Are bananas (and other foods) radioactive?
Can we find radiation in our food?
Yes, you read that right. Radioactivity in fruits? Don't worry, the amount of radioactivity in bananas is so low, it doesn't represent any danger to our health. Actually, almost everything around us is slightly radioactive – even ourselves.
But what makes something radioactive? Well, first, we need to take a look at the particles that make the matter: the atoms. They consist in a nucleus of protons and neutrons and are surrounded by electrons.
The main difference between elements of the periodic table is the number of protons they have in their nucleus. For example, Hydrogen has one proton and Oxygen has eight. Protons are particles with positive charge, and electrons, negative ones. This leaves us with neutrons, that have neutral charge. They increase the strong nuclear force, which keeps the atom cohesive.
Now, an element will always have the same amount of protons, but it can have different amounts of neutrons to keep its nucleus confined; the same element with different amounts of neutrons is what we call an isotope.
An atom is radioactive when the amount of neutrons can't keep the protons retained, and becomes unstable. When this happens, the excess particles are expelled. These particles are what we call radiation. When expelled, they can break the chemical bonds that keep together the atoms that make up our DNA, and this could be dangerous to our health.
To get an idea of this in real terms, the average amount of radiation (in my case) a Spanish person receives a year is 3.7 mSv, with most of it coming from cosmic rays, radioactive materials in the Earth, man-made sources, and also, from food.
Potassium-40 is the main source of internal radiation of our body. Since bananas are very rich in potassium, and some of those potassium atoms could be their radioactive isotope, bananas are more radioactive than other foods, but actually, all foods are slightly radioactive. The amount of radiation a banana could give us is 0.1 μSv, which is 0,0001mSv, aka still a very small amount.
In fact, bananas are not the most radioactive food, here's the top 5:
1. Brazil nuts: Contain amounts of radioactive elements – potassium and radon
Gadini - Pixabay
2. Butter beans: These are high in potassium and radon too.
Zoosnow - Pixabay
3. Bananas, as we saw, very rich in potassium.
Mockup Graphix - Unsplash
4. Carrots contain high levels of potassium and radon
Gabriel Gurrola - Unsplash
5. Potatoes are rich in potassium and radon as well
Lars Blankers - Unsplash
As we have seen, the amount of radiation we get from food is not harmful, and most of it goes though our body and we process it normally. So don't worry, you won't get a third eye or superpowers from eating that banana.