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.
Helium-3 was thought to be a radioactive isotope until helions were also found in samples of natural helium, which is mostly helium-4, taken both from the terrestrial atmosphere and from natural gas wells.