A Dose-response Study of Arsenic Exposure, Folate, and Genomic Methylation of Peripheral Blood Mononuclear Cell DNA in Bangladesh

S-29B7-3 Background/Aims: Chronic arsenic exposure is associated with increased risk for cancers of the skin, lung, liver, and bladder; however, the mechanism(s) underlying arsenic-induced carcinogenesis are poorly understood. Animal and in vitro data suggest that chronic arsenic exposure induces genomic hypomethylation of DNA. In contrast, our previous study in adults chronically exposed to arsenic-contaminated drinking water in Bangladesh suggested that arsenic exposure is associated with increased genomic methylation of total leukocyte DNA, and that this association is contingent on adequate folate. Methods: We undertook a cross-sectional study specifically designed to evaluate the dose-response relationship between arsenic exposure and genomic methylation of peripheral blood mononuclear cell DNA. We recruited 375 participants between 30 and 65 years of age, including 75 for…