Physico-chemical controls on artificial radionuclides in soil

Radionuclides in the environment come from a wide range of sources, some natural and some artificial. Their biogeochemical behaviour is influenced both by their own physico-chemical properties and by those of the soil with which they interact. The source of the radionuclides is important, as are any changes in physico-chemical characteristics that occur during transport and deposition. Once in the soil further reactions can occur as the radionuclides equilibrate. These include immobilization by ion exchange and precipitation and remobilization by complexing and dissolution. Land management and environmental changes that alter conditions in the soil result in changes in the interactions of radionuclides with the soil and thereby to changes in mobility in the soil.