Wichita ? Kansas has been one of the world’s biggest producers of helium for more than a century. But that may be ending.

The Wichita Eagle reports that a recent helium shortage has pointed up the precariousness of the world supply of helium, which is used in MRI machines, semiconductor manufacturing, and, of course, balloons.

In 1925, the federal government took over helium production in the gas fields of the Texas and Oklahoma panhandles and western Kansas. It now supplies about 2 billion cubic feet of the gas that is 78 percent helium to private refiners along a pipeline that runs from Amarillo to Kansas. Those plants refine the crude gas to pure helium and sell it.

But the fields are close to exhaustion and are expected to last until 2020.