@afewbugs
@KimSJ

The garbage is a mad issue to be sure, but please be aware that helium in MRI is not the same helium we use in balloons. He has 2 isotopes (He3 and He4). He3 was only formed in the initial stages of our solar system so is exceedingly rare, unless you are in the core pf our and/or somewhere where solar eind can accumulate (ie moon). In face we geochemists use the He3/4 ratios to figure out of something might have come from deep within the earth's interior.

He4 is the second most abundant element in the universe. Balloons use He4, MRIs use He3.

I believe we're talking about different things, Helium is plentiful on a galactic scale, but here on the earth, it escapes into the atmosphere very readily, and only comes in useful quantities from underground reservoirs. Most of the usage of helium for science and medicine is liquid helium being used for cooling equipment to temperatures that simply cannot be reached any other way. That doesn't require special isotopes, just anything that has a nearly 0 K boiling point.

Now there are different purity grades for helium, but that's simply a matter of how well they've separated the other gases out.

https://meritusgas.com/balloon-helium/

https://anytvnews.com/business/helium-crisis-explained-how-balloon-gas-became-the-worlds-need-know-how-iran-war-affected-the-supply/

@PhilGopon @afewbugs @KimSJ

@sellathechemist @afewbugs @JessTheUnstill @KimSJ
Yes absolutely. It's is actually a really interesting crossover between geochemistry (ie how abundant what elements are where on Earth), but also how hard they are to refine. Si for example is the second most abundant element but also one of the most difficult to refine to high purity, which is why high purity wafers are so expensive but SiO2 costs next to nothing.

Didnt want to imply that helium was abundant where we live, its actually somewhere between palladium and gold in terms of crustal abundance, so quite rare. But however rare He is, He3 is orders of magnitude less abundant (0.0002% of all Helium on Earth).

There are places of much higher concentration, which is both an interesting geochemical but also economic question.
Some gas seeps in southern Tanzania have up to 10% He, and are actually also enriched in He3.

One of the reason i love Economic Geology, where geochemistry and real world issues overlap =)

@PhilGopon @sellathechemist @afewbugs @JessTheUnstill @KimSJ

Balloon gas also contains air to prevent it being a cause of accidental (or even deliberate) asphyxiation. I still think the party balloons should be banned/restricted due to the environment impact.

Also a few years back saw a group of youths get chewed out by train guards at the railway station as they were letting their mylar / foil party balloon float perilously close to 25 000 V overhead line - they were putting themselves at danger or at very least could have caused a flashover which would result in emergency switch off of power and all the London/Norwich trains being delayed for hours..