ABSTRACT
The chemical and physical properties of 218Po immediately following its formation from 222Rn decay are important in determining its behavior in indoor atmospheres and play a major part in determining its potential health effects. In 88% of the decays, a singly charged, positive ion of 218Po is obtained at the end of its recoil path. The modes of neutralization, small-ion recombination, electron transfer, and electron scavenging are reviewed. In typical indoor air, the ion will be rapidly neutralized by transfer of electrons from lower ionization potential gases such as NO2. The neutral molecule can then become incorporated in ultrafine particles formed by the radiolytic processes in the recoil path. Evidence for the formation of these particles is presented.
