Size distribution, equilibrium ratio and unattached fraction of radon decay products under typical indoor domestic conditions

In order to characterise the behaviour of radon decay products under domestic conditions, long-termmeasurements were carried out from May 1997 to April 1998 in a typical dwelling located in Brittany(France). In particular, the unattached fraction and equilibrium factor were continuously measured.Moreover, the size distributions of unattached and attached radon daughters were investigated byusing specific instruments implemented in the laboratory. All these experiments were carried outunder different typical aerosol conditions. The results evidenced the strong influence exerted by thecharacteristics (concentration, size) of ambient aerosol on these different parameters