Helium (He) and water
Helium is a chemically inert noble gas. Small amounts dissolve physically in water, and groundwater can contain additional helium from geological sources. Dissolved helium is useful to hydrogeologists as a tracer of groundwater age and flow; it is not generally treated as a routine drinking-water contaminant.
Helium in water
Helium does not react with water under ordinary environmental conditions. Its dissolved concentration depends on gas pressure, temperature and water chemistry. Groundwater helium can come from air trapped during recharge, tritium decay, and helium produced in rocks by radioactive decay or transported from deeper crustal and mantle sources. These contributions vary by aquifer, so a single concentration is not representative of all waters.[1]
Environmental and health considerations
Dissolved helium is not known to have a biological role, and trace amounts in water are not normally a health concern. The established safety hazard is inhalation of helium gas in a confined or poorly ventilated space: it can displace oxygen and cause asphyxiation. This is a gas-handling hazard, not a toxicity effect from drinking water.
Helium removal from water
Most drinking-water systems do not require helium removal. Where dissolved gases interfere with a process, physical degassing may be assessed based on the gas mixture, pressure, temperature and downstream use. Sampling must avoid headspace and gas loss when accurate dissolved-helium measurements are needed; USGS describes specialized collection and analysis procedures.[1]
Last reviewed: 31 October 2026 by Lenntech.
Sources and further reading
- U.S. Geological Survey: Measurement of dissolved helium in groundwater.
- U.S. Geological Survey: Dissolved noble-gas data and helium mass-balance models.
Literature and the other elements and their interaction with water