Capturing radon on tobacco smoke

Abstract

Radon is one of the largest causes for lung cancer in the world. In fact, it is second only to smoking. It has been observed that tobacco smoking increases the risks of radon-induced lung cancer, but there does not appear to be any theory that quantitatively describes why this is. This thesis is a study of a possible reason for this increase in mortality. I have investigated if and how radon atoms adsorb onto some molecules present in tobacco smoke and other types of smoke. My study can therefore also help to develop an understanding of possible radon-associated health effects that may follow from enjoying an open replace. If radon does adsorb onto the smoke it may increase the likelihood of these radioactive atoms decaying in the lungs and depositing their daughter nuclei there. Most of the daughter nuclei are radioactive and of them at least lead is also toxic. The investigation was done through electronic structure calculations using density functional theory. I have chosen a non-empirical method because there are not many experiments on radon interactions. The van der Waals density functional was used to account for the van der Waals interactions. Adsorbtions of between 70 meV and 156 meV were found on all investigated molecules from the smoke. Large polycyclic aromatic hydrocarbons gave the strongest adsorbtion. In a trend study with different noble gas atoms, bigger atoms adsorbed more strongly, including radon which adsorbed most strongly. The thesis includes an overview of the theory behind the density functional theory used in the calculations.