Most jug-style water filters remove unpleasant-tasting chlorine (which is added to the water supply to disinfect it) as well as certain pesticides and pharmaceutical residues. They can also reduce levels of lead and copper, and some can even help to soften hard water by reducing its calcium and magnesium content.
But they don’t necessarily remove all contaminants. They don’t remove nitrates from agricultural run-off, for instance, or small molecules including hormones, bacteria and viruses.
They also struggle with heavy metals like arsenic and mercury and vary widely in their ability to eliminate toxic chemicals called PFAS (dubbed ‘forever chemicals’ for their tendency to persist in the environment and accumulate in our bodies).
The jury’s still out on whether jug filters effectively remove microplastics from tap water, but one study from 2023 suggests that they could reduce PET and PVC fragments by more than 75 per cent.
This article is an answer to the question (asked by Nicky, Norfolk) 'What exactly do water filters filter out?'
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