Bananas are slightly radioactive.
Bananas are rich in potassium, and a small fraction of all potassium is the radioactive isotope potassium-40. Eating one exposes you to a tiny dose of radiation, which scientists jokingly call a banana equivalent dose.
Why is this true?
The dose is harmless, and your body keeps its potassium level constant no matter how many you eat. Shipments of bananas have nonetheless occasionally set off radiation detectors at ports.
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