✗ The myth everyone repeats
Bananas are dangerously radioactive because they contain potassium-40, and eating them poses a radiation health risk.
✓ What is actually true
Bananas do contain potassium-40, a naturally occurring radioactive isotope present in all potassium. However, the radiation level is negligible, eating a banana exposes you to less radiation than spending an hour at sea level. You would need to eat millions of bananas to receive a harmful dose. The 'Banana Equivalent Dose' is sometimes used in radiation science as a humorous measurement.
Reception
The receipts 2 sources