if you wash it and its also mostly copper youre fine. same thing with gold.
it is well known that copper is used: As a naturally biostatic surface in hospitals (Bacteriostatic antibiotics limit the growth of bacteria by interfering with bacterial protein production, DNA replication, or other aspects of bacterial cellular metabolism.) and to line parts of ships to protect against barnacles and mussels, originally used pure, but superseded by Muntz metal. Bacteria will not grow on a copper surface because it is biostatic. Copper doorknobs are used by hospitals to reduce the transfer of disease, and Legionnaires' disease is suppressed by copper tubing in air-conditioning systems.
also for gold
Pure metallic (elemental) gold is non-toxic and non-irritating when ingested[53] and is sometimes used as a food decoration in the form of gold leaf.
so keep on suckin those coins. after you wash them 😉
cough