Evaluation of the Ventilation Rate from the Decay of Filterpaper Air Samples of Thoron or Radon Daughters

The inhalation hazard associated with the processing of thorium and uranium is mostly due to the daughter products of thoron and radon than to the parent gases themselves. With the provision of ventilation the equilibrium between the parent and the decay products is disturbed resulting in a marked reduction of the inhalation hazard. TSIVOGLOU et al.described a method of estimating the relative proportions of the various daughter products of radon in the atmosphere, based on an analysis of the shape of the α-decay curves of filter-paper air samples.