Dioxin-like compound exposures and DNA methylation in the Anniston Community Health Survey Phase II

In this epigenome-wide association study (EWAS), we examined the associations between PCDD, PCDF, and PCB exposures and DNA methylation. Whole blood DNA methylation was measured using Illumina EPIC arrays (n=292). We modeled lipid-adjusted toxic equivalencies (TEQs) for: ΣDioxins (sum of 28 PCDDs, PCDFs, cPCBs, and mPCBs), PCDDs, PCDFs, cPCBs, and mPCBs using robust multivariable linear regression adjusting for age, race, sex, smoking, total lipids, and estimated percentages of six blood cell types. The Anniston Community Health Survey (ACHS-I) was initially conducted from 2005-2007 to assess PCB exposures in Anniston, Alabama residents. In 2014, a follow-up study (ACHS-II) was conducted to measure the same PCBs as in ACHS-I and additional compounds e.g., polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and dioxin-like non-ortho (cPCBs) substituted PCBs. The primary objective of this study was to carry out an epigenome-wide association study (EWAS) assessing if exposures to AHR ligands such as, PCDDs, PCDFs, cPCBs, and mPCBs, were associated with altered methylation at any genome-wide CpGs.