Did you know that your favorite banana you just ate is actually radioactive? Yes, it's not a joke! Every banana contains naturally occurring isotopes, but don't panic, it's completely safe. The main culprit is potassium-40, a naturally occurring radioactive isotope. Bananas, such as the popular Cavendish variety, are particularly rich in it. One medium banana contains about 450 milligrams of potassium, of which only a tiny fraction is radioactive potassium-40. The radioactivity of a banana is measured at approximately 0.1 microsieverts. For comparison, a typical flight from Moscow to Sochi will add about 30 microsieverts, and the average annual dose from natural sources is 2,400 microsieverts. Our bodies also contain potassium-40, which is naturally regulated. The body constantly maintains stable potassium levels, eliminating any excess. Therefore, when you eat a banana, you don't accumulate radiation; your body simply metabolizes it. To receive a dangerous dose of radiation from bananas alone, you'd have to eat about ten million of them in one sitting. Or one hundred thousand bananas a day for many years. So enjoy this delicious fruit without any worries!