Abstract

A critical review is presented of the available experimental data on regional aerosol deposition in man. The data agree well for nasal and extrathoracic deposition. For the fast and slow cleared components of thoracic deposition, however, agreement is less satisfactory. The different experimental techniques are critically evaluated, and possible reasons for the observed discrepancies are discussed. Additionally, a semi-empirical model is presented which takes this evaluation into account, and which enables regional deposition to be calculated as function of particle size and respiratory parameters without lengthy computer models. The proposed equations explain and eliminate some of the intra- and inter-individual scatter of the data, and some of the discrepancies between the data from different laboratories. Where these discrepancies could not be eliminated, an additional 'conservative' model for dose estimations is offered which takes account of the uncertainty inherent to the data. A summary of the model equations is given in the appendix.