Radon decay products modeling size distributions

Raes, F. A. Jannsens, and H. Vanmarcke, Modeling Size Distributions of Radon Decay Products in Realistic Environments, this volume (1987). 

A Model for Size Distributions of Radon Decay Products in Realistic Environments... 

In all dosimetric models, the dominant parameter related to dose is the activity size distribution of the radon decay products in air as the original deposition destination and amount of... 

A model has been developed to calculate the size distributions of the short lived decay products of radon in the indoor environment. In addition to the classical processes like attachment, plate out and ventilation, clustering of condensable species around the radioactive ions, and the neutralization of these ions by recombination and charge transfer are also taken into account. Some examples are presented showing that the latter processes may affect considerably the appearance and amount of the so called unattached fraction, as well as the equilibrium factor. 

The amount of particles determine the quantity of decay products that stay in the air (equilibrium fraction, F) and the fraction of activity associated with the "unattached or ultrafine mode of the size distribution (fDot) These decay products are certainly harmful at high concentrations but we cannot yet detect the effects at normal levels because the vast majority of lung cancer death are due to smoking. Models predict that potentially 9000 lung cancer deaths per year in the United States are due to indoor radon. Methods are currently available and new methods are being developed and tested for lowering the levels of radon in indoor air. 

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