Daily intake of copper from drinking water among young children in Sweden

Copper is an essential trace element that may cause intoxication if intake becomes excessive. Young children are at risk of intoxication because of hi gh consumption of drinking water and immature copper metabolism. The aims o f this prospective study were to estimate concentrations of copper in drink ing water, volumes of drinking water consumed by children, and children's d aily intake of copper. Concentrations of copper in unflushed drinking water were analyzed for 1,178 children living in Uppsala and Malmo, Sweden, and concentrations and amounts of copper consumed from drinking water were esti mated for 430 of these children, 9-21 months of age. The study children wer e from Swedish families, were not enrolled in publicly provided day care, a nd were not breast-fed more than three times a day. In the initial populati on, the 10th percentile for copper concentration in unflushed drinking wate r was 0.17 mg/L, the median was 0.72 mg/L, and the 90th percentile was 2.11 mg/L. In the subpopulation of 430 children, the 10th percentile for daily intake of copper from drinking water was 0.03 mg/L, the median was 0.32 mg/ L, and the 90th percentile was 1.07 mg/L. The median daily intake of copper From drinking water was higher in Uppsala, at 0.46 mg, than in Malmo, at 0 .26 mg. For groups of children whose families took part in a later prospect ive diary study, the copper concentration in consumed water could, to some extent, be predicted from the concentration of copper in unflushed drinking water. The lowest concentrations of copper in drinking water were found in households with old water-pipe systems and in those living in detached hou ses. A large proportion of the young children satisfied their daily require ment of copper solely from drinking water. About 10% of the children had a copper intake above the level recommended by the World Health Organization.