Fact #27
June 25, 2026Bananas Are Naturally Slightly Radioactive
Bananas contain potassium, and a tiny amount of that potassium is a naturally radioactive form called potassium-40. Every banana gives off an incredibly small amount of radiation, but it's completely harmless. You'd have to eat millions of bananas at once for the radiation to become dangerous.
Mini Facts
1
Your own body is naturally radioactive because it also contains potassium-40.
2
Potassium-40 has existed since Earth formed over 4.5 billion years ago.
3
Scientists sometimes jokingly measure tiny radiation doses using the "Banana Equivalent Dose."