The biochemical mechanism by which metals are mutagenic is by their effects on DNA. The main pathway shared by iron, copper, chromium, vanadium and cobalt is by redox-cycling reactions and mercury, cadmium and nickel by depleting glutathione and bonding to sulfihydryl groups (1). Free iron, in particular, can cause oxidative damage on DNA that can cause cancer in the spleen (2). Arsenic, in particular binds directly to critical thiols producing DNA damage (1). Cadmium interferes with and inhibits DNA repair (3;4).
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3. Slebos RJ, Li M, Evjen AN, Coffa J, Shyr Y, Yarbrough WG. Mutagenic effect of cadmium on tetranucleotide repeats in human cells. Mutat Res 2006;602:92-9.
4. Giaginis C, Gatzidou E, Theocharis S. DNA repair systems as targets of cadmium toxicity. Toxicol Appl Pharmacol 2006;213:282-90.