QuickCheck: Are bananas radioactive?

IF you were to use a Geiger counter on a banana, it would detect that it is radioactive.

Is this true?

Verdict:

TRUE

Yes, bananas are radioactive but you would need a very sensitive Geiger counter to pic up the radiation emitted from one banana.

Bananas are full of potassium which is necessary for your body as it helps your muscles work, including the ones that control your heartbeat.

However, bananas are high in both Potassium and one of its natural isotopes, potassium-40, which is radioactive.

One banana radiates about 0.1 microsieverts of radiation, so about 50 bananas (5 microsieverts) would emit a similar amount of radiation as a dental X-ray.

A whole lorryful of the fruit would trigger a false alarm on a radiation detector looking for smuggled nuclear weapons.

However, eating a banana won't make a person more radioactive as a typical adult contains around 16g of potassium-40, making them 280 times more radioactive than the fruit.

To consume enough bananas for the radiation to be lethal, one would have to eat 50 million bananas.

Other rich sources of Potassium-40 include potatoes, kidney beans, sunflower seeds and nuts.

References:

1. https://www.mcgill.ca/oss/article/you-asked/it-true-banana-radioactive