Bananas are slightly radioactive — they contain potassium-40, a naturally occurring radioactive isotope, and the radiation dose from eating one banana is so consistently measurable that nuclear scientists use it as an informal unit of measurement, called the “banana equivalent dose,” for explaining low-level radiation exposure to the public

Bananas are slightly radioactive. They are one of the most potassium-rich common foods, with about 0.5 grams of potassium in a typical 150-gram fruit, and 0.0117 percent of all naturally occurring potassium on Earth is the isotope potassium-40, which is radioactive. A medium banana therefore contains roughly 15 becquerels of radioactivity, meaning about 15 atoms […]