Pacing balloons soon to be a thing of the past?

Tom Welton, a professor of sustainable chemistry at Imperial College, London, believes that a global shortage of helium means it should be used more carefully. Helium cools the large magnets inside MRI scanners - the medical devices that provide doctors with detailed images of what is happening inside their patients' bodies.

In an interview, Prof Welton said...."We're not going to run out of helium tomorrow - but on the 30 to 50 year timescale we will have serious problems of having to shut things down if we don't do something in the mean time. The reason that we can do MRI is we have very large, very cold magnets - and the reason we can have those is we have helium cooling them down. You're not going into an MRI scanner because you've got a sore toe - this is important stuff. When you see that we're literally just letting it float into the air, and then out into space inside those helium balloons, it's just hugely frustrating. It is absolutely the wrong use of helium."

Helium is extracted from deep underground, mainly in the USA where deposits of the gas have built up. It is usually mined as a bi-product of natural gas extraction. But resources are finite and demand is increasing, which is why supplies are restricted. Two years ago, the shortage of helium prompted the American Nobel Prize-winning scientist, Robert Richardson, to call for the price of one party balloon filled with the gas to cost more than £60.

"There is a current shortage," said Doug Thornton, chief executive of the British Compressed Gas Association - the body which represents commercial suppliers of helium and other gases. "That has led to a two-year price-hike, although we expect that prices may drop again, as new reserves are found in places like Russia. But there aren't many alternatives in terms of supply."

Last month the UK's Balloon Association, which represents the party and promotional balloon industry, said prices were going up and supplies were under pressure. It estimates that at present it costs between 30p and 50p to fill a single balloon with helium.