Effect of sitespecific bronchial radon progeny de

Authors: Árpád Farkas Werner Hofmann Imre Balásházy István Szőke Balázs G Madas Mona Moustafa

Publish Date: 2011/02/15

Volume: 50, Issue: 2, Pages: 281-297

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Abstract

Inhaled shortlived radon progenies may deposit in bronchial airways and interact with the epithelium by the emission of alpha particles Simulation of the related radiobiological effects requires the knowledge of space and time distributions of alpha particle hits and biological endpoints Present modelling efforts include simulation of radioaerosol deposition patterns in a central bronchial airway bifurcation modelling of human bronchial epithelium generation of alpha particle tracks and computation of spatiotemporal distributions of cell nucleus hits cell killing and cell transformation events Simulation results indicate that the preferential radionuclide deposition at carinal ridges plays an important role in the space and time evolution of the biological events While multiple hits are generally rare for low cumulative exposures their probability may be quite high at the carinal ridges of the airway bifurcations Likewise cell killing and transformation events also occur with higher probability in this area In the case of uniform surface activities successive hits as well as cell killing and transformation events within a restricted area say 05 mm2 are well separated in time However in the case of realistic inhomogeneous deposition they occur more frequently within the mean cycle time of cells located at the carinal ridge even at low cumulative doses The sitespecificity of radionuclide deposition impacts not only on direct but also on nontargeted radiobiological effects due to intercellular communication Incorporation of present results into mechanistic models of carcinogenesis may provide useful information concerning the dose–effect relationship in the lowdose range

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