The second issue of Food Security is now published, and is free online. It documents some of the multiple causes of food insecurity.
Helium can be found in underground deposits in the earth. Helium can also be found in stars and other planets. The helium underground - and extracted from natural-gas - is a by-product of the natural radioactive decay of uranium, though is far too stable to be radioactive itself. It also occurs in very small amounts in the atmosphere.
On Earth it is relatively rare â 5.2 ppm by volume in the atmosphere. Most terrestrial helium present today is created by the natural radioactive decay of heavy radioactive elements (thorium and uranium, although there are other examples), as the alpha particles emitted by such decays consist of helium-4 nuclei.elium has a valence of zero and is chemically unreactive under all normal conditions. It is an electrical insulator unless ionized. As with the other noble gases, helium has metastable energy levels that allow it to remain ionized in an electrical discharge with a voltage below its ionization potential.