Mepụta ụdị okwu a dị mgbagwoju anya Arsenic, chromium, iron, na nickel nwere ike ijikọta ya na mmepụta nke ụdị oxygen na-emeghachi omume, ụfọdụ n'ime ndị a nwekwara ike ịgbanwe iguzosi ike n'ihe nke mmegharị DNA.
N'ezie, ụdị okwu dị mgbagwoju anya nke ahịrịokwu ahụ bụ "Arsenic, chromium, iron, na nickel nwere ike jikọta ya na mmepụta nke ụdị oxygen na-emeghachi omume, nickel nwekwara ike jikọta ya na hypermethylation DNA na histone deacetylation, ebe cadmium nwere ike igbochi mmezi nkwekọrịta DNA. "