Radiation Protection Dosimetry Advance Access published online on September 18, 2009
Radiation Protection Dosimetry, doi:10.1093/rpd/ncp183
LUNG DOSIMETRY FOR INHALED RADON PROGENY IN SMOKERS
1 Department of Atomic and Nuclear Physics, University of Bucharest, PO Box MG-11, 077125 Magurele (Ilfov), Romania
2 Division of Physics and Biophysics, Department of Materials Research and Physics, University of Salzburg, 5020 Salzburg, Austria
3 Faculty of Environmental Sciences, Babes-Bolyai University, 400192 Cluj-Napoca, Romania
* Corresponding author: paul_baias{at}yahoo.com
Received June 18, 2009, amended August 12, 2009, accepted August 25, 2009
Cigarette smoking may change the morphological and physiological parameters of the lung. Thus the primary objective of the present study was to investigate to what extent these smoke-induced changes can modify deposition, clearance and resulting doses of inhaled radon progeny relative to healthy non-smokers (NSs). Doses to sensitive bronchial target cells were computed for four categories of smokers: (1) Light, short-term (LST) smokers, (2) light, long-term (LLT) smokers, (3) heavy, short-term (HST) smokers and (4) heavy, long-term (HLT) smokers. Because of only small changes of morphological and physiological parameters, doses for the LST smokers hardly differed from those for NSs. For LLT and HST smokers, even a protective effect could be observed, caused by a thicker mucus layer and increased mucus velocities. Only in the case of HLT smokers were doses higher by about a factor of 2 than those for NSs, caused primarily by impaired mucociliary clearance, higher breathing frequency, reduced lung volume and airway obstructions. These higher doses suggest that the contribution of inhaled radon progeny to the risk of lung cancer in smokers may be higher than currently assumed on the basis of NS doses.