title: Comparison of thorium gamma spectra in smokers and nonsmokers.
mesh_terms: D005720:Gamma Rays; D006801:Humans; D008168:Lung; D008297:Male; D008875:Middle Aged; D012907:Smoking / Q000150:complications*; D013910:Thorium / Q000032:analysis*
chemical_list: D013910:Thorium