The following is a listing of the USNRC’s “Interim Screening Values of Common Radionuclides for Soil Surface Contamination Levels”, as they appeared in the December 7, 1999 edition of the Federal Register (64 FR 68395). The values shown below are in units of “picocuries per gram”. (For radionuclides followed by a “+C”, the screening value assumes the progeny in that decay series are in equilibrium with the parent.)
Actinium
Americium
Calcium
Carbon
Cesium
Chlorine
Cobalt
Curium
Europium
Hydrogen
Iodine
Iridium
Iron
Lead
Manganese
Nickel
Niobium
Plutonium
Protactinium
Radium
Scandium
Sodium
Strontium
Sulfur
Technetium
Thorium
Uranium