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 is in the Sun. That's right. If you were to look at everything in the sun you would discover large amounts of helium. The Sun is a really big ball of gases and all those gases are on fire. One of the results of that fire is helium.