The initial behavior of 218Po in indoor air

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. The neutral molecule can then become incorporated in ultrafine particles formed by the radiolytic processes in the recoil path. The evidence for these particles is presented