Availability to and uptake by plants of radionuclides under different environmental conditions

The availability of radionuclides from the ground depends on many different factors, such as the composition and consistency of the soil, the presence of other metal ions and complexing organic compounds, the local climate and the residence time of the radionuclides in the ground, to mention just a few. Besides there are airborne radionuclides which settle directly on to the plants by dry and wet deposition from nuclear fall‐out. Some of these radionuclides are readily absorbed to various degrees by the plants from the leaves and distributed within the whole plant. This form of contamination is very much faster than the uptake from the soil by the roots since it eliminates the migration of the nuclides through the ground. We have also studied the availability of 226radium from soil containing 40 x 103 Bq of radium chloride/kg of soil contaminated about 50 years ago. Our results with this well weathered matrix as compared to freshly prepared radium‐soil mixtures show that the bioavailability of this radion...