On average, one `Banana equivalent dose' per banana: http://en.wikipedia.org/wiki/Banana_equivalent_dose http://en.wikipedia.org/wiki/Banana_equivalent_dose An

On average, one `Banana equivalent dose' per banana: http://en.wikipedia.org/wiki/Banana_equivalent_dose http://en.wikipedia.org/wiki/Banana_equivalent_dose And no, that's not a joke; it's a convenient measure of low radiation levels. Bananas are more naturally radioactive due to high potassium contents.