Radiation uptake in edible plants.

The radioactive contamination of food is a growing problem. It’s useful to know which food plants are affected more than others, and which radionuclides different plants absorb more than others. I found an interesting and very large document “Radiological assessment: A textbook on environmental dose analysis”, which was prepared for the NRC in 1983.

The table which can be downloaded here contains the ratio of radioactive materials found in edible portions of plants, to that of radioactive materials found in the soil. If the amount of a radionuclide in soil is X, the table shows how much is in the plant relative to X. For example, the value of 3.1 in the row “strontium-90” and column “alfalfa” means that 3.1 as much strontium-90 is in the alfalfa than in the soil, per unit weight.

The first thing that is obvious from the table is how much higher the values are for strontium-90 than other isotopes. This shows how dangerous Sr-90 is, how pervasive it is in the environment. This isotope, which causes bone cancer and leukemia, concentrates in bones and bone marrow. Note that 8 times as much collects in wheat, versus corn and rice. Also 33 times as much Sr-90 is absorbed into alfalfa than cesium-137. Alfalfa is fed to dairy cows. Trying to gauge the safety of milk and dairy products by cesium alone is misleading.

Iodine-129 is also very high in alfalfa (20 times the ratio of Cs-137). We can see that the highest risk in milk is in Sr-90 and I-129 (which causes thyroid cancer). These two isotopes are also found in grasses, which is the food source for beef cattle.

Note that the ratio of plutonium-239 is very low. The main risk for exposure to Pu-239 is in air and drinking water. Plutonium binds tightly to clay soil. But note americium-241 has a much higher ratio. Pu-241 decays to Am-241 with a half-life of 14 years. Americium is a bone seeker like strontium and plutonium.

14 thoughts on “Radiation uptake in edible plants.

    • Thanks. Some legitimate comments are being mistakenly flagged as spam by the anti-spam plugin. I apologize for this… this blog is being massively spammed lately.

  1. Thanks very much for your work. I’d like to provide you an update with a recent discovery of contaminated milk products how to New Zealand. The product that was being tested was goat milk. The news has hit the South Korean media in the past few days. The results have been basically an attack by the media against the group that conducted the readings (donated privately from concerned parents) and supporting the milk company saying that we are agents of another belt company.

  2. Furthermore, it appears that a lawsuit will be launched against the manager of the blog that posted the results of the contamination
    . The milk company, Ildong, of course has denied any wrongdoing. 
    And this is where the story leads to speculation about why the milk is contaminated. One of the possibilities is that the milk company is obtaining their DHA source from fish/ fish oils from or near Japan. 

    The company might be placed contaminated food additives into what possibly was an uncontaminated food source and thus contaminating it.
     At this point, it’s not clear what is causing the contamination.  When I go to the supermarket in korea the milk product is still there.

    • Thank you, David, for the update. It shows how contamination might spread into foods in places that are otherwise not contaminated.

      Of course, the people who inform others about the poison get sued, while the poisoners get off scot-free.

  3. Thanks, David, I wanted to ask you what lab would be so honest!

    We switched to a vegan DHA oil made straight from the algae (that the fish get DHA from) and like that better, it is manufactured in a sterile environment.

  4. I just read a website with a list of things that absorb radiation after a CT Scan. One was Alfalfa. Now I’m confused as it’s said here that Alfalfa contains several X amounts of Radiation gained by absorption from soil.

    • Absolutely. Alfalfa absorbs radiation after the CT scan. It also absorbs radionuclides from the soil, for the same reason.

      You can say the same thing about mushrooms. They absorb radioactive substances much better than alfalfa. A very good thing to eat if they are clean. But if they are grown without any concern for radiation, they are one of the very most contaminated foods.

      • Absolutely! I do not know what to do with reishi mushrooms harvested this summer from the local woods. They are very good immunomodulator, but I do not dare to give them to those who need . One more friend died in pain from cancer, many people I know struggle to survive. Chernobyl did this. May be I can try the effects of reishi myself. Dark mushrooms contain melanin, which deals with energy. Oh, if our own melanin could work the same way and in the whole body!

  5. And also, they irradiate Alfalfa Seeds with gamma rays. One called Viking 3000. I wonder what other seeds are irradiated for preservation purposes. Wheat too?

Leave a Reply

Your email address will not be published. Required fields are marked *