How radioactive are bananas and other radioactive foods?

Hi! You may have heard, that bananas are radioactive. But why would they be and how bad is it? Is the slippery peel or the delicious pulp the most active? And what about brazil nuts? Are they the most radioactive you can buy in a grocery store? Let's find out! Always respect radioactivity and take precautions. Though most samples in this video are edible. Except the radioactive mushrooms. I would not eat those. I will also use open flames on flammable foods. Don't let fire play with you... Let us get straight to it by putting my most sensitive geiger counter near a stack of different bananas. The average background radiation in my home is between 0.11 and 0.13 microsieverts per hour. It can fluctuate between zero and 0.2 but if it stays above 0.2 for a longer period something is surely adding to the background radiation. I don't see or hear anything above the natural background radiation. Is the geiger counter even working? Yep, it is working all right. What if I burry all my geiger counters inside the stack? Will one of them notice something? Even when surrounded by bananas I don't see any unusual readings. Maybe I will have more luck with the brazil nuts. These are often quoted for containing up to a 1000 times more radium than other foods. Making them the most radioactive food. Seems odd, they would contain radium. The reason is that they have a high concentration of barium. Let me explain. Chemically, barium and radium are very similar. The tree can't tell the difference and stores radium as was it barium. And brazil nuts come from one of the tallest trees in the rainforest. A tree with an extensive root system reaching a lot of soil with natural radium from uranium and thorium decay in the ground. However, I am still not detecting anything. Why would bananas and brazil nuts even be considered radioactive then? The main reason is a metal called potassium. Potassium is essential to life but a tiny part of natural potassium is special because it has an extra neutron in the nucleus. In stead of 39 nucleons it has 40. It is known as potassium-40 and this is unstable - radioactive. So anything containing natural potassium will be slightly radioactive. Including bananas, brazil nuts and your body. They also contain carbon. An element which also has a natural radioisotope with an extra neutron in it. This is known as carbon-14. But potassium is by far the most active so I will focus on that. Here, I have some low-sodium salt where 40% of the usual table salt - sodium chloride - has been replaced by potassium chloride. It even contains a tiny amount of potassium iodide. This low-sodium salt is way more rich in potassium than the foods I have shown so far. Let's see if the geiger counter can detect it. It does! 0.27 μSv/h in average is more than twice as much as my usual background radiation. At the higher concentration, the potassium is detectable with a geiger counter. Going even higher in concentration you can buy salt substitute where all of the sodium is replaced by potassium. I couldn't find an example in the local stores but this bag contains 1 kg of 99.9% pure potassium chloride. Known as food additive E508. Surely, the geiger counter will detect the potassium in this. Ah yes, this is around five times the background radiation at my place. The geiger counter send out an SOS telling me something more radioactive than normal is near. Not surprisingly - The higher concentration and larger amount of potassium, the more radioactive and easier to detect. It is therefore time to do some simple chemistry on the bananas. I need to concentrate the potassium in them. The simplest way is to remove the water content. Bananas are around 75% water, so let's cook that away in a pot reserved for experiments. As the water vapor turns into smoke the induction cooker shuts off with an error code. E3 means the cooker is asking me: Are you sure the pot is not empty? All right... Time to go full viking on it! No more fine Maillard reaction - just burn it. There we have it. Looking good. Not the worst meal I have cooked... Dinner is served... for the geiger counter. Will the concentrated bananas have a detectable amount of potassium? No. The radioactivity of bananas is very low - even in concentrated form. At least on the part you eat - the pulp. I got a tip that I should try testing the peel too. The peel has an interesting feature. Around the black spots that form when bananas ripen there is a fluorescent ring. Try shining a blacklight or an intense ultraviolet LED on it, as I do here. Anyway, this is non-ionizing radiation and not what we are looking for. Before we concentrate the peels, let me quickly try the brazil nuts. Unlike the bananas, these are mostly made of fat. In fact, they are fattier than the butter I use, so you can do this... If your nuts can be lit like a candle, you may want to consider your diet... It however makes it easier to concentrate these. Just make a bonfire out of them! After another succesful cooking, it is time to test the concentrated brazil nuts. OK. It is a bit elevated. Most likely, I am detecting the potassium since brazil nuts are almost twice as rich in potassium as bananas. But what about the banana peels? You know the drill by now... Sounds like more clicks to me. Is it just a coincidence - a fluctuation in the background radiation? Or is it persistent? The geiger counter has spoken. I tested it several times with similar results. Finally, I found some detectable activity in a banana. All it took was the ash from five peels. It is known that the potassium concentration is the highest in the peels but I am surprised to see 3-4 times background radiation from this small amount. More than from half a kilogram of the low-sodium salt and more than from the ash of half a kilogram of brazil nuts. Wish I had a gamma-ray spectrometer. I could detect what causes the radiation. You can help me save up for one through Patreon. Link in the description. I do wonder if bananas gather naturally-occuring radioactive materials in the peels? Anyway, I still eat bananas and brazil nuts, and so should you. They are not much more radioactive than you are and their radioelements do not accumulate in your body. Watch out for the high selenium content in brazil nuts though. Hold on for an example of something edible and radioactive you shouldn't eat. Thanks to all my patrons! I appreciate your help with saving up for the often expensive equipment needed for my videos. Currently, a gamma-ray spectrometer is high on my wishlist to figure out what's in the banana peels. You can help out on Patreon - link in the description under the video. Thank you! These dried mushrooms were sent to me to try out, because one of the samples is... angry. They are not super hot, but unlike the previous samples there is an issue with the radioisotope in them. These have grown in the outskirts of an infamous exclusion zone and accumulated caesium-137. That is not naturally occuring and will accumulate in your body so don't eat mushrooms containing nuclear fission products, please. So what is the most radioactive you can buy in a grocery store? It is salt substitute or low-sodium salt - and perhaps banana peels. My sample of brazil nuts were not very active but it is a natural product with great variations depending on what tree they came from. But no brazil nuts will be stronger than potassium chloride salt substitute, making it a clear winner. I hope you enjoyed this video. If you did, then go nuts on the thumbs up button to let me know. And make sure you are subscribed for the next video. Thanks for watching. Bye for now.

Channel: Brainiac75

Views: 584,424

Keywords: radioactivity, radioactive, geiger, counter, potassium, radium, cesium, caesium, cæsium, salt, substitute, low-sodium, low sodium, banana, brazil nuts, mushroom, test, experiment, science, elements, isotopes, becquerel, fun, interesting, beautiful, fluorescence, fluorescent, ultraviolet, peel, pulp, educational, learning, safety, safe

Id: OLdDKb9Bago

Length: 11min 8sec (668 seconds)

Published: Fri Jul 31 2020