Did you know that a banana is naturally a little radioactive?

A banana does not need to come out of a laboratory to contain a small amount of radioactive material. It naturally contains potassium. A small fraction of it consists of potassium 40, a radioactive isotope present in the environment.

The U.S. Environmental Protection Agency uses this food to explain that radioactivity also exists in ordinary products. This finding does not transform the fruit into a particular danger: the exposure associated with its normal consumption is very low. The word “radioactive” alone does not give the measure of a risk.

The discovery moves an imaginary boundary. Radioactivity had been placed on the side of plants and specialized equipment; part also belongs to the natural world. The banana does not hide an anomaly. It reveals a property of certain atoms that we do not notice when peeling a fruit.