Table 1. An overview of the epigenetic effects of metal exposure.

	DNA methylation	Histone modifications	ncRNA expression
Arsenic	+/−	H3S10p, H2AXp, H3K9/K27/K16/K18ac, H3K4me2/me3, H3K9me2, H3K27me3, H3R3me2, H3R17me2	Let-7 family, miR-16, miR-17, miR-19, miR-20, miR-22, miR-24, miR-26b, miR-29a, miR-30, miR-34a, miR-96, miR-98, miR-107, miR-126, miR-195, miR-200b, miR-210, miR-221, miR-222, miR-454
Cadmium	+/−	H3p, H3ac, H3K4me3, H3K9me3, H3K27me3	Let-7 family, miR-15b, miR-23b, miR-101, miR-144, miR-130a, miR-361-5p, miR-455-3p, miR-1233, miR-1275
Chromium	+/−	H2AXp, H3K4me2/me3, H3K9me2/me3	miR-143, miR-222. miR-3940-5p
Copper	ND	H3ac, H4ac	miR-398
Lead	−	H3K9ac, H4K8/K12ac, H3K4me2	miR-146a, miR-222
Mercury	+/−	H3ac, H3K27me3	miR-141, miR-196b, miR-302b, miR-367, miR-382
Nickel	+	H3S10p, H3K9ac, H4ac, H2Aub, H2Bub, H3K9me2	miR-222
Organotin	−	H3ac, H4ac	ND

(+), hypermethylation; (−), hypomethylation. Ac, acetylation; Me, methylation; P, phosphorylation; Ub, ubiquitination. ND, no data.