Concentration of trace metals in the blood of children.

Tipton (1960), Butt et al. (1964), and Stitch (1957) have shown that 20 trace metals are consistently present in human tissues although only seven of these are known to be essential to man. In addition to the ingestion of trace metals from food, materials such as paints, plastics, and rubbers, which contain many metals, may be mouthed and chewed by children. Excessive ingestion of lead is a well-known health hazard for children, particularly for those who have pica (Greenberg et al., 1958; Bicknell, Clayton, and Delves, 1968), and is associated with increased concentrations of lead in blood. The purpose of the present study was to establish 'normal' values for a series of metals in the blood of children, and to determine whether they were altered in children in whom the physician was considering a possible diagnosis of lead poisoning, since so many materials contain a mixture of metals. The choice of the metals to be investigated in our study was determined by the available analytical techniques. Spark-source mass spectrometry permits determination of all the metals of interest (Table I)