What it is
Cadmium is a soft metal used in batteries, pigments and coatings. It is present in nature only at very low levels, and there is no safe role for it in the body.
Where it comes from
In drinking water cadmium usually comes from galvanised (zinc-coated) pipes and fittings, where it is an impurity in the zinc, and from some solders. Other sources are industrial pollution, phosphate fertilisers and contaminated land. Soft, acidic water picks it up more readily.
Why it matters
Cadmium accumulates in the kidneys over a lifetime and long-term exposure above the guideline can damage them and weaken bones. The guideline is set to keep lifetime intake from water well within safe limits. Levels in UK supplies are normally far below it.
What can be done about it
If cadmium is detected, identify and replace the pipework or fitting it is coming from and correct any low pH that is making the water aggressive. Reverse osmosis or a filter certified for heavy-metal removal at the kitchen tap gives protection in the meantime.
Information last reviewed 5 October 2026 by Pozzani Pure Water.