The Uptake of Lead by Children in Differing Environments

Balance studies have been performed for lead upon eight healthy children in three different home environments and upon eight children with inborn errors of metabolism in hospital (consuming two different types of synthetic diet). The balances were for 3 days and involved the use of metal-free diapers where indicated. The concentration of lead in all the samples was determined by atomic absorption spectroscopy after suitable sample preparation. In addition, the total population of children under the age of 16 living in a working class area exposed to undue amounts of lead was examined in an attempt to determine whether their mental development had been affected. Blood lead levels, general intelligence, reading ability, and rate of behavior disorder were measured. The results of the balances showed that the mean daily intake of lead in both groups of children was lower than previously recorded figures, being lowest of all in the breastfed infant. The healthy group absorbed a mean value of 53% and retained 18% of the dietary intake and there was no relationship to age or month of the year of study. The children with inborn errors showed a significantly lower percentage absorption of lead. The preliminary results of the population survey showed that distance from the polluting lead source was related to blood lead level, but no relationship could be found between blood lead level and any measure of mental function.