Helium is the second most prevalent element in the universe, after hydrogen. However, the atmosphere contains only 5 ppm volume of helium. Helium concentrations in seawater are no higher than 4-7 ppt. Concentrations are relatively low, because helium as a noble gas only occurs as separate atoms, and usually does not react with any other particles.
In what way and in what form does helium react with water?
Atomic helium does not react with water, nor with any other substance. (We can now produce some non-stable helium compounds, such as VHe3+ and HePtHe2+).
Solubility of helium and helium compounds
No single gas has a lower solubility than does helium. At T = 20oC and pressure = 1 bar, only 1.5 mg helium dissolves in water.
Why is helium present in water?
Uranium minerals contain small amounts of helium. Helium may escape through splits in the earth's crust. However, it does not end up in water.
Helium is applied as a cooling agent for nuclear reactors, in scuba diving, in hot air balloons (it has the same capacity as hydrogen), and for light bow welding. It is also applied in gas lasers, and as a protective coating for various substances. Helium is very suitable for low-temperature instruments, because it is liquid only when temperatures are below -269oC. Helium compound E939 is applied as a food additive.
Helium can end up in water directly, when it is applied as a tracer to find leaks. After nuclear accidents or nuclear weapon testing, helium can be applied to determine radioactivity and water contamination.
The 3He isotope is a tritium splitting product that does not escape to the atmosphere, but rather accumulates in water.
What are the environmental effects of helium in water?
Helium does not dissolve in water, and therefore normally does not damage the environment. As was described earlier, helium is only present in water in very small amounts. Helium is not a dietary mineral for any organism. There are two separate helium isotopes that are both non-radioactive. Today, six other unstable isotopes exist.
What are the health effects of helium in water?
Helium is not a dietary mineral for humans, and only an extremely small amount is present in the human body. Helium does not play any vital role in physical processes, but it is not toxic, either.
Helium in drinking water is insignificant, for all the above-mentioned reasons.
Helium gas is relatively harmless, when inhaled in small amounts. If one inhales larger amounts of helium gas this may force away oxygen, and therefore lead to asphyxia.
Which water purification technologies can be applied to remove helium from water?
Helium is not a water contaminant.
Literature and the other elements and their interaction with water