Bio-Accumulation of radiation occurs as fallout in soil, precipitation and bodies of water is absorbed by plants and animals. Bio-Magnification occurs as higher concentrations of a contaminant accumulate at higher levels of the food chain.
Last night I decided to search the research on this subject. One of the most helpful articles I read is titled, Zhu, Y-G, & Smolders, E. (200). Plant Uptake of Radiocaesium: A Review of Mechanisms, Regulation and Application. Journal of Experimental Botany, 51(351), 1635-1645.
The article explains that radiocaesium is an important artificial radionuclide because of its long half life, 30 years for C137 and 2 years for C134.
According to the article, three lines of research ensued after Chernobyl on caesium:
1. Mechanism of plant uptake of radiocaesium
2. Regulations of plant uptake of radiocaesium
3. Formulation of agricultural countermeasures for the remediation of soil with radiocaesium
Caesium is “a weakly hydrated alkaline metal with chemical similarities to potassium (K)” (p. 1636).
Potassium, or K, is also an alkali element.
“Caesium can be readily absorbed by plant roots from solution and can be translocated to the above-ground plant parts.” (1636)
“The mechanism by which Cs is taken up by plant roots are not completely understood. At least at low K concentrations there is evidence that Cs is absorbed by the K uptake system of the root.”
The article also mentions that “K strongly suppresses Cs uptake…” (1636).
Lowering concentrations of K in solution strongly increases uptake of Cs.
The article examines in some detail the nuances of uptake by Caesium and Potassium. I will not elaborate on the research but I think several findings are important:
Plants absorb caesium as if it were potassium .
The presence of high levels of potassium in the water based solutions used to grow plants (and also calcium) combats the uptake of caesium.
Soil texture and potassium level impact uptake of caesium by plants grown in soil.
“Caesium has a high mobility within a plant. Similarly to K, Cs can be distributed to leaves, flowers, and fruits” (1641)
Knowledge about cesium remediation is relatively undeveloped.
Majia here: We can conclude from this research review that we are all going to be eating cesium and the cesium in the plants is going to be bio-amplified in animals higher up on the food chain.
For instance, here are some reports on Cesium levels found in Japan