In A Nutshell
Bananas, that beloved yellow berry—and yes, it’s actually a berry—contain radioactive isotopes courtesy of the element within them, potassium. They contain enough radiation to be detected in ports and there is even a unit of measurement for radiation called—you guessed it—the Banana Equivalent Dose.
The Whole Bushel
Botanically speaking, bananas are berries, for starters. Second, they are believed to have originated in Southeast Asia and have spread their delicious influence from there to (maybe) the Middle East. They were introduced to South America by the Portuguese who brought them from West Africa. So where does the radioactivity come in?
Potassium, like numerous other elements, has radioactive isotopes and since said element is in bananas, bananas are a wee bit radioactive. How radioactive? Not enough to hurt you unless you’re some sort of banana connoisseur who is willing to eat them in the several millions. Then you’re in trouble (for more than one reason).
And then we reach the Banana Equivalent Dose—a measurement of radiation just like rads and rems and whatnot. Do not worry—even though it is indeed a measurement of radiation, it will take millions of bananas to kill you. I, for one, will go back to enjoying banana fudge sundaes in peace.