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.
Most of the helium that is removed from natural gas is thought to form from radioactive decay of uranium and thorium in granitoid rocks of Earth's continental crust. The values above are estimated helium resources from the USGS Mineral Commodity Summary [3]