Lead causes hyperactivity in children, and may reduce learning ability. In water, the maximum European permitted lead concentration is 50 micrograms per litre of water. In 1989 the drinking water in every Scottish region was found to be in excess of those levels. Water absorbs the heavy metal as it flows through lead pipes.

Radium, which causes bone cancer if ingested through polluted waters, is a by-product of mining uranium a radioactive metal used in the production of nuclear power.