Imre Balásházy

Learn More
The primary objective of this study was to quantify the local inspiratory and expiratory aerosol deposition in a highly asymmetric five-generation tracheobronchial tree. User-enhanced commercial codes and self-developed software was used to compute the air velocity field as well as particle deposition distributions for a large size range of inhalable(More)
The apparent discrepancy between the reported preferential occurrence of bronchial carcinomas in central bronchial airways and current dose estimates for inhaled particles suggests that experimentally observed local accumulations of particles within bronchial airway bifurcations may play a crucial role in lung cancer induction. Here, we computed(More)
Penetration probabilities of inhaled man-made mineral fibers to reach central human airways were computed by a stochastic lung deposition model for different flow rates and equivalent diameters. Results indicate that even thick and long fibers can penetrate into the central airways at low flow rates. Deposition efficiencies and localized deposition patterns(More)
One way of studying the risk to human health of low-level radiation exposure is to make biological experiments on living cell cultures. Two 210Po alpha-particle emitting devices, with 0.5 and 100 MBq activity, were designed and constructed to perform such experiments irradiating monolayers of cells. Estimates of dose rate at the cell surface were obtained(More)
Inhaled short-lived 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(More)
PURPOSE In this study a biophysical mechanism-based microdosimetric model was applied to predict the biological effects of inhaled radon progenies in homes and in uranium mines. MATERIALS AND METHODS The radon daughter concentrations of more than 2000 homes were averaged in case of home exposure and the New Mexico uranium mine data were used in case of(More)
The risk to human health of exposure to low-level radiation is not precisely known yet. One way of studying this is to carry out in vitro biological experiments with cell cultures and to extend the conclusions to biological models. To relate the macroscopically deteminable 'low dose' to the damage of cells caused by a certain type of ionising particle is(More)
The CONRAD Project is a Coordinated Network for Radiation Dosimetry funded by the European Commission 6th Framework Programme. The activities developed within CONRAD Work Package 5 ('Coordination of Research on Internal Dosimetry') have contributed to improve the harmonisation and reliability in the assessment of internal doses. The tasks carried out(More)
In this study local distributions of deposited inhaled particles such as radon progenies in realistic human airway bifurcation models of bronchial generations one to six are computed for different geometries, inlet flow profiles, flow rates and particle sizes with computational fluid particle dynamics methods. The movement of the mucus layer in the large(More)
Aerosol deposition studies with tracheobronchial casts and models have demonstrated that inhaled particles are preferentially deposited within transitional bifurcation zones, exhibiting hot spots in the vicinity of carinal ridges. The goal of the present study is to quantify the inhomogeneity of theoretically predicted deposition patterns by local(More)