An epigenome-wide DNA methylation study of workers with an occupational exposure to lead.

Using the Illumina Infinium Methylation EPIC BeadChip (850 K), we report genome-wide differences in DNA methylation between occupational workers with high blood Pb levels (BLL) and low BLL. We observed 356 significant CpG sites. In particular, GSTM1 methylation was negatively associated with high BLL. Gene ontology and KEGG pathway enrichment analysis were performed to determine the complex biological systems of Pb exposure. Enriched gene sets were involved in the oxidation-reduction process, glutathione derivative biosynthetic process and nervous system development. To our knowledge, this is the first study to employ an 850 K array to examine whether workers with occupational exposure to high levels of Pb can have an epigenetic effect on the DNA methylation pattern.