Bananas

Potassium is naturally abundant in bananas. Bananas have a little amount of radioactivity because potassium is a mixture of isotopes that includes the radioactive potassium-40. The typical banana has 450 mg of potassium and emits roughly 14 decays per second. Unless you are transporting a large quantity of bananas across an international border, you shouldn't be concerned about it. Bananas can cause a radiation alert to go off for officials looking for nuclear waste, similar to cat litter.

Don't assume that the only radioactive foods are Brazil nuts and bananas. Basically, potassium-40, which is mildly but considerably radioactive, is present naturally in all foods that are high in potassium. This contains red meat, lima beans, potatoes (radioactive french fries), and carrots. Radon-226 is also present in lima beans, potatoes, and carrots. When it comes down to it, every food has a tiny amount of radioactivity in it. You consume food, making you slightly radioactive as well.