In addition to the geological weathering of rock and soil, NORM concentrations and exposure rates vary because of physical and chemical processes, both natural and anthropogenic. If mobilized, the NORM radioisotopes are available for transport. When radionuclides are dissolved in groundwater, the isotopes tend to travel with the water until redeposition takes place.
Air flow serves to transport fine particulates, combustion or volatilization products.
We will discuss radon emanation in the sections pertaining to industrial sectors. Mobilization by human activity can be intentional or unintentional. Unintentional mobilization occurs when the element is desirable for its non-radiological properties. Vanadium and uranium were originally mined for their non-radiological properties. Generally, redeposition involves the same factors as mobilization.