)] and urinary trichloroacetic acid (TCAA) were measured during late pregnancy. DNA methylation in Alu and long interspersed nucleotide element-1 (LINE-1) repetitive elements from cord blood samples (n=115) was measured by pyrosequencing. We used multivariable linear regression to estimate the associations of DNA methylation in cord blood with maternal blood THMs and urinary TCAA. We found no statistically significant association between urinary TCAA and DNA methylation. However, we found that blood TBM was associated with decreased Alu methylation (-0.39%; 95% CI: -0.83%, 0.05% for the highest versus lowest exposure group; p for trend=0.08) and decreased LINE-1 methylation (-1.27%; 95% CI: -2.91%, 0.36% for the highest versus lowest exposure group; p for trend=0.06). Our results suggest that prenatal exposure to drinking water TBM is associated with DNA hypomethylation in cord blood. However, further studies are needed to confirm our findings.
Department of Occupational and Environmental Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, PR China; Key Laboratory of Environment and Health, Ministry of Education, Ministry of Environmental Protection, Huazhong University of Science and Technology, Wuhan, Hubei, PR China; State Key Laboratory of Environmental Health (incubating), School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, PR China.
Pan
P
Yang
Department of Epidemiology and Biostatistics, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, PR China.
Bin
B
Zhou
Department of Occupational and Environmental Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, PR China; Key Laboratory of Environment and Health, Ministry of Education, Ministry of Environmental Protection, Huazhong University of Science and Technology, Wuhan, Hubei, PR China; State Key Laboratory of Environmental Health (incubating), School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, PR China.
Wen-Cheng
WC
Cao
Department of Occupational and Environmental Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, PR China; Key Laboratory of Environment and Health, Ministry of Education, Ministry of Environmental Protection, Huazhong University of Science and Technology, Wuhan, Hubei, PR China; State Key Laboratory of Environmental Health (incubating), School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, PR China.
Yi-Xin
YX
Wang
Department of Occupational and Environmental Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, PR China; Key Laboratory of Environment and Health, Ministry of Education, Ministry of Environmental Protection, Huazhong University of Science and Technology, Wuhan, Hubei, PR China; State Key Laboratory of Environmental Health (incubating), School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, PR China.
Zhen
Z
Huang
Department of Occupational and Environmental Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, PR China; Key Laboratory of Environment and Health, Ministry of Education, Ministry of Environmental Protection, Huazhong University of Science and Technology, Wuhan, Hubei, PR China; State Key Laboratory of Environmental Health (incubating), School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, PR China.
Jin
J
Li
Department of Occupational and Environmental Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, PR China; Key Laboratory of Environment and Health, Ministry of Education, Ministry of Environmental Protection, Huazhong University of Science and Technology, Wuhan, Hubei, PR China; State Key Laboratory of Environmental Health (incubating), School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, PR China.
Wen-Qing
WQ
Lu
Department of Occupational and Environmental Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, PR China; Key Laboratory of Environment and Health, Ministry of Education, Ministry of Environmental Protection, Huazhong University of Science and Technology, Wuhan, Hubei, PR China; State Key Laboratory of Environmental Health (incubating), School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, PR China. Electronic address: zengqiang506@163.com.
Qiang
Q
Zeng
D002725:Chloroform / Q000097:blood; D019175:DNA Methylation; D004202:Disinfectants / Q000032:analysis*; D060766:Drinking Water / Q000737:chemistry*; D005260:Female; D005312:Fetal Blood / Q000737:chemistry*; D006801:Humans; D018811:Maternal Exposure; D011247:Pregnancy; D014238:Trichloroacetic Acid / Q000652:urine; D022882:Trihalomethanes / Q000097:blood; D014874:Water Pollutants, Chemical / Q000032:analysis*; D018508:Water Purification
D004202:Disinfectants; D060766:Drinking Water; D022882:Trihalomethanes; D014874:Water Pollutants, Chemical; D014238:Trichloroacetic Acid; D002725:Chloroform
DNA methylation; Disinfection by-products; Exposure; Trichloroacetic acid; Trihalomethanes