title: Specificiation of units for natural uranium and natural thorium.
mesh_terms: D006801:Humans; D007668:Kidney / Q000528:radiation effects; D011829:Radiation Dosage; D011830:Radiation Effects; D011835:Radiation Protection; D011868:Radioisotopes; D013910:Thorium; D014481:United States; D014501:Uranium
chemical_list: D011868:Radioisotopes; D014501:Uranium; D013910:Thorium