Treatment for Removal of Inhaled Radioactive Ceria (¹⁴⁴CeO₂) from the Lungs of Rats

Abstract

INHALATION is one of the most probable routes for entry of radioactive elements into the body. Relatively insoluble, radioactive particles deposited in the lung are normally retained for long periods of time resulting in high, local radiation dosages which may lead to pulmonary damage, for example, fibrosis and carcinoma¹. Therefore, it is important that methods are available for increasing the rate of clearance of radioactive particles from the lung and from the body. This communication reports preliminary results of tests to remove inhaled ceria (¹⁴⁴CeO₂) (in equilibrium with its daughter product, praseodymium-144). Cerium-144 is a fission product occurring mainly in insoluble form and accounts for much of the radioactivity remaining 1–4 years after nuclear fission². Cerium-144, with a 290-day half-life, decays by β–γ emission to praseodymium-144, which has a 17-min. half-life.