Bananas are radioactive

Yes it’s true, they are radioactive! I’m not lying to get your attention!
But there is no need for panic, you won’t die from eating one after your workout or after having a banana smoothie. Let me explain!

Photo credit The Photographer via Wikimedia

A little fella called Potassium.
Bananas naturally contain Potassium, and some of this Potassium is radioactive.

The radioactive Potassium houses one extra neutron in the nucleus compared to the stable one. The overpopulation of neutrons causes the nucleus to decay and emit radiation.

This means that every second there are 15 nuclei decaying in a banana, which in physical terms would mean that the banana contains 15 Becquerel (Bq) of radiation.

I don’t think this says much about anything, so lets put things into perspectives.

How many bananas can I eat a day?
Acute radiation poisoning usually occurs if you are exposed to 1 Sievert of radiation. This is a whole lot of radiation and the only time in history that civilians have been exposed to these amounts have been in atomic bombings and nuclear accidents, such as Chernobyl, Nagasaki and Hiroshima.

So it’s not like this is a common thing and obviously you have already figured out that no one has ever died from eating bananas (unless you choke on one or slip on a banana peel).

Photo credit Giovanna Colombi via Wikimedia.

In order to receive a deadly amount of radiation you’d have to eat 10 million bananas at once. Even if you were a magician I think you’d have a difficult time of doing so. You won’t even eat 10 million bananas in a life time, unless you eat a banana every minute of your life. Don’t accept this as a challenge, please…

Banana Equivalent Dose
There is a fun quantity some people like to use when talking about radiation doses. It’s called banana equivalent dose, BED for short.

What it does is it simply converts any radiation exposure to number of bananas.

Usually we say one banana gives 0.1 micro Sievert, so a dental X-ray would be as eating 100 bananas. A mammography would be equal to eating 1000 bananas, which is a bit more. But it’s still way less than 10 million.

What about flying? A return flight from Melbourne to Los Angeles would be as eating 660 bananas, due to cosmic radiation. So you can argue that traveling is dangerous, yet this fact has never stopped or banned any backpacker from flying across the globe. I think we should be more worried about not getting enough leg space on long haul flights than be concerned about radiation.

Photo credit Michel Temer via Flickr.

So is there any reason to exclude bananas from our diet? NO! You can have as many as you like! What you do need to worry about is not slipping on a banana peel or picking moldy bananas in the store, that’s when you really get sick or injured.

Anyways, all this talk about bananas made me crave for some banana smoothie. I’m off to the store!


5 Responses to “Bananas are radioactive”

  1. Hanna Tomic says:

    Thank you so much everyone, first time I heard of bananas being radioactive I was shocked and I remember how fascinated I was with the concept of BED. I’m glad I got the chance to tell more people about this!

  2. Kalani Paranagama says:

    This was such an interesting read Hanna! I never knew this about bananas!

  3. Lauren Cain says:

    This was a really good read, very interesting and a little quirky! The piece had a good flow and explained everything clearly. I especially liked the part about the Banana Equivalent Dose, which I’ll be thinking about next time I fly somewhere.

  4. Kelley Leech says:

    I have definitely learned something new today! Your piece was really enjoyable and fun to read, and very well explained. I’ll never look at a banana the same way again!

  5. Sally Jenkins says:

    Great post Hanna! I really like the flow of your piece, it has a really nice structure that’s easy to read.