Thorium Dioxide


Chemical information

Thorium Oxide; Torio, dióxido de.
Chemical formula: ThO2 = 264.0.
CAS — 1314-20-1.


Colloidal solutions of thorium dioxide were formerly used as Xray contrast media for examination of the liver and spleen, for arteriography, and occasionally for outlining the cerebral ventricles. Its elimination is very slow and incomplete. It accumulates in the reticuloendothelial system, especially in the liver and spleen. As it is radioactive (half-life: 1.41 × 1010 years), this accumulation is dangerous and there is strong evidence that the ensuing prolonged exposure to its radiation is a contributing factor in the development of malignant diseases and blood disorders often 20 to 30 years after its use.
Published May 08, 2019.