title: An argument against the use of the special curie for natural uranium and natural thorium.
mesh_terms: D000398:Air Pollution, Radioactive; D008452:Maximum Allowable Concentration; D011851:Radioactivity; D013910:Thorium; D014501:Uranium; D014894:Weights and Measures / Q000592:standards*
chemical_list: D014501:Uranium; D013910:Thorium