Dietary sources of copper

Copper in drinking water--an investigation into possible health effects

A study was carried out to examine the possible relationship between levels of copper in drinking water and the incidence of specified childhood liver complaints presenting at a major UK paediatric liver unit. Public drinking water supplies were generally found to have levels of copper which were well below the EC standard of 3,000 micrograms/l. In private supplies, a slightly greater number of samples were found to exceed the prescribed concentration; in one instance a value of 26,000 micrograms/l was recorded. Data describing infant patients reporting to Kings College Hospital, London with specified liver complaints were examined. Where the address of patients could be determined (220 out of 240 cases), all patients were found to live in areas served by public drinking water supplies and were, thus, unlikely to have experienced elevated drinking water copper concentrations.

Transport and storage of metals

Current understanding of the means by which the trace metals copper, iron, and zinc are transported and stored in the human body is reviewed. Although metal-related inherited metabolic diseases manifest themselves as deficiencies in metalloenzymes, these deficiencies in fact arise from disturbances in the absorption/rejection or transport or storage phases of the metal metabolism. The considerable information available on iron metabolism shows these phases to be closely interrelated with a number of feedback mechanisms operating as controls on the various metabolic stages. Copper and zinc have vastly different roles in their enzymes but, following their close coordination chemistry properties, have similar metabolic routes. Both make use of albumin for transport and of metallothionein at the absorption and hepatic-binding stages. In contrast to iron, copper and zinc have no well-defined storage system; instead they make use of body reserves distributed in various tissues. Our knowledge of the transport and storage systems of the trace metals is still very incomplete. More research is needed on the dynamics of movement of the trace metals between the various body tissues and fluids. Further advances will also come from the study of related metal inherited diseases in other animal species.