My friend of considerable musical talent and vision Michigan native O Cigano Baggs recently posed a question about the potential negative health effects of using a penny to pick guitar strings. I decided to run some numbers for him about his penny.
Let's Get Specific - Mr. Baggs reports he is using a penny from before 1982 for the sake of this discussion lets assume it is a penny manufactured between the years of 1962 - 1982. In 1962 the mint removed all traces of tin leaving pennies comprised of 95% copper and 5% zinc - these pennies weigh 48 grains or 3.11 grams.
Some quick math would reveal 2.9545 grams of copper in each penny with the remaining 0.1555 grams being zinc. Now that we know what the pick is made out of and how much of those substances are present - how safe is it?
How Dangerous is Copper Anyway?
It depends where you put it and for how long. Routes for exposure to copper include: ingestion, eye contact, inhalation and absorption through the skin. Assuming Mr. Baggs is kept full of Kale chips he probably won't eat his pick - but what if he did? Would he be struck down with a serious case of copperiedus (copper toxicity)?
Probably not, healthy humans are capable of excreting excess copper effectively. No studies have been done linking ingestion to mortality. Surely many a child between 1962 and 1982 swallowed a penny to no long lasting damage.
It would appear that the biggest risk for Mr. B is in the dust created by picking metal strings. What data does exist about copper dust has been gleaned mostly from workers in industries that make use of copper in manufacturing processes. It would appear that a standard of 1 mg of copper dust per cubic meter is a very safe limit even in an industrial 8hr a day setting.
Dust Type and Distribution: Human powered rubbing and scraping will not produce as fine of dust as a machining process. The larger the dust particles are the heavier they will be and the faster they will settle out of the air. Without an accurate scale and multiple tests we won't know for sure how much dust is being created after how much playing. I think a liberal estimate would be 2mg per jam session. If he somehow used the whole pick he would release 2954.5 mg of copper dust. Assuming a loss of 2mg per average playing session - he would get roughly 1500 plays out of it. Again I think this is a very liberal estimate and in all reality probably less than 2mg is lost per session.
Conclusion:
In order to get out of the safety range it would require being in a room the size of a very small closet and creating enough dust in a few minutes to remove at least 2mg from the penny. Even then unless this was a daily thing for multiple hours he'd be unlikely to suffer any ill effects.
Take Aways: Wash your hands after handling metals. Don't rub dust in your eye.
Sources:
https://www.usmint.gov/learn/history/coin-production
