Children who swallow U.S. pennies minted after 1982 may face
an unexpected health threat due to these coins' zinc
content.

Background: A new study at Duke University Medical Center
has found that, when a child or pet ingests a penny minted
after 1982, the coin can react with stomach acid to create a
toxic mixture as corrosive as battery acid. If the coin stays
in the stomach for several days, this process can lead to
severe stomach inflammation and even ulcers.